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Retrocommisioning Buildings for Energy Efficiency

Learner GuideProduced by the Australian Institute of Refrigeration, Air

Conditioning and Heating

Supported by the NSW Government as part of the Energy Efficiency Training Program — visit savepower.nsw.gov.au

Copyright and disclaimer The Office of Environment and Heritage and the State of NSW are pleased to allow this material to be used, reproduced and adapted, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. The Office of Environment and Heritage has made all reasonable effort to ensure that the contents of this document are factual and free of error. However, the State of NSW and the Office of Environment and Heritage shall not be liable for any damage which may occur in relation to any person taking action or not on the basis of this document. Office of Environment and Heritage, Department of Premier and Cabinet59 Goulburn Street, Sydney NSW 2000PO Box A290, Sydney South NSW 1232Phone: (02) 9995 5000 (switchboard)Fax: (02) 9995 5999TTY: (02) 9211 4723Email: [email protected]: www.environment.nsw.gov.au

Retrocommissioning buildings for energy efficiency

Learner Guide

This project has been supported by the NSW Government as part of the Energy Efficiency Training Program – visit savepower.nsw.gov.au.

This project was developed by the Australian Institute of Refrigeration, Air Conditioning and Heating, Inc (AIRAH) with funding from the NSW Government as part of the Energy Efficiency Training Program.

These training resources were developed and project managed by Vincent Aherne in conjunction with Reece Lamshed (Binary Blue) and Carolyn Hughes (AIRAH).We would like to thank all project partners for their support and assistance to make this project a reality.

Project Partners:The Australian Institute of Refrigeration Air conditioning and Heating (AIRAH)A G Coombs Group Pty Ltd (lead partner)Crest Air Conditioning Pty LtdInvesta Property GroupHoneywell LimitedNorman Disney & Young groupOptimus Pty LtdStockland Property ManagementThe GPT Group

Second Edition November 2011

This material is copyright. Apart from any use permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission of the Australian Institute of Refrigeration, Air Conditioning and Heating (Inc).

DisclaimerThe information or advice contained in these documents is intended for use only by persons who have had adequate technical training in the field to which the documents relate. These documents have been compiled as an aid only and the information or advice should be verified before it is put to use by any person. The user should also establish the applicability of the information or advice in relation to any specific circumstances. While the information or advice is believed to be correct, the Australian Institute of Refrigeration Air Conditioning and Heating (Inc), its officers, employees and agents, disclaim responsibility for any inaccuracies contained within the documents including those due to any negligence in the preparation and publication of the said documents.

Retrocommissioning buildings for energy efficiency Learner Guide

Contents

Welcome...................................................................................................................3Learning outcomes................................................................................................................................................. 3Course outline........................................................................................................................................................... 4Assessment................................................................................................................................................................. 5How to use this Guide............................................................................................................................................ 5

Topic 1: Introduction.................................................................................................8

Topic 2: What is retrocommissioning?.......................................................................9

Case Study 1 - Video presentation: 66 Waterloo Road..............................................12

Topic 3: How is energy consumed in buildings?.......................................................14

Topic 4: Why retrocommission?..............................................................................18

Topic 5: Which buildings are suitable?.....................................................................20

Activity 1: Building suitability...................................................................................23

Topic 6: The retrocommissioning team....................................................................26

Topic 7: Starting the process....................................................................................30

Topic 8: Making preparations..................................................................................33

Topic 9: The retrocommissioning process phases....................................................35

Topic 10: Phase 1 – Planning....................................................................................36Summary.................................................................................................................................................................. 47

Topic 11: Phase 2 – Investigating.............................................................................48Summary.................................................................................................................................................................. 62

Topic 12: BMCS and retrocommissioning.................................................................63Tutorial: Using meters, sub meters, BMCS trend logs or data logging as a diagnostic tool 68

Activity 2: Answer the following questions on reading and analysing the data provided by a BMCS.................................................................................................68

Activity 3: Work Based Group Project.......................................................................93Project Brief.............................................................................................................................................................96

Survey Part 1.......................................................................................................................................................... 96Survey Part 2.......................................................................................................................................................... 97Survey Part 3.......................................................................................................................................................... 98Diagnostics.............................................................................................................................................................. 98

Activity 4: Project report back................................................................................102

Topic 13. Phase 3 – Implementing.........................................................................103Summary............................................................................................................................................................... 113

Topic 14: Phase 4 – Handing over..........................................................................116Summary............................................................................................................................................................... 119

Topic 15: Costs of a retrocommission....................................................................121

Topic 16: Cost benefits of a retrocommission........................................................123

Activity 5: Building retrocommissioning cost analysis............................................129

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Retrocommissioning buildings for energy efficiency Learner guide

Topic 17: Persistence Strategies.............................................................................132Post occupancy evaluation............................................................................................................................ 132Building documentation management.................................................................................................... 132Ongoing training............................................................................................................................................... 133NABERS ratings.................................................................................................................................................. 133Automated monitoring and alarm............................................................................................................. 133Operational strategies..................................................................................................................................... 133Maintenance strategies.................................................................................................................................. 134Building tuning (ongoing)............................................................................................................................. 134Recommissioning............................................................................................................................................... 135

Case Study 2 – Freshwater Place............................................................................136

Topic 18: Lessons learned......................................................................................138

References.............................................................................................................140

Further resources...................................................................................................141AIRAH..................................................................................................................................................................... 141ASHRAE.................................................................................................................................................................. 141CIBSE....................................................................................................................................................................... 141NABERS.................................................................................................................................................................. 141NEBB....................................................................................................................................................................... 141Commissioning................................................................................................................................................... 142Retrocommissioning........................................................................................................................................ 142Controls.................................................................................................................................................................. 142Measurement and verification..................................................................................................................... 142Websites................................................................................................................................................................ 142

Additional material................................................................................................143



Welcome

Welcome to this course Retrocommissioning Buildings for Energy Efficiency.

This course is designed to promote the adoption of a clearly articulated retrocommissioning process for existing buildings to improve energy efficiency and to train you to use this process successfully.

In many ways, this is a unique course in that it includes both the building owners, managers and their representatives, and the technical service providers (technicians, engineers and the like) involved in the design, installation, control and maintenance of the buildings and their systems. This brings together in training the two sides of industry; a practice that in the retrocommissioning process is critical to achieving an effective outcome in terms of energy and water efficiency.

The course is not accredited at this stage, but you will receive a Certificate of Completion when you successfully complete it. There are several activities and a project that will be assessed.

To make the training more enjoyable and dynamic, you will be placed in small groups that will be made up of owner’s representatives/facility managers and technicians / engineers. You will work in this group for your major project assignment.

Due to this mix of industry representation there is an opportunity to learn from each other and to view issues from each other’s perspective, particularly during the group project work. Communication with other members of your team will be important.

The AIRAH Manual DA 27 Building Commissioning is an essential resource for this course. You have been provided with a copy of Section 9 and Appendices B and C of the AIRAH Manual DA 27 Building Commissioning. Please read Section 9 on retrocommissioning before attending the training sessions.

This has been provided to you as pre-reading for the course and should now be inserted into the back of this folder.

There are two face-to-face sessions, the first of 5 hours and the second of 4.5 hours duration, with a break of four weeks in between, during which you will undertake your project.

Learning outcomes

It is important to read and understand the learning outcomes that underpin this course. The activities and project are designed so that you meet these learning outcomes.

On the completion of this course, you will have the skills and knowledge to:



Describe the retrocommissioning process Determine whether a building is suitable for retrocommissioning Interpret indicative BMCS and metering data useful for a

retrocommissioning process Undertake a preliminary building investigation for a retrocommission Estimate costings for a building retrocommission Explain persistence strategies after retrocommissioning.

Course outline

The Topics are listed in the tables below.

DAY ONE

Topic

1. Introduction

2. What is retrocommissioning?

3. How is energy consumed and wasted?

4. Why retrocommission?

5. Which buildings are suitable?

Activity 1: Building suitability

6. The retrocommissioning team

7. Starting the process

8. Making preparations

9. The retrocommissioning process phases

10. Retrocommissioning process Phase 1 - Planning

11. Retrocommissioning process Phase 2 - Investigating

12. BMCS and retrocommissioning

Activity 2: Building diagnostics

Project brief

WEEK 1 - 3

Topic

Activity 3: Project



DAY TWO

Topic

Activity 4: Report back to group

13. Retrocommissioning process Phase 3 - Implementing

14. Retrocommissioning process Phase 4 - Handing over

15. Costs of a retrocommission

16. Cost benefits of a retrocommission

Activity 5: Cost estimating

17. Persistence strategies

18. Lessons learned

Assessment

This is not an accredited course, but you will be assessed on the Activities and Project assignment.

Certificates of Participation will be provided to students who successfully complete the course. The table below suggests the way in which scores will be attached to measure competency. Anyone who achieves less than 50% of the total will not be provided with a Certificate.

Activity Score

Class attendance 20%

Participation in discussion 10%

Contribution to class activities 30%

Contribution to Project 30%

Contribution to report-back class presentation 10%

How to use this Guide

You MUST bring this Guide to the training sessions.

The Guide is divided into the two training sessions and the Topics that will be addressed in each. Use the spaces in the Guide for taking notes and answering the questions for the Exercises, Activities and Project.

The Exercises in the Guide are for your own purpose – they act as notes for future reference – and will NOT be assessed. The Activities and Project will be assessed.



This page is intentionally left blank.



SESSION 1



Topic 1: Introduction

The trainer will introduce him / herself and the other students in the course.

To make the training more enjoyable and dynamic, you will be placed in small groups that will be made up of owner’s representatives/facility managers and technicians / engineers. You will be assigned to a work group for the duration of this course, including for your major project assignment.

In the table below, note the name of the group (to be decided collectively) and the contact details of each member of the group.

It is important that this information is filled in as group members will need to contact and communicate with each other out of class to facilitate the group project.

Name of Group

Names of members Phone Email

1.

2.

3.

4.

5.

6.

As you go through this Learner Guide you will find exercise boxes. These exercises have been provided so that trainees can note down answers and information from the discussions being held on particular topics and aspects of retrocommissioning.Trainees are encouraged to make notes and comments in these exercise boxes so that these concepts and knowledge can be captured for future review.



Topic 2: What is retrocommissioning?

Retrocommissioning is a term that means retrospective commissioning.

Typically, it focuses on improving the overall performance of a building by investigating and improving how systems operate together.

Retrocommissioning is a process that:

Applies to existing building stock Follows a structured and well documented process Concentrates on the whole of building systems Sets goals based on current building performance Is collaborative.

There is often confusion between what comprises retrocommissioning and what comprises recommissioning.

Retrocommissioning applies to buildings that have never been commissioned and buildings or systems that have been significantly updated or altered. Retrocommissioning is not always applied to the whole building as particular plant or systems may be the focus depending on the project objectives. Systems are generally tested using test methods and procedures developed specifically for the project.

Recommissioning is the commissioning of existing buildings and systems that have already been through the commissioning process. These systems are generally tested using the same methods and focus as was used in the original commissioning process. Recomissioning is not intended to be a repeat of the entire commissioning process; rather it is a review of the building and system performance to ensure that the original criteria are being achieved. This may require a review or repeat of some of the original commissioning test methodology.

Retrocommissioning focuses on the current use and requirements of the building and its systems whereas recommissioning brings the building and its systems back to the original designed performance and operation.

There is more information about this in the AIRAH Manual DA27 Sections 2.3 and 9.2.



The following table highlights the similarities and differences between commissioning, building tuning, recommissioning and retrocommissioning.

Table 2.1 from DA 27 - The different faces of commissioning

Commissioning Characteristic

Commissioning Type

Commissioning Building Tuning Recommissioning Retrocommissioning

Application

New buildings, early implementation, optimise outcomes, minimise risks

All buildings, constantly optimised energy and performance, optimum outcomes

Existing buildings previously commissioned, ongoing maintenance and management, maintain performance, minimise risks, change of use

Existing buildings never commissioned, poorly performing buildings or systems/buildings that have been significantly upgraded or changed

TimingBegins at concept or pre-design stage

Commences after building has been commissioned, recommissioned or retrocommissioned

Periodically at scheduled intervals or in response to operating problems

In response to underperforming buildings or buildings that have been modified or updated

PurposeOptimum performance of building

Continuously maintain optimum performance of building

Periodically maintain optimum performance of building

Identify and remove barriers to optimum performance of building

Method Review, testing and verification.

Monitoring, trending review and tuning on a seasonal basis

Tuning, calibrating, testing and verification

Survey and diagnostics, alterations and improvements, testing and verification

Focus Specified design or performance.

Evolving design, current performance requirements

Original design and performance requirements

New design and performance requirements

Test basis

Uses new tests developed specific for building

Uses ongoing testing specific to building and current use

Uses existing tests developed for original building commissioning

Uses new tests developed specific for project

Frequency Once at initial build

Continuous once installed Every 3 - 5 years As needed due to age,

every 10 - 15 years



For this exercise, note down answers and information from the discussion.

EXERCISE 1 In your own words, briefly explain the difference between an energy audit, a commissioning process and a retrofit.

Retrofit

Commissioning

Energy Audit



Case Study 1 - Video presentation: 66 Waterloo Road

Refer to the back of your learner guide for documentation on the 66 Waterloo Road Project.

Make notes on the video presentation on 66 Waterloo Road Project.Video Presentation Make notes on the following questions:

What were the first steps?

How was the BMCS used?

What was the role of meters and sub meters?

What is the difference between data and information?

What types of interventions were involved?

What communication lines were utilised?

What is a night audit?

Other notes



Topic 3: How is energy consumed in buildings?

Retrocommissioning is primarily aimed at improving the energy efficiency and reducing the energy consumption of the building (there are also other reasons such as water efficiency, improved tenant relationships, safety and risk management, asset enhancement).

The illustration (Chart 1) below shows in a temperate zone (such as southern Australia), the way in which energy is consumed by different elements of a building. You can observe from this that by far the largest consumer is the heating and air conditioning system (HVAC).

Chart 1: Indicative CO2 emissions for each application.

Chart 2 shows the different components of an air conditioning system and the energy each consumes as a proportion of the total. Again, this is for a building in a temperate zone.Note: These slides depict examples of typical building energy consumption data, not an average for all commercial building stock.

The amount of energy that HVAC consumes on a large building is, therefore, substantial – i.e. about 40 – 60 % of total. This is a large cost in terms of the money paid by owners to provide heating and cooling, but also a cost to the environment in terms of the CO2 emitted to produce the electricity or gas (fuel) to drive the system.



Chart 2: Indicative energy consumption rates

Therefore, anything that can be done to REDUCE the consumption is beneficial.

But, there is also WASTED energy in a building. This can be caused by many things such as the system not being maintained properly, the system being out of balance due to faulty sensors or changes over time to the temperature (and other) set points in various locations, leakage into the building (affecting heating and cooling loads and air pressure within the building), temperature set points too high (in winter) and too low (in summer), unnecessary loads on the system (heat from uninsulated external walls, and unshaded windows or unnecessary equipment and lights), incorrect or no system integration testing, etc.

Energy is often wasted by HVAC systems and often this is masked by the system itself whilst it continues to provide adequate comfort to occupants.

Some of the areas of energy waste typically encountered in HVAC include:

Control set points and schedules (internal temperatures, 24/7 plant operation)

Absence of temperature lock outs Simultaneous heating and cooling (Cooling and heating systems working

against each other) Excessive use of reheat (can mask control and operation problems) Dirty or blocked heat exchange surfaces (chillers, boilers, cooling towers,

coils) Clogged or blocked filters (air and water) Incorrect refrigerant charge (chillers and DX) Water leaks and excessive water use (cooling tower bleed) Bypass in valves and dampers Excessive outdoor air ventilation flow rates Air leakage in ducts, connections, access panels



Incorrect economy cycle operation (operating during high/low outdoor temperatures)

Poor air handling control (VAV pressure control) Inappropriate or ineffective mechanical night purge (in high thermal mass

buildings) Inappropriate pre-heating/pre-cooling schedules (non optimum start/stop) Thermal bridging (duct/pipe insulation, equipment insulation, building

fabric) Excessive air infiltration (building pressure, facade integrity, zoning) Excessive throttling using dampers or valves (particularly on index circuits) Inefficient motor use or missed VSD opportunities Missed energy recovery opportunities Incorrectly calibrated temperature and humidity sensors Deferred maintenance (covering many of the above items as well as

manufacturer’s instructions) Inappropriate access to controls (unlocked thermostats) After hours system access (systems running 24/7 instead of on demand) Lack of knowledge of BMCS and graphical user interface (diagnostic screens,

alarms, trends).

Therefore, STOPPING energy waste is also tremendously beneficial.

The objective of retrocommissioning is to address many of these issues of waste, and the common areas include:

Simultaneous heating and cooling Oversized plant and equipment Overridden variable speed drives Overridden economy cycle False or repeatedly ignored alarms Inefficient piping and ducting layouts Poorly located or calibrated sensors Poor system integration Inappropriate control sequences Altered control set points Inappropriate lighting and controls Envelope air leakage and moisture management. Afterhours access to air conditioning

Appendix B of AIRAH Manual DA27 provides a checklist of things that should or could be addressed in a retrocommissioning program.




EXERCISE 2 Make notes from the discussion on the sources of energy waste.



Topic 4: Why retrocommission?

There are many reasons why retrocommissioning is beneficial.

At the highest level, using a retrocommissioning process to improve energy efficiency will:

lower building operation costs (note that the cost of fuel and energy are likely to increase even further)

reduce greenhouse gases (CO2 emissions) contribute to the mitigation of climate change.

But the retrocommissioning process to improve energy efficiency also has more immediate effects on the operations of the building itself. This can include solving building problems such as:

high power and water consumption poor or non-existent documentation incorrect commissioning uncontrolled tenancy modifications poor system performance poor building performance non-compliance with mandatory certification.

The retrocommissioning process therefore contributes to:

better indoor air quality (IAQ) and indoor environment quality (IEQ) reduced risk reduced maintenance longer service life reduced water use better documentation better training/knowledge.

Recent research in the US shows that retrocommissioning results in on average 20-40% building energy savings. (See Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions, Evan Mills, 2009) We will also explore the costs and benefits of retrocommissioning in Topics 15 and 16.



AUDIO PRESENTATION – Why Retrocommission?

Make notes on the audio presentation from Dr Paul Bannister.

Audio Presentation Make notes on the following questions:

What change has happened in the last 10 years?

What common errors or failures happen in existing buildings?

What common errors or failures happen in new buildings?

Can most buildings be retrocommissioned to achieve 4 NABERS Energy stars?

What effect will Commercial Building Disclosure legislation have?

Are the hotel and retail property sectors markedly different to the office sector in terms of quality of delivery?



Topic 5: Which buildings are suitable?

One of the starting points in a retrocommissioning process is in determining whether the building is suitable, or whether some other process such as a complete refurbishment or retrofit would be better.

The point is that not all buildings are suitable for a retrocommissioning process. There are buildings that are suitable, and those that are not suitable, and there are also buildings that lend themselves better for a retrocommission.

In other words, all buildings will have pros and cons when deciding on a retrocommissioning process.

The first step is to determine whether the building is suitable for the process. Retrocommissioning can be applied very effectively to buildings that have:

constant occupant comfort complaints high operation costs unexplained energy peaks regular system or unit failures high maintenance costs not been commissioned (no documentation or commissioning data) incorrect HVAC operations unused or incorrectly used DDC and BMCS overly complex mechanical and digital controls high occupant churn.

Next, look at the other end of the scale, to determine whether the building is unsuitable. This generally means those buildings that:

are due for refurbishment (ageing or dilapidated building services) incorporate extensive electric or pneumatic control systems are closely monitored by owners /managers where there are ongoing

improvement strategies.A building is not a good retrocommissioning candidate if most or all of its equipment has aged to a point where retrocommissioning cannot produce improvements that would avoid equipment replacement. If only some equipment needs to be replaced, however, this can be coordinated with retrocommissioning to maximize benefits. Incorporating retrocommissioning with the replacement process improves system performance by ensuring that new equipment is properly integrated with other building systems.Although buildings with fully pneumatic controls can have good retrocommissioning opportunities, buildings with digital building management and control systems (BMCS) are typically more cost effective for the process. Pneumatic controls easily drift and need constant attention and calibration for benefits to last. Also, because of its trending capabilities, a BMCS can be used as a diagnostic tool during the retrocommissioning process to capture the building and systems operating data.

It is the case though that some building characteristics lend themselves to a retrocommission process, and these include:



an engaged and informed operating and maintenance team DDC or BMCS control systems accessible and accurate building documentation.

The reason for this is that the process will be easier to implement if these are available. For a successful retrocommission, it’s a team approach and the operating and maintenance team are integral to it, particularly when implementing strategies to continue the good performance of the building achieved as a result of the retrocommission. Retrocommissioning performed in buildings with experienced, knowledgeable, interested, and available building staff is more likely to be cost-effective and have good persistence or lasting results. It is difficult to run diagnostic tests, monitor performance and conduct measurements on improvements if there is no DDC or BMCS. And finally, having accurate and reliable documentation (such as as-installed drawings, operating manuals, maintenance procedures and maintenance logbooks) on how the building should function will assist in benchmarking and diagnosing problems that may be contributing to poor operating performance. Clear, complete, up-to-date documentation expedites the planning and investigation phases of a retrocommissioning project. Buildings that lack good documentation, especially in regards to the mechanical services and control systems, can drive costs up if the team has to spend time gathering and recreating critical information in order to assess system operation.

Finance

The owner’s financial criteria such as the required simple payback period and the cost limits such as capital budget vs. the operating budget will also affect a buildings’ suitability for the retrocommissioning process. These criteria, along with budget cycle information, can also help the retrocommissioning manager and owner prioritize the work during the process and develop implementation strategies that can fit within the financial criteria.

If the building is located where there are tax incentives or rebates available these can help off-set some of the costs and help reduce payback times, allowing more expensive improvements to fit into the owner’s financial requirements.

Addressing a portfolio of buildings

Owners of multiple buildings (private building owners, investment trusts, and property management firms) can consider a portfolio approach to selecting the best candidate(s) for retrocommissioning. Evaluating energy improvement potential across a portfolio of buildings and selecting those with the greatest likelihood for success can assist owners with long-term planning and enable them to capitalize on short-term paybacks. Owners often want to retrocommission their worst performing buildings first, but these facilities are not necessarily the most cost-effective choices.

Although larger buildings are often thought to be better retrocommissioning candidates, a building of any size with complex mechanical systems and controls can be a good choice for a retrocommissioning project.While having missing or out-of-date building documentation should not eliminate a building from consideration, in the interest of cost effectiveness, owners may



wish to conduct retrocommissioning first in those buildings with better documentation. Complete, well-organized documentation can expedite the retrocommissioning process.

Expert evaluations

Because buildings are complex and energy waste is often hidden, many buildings that exhibit none of the above characteristics may still prove to be good candidates for retrocommissioning. Experienced retrocommissioning providers understand how to uncover this hidden energy waste. A provider can be brought in early in the decision-making process to assist in identifying a building that is suitable for retrocommissioning. A provider can evaluate buildings in more detail than is possible using only a benchmarking score and can estimate the opportunity for reducing costs. The information a retrocommissioning provider uses to analyse sites would include:

Building type and use Number of occupants Size (NLA) Annual hours of operation Year of construction Year of last renovation Mechanical, lighting and control systems (types and sizes) Energy data (ideally, 12-24 months) Annual electricity use (kWh/year) Peak demand Annual gas use (MJ/year) Operations overview HVAC schedules relative to operating hours Set points Minimum outdoor air ventilation rates Extent of variable flow systems (air and water) Preliminary discussions with facility staff members Simulation of building optimal energy consumption: Differences between optimal and real data



Activity 1: Building suitability

For the three building scenarios presented below, assess whether they are suitable for retrocommissioning or not and provide reasons why you came to this conclusion.

Scenario 1

208 Pitt Street is a 10 storey commercial office building. It was originally built in 1958 as a 6-storey building, and then renovated in 1965, when another 4 storeys were added. This meant, in effect, two separate HVAC systems – one operating from the basement servicing the lower 6 floors, and the other operating from the roof. The HVAC systems were renovated in the early 1980s, adding a new chiller and boiler into the mix. The building controls are a mix of pneumatic and electric components. There have been significant levels of deferred scheduled maintenance and occupant complaints have steadily in the past two years and only 4 of the available 10 floors are currently leased.

Recently, a new owner took over the building, and an energy audit was conducted, which estimated a 1.5 star NABERS Energy rating. The intention of the new owner is to invest in the building to bring it up to a 4.5 Star NABERS rating.

Assessment

Reasons



Scenario 2

A building was built in Darling Harbour in 2007, using the best architectural features and HVAC system design practice of the day. It’s a 15 storey office building facing directly west, with a fully glazed façade, but surrounded by buildings on the other sides.

There have been many tenant complaints about the air conditioning – too hot in some areas, and too cold in others. The building has a BMCS and the new facilities manager has been trying to rectify the performance of the building and air conditioning by adjusting, generally on a weekly or ad-hoc basis, the temperature set points in various locations, particularly on the top three floors.

An audit was conducted recently, and the result was 3.5 star NABERS Energy rating. The owner had been provided a 5 Star NABERS Energy rated building by the building / HVAC contractors in 2007. A Government tenant currently leases 8 floors of the building and this lease is due for renewal in early 2013.

Assessment

Reasons



Scenario 3

Dyson House is a heritage building nestling on the harbour. It was built in the 1800s, and has been renovated many times since. The last time was in 1998. This renovation redeveloped each floor and installed a completely new HVAC with sophisticated digital BMCS. Because of the size of the building (5 storeys), it was decided to install a separate reverse cycle DX systems to service each individual floors. The heating is also provided by the same system. The current building classification is Class 5 office space.

The monthly energy bills have been significant and are rising every month, maintenance callouts are also becoming more frequent. Due to the spiralling operational costs, the building management wish to make the system more efficient and reliable. They have not conducted a NABERS Energy rating at this stage. Essential services are in place and certified annually.

Assessment

Reasons



Topic 6: The retrocommissioning team

As discussed in Topic 2, retrocommissioning is a collaborative exercise, and this means that a team is assembled around the process.

There are two aspects to this:

1. Selecting a retrocommissioning manager, and 2. Assembling a team.

While not necessarily a technical expert, the retrocommissioning manager should have the following skills and knowledge:

Good knowledge of building services and systems.

Have a working knowledge of relevant legislation.

Hands on experience with HVAC systems and controls.

Good understanding of BMCS and control issues.

Good understanding of other disciplines including building contracting.

Good understanding of operability, maintainability and commissionability factors.

Methodical approach to testing and documentation.

Computer literate including project management software.

Have experience suited to the building and system types being commissioned.

Employ or partner with a technology specialist who has experience in systems in which they do not.

Have extensive experience in troubleshooting commissioned systems.

Excellent written and verbal communication.

Diplomacy and an ability to resolve conflict.

Good project management and organisation skills.

For complex projects, have similar experience in four projects or, for other simpler projects in two.

Experience should be confirmed by references.

Provide an objective unbiased point of view at all times.

The building owner will most likely appoint the retrocommissioning manager. Retrocommissioning managers are important as they are the central point for the collation of the wide range of issues that may exist. They may come from a variety of backgrounds, including:

An independent commissioning agent A design engineer with commissioning experience A mechanical contractor with design and controls experience A National Environmental Balancing Bureau (NEBB) Certified Professional



A TAFE Certificate IV certified supervisor. A high level controls or commissioning technician.

The responsibilities of the retrocommissioning manager could include the following:

Organise and lead the retrocommissioning team.

Ensure the owners expectations are adequately documented and carried through to completion.

Prepare, monitor and update the retrocommissioning plan.

Organise and lead regular retrocommissioning team meetings.

Implement the retrocommissioning plan.

Interrogate the team’s previous experience and implement any changes thought necessary.

Observe construction in relation to program and technical requirements.

Observe and witness functional testing and raise any shortfalls as necessary.

Check and verify the buildings operation and maintenance manuals are complete and representative.

Review staff training plans, attend training sessions and confirm training procedures are appropriate and acceptable.

Prepare and submit the final retrocommissioning report.

Ensure the installation has all the required testing and commissioning facilities provided to enable the testing and commissioning to be carried out.

Ensure the correct testing equipment is available for carrying out the necessary tests.

Liaise with equipment suppliers regarding specialist testing of equipment.

Monitor the program and installation to ensure the commissioning engineers are available when the work is ready to start.

Provide or verify work method statements for all testing and commissioning procedures.

Agree and setup the format for recording all tests.

Provide or verify all the required specific information for the operating and maintenance manuals.

Conduct periodic site visits during the first year of occupancy, conduct any deferred testing, assess the level of building tuning necessary, and review the maintenance records in the Operating and Maintenance Manuals.




EXERCISE 3 From the discussion, make notes on the following:

Why is the selection of the retrocommissioning manager important?

Why an engineering background?

What attributes does the person need?

What responsibilities do they have?

The make-up and size of the team required will depend on the size and scope of the retrocommissioning project.

The objective is to make it as broad as possible so that there is input from a wide cross-section of those staff and technicians who deal with the management, maintenance and performance of the building. This may include:

The retrocommissioning manager The owner’s representative (business manager, building manager, facilities

manager) The resident controls company The resident maintenance provider The testing and balancing company The fire or essential services maintenance company Tenant representative or OHS representative Independent testing teams or specialists.

There is more information on the role of the retrocommissioning team in the AIRAH Manual DA27 Section 9.9.3.




EXERCISE 4 From the discussion, make notes on the following:

Why is a broad team necessary?

What roles do the various team members play?

How should they meet and communicate?

How should documentation be managed?



Topic 7: Starting the process

The issue in many circumstances is knowing when to introduce a retrocommissioning process, and how to bring the idea or concept into the manager / owner decision-making processes of the building.

The triggers and opportunities for a retrocommission are varied and many. For instance, it could be when faced with the need to:

Reduce operating and maintenance costs Introduce a better performing asset Respond to Government financial incentives Address long standing tenant complaint Face potential sale or change of building classification Respond to requirements of Commercial Building Disclosure (CBD). Respond to government or private leasing requirements.

If the building you are connected with is a commercial office building and has a floor space in excess of 2000 sq m, then disclosure of energy efficiency or performance of the building when it is leased, sub-leased or sold is mandatory. This requirement is likely to be extended to all commercial buildings over time. (For further information, visit www.cbd.gov.au.)

Other triggers / opportunities might include such things as:

NSW Energy savings Scheme (www.ess.nsw.gov.au/) Low Carbon Australia (www.lowcarbonaustralia.com.au/) Green Building Fund

(www.ausindustry.gov.au/InnovationandRandD/GreenBuildingFund/Pages/GreenBuildingFund.aspx)

Tax breaks for green buildings (www.alp.org.au/agenda/environment/tax-breaks-for-green-buildings)

Green leases/Government leases Energy performance contracts Green Star – Performance, Green Building Council of Australia (GBCA) Melbourne 1200 buildings project. Environmental upgrade agreements




EXERCISE 5 Suggest how the following programs could provide opportunities for building retrocommissioning projects:

NSW Energy savings Scheme

Low Carbon Australia

Green Building Fund

Tax breaks for green buildings

Green leases

Energy performance contracts

Green Star – Performance

Melbourne1200 buildings

Environmental upgrade agreements

Of course, to be able to advocate this with the owners / managers of the building, the timing of the retrocommission is important and this is best set at the appropriate point of the a) budget cycle or b) tenant changes.



EXERCISE 6 a) From experiences you have had with buildings, when would you consider it an opportunity to raise the idea of retrocommissioning?

b) From your experience, what is the best timing in which it could be raised with the building management?



Topic 8: Making preparations

With a retrocommission process, there is quite a lot that can be done before the process begins, which will make the retrocommissioning process much more efficient and less expensive. This work can be done by the owner /representatives.

This could include:

Searching for building documents – as installed drawings, O&M manuals, maintenance log, system schematics, operational matrix, fire matrix, BMCS functional descriptions including documenting the actual control measures and the performance outcomes.

Surveying staff and contractors – questioning the current operations team to identify common comfort and operational complaints or where small improvements can be made.

Making immediate improvements – such as calibrating controls and sensors, resetting damper and valve positions and verifying control set points and time clocks.

Collecting metering and monitoring information – fundamental operational data such as how much water, fuel and energy the building and its individual systems is actually using.

Benchmarking – critical to establish a baseline data on which to measure overall building performance and improvements made as a result of the retrocommissioning process.

Measurements could include:

Electrical energy Gas Fuel oil Water BMCS trends (pinpoint areas, weekly, monthly, quarterly, annual trends) Air and water readings relating to the initial design specification and/or

commissioning data in O&M manual.




EXERCISE 7 Note from the discussion how to best capture and record baseline data?

The AIRAH Manual DA27 notes that the maintenance and continual upgrading of the building documentation would significantly reduce the time spent and cost of evaluating the building.



Topic 9: The retrocommissioning process phases

There are four phases in the retrocommissioning process:

1. Plan

2. Investigate

3. Implement

4. Handover

This is NOT linear or rigid process. In reality, it will be a stop-start, iterative process, with some phases implemented whilst others are still being investigated, making for a more complex process.

Secondly, not every step in a stage will necessarily be implemented for every building. It will depend on the size and scope of the retrocommission – that is, what problems are revealed when the building is investigated, and what has to be done to solve them.



Topic 10: Phase 1 – Planning

PLAN INVESTIGATE IMPLEMENT HANDOVER

There are eleven steps in the planning phase. Based on advice from people who have conducted retrocommissions, it is vital that this stage is conducted well and not hurried. The more time spent on planning, the better the retrocommission outcomes will be.

All information collected during the planning phase is documented in a Retrocommission Plan.

Step 1: Set the scope and goals for the project

The goals need to be defined in a way that they are measureable, as they will be used at the end of the process to measure the success or otherwise of the project.

The goals may be only one, such as a NABERS Energy rating (e.g. 5.0 star), or they may include other targets, such as:

Reducing power / water consumption (by a defined amount) Reducing occupant complaints Retaining tenants Ensuring compliance of essential safety measures and systems.

The NABERS Energy rating is considered by many in government and industry to be the industry standard benchmark for energy analysis of existing buildings. It is this energy rating system that underpins the CBD program.

The scope of works will depend on the building and what is required when investigated further, but could include such things as:

Reviewing and updating documentation Analysing energy consumption Recommending and implementing corrective action and upgrades Commissioning Training.

The scope of works should also clearly identify exclusions from the retrocommissioning project. For instance the essential services are often excluded, particularly non HVAC based essential services such as detection systems, sprinklers, fire hydrants and emergency warning and evacuation systems.It should be ensured throughout the process that retrocommissioning activities do not detrimentally impact on essential services systems.

Step 2: Select retrocommissioning manager

This has been dealt with in Topic 6.



Step 3: Assemble the team and assigning responsibilities

This has been dealt with in Topic 6. See more AIRAH Manual DA27 9.9.3.

Step 4: Develop Project Operating Requirements (POR)

The Project Operating Requirements (POR) spell out in detail the design and operational requirements of the building, such as space temperatures, humidity levels, time schedules, after hours requirements, tenancy lease agreements and fitout requirements, data room operation, billing arrangements, etc. The POR is developed by the building owner and essentially specifies how the building is intended to operate.

The building operation staff must be involved in developing the POR. No retrocommissioning project should proceed without a clear POR document, which should be signed off by the building owner prior to commencing any work.

Step 5: Survey existing systems

This is a very important step in the planning process. The point of the exercise is to gather information that will help in understanding how the building is currently performing.

As part of the pre-planning phase, building documentation was located. This step highlights the importance of gathering this material. Unfortunately, not all buildings will have consistently updated or properly stored documentation and it is an expensive exercise to restore it.

The second part of this step is to walk around the building and:

Obtain all the energy and fuel invoices (12 – 24 months) Locate the existing meters Define the existing plant capacities (current and new) Track all the distribution systems - the duct systems (for air conditioning and

ventilation) and the pipe systems (for chilled/hot water Determine all control schematics and layouts Observe the operation and interaction of plant items, including valves and

dampers Interview operation and maintenance staff and sub-contractors Review all maintenance records Review essential safety measures.Note: This type of data gathering can be expensive and owners or investors may be reluctant to undertake this extent of forensic data gathering. This should not be a “stopper” for the retrocommissioning project and often a lack of current systems performance data can be counterbalanced by the experience and knowledge of the persons undertaking the survey work, of the retrocommissioning manager and other team members.




EXERCISE 8 a) Note from the discussion what should be done if the relevant documentation is not available.

b) Why is it necessary to obtain / locate / observe/ interview or review the following?

Energy/fuel invoices

Existing meters

Plant capacities

Control systems and layouts

Plant operation and interaction

Operation and maintenance staff

Maintenance records

Essential safety measures



Step 6: Review essential safety measures

The scope of works should clearly identify exclusions from the retrocommissioning project. For instance the essential services are often excluded, particularly non HVAC based essential services such as detection systems, sprinklers, fire hydrants and emergency warning and evacuation systems.

However HVAC based aspects of the essential services will often be impacted by retrocommissioning projects. HVAC based essential services including smoke control systems, smoke hazard management systems and fire and smoke dampers may need to be included within the project scope.

Ensuring that the building meets the AS 1851 Standard or the mandatory regulated state or territory regimes with regard to HVAC based essential safety system maintenance is often considered to be part of the retrocommissioning process.

The system must function, be tested at the correct intervals and have test documentation in place to prove that the maintenance has been carried out correctly. If the documentation is not in a proper order, then the essential safety systems should be inspected, investigated and tested as part of the retrocommission project or more likely as a separate project.

It should be ensured throughout the process that retrocommissioning activities do not detrimentally impact on essential services systems.

Step 7: Benchmark existing systems

Benchmarking is used to determine, on the basis of the industry standard NABERS, how the building is currently performing. This then forms a baseline from which to measure the results (improvements) of the retrocommission process.

Using the NABERS rating is a measure that compares the building’s performance to other similar buildings.

The fundamental data, obtained from permanent utility meters or temporary data loggers, is the water, electricity and fuel (primarily gas). Other data that may be tracked is maintenance costs and occupant complaints.

The National Australian Built Environment Rating System (NABERS) is a national initiative managed by the NSW Office of Environment and Heritage. (Visit http://www.nabers.com.au/)

NABERS is a performance-based rating system for existing buildings. NABERS rates a building on the basis of its measured operational impacts on the environment, and provides a simple indication of how well you are managing these environmental impacts compared with your peers and neighbours.

To determine a NABERS Energy rating you also need to specify the area of the building, the operating hours and the location (postcode).




EXERCISE 9 Why is NABERS an effective benchmark for measuring building performance?



Step 8: Survey occupants, operators and contractors

Gathering as much information as you can from people associated with the building in different ways will also provide insights into the way the building is currently performing.

This is an important step and allows the retrocommissioning team to mine knowledge about the building and its performance from the occupants and staff.

EXERCISE 10 What are the kinds of questions you would ask the following groups?

Occupants

Maintenance contractors

Security

Cleaners



Step 9: Draft performance test procedures

The building plant and systems will need to be tested to determine their performance. It is necessary therefore in the planning stage to work out which functional tests will be required for each system component and the overall plant performance that is required or expected.


EXERCISE 11 Note from the discussion, what tests might be conducted to test performance?

1.

2.

3.

4.

Step 10: Draft monitoring plan

As part of investigating the building’s current performance, time series data of specified operating variables or parameters are captured. These parameters can include energy use (overall and individual equipment), temperatures, flow rates, pressures, weather conditions, equipment runtime and status, actuator positions and control setpoints.

The parameters specified for the monitoring plan will represent key performance indicators (KPI) for the building or for the systems covered under the scope of the project.



The monitoring plan could include:

What data is to be monitored How the data is to be recorded The resolution or sampling rate Synchronisation of all time clocks Downloading and formatting protocols (relates to the communication

protocols of the various devices).

Data analysis method


EXERCISE 12 Data can be captured and analysed using the tools listed below. From the discussion, note what each is capable of measuring.

Data loggers

BMCS

Meters

Hand held instruments



Step 11: Develop retrocommissioning plan

The retrocommissioning plan is a document that records all of the discussions conducted by the team in the planning (and other) phase. It is a dynamic document that will be progressively updated with each of the phases of retrocommissioning project.

The format of the plan should contain the following elements:

1. A description of the building and the systems within it.

2. Project goals and objectives

3. The Project Operating Requirements (POR)

4. Project asset list (including age and expected replacement date)

5. Project team (contacts, roles and responsibilities)

6. Safety requirements (staff OH&S)

7. Formats of all works (work method statements)

8. Work schedule

9. Survey/interview results (occupants, staff, maintenance, security)

10. Baseline data (fuel, energy, water)

11. Test procedures

12. Monitoring plan

13. Performance and functional testing results

14. Recommendations (improvements)

15. Works carried out (implemented improvements)

16. Final test results (commissioning of new and modified systems)

17. Final report with recommendations

18. Training plan

19. Future performance (recommended strategies for persistence)

The retrocommissioning plan is a “live” document that gets updated as the project progresses and at the end of each phase.

As the retrocommissioning plan is developed after the various phases of the project it should also make reference to:

Investigation report.

Implementation plan.

Measurement and Verification plan.



Summary

The steps in the planning phase are:

STEP 1 Set the scope and goals for the project

STEP 2 Select retrocommissioning manager

STEP 3 Assemble the team and assigning responsibilities

STEP 4 Develop Project Operating Requirements (POR)

STEP 5 Survey existing systems

STEP 6 Review essential safety measures

STEP 7 Benchmark existing systems

STEP 8 Survey occupants, operators and contractors

STEP 9 Draft performance test procedures

STEP 10 Draft monitoring plan

STEP 11 Develop retrocommissioning plan



Topic 11: Phase 2 – Investigating


There are nine steps in the Investigation phase.

The steps in this phase will require a good knowledge of commissioning and building services, as the review, testing and analysis of building systems is a technical activity.

It’s important in this phase for all members of the team to be open-minded about the findings, and not side-step any of the issues (due to vested interests).

All information gathered in this phase will be documented in the Retrocommissioning Plan.

The retrocommissioning team would be meeting to discuss issues and decide outcomes throughout the process.

Step 1: Review O&M documentation and practice

All the building documentation should have been located in the planning phase. This step is to bring all the documentation before the project team, where they assess the quality of the documentation and recommend what steps to take if the documentation is incomplete or inaccurate.

This documentation should include a detailed description of the essential services equipment and an operation matrix – including every damper, AHU and fan that has been tested and updated.

Building documentation such as operating and maintenance manuals, as-installed drawings, system schematics, operational matrix, fire matrix, BMCS functional descriptions often don’t exist or are inaccurate or incomplete. Although this documentation is very useful for retrocommissioning the process can be implemented without this and the important system and building information and knowledge can be documented as the project progresses.


EXERCISE 13 From the discussion, note what to do in case the O&M documentation is lacking or non-existent.



Step 2: Measure and analyse building performance

The monitoring plan previously devised is now implemented. It’s purpose is to take a snapshot of the actual / current performance of the building.

The type of measurements undertaken could include:

Sensor calibration (targeting critical sensors) Complete set of air and water readings Current draw on relevant equipment Determining system operating points Flush rate measurements for toilets and urinals Water flow rates of tapware Detailed AHU, fan and pump tests Duct, room and building pressurisation tests. Infrared imaging for thermal bridging and leakage (ducts, rooms, facades).

Depending on the depth and scope of the retrocommissioning project the measurement and analysis of all these building/system metrics may not be practicable. The retrocommissioning team may need to look at a building and its systems and decide where best to direct the measurement and analysis resources to achieve the project goals.

Note: This type of data collection can be expensive and owners or investors may be reluctant to undertake this extent of forensic data gathering. This should not be a “stopper” for the retrocommissioning project and often a lack of current systems performance data can be counterbalanced by the experience and knowledge of the persons undertaking the diagnostic monitoring work, of the retrocommissioning manager and other team members. The building and its systems can be reviewed by the team and decisions made about where best to direct the measurement and analysis efforts.


EXERCISE 14 Note from the discussion:

Who performs these tests?

How are the results reported to the team?

How are the results documented?



What problems could be encountered?

Step 3: Perform diagnostic monitoring

Diagnostic monitoring includes monitoring and analysing the performance of the mechanical plant to identify operational issues, equipment faults and plant control inadequacies.

Monitoring tools could include portable data loggers, meters and the BMCS.

Areas that could be targeted in this include:

Power and water utility meters Chiller run hours and number of starts Source of minimum load call up for cooling and heating Chiller unloading characteristics Chilled water and bypass valve positions. System operating set points Water temperatures Load stability and rate of change Power and water consumption through BMCS monitoring.

Note: It is not uncommon in retrocommissioning projects to discover that the building BMCS is not capable of the level of trending and reporting required for diagnostic monitoring. Often an early step in a retrocommissioning process is to upgrade the BMCS to provide for adequate functionality for the required diagnostic and reporting functions and to provide for system access for tuning and adjustments. Upgrades usually include for new or additional software and controls technicians time and the diagnostic monitoring process should be carried out in conjunction with the BMCS provider in a constructive arrangement.



Who performs diagnostic monitoring






Step 4: Test systems performance and integration

Individual tests will need to be conducted on individual plant and systems. This may require functional testing, where the system is forced into particular operational modes and the system responses are observed and recorded.

Each test procedure and the associated results must be clearly documented, and if possible, supported with a snapshot from the BMCS interface screen.



Who performs these tests






Step 5: Identify system improvements

From the data collected and analysed in the performance analysis, diagnostic monitoring and testing, system improvements are identified.

System improvements could include such things as software changes, sensor recalibration or relocation, and equipment modification or replacement.

It may be possible, especially in some minor cost cases, to implement the improvements immediately – such as installing variable speed drives on fans and pumps, providing additional dampers, balancing valves and sensors.



Who makes these decisions?

How are these decisions reported to the team?

How are the decisions documented?

Step 6: Develop Investigation Report

All the findings from the investigation are compiled into an Investigation Report. This report includes the results and findings of all the investigations, any changes made immediately and a list of recommendations with priorities, estimated costs, savings and payback period.

This document will go to the building owner for their approval.





Who writes the report?

How is the team involved?

Step 7: Prioritise system improvements

This Investigation Report is passed on to the owner to consider and decide on the priorities provided in the recommendations.

Their decision will be based on such things as:

Budget/Capex (capital expenditure) limitations Is it still economically viable to proceed with the retrocommissioning? Can any additional items of the system be improved prior to

retrocommissioning? Is it best to implement the improvements gradually? What is the likely impact on the tenants?



What criteria will the owner use to decide?

What problems could arise at this stage?



How can these issues be best resolved?

What happens if the owner chooses not to proceed?

Step 8: Draft Implementation Plan

Once approval to proceed has been given, an Implementation Plan is drafted.

The plan should detail:

A scope of work for each improvement A schedule of work for each improvement Measurement and verification requirements for each improvement Program of proposed works.



Who drafts the plan?

How is the team involved?

What problems could arise in developing this plan?



How could these best be resolved?

Step 9: Update Retrocommissioning Plan

The retrocommissioning plan is updated to include all the findings of this phase, including all system improvement recommendations and all accepted or approved improvements.

The retrocommissioning plan should also be updated to include the draft implementation plan. It needs to be presented to the building owner / manager for signoff.

Summary

The steps in the Investigating phase are:

STEP 1 Review O&M documentation and practice

STEP 2 Measure and analyse building performance

STEP 3 Perform diagnostic monitoring

STEP 4 Test systems performance and integration

STEP 5 Identify system improvements

STEP 6 Develop Investigation Report

STEP 7 Prioritise system improvements

STEP 8 Draft Implementation Plan

STEP 9 Update Retrocommissioning Plan



Topic 12: BMCS and retrocommissioning

As discussed in previous topics, a Building Management and Control System (BMCS) is an extremely valuable tool used in the retrocommissioning process, to perform diagnostics, indicate trends and measure performance.

Note: BMCS are also referred to as Building Management systems (BMS), Building Automation Systems (BAS) or Building Automation and Control Systems (BACS). All of these terms refer to the same thing.

A BMCS consists of a number of digital controllers that communicate via a network infrastructure and report to a computer, referred to as a head-end, supervisor or operator workstation. The operator workstation can send operational parameters to the controllers such as set points and time schedules. Conversely, the controllers can send operational information to the workstation, such as temperature, alarms and system performance information.

The controller software controlling the HVAC is known as direct digital control (DCC).

The BMCS can be web or non-web based systems.

The elements of the control system and its relationship to the BMCS are shown in the illustration following.

The BMCS that can be used to advantage in a retrocommission project to capture performance data at instantaneous, historic or pre-defined time intervals. This data can be collected into trend logs.

Trend log is the term used for the data files compiling the trend variables for analysis. A trend log is created by sampling and recording a system point at a predefined interval. This interval can be either time based or change of value (COV) based. A trend log can be associated with any control point on the system, either digital (on/off) or analogue (variable), real (measured) or virtual (calculated).

Trend analysis is performed by attempting to analyse the data to identify trends or patterns over a set time period or change of value (COV). Once a trend log has been defined for a system, anomalies are easier to detect.



Elements of the control system and relationship to BMCS

Trend logs can create large amounts of unnecessary data if not managed correctly. For instance, a trend log set up as a COV will record the point value whenever there is a value change outside the predefined limits. A temperature sensor log may be set up with a COV limit of 0.1°C. Every time the temperature sensor reads a 0.1°C change, the value will be recorded. This small incremental change of value in temperature would not be appropriate in most cases because the change occurs too frequently and the change is not significant. This trend log would create too much data and would be impractical to use in most buildings.

Not all buildings of course have a BMCS – particularly older ones.

Not all buildings have the same BMCS – they vary in the way they provide a representation of the control systems, the management of these controls and the quality / quantity of the data produced. However, as explained above, the principles of their function are much the same across all types.



There are several points in the retrocommissioning process where the BMCS is important, and this discussed in the AIRAH Manual DA27, Section 9.9.7. Sections 9.9.10 and 9.10.3 relate to testing in the final stages of retrocommissioning.

Updating or upgrading a BMCS system is often a pre-project step or the first step in a retrocommissioning project. If a BMCS was not installed in a building, installing a digital control system with a BMCS may be the first action to take, so that the performance of the building can be determined. Some buildings have a dedicated Energy Management System (EMS). Otherwise, data loggers and data retrieved from meters and sub meters can be used as an alternative.

Accurate system performance trending is the best tool at the disposal of the retrocommissioning team. The monitoring and trending of system performance and operating characteristics are a pre-requisite of the process. Time-series data of various building operating variables such as energy use (overall and individual equipment), temperatures, flowrates, pressures, weather conditions, equipment runtime and status, actuator positions, control setpoints etc. can be collected and analysed. Analysis of the data includes a diagnostic assessment of system or building faults.

Monitoring and the generation of trend logs can be carried out in several ways:

1. Data loggers – Where BMCS sensors are not available, portable data loggers, which are stand-alone electronic data gathering devices, can be temporarily installed to collect system/equipment performance data. Data loggers are typically available for monitoring and recording current draw, temperature, pressure, humidity, and indoor air quality indicators (CO2 and mixed gas sensors).

2. BMCS – Where BMCS sensors exist, select sensor and ensure trend logs are carried out. Cross check that BMCS sensors are within acceptable deviation with regard to HVAC equipment sensors to ensure consistency.

3. Existing meters – Where meters exist, they should be calibrated before use in the monitoring plan.

4. Spot measurements – Key performance indicators can be measured using suitable calibrated hand held instruments if required.

The fact that a BMCS can manage the performance of a building does NOT mean that it can be used to randomly change system settings. It is vital that you read and understand the functional description, so that you understand how the system is intended to operate, before making any changes to any system using the BMCS.

A functional description is a plain English or narrative description outlining the logic of the mechanical design and associated control system. It is clear, provided in a non-technical language and generally written by the systems designer. It shows:

the intended logic of the operational sequences and control strategies how all the system components interact a list of all the physical and key virtual points.Functional descriptions must be system and building specific and not generic control strategies.



If functional descriptions of the BMCS do not exist, this may become one of the tasks of the retrocommissioning project to write this document.

Note: Writing a detailed functional description can be an expensive exercise and it is possible to retrocommission and tune systems without one. However, it is important that any new or updated functional description (of whatever detail) is kept up to date with system changes and similarly a process is put in place that controls and records how and when the BMCS or controls are modified.

VIDEO PRESENTATION - Why is the BMCS necessary for Retrocommissioning?

Make notes on the video presentation from Jon Clarke.

Video Presentation Make notes on the following questions.

What is the biggest issue for BMCS commissioning?

What is the major difference between commissioning and retrocommissioning?

How is the BMCS used in retrocommissioning?

How should the BMCS be set up to achieve this?

What are trend logs?

What are alarms?

What are exception reports?

How are these used in building diagnostics?

Other notes?



Tutorial: Using meters, sub meters, BMCS trend logs or data logging as a diagnostic tool

Activity 2: Answer the following questions on reading and analysing the data provided by a BMCS

BACKGROUND

A 2 year old building was originally designed to achieve 4.5 Star NABERS Energy rating. It has a sophisticated variable air volume system with an economiser cycle and very efficient chillers. When you asked the development manager about the construction process it was explained that the building was delivered with a lot of time pressure at the end. You are very suspicious about the controls and commissioning as you know this is critical to a building functioning well, and that commissioning is very time consuming.

You start to interrogate the building energy metering and sub-metering data and BMCS screen shots to see if you can establish whether this new building is performing as per the original design intent.



Question 1: Daily demand/load profile graph

This graph shows the total base building daily electricity demand. Identify any apparent anomalies and suggest any investigations or corrective actions that could be taken.

Write in the correct response and points to note here:

Activity 2 Question 1 response



Question 2: Weekly demand/load profile graph

This graph shows the total base building daily electricity demand for an entire week.

a) Why are there differences in the demand for energy on different days of the week?

b) What variables might account for these variations?

c) What additional information would be useful to better understand the variation in demand for energy?

d) Why is there demand for energy overnight when the building is unoccupied?

e) What might account for any variation in overnight load?



a.



b.

c.

d.

e.



Question 3: Daily consumption Vs Temperature graph

This graph compares daily energy consumption with average daily temperature.

a) Why is the curve relatively flat up to 15 degrees?

b) What might account for the variation shown at 28 degrees (i.e. 28,000 kWh compared to 38,000 kWh on different days but same average temperature)?

c) How could we use a graph like this to determine whether daily consumption in a building is relatively “normal”?



a.

b.

c.



Question 4: Weekly load profile.

This graph shows the total base building daily electricity demand for an entire week.

Identify any apparent anomalies and suggest any investigations or corrective actions that could be taken.





Question 5: Seasonal load profile

The graph shows the load profile for the base building on 3 different dates (each in a different season) in the year.

a) Review the load profile. Identify any apparent anomalies and suggest any investigations or corrective actions that could be taken.

b) Identify reasons for the difference between days and seasons.



a.

b.



Question 6. Daily load profile – Air conditioning (cooling) sub-meter data

This graph shows the daily energy load profile for all AC cooling in the building on a single day.






Question 7: Reviewing energy sub-meter data

This graph shows all of the energy consumption for a month from the chiller and cooling tower sub-meter and shows all information on a single graph.

What is this graph indicating? Review after-hours energy data. What could be causing this (at least 2 answers should be supplied).]



1.

2.



Question 8: Reviewing sub-meter data with BMCS data

The graph indicates the lift power usage in blue, and the pink dot shows when the after-hours air conditioning request signal came on the BMCS. The straight lines are at midnight.

What do you think the purpose of this analysis was? What are your interpretations of this data?





Question 9. Daily profile – Air conditioning fans sub-meter data

This graph shows the daily energy load profile for all air conditioning fans in the building.






Question 10. Daily profile – Air conditioning pumps sub-meter data

This graph shows the daily energy load profile for all of the pumps associated with the air conditioning in the building.






Question 11. Daily profile - Light and power sub-meter data

This graph shows the daily energy load profile for all light and power in the building.




Anomalies – Corrective actions



Question 12: Air handling units – BMCS data

This system is designed to use air with relative humidity in the design range (40-60%) and tightly controlled temperature bands. The following BMCS screen shot was taken when it was raining outside.

Can you see a problem? What is the problem?Suggest any investigations or corrective actions that could be taken.



Problem – Corrective actions



Question 13: Temperature set points – BMCS data

The attached BMCS screen shot shows the temperature set points for each VAV box on one floor of an office block. Is there anything unusual about the information displayed?






B

A


Question 14: VAV terminal units – BMCS data

The following is a BMCS screen shot for a VAV box or terminal unit located on one floor. What is this BMCS screenshot telling us?







Question 15: Weekly load profile curve

This graph shows the total base building daily electricity demand for each day of an entire week.




Anomalies – Corrective actions



At the end of the tutorial discuss with the trainer what you have found out about using BMCS and energy metering as a building diagnostic tool.


EXERCISE Make notes from the discussion on using BMCS and energy metering.

VIDEO PRESENTATION - Using the BMCS in Retrocommissioning

Make notes on the video presentation from Jon Clarke.

Video Presentation Make notes on the following questions.

What is the biggest issue for BMCS commissioning?

Why write functional descriptions for mechanical plant?

Where should you never test controls software?

What is control valve authority?

How can unstable controls degrade mechanical plant?

What is a building dashboard?

What are global set points?

What does the building operator need from BMCS documentation?



Activity 3: Work Based Group Project

The project is to be completed during the break between the two sessions. You will work in the project in the designated teams. You need to decide as a group which building you will conduct your project in. You will need access to the building itself (to survey various components, equipment and plant), the building documentation, and to the building’s BMCS.

You will be expected to write a report answering all the questions that are framed in the project brief provided, and present a summary of your findings to the group in Session 2.

Decide how you will communicate during the project and who will be responsible for writing up the draft document. Remember, this is a group project and your equal participation in conducting the survey and building diagnostics is important.

The group needs to nominate people to undertake the following tasks:

Leader Person to organize and provide access to the buildingDrafter Person or persons to write the reportPresenter Person or persons to present the reportTester Person or persons to operate the test equipmentRecorder Person or persons to record the tests as they are carried out and the

test results.

All group members are expected to attend the building together during the group project work.

At the beginning of the next session, you will be required to submit your project report addressing all of the questions outlined in the project brief and give a brief presentation (no longer than 10 minutes) to the class on your project, including:

1. Background on the building you selected. The type and size, architecture and age. Description of critical plant and equipment.

2. Some of the findings you made. With regard to the questions you were asked in the survey and diagnostics sections of the project brief, what were some of the significant findings (provide at least 4)?

3. Preliminary recommendations regarding areas to target in a possible building retrocommission:

Is the building suitable for a retrocommission? Why or why not? If it is, what is the likely scope of this? What objectives would you realistically suggest? What building / system upgrades or solutions are recommended to

improve energy efficiency? What risks are likely to be encountered in the retrocommissioning

process? How would you present an argument to the owner?



4. Issues you encountered in carrying out the project. Did you encounter building access issues? Was the documentation you needed available? What challenges did you have getting BMCS data and interpreting it?

5. How did the project team work together and communicate? What did they learn about team coordination?

The report may be a PowerPoint, Word or PDF presentation but must be in a format that can be accessed by the class at the next session.

The presentation should be made as if the team were presenting to an investor.

Please select a person in your team to make this presentation.

This is an assessable activity. You will be assessed on:

a) The quality of the presentation of your report.

b) The detail of the responses you provide for each question.

c) The quality of the class presentation.

d) The number of specified activities completed/attempted.

The project comprises two sections:

1. Survey activities

2. Diagnostic activities.

If you are unable to complete any of the specified activities you should note why you are unable to complete in your report and move on to the next activity.

NOTE: SURVEY ACTIVITY 1 MUST BE COMPLETED BY ALL GROUPS

You will need some equipment to carry out some of the specified activities including a calibrated thermometer and a means of communication with other team members.



Project Brief

Survey Part 1

An essential step in any retrocommissioning project is planning. One of the key steps in the planning phase includes surveying the existing building services systems and establishing what is actually there.

Survey activity 1

Obtain energy and fuel consumption data for the last 12 months. Answer the following questions:

1. What is the annual electrical energy (kWh) and fuel consumption (MJ) for the base building?

2. What are the operational hours of the building (hours/week)?

3. What is the occupied area of the building (m2)?

4. What is the total number of computers in use in the building?

5. What is the postcode for the location of the building?

6. Can this information be used to determine a NABERS energy rating?

7. What NABERS energy rating did you calculate?

All groups must source the annual electrical energy (kWh) and fuel consumption (MJ) for the base building.

Survey activity 2

Locate and assess building documentation including operating and maintenance manuals and as-installed drawings. Answer the following questions:

1. Is the building documentation available?

2. Are the documents accurate and complete?

3. Are the documents up to date with any changes since original construction?

If any of the answers to the above questions was no; find out why and comment.

Survey activity 3

Locate all existing meters and sub meters. Answer the following questions:

1. Are there sufficient meters and sub meters to monitor all major energy using systems in the building

2. What energy using systems are sub metered?

3. Is the data being read and stored automatically?

4. Does the metering/sub metering system allow analysis of peak Vs off peak energy consumption?




Survey activity 4

Define existing plant capacity.

1. Is the capacity of all major plant items defined?

2. Do plant capacities concur with as-installed building documentation (asset list, O&M manual)?

3. Do plant capacities concur with design documentation?

If any of the answers to the above questions was no, find out why and comment.

Survey activity 5

Research drivers for retrocommissioning.

1. Does the building have a current NABERS Energy rating?

2. Does the building have any Government tenants?

3. Are there any leasing commitments to tenants regarding energy use?

4. Is there any history of tenant complaints regarding building comfort or operation?

Do the answers to the above questions provide drivers for the retrocommissioning of this building? Comment.

Survey Part 2

An essential aspect of any survey process is to determine the current condition of the building services plant and the level of maintenance being applied.

Survey activity 6

For your selected building answer the following questions:

1. Does the building management team have a maintenance plan in place?

2. Are there maintenance records or logs detailing all maintenance activities?

3. Are essential services being maintained to regulated requirements?




Survey Part 3

Interviewing building management, operation and maintenance staff can be a useful source of information in any survey. For this exercise you are asked to create an evaluation form listing 10 questions that you would like to ask building operation and maintenance staff. Building operational staff can include cleaners and security staff or contractors.

Survey activity 7

Compile a list of (at least) 10 questions that you believe should be included on a “building survey form” for building operation and maintenance staff.

Diagnostics

Another essential step in the retrocommissioning project is diagnostics. Once you have collected data how do you use this data to interpret what is happening in the building? How do you ensure that the data being provided is accurate and true?

Diagnostics activity 1: Sensors

Locate all of the sensors on one floor of the building and any outdoor sensor. Answer the following questions:

1. Are all internal sensors reading the same temperature (within design tolerances)?

2. Are all sensors correctly installed and located? Refer to error check sheet below.

3. Are all sensors (indoor and outdoor) calibrated correctly? (Check calibration with thermometer.)


Error Check Sheet for Temperature Sensors

Common errors that occur with the installation of temperature sensors include: External ambient temperature sensors should be installed remote from any building

exhaust air discharge and out of the direct sunlight. Sensors should not be located where they can be affected by spurious environmental

factors, e.g. locating a room temperature sensor near the external facade in direct sunlight.

When sensors are mounted on a column, particularly an external column, cold bridging can occur resulting in false readings. In this case an insulating pad can be installed behind the sensor to avoid biasing.

Sensors should not be located where they are affected by the performance of the



system being controlled, e.g. a room temperature sensor that is located too close to a supply air grille.

Interference between zones can occur where sensor placement options are limited and the sensor for one zone may be affected by supply air from another zone.

Lack of sealing behind sensor as a result of over large cable penetration can cause sensing errors. This is particularly acute in hollow partitions with access to ceiling space air, which may be either positive or negative with respect to the room.

Localised heat sources such as photocopiers can create a microclimate around a room temperature sensor and in these cases the sensor should be relocated.

Solar radiation falling on a room temperature sensor can bias the sensor. Furniture or furnishings that cover up a room temperature sensor will insulate the

sensor from the space it is trying to sense.

Diagnostics activity 2: Outdoor air / Economy cycle

Locate the outdoor air intake for the building ventilation system. Answer the following questions:

1. Are provisions included in the system to allow the outdoor air quantity coming into the system to be measured?

2. Does the air conditioning/air handling system incorporate an outdoor air economy/economiser cycle?

3. Do the controlling dampers move to the correct position during an economy cycle?

4. Is the cycle locked out for particular ambient conditions (Check BMCS)?

5. Are outdoor air intakes appropriately located (away from building exhausts or areas generating contaminants)?


Diagnostics activity 3: Plant scheduling

Answer the following questions:

1. Is the plant scheduling controlled by a BMCS/DDC system?

2. Do schedules reflect the operating profile of the building users?

3. Are schedules locked in or can they be easily changed?

4. What is the arrangement for after hour’s air conditioning access (switching and zoning)?

Diagnostics activity 4: Data verification



This activity requires you to identify and verify particular data being provided by the control system.

1. Identify the displayed room temperature displayed by the BMCS/DDC system and verify with an independent calibrated thermometer

2. Identify the supply air temperature displayed by the BMCS/DDC system and verify with an independent calibrated thermometer

3. Identify the chilled water temperature displayed by the BMCS/DDC system and verify with an independent calibrated thermometer

4. Identify the condenser water temperature displayed by the BMCS/DDC system and verify with an independent calibrated thermometer.

If any of the results of the above investigations show an inaccurate reading; investigate why and comment.

Diagnostics activity 5: BMCS Trending.


1. Does the building have BMCS/DDC controls?

2. Do the controls facilitate trending of system performance indicators?

3. What trends can be produced with the BMCS? (Provide samples.)

Diagnostics activity 6: BMCS graphics.


1. Does the building have BMCS graphic user interface?

2. Are the graphics understandable and user friendly?

3. Are the graphic images consistent with the systems layouts?

Diagnostics activity 7: BMCS security.


1. Does the building have BMCS/DDC controls?

2. Can system set points be changed without authorisation?

3. Does the system automatically log any changes made and who made them?



SESSION 2



Activity 4: Project report back

The first hour of the second training session will be the groups presenting the findings of their project to the class. This presentation is based on the written report your group has prepared. You may wish to develop a basic PowerPoint presentation to assist in your report to the class.

Please select a person from your group to make this presentation.

The presentation should be made as if the team were presenting to an investor.

The presentation should be no longer than 10 minutes. It should cover:

4. Background on the building you selected. The type and size, architecture and age. Description of critical plant and equipment.

5. Some of the findings you made. With regard to the questions you were asked in the survey and diagnostics sections of the project brief, what were some of the significant findings (provide at least 4)?

6. Preliminary recommendations regarding areas to target in a possible building retrocommission:

Is the building suitable for a retrocommission? Why or why not? If it is, what is the likely scope of this? What objectives would you realistically suggest? What building / system upgrades or solutions are recommended to

improve energy efficiency? What risks are likely to be encountered in the retrocommissioning

process? How would you present an argument to the owner?

7. Issues you encountered in carrying out the project. Did you encounter building access issues? Was the documentation you needed available? What challenges did you have getting BMCS data and interpreting it?

8. How did the project team work together and communicate? What did they learn about team coordination?

You will be encouraged to ask questions of other group’s reports.



Topic 13. Phase 3 – Implementing


The implementation phase of the retrocommissioning process has 10 steps.

Even though the work may not be carried out by members of the retrocommissioning team, this team needs to meet and function, and the reports / documentation on the implementation need to continue in this phase.

Step 1: Select contract approach

The plan and schedule have been devised by the retrocommissioning team, and the owner has agreed to the recommendations. A suitable contractor will be now be engaged to implement the planned works.

There are three main approaches:

1. Engaging the retrocommissioning manager. The company undertakes all implementation and is responsible for sub-contracting the work.

2. Engaging in-house staff with the assistance of the retrocommissioning manager. In-house staff undertake the implementation work and continue to liaise with the retrocommissioning manager.

3. Engaging outside contractor. The owner may prefer to work with contractors that they know or have previously worked with. The retrocommissioning manager should be retained to oversee the implementation and assist with verification and handover.

These approaches will depend on past practices, the experience of the in-house staff and relationship that has been developing in the first two phases of the project with the retrocommissioning manager.

For this exercise,e note down answers and information from the discussion.

EXERCISE 21 Note from the discussion the pros and cons of each approach:

Retrocommissioning- manager

In-house staff

External contractor

Maintenance provider



In what circumstances would a Performance Contract be suitable?

Step 2: Implement selected system improvements

The implementation will follow the agreed Implementation Plan. However, it is likely as the modifications and upgrades are made, that other issues will be encountered and solutions will be found. All the issues should be communicated to the retrocommissioning team, and the documentation recording the changes needs to be maintained.


EXERCISE 22 Note from the discussion, the following:

How is the Implementation Plan communicated to the contractor?

How is the project kept on track?

How are issues / changes communicated to the team?

Issues encountered



Step 3: Conduct pre-functional tests

As the new plant and equipment is introduced, it should be fully tested prior to testing, adjusting and balancing (TAB) and system integration tests. This also applies to dampers and valves and associated components that should be individually tested prior to conducting any system tests.


EXERCISE 23 Note from the discussion, the issues involved in pre-functional testing.

Step 4: Conduct testing, adjusting and balancing (TAB)

When all equipment and plant has been installed, a full or partial air and water balance can be conducted. Areas requiring particular attention would include:

VAV calibration Instrument and control calibration Partial or complete proportional balance of water and air distribution

systems Changing fan and pump speeds to allow systems to operate at optimum

points Addressing any area or unit which is being starved of water or air Setting up and verifying minimum outdoor air quantities. Assessing duct leakage.


EXERCISE 24 Note from the discussion, the issues involved in testing, adjusting and balancing (TAB)



The testing schedule must be structured so that testing builds from the simple to the complex following this hierarchy. Early functional tests focus on components and connections and can be carried out in parallel with other component functional tests.

Once functional tests are completed, system testing and balancing (TAB) can be carried out. TAB can be carried out in parallel with the TAB and functional testing of other systems. Systems integration tests are carried out after functional and TAB tests confirm the readiness of each individual system. Whole building tests and building tuning tests follow, leading to ongoing monitoring, ongoing tuning and eventual recommissioning tests.

Step 5: Test system performance and integration

Once improvements have been made, components tested and systems balanced, further system testing is required. This is the commissioning of new and modified systems and is a cyclic, on-going process until satisfactory performance results have been achieved.


EXERCISE 25 Note from the discussion, the issues involved in testing system performance and integration.

Step 6: Implement measurement and verification plan

Performance measurements of the modified building and systems are conducted and recorded so that the new performance can be compared to the initial benchmarks and baseline (conducted in the planning phase). This focuses on the energy improvements, operational improvements and improvements in safety, risk or compliance with legislation.




EXERCISE 26 Note from the discussion, the issues involved in measurement and verification.

Step 7: Update Retrocommissioning Plan

As stated earlier in this course, the Retrocommissioning Plan is an on-going document, and should be updated throughout the process. Therefore, all issues / solutions that were encountered or implemented in this phase need to be documented in this plan.



Who updates the plan?

How is information collected?

How is the plan communicated to the team?



Step 8: Draft training plan

As a consequence of the retrocommissioning and depending on scope and scale of the project, there will most likely be new and modified systems that need to be understood, controlled and managed by the building staff.

A plan therefore needs to be devised that ensures that the staff will know (depending on the project):

How the system works Project operating requirements (POR) Operation and maintenance protocols What improvements have been made and why, and the improved

performance How to use the BMCS, including creating trend logs and analysing data How to measure, monitor and analyse energy usage What fine tuning is required Operating schedules and sequences of operation O&M requirements for the modified system Alarms – how to set them up, what they mean and how to respond Fault detection and diagnosis Strategies for persistence of benefits, including a recommissioning plan.The training of tenants and building occupants also needs to be considered and addressed, particularly in the operation of user controls.

For this exercise,e note down answers and information from the discussion.


Who devises the plan?

How is information collected?

What resources are required?



Step 9: Revise and update building documentation

Changes to the as-installed documentation (O&M Manual, As-installed drawings, Building user guide) are critical, as this is a record of the work implemented. The extent of document changes will depend on the works carried out.

Any new plant or equipment will need to have operating and maintenance information inserted in to the O&M Manual.

Updating building documentation is an important step but can be a very expensive and time consuming task depending on the quality of the current documentation. The extent of existing documentation updates needs to be discussed and agreed with the client. It is essential, whatever extent of documentation is decided on, that this work be planned for and documentation developed as the retrocommissioning works progress. It can be very expensive to go back after the project and attempt to update. There are also a number of IT related opportunities that could be applied to minimise the cost of producing records and maximising their usability



Who is responsible for doing this?

How is information collected and compiled?



Step 10: Draft final Retrocommissioning Report

This document reports on all the activities and improvements that have been made as a result of the retrocommissioning process.



Why is this report necessary?

Who is responsible for writing it?

How is information collected and compiled?

Where does the report go and where is it stored?



Summary

The steps involved in the Implementation phase are:

STEP 1 Select contract approach

STEP 2 Implement selected improvements

STEP 3 Conduct pre-functional tests

STEP 4 Conduct testing, adjusting and balancing (TAB)

STEP 5 Test system performance and integration

STEP 6 Implement measurement and verification plan

STEP 7 Update Retrocommissioning Plan

STEP 8 Draft training plan

STEP 9 Revise and update building documentation

STEP 10 Draft final Retrocommissioning Report

VIDEO PRESENTATION – Lessons learned

Make notes on the video presentation from Bryon Price.

Video Presentation Make notes on the following questions

Do most buildings have good data and documentation for retrocommissioning?

What stakeholders need to be managed during the process?

Are existing BMCS generally suitable for supporting a retrocommissioning process?

Historically, what has been the biggest challenge or barrier to retrocommissioning?

Can the retrocommissioning process be staged?

How are tenants managed?

What are the issues for occupied spaces?

How important is planning?

What role can tenants play?

How important is communication?





Topic 14: Phase 4 – Handing over


This is a crucial stage and unfortunately in a lot of building commissioning projects, it is not done well. In order for the building to be successfully operated at it maximum performance levels, it’s critical that the operations and maintenance staff know how the building operates and that all documentation on the building is handed over and stored safely.

Step 1: Deliver updated building documentation

Building documentation including updated As-installed drawings, updated O&M manuals and updated building user guides are submitted to the building owner.

Updated building documentation provides support for ongoing testing, calibrating, tuning and energy efficiency focused maintenance. Using the documentation provided by retrocommissioning, maintenance service providers can be encouraged by building owners and managers to focus on the risk areas of energy wastage associated with the buildings mechanical systems.



Why is this important to do?

Where should the document be kept / stored?



Step 2: Deliver training

The training plan is now implemented. The training is delivered to owners, operators and occupants as appropriate.



Who conducts the training?

How is it best conducted?

How does it differ for the different cohorts?

Step 3: Deliver recommissioning plan

This plan maps out a series of recommended future tests and the schedule when this is to be carried out. As the team that created this document will now be disbanded, this document is critical for any new building personnel.





Who writes the plan?

Where is it delivered?

Where is it stored?

Step 4: Deliver final retrocommissioning report

The final Retrocommissioning Report, drafted in the implementation stage, can be finalised and passed on to the building owner.



Who passes the document on?

Who has access to this document

Where is it stored?



Step 5: Conduct lessons learned meeting

This is the final meeting of the retrocommissioning team, to receive the final retrocommissioning report and to discuss lessons learned from the process.



Why is this an important meeting?

What is the likely agenda?

What is done with the minutes?

Summary

The steps involved in the Handover phase are:

STEP 1 Deliver updated building documentation

STEP 2 Deliver training

STEP 3 Deliver recommissioning plan

STEP 4 Deliver final retrocommissioning report

STEP 5 Conduct lessons learned meeting



Topic 15: Costs of a retrocommission

It is not easy to provide a clear picture on the costs, as these will vary so markedly from one building to another. On the other hand, the building owner will want to know this very early on.

We can therefore break it down into components:

The initial retrocommissioning plan – sufficient to have an outline of the recommendations made to how to improve the building’s performance. Here the costs will depend on the size of the building, and the size of the team that has been engaged or contracted in stages 1 and 2 of the retrocommissioning process. These costs include engagement of team, survey and diagnostics and development of the investigation report.

Once an Investigation Report has been developed, which includes all the recommendations, costs, estimated savings and payback periods, then all the costs (and benefits) will be known. (See AIRAH Manual DA27 9.10.6.) These costs include the capital costs of the improvements including removal existing, installation new plant, TAB, integration and commissioning.

Additional costs that might impact on the budget are in the handover stage – depending on the sophistication of the project and the training and resource development involved. This may be absorbed by the ongoing building management, although in a small building, this could be an actual cost. These costs include:

o Training delivery o building documentation delivery o final retrocommissioning report and o lessons learned analysis.

Some of the project specific factors that will affect the cost of a retrocommissioning project include:

Scope and depth of the project Availability of system/building documentation Number and complexity of systems, building, zoning Existing BMCS, meters, sub meters and system instrumentation Involvement of retrocommissioning specialist Extent of in-house/on-site staff involvement Extent of reporting and measurement and verification required.

Some of the factors that will affect the project savings:

Adoption of strategies for the persistence of benefits (see Topic 17) Partial implementation of recommendations only Lack of credible baseline data.

Cost has been a very significant reason why retrocommissioning hasn’t been carried out in the past and why building systems have been allowed to deteriorate.



A significant issue for practitioners is how to improve the cost effectiveness of retrocommissioning or how to achieve the required outcomes for the least cost.

As practitioners and organisations improve their retrocommissioning skills and abilities and with additional drivers such as energy efficiency, sustainability and carbon mitigation at play it is likely that these services will be provided more cost effectively in the future.



Topic 16: Cost benefits of a retrocommission

The owner’s agreement to a retrocommission is often based on a cost/benefit analysis, i.e. weighing up the costs of the retrocommission against the benefits.

In discussing the benefits, the owner will want to know this, not in terms of generalities (reduction in CO2 emissions, etc) but in terms of dollars. Therefore, for each item of benefit, you will need to provide a dollar figure. Then you can more realistically determine how the costs measure up against the savings, and what the actual payback period will most likely be.

The benefits derived from the retrocommission include:

Reduced operating costs

This applies directly to the savings made in energy (electricity, gas), fuel (gas, oil) and water. A successful retrocommission might lower the energy costs of a base building by up to 40 – 50%. If the initial baseline has been conducted (as it should), the actual savings can be calculated in dollar terms, and this projected over a number of years.

Reduced operational risks

The retrocommission will have increased the reliability of the plant and equipment and system performance, with enhanced asset protection. This in effect means that the plant and equipment should have an extended life cycle (will not need to be replaced for a longer period). This is an estimatable item and can be translated into dollar figures.

Reduced maintenance costs

One of the reasons for conducting a retrocommission may have been the periodic breakdown of plant and equipment, and the consequent high maintenance and servicing costs. Having the plant and equipment modified or upgraded and making it work at optimal performance will save on maintenance costs. This can be estimated as an actual dollar saving.

Improved sustainability

The retrocommission has modified or upgraded plant and equipment, and optimised building performance. This means improved occupant satisfaction (fewer complaints) and a reduced resource use. Complaints are a constant drain on building management resources in dealing with small, but time consuming and annoying issues. This is a direct cost saving and can be estimated in terms of saved staff time following up tenant calls, calling service contractors, monitoring and checking the fix, informing the tenant again, etc.

Increased knowledge



The retrocommissioning process ensures that operators are better trained and understand how to operate the system at its optimal level. This means that the knowledge is retained by the building owner manager, and does not rely on expensive external support contractors.

The retrocommission process also created a set of valuable building documents that are comprehensive and up-to-date. Thus, any further commissioning or fine-tuning required in the future will be supported by the relevant documentation. This too is a cost-saving, and can be estimated.

Improved tenant relationship (less churn, longer leases and potentially higher rents)

The impact on tenants can be significant with an improved “sustainable or green” building. It may mean lower tenant churn (this can be calculated from past records) which is a cost when floors /space is vacated as one tenant leaves and another moves in. The upgraded building may attract larger tenants with longer leases (again, a cost saving on advertising, etc.) The improvements to the building performance may mean that higher rentals can be imposed (as the upgrade will mean cost savings for the tenants as well). These are less tangible and more potential benefits, but never-the-less, if the building had a record of high tenant turn-over, a dollar cost benefit can be estimated.

Improved comfort and productivity

This is not a direct benefit for the owner (unless they are an owner occupier), but will translate into improved tenant satisfaction. If staff productivity can be increased the financial returns can be huge. Building owners and occupiers should be informed of the potential for the retrocommissioning process to improve the building’s indoor environment quality (IEQ) leading to improved productivity for occupants leading to greater organisational profits.

Improved property value

This is often an over-looked benefit in the cost benefit equation. The retrocommission has improved the value of the property by upgrading the essential systems and operating performance of the building. It is difficult to quantify, but a check with a property vendor or valuer could estimate a dollar figure for this.

In order to provide a realistic picture of the costs of retrocommissioning, which will be most acceptable to the building owner, it will be necessary to conduct a cost analysis.

This cannot be generalised, but conducted for each building project, because the costs associated with building retrocommissioning will vary from project to project depending on the scope and goals of the project and the opportunities presented by the building and its systems.



In general terms, however, the costs incurred are largely related to the energy efficiency gains required.

For example, the so-called “low hanging fruit” of a building might be addressed relatively cheaply to achieve the first 10-15% energy savings (e.g. scheduling, control strategies and settings, sensor calibration).

For greater savings beyond this, further investment may be required including a deeper analysis of the building systems and more capital intensive improvements (e.g. BMCS upgrades, terminal unit replacement, variable speed drives).

For maximum savings to be achieved, the higher end capital improvements may be required (e.g. building facade work, central chiller/boiler plant replacement).

The AIRAH retrocommissioning model is not proposed as a capital works intensive process. The process instead looks to optimise the performance of existing systems and plant rather than embark on wholesale replacement and upgrades. Ultimately, however, it is the building owner or client who will make the capital investment decisions.

To assist this process the AIRAH Manual DA27 requires that each proposed system improvement is detailed in the investigation report and includes the estimated savings, the costs to proceed and the simple payback period, return on investment or other agreed financial criteria for each recommendation. The AIRAH Manual DA27 notes that, as a general guide, the payback period for any retrocommissioning works should be no more than 2 years to become an attractive business option. Retrocommissioning programs with payback periods in excess of 5 years are unlikely to be undertaken.

There are several financial analysis methods that can be used to conduct a costs analysis, and a brief explanation of these are provided below.

The “Simple Payback Period” is used in the AIRAH retrocommissioning process and trainees should ensure that they understand this method. The information on the other methods is provided for information, background and comparison only.

Simple Payback PeriodCalculating a simple payback period is the most basic of economic analysis tools and the simplest to apply. It is most applicable in situations where a reduction in operating costs relative to business as usual (or some other alternative) will be achieved. Simple payback roughly calculates the number of years before capital is recovered but does not include savings beyond that time, and therefore does not calculate return on investment (ROI).Simple payback period can be calculated using the following equation:

Payback Period (Years) = Total Investment ($) / Savings per year ($)Or if non-energy impacts and benefits are to be included, payback period =

Retrocommissioning cost +/- Non-energy impactsAnnual energy savings +/- non-energy benefits



The advantages of this simple payback analysis is that it is intuitive and easily understood, does not rely on discounting and does not require a stipulated measure life span.

Net Present ValueNet Present Value (NPV) analysis calculates the net value (all benefits minus all costs) of an action in today’s dollars terms so that direct comparisons can be made. It is the recommended tool for identifying the optimal outcome among a number of optionsThe major benefit of NPV is that it acknowledges the time value of money; that is $1 today is worth more than $1 in X years. The time value of money is represented in the calculations by a ‘Discount Rate’ which reduces the value of money in future years by a certain rate per year (usually in the range of 5-10% depending on the application).The ability to include discount and inflation rates (as well as other factors as required) results in the generation of a good indication of the economic outcome of an action, however as these rates are assumptions of future trends they can also include a degree of inaccuracy.

Internal Rate of ReturnInternal Rate of Return (IRR) analysis is similar to NPV however rather than attempting to calculate a monetary value as the output it identifies the discount rate at which the NPV is zero. This eliminates one of the assumptions required for NPV calculations. IRR has benefits over NPV. However it requires some understanding of the underlying economics for the output to be meaningful and is therefore not always applicable when persuading others.

Life Cycle CostingLife cycle costing is a systematic methodology for assessing all the significant costs of ownerships over a selected period expressed in equivalent monetary terms. It recognises that the various operational elements within a building system are inter-related over time. That is, a decision made today regarding building services characteristics will not only affect present functioning but will have an impact over the useful life of the facility.

Apart from capital costs, the ongoing life cycle costs are formally titled "Cost-in-use" and comprise:

operating costs maintenance costs

cleaning costs alteration and replacement costs.

These costs often far exceed the initial capital cost when taken over the useful life of a facility and may have other long term impacts on productivity cost (noise, air quality, thermal comfort) than may be immediately apparent. There is an obvious incentive towards the concept of life cycle costing for an owner-occupier whose interests are best served by ensuring economics for the life of the plant as compared with a developer with motivation towards selling or leasing. An application guide to life cycle costing is provided by Australian Standard AS/NZS 4536 – Life Cycle Costing, An Application Guide.

Life Cycle Analysis



Life Cycle Analysis (LCA) is a detailed analysis technique that aims to quantify all environmental costs, past, present and future, attributable to an action or product whether they are direct or indirect. LCA goes beyond simply maximising the economic return to the building owner, it also aims to minimise environmental costs rather than costs borne by the owner.When presented with a LCA the scope and goals should always be scrutinised as they are critical factors and the outcomes are largely meaningless unless presented in context. The benefits of a positive LCA should be understood and products or services that have had a LCA conducted for them and have achieved a positive result should be given preference in the procurement process.

VIDEO PRESENTATION – Costs/benefits of retrocommissioning

Make notes on the video presentation from Craig Roussac.Video Presentation Make notes on the video presentation on the

following questions

How are commercial office buildings valued?

How important is return on investment (ROI) to retrocommissioning?

What uncertainty factors can impact on ROI?

Are intangible benefits important or valued?

Is retrocommissioning reactive or proactive?

How can retrocommissioning affect tenant retention and investment return?



Activity 5: Building retrocommissioning cost analysis

An important aspect of the building retrocommissioning for energy efficiency process is estimating the likely energy savings that could be achieved by the process. One point to remember is that the greater the depth of the process (e.g. extent of project scope and goals, depth of investigation, extent of capital intensive improvements etc.) the greater the extent of energy savings.

All buildings are different and individual retrocommissioning projects will have different goals and outcomes so generating actual energy saving data for this activity is not possible.

This activity will require you to source the actual energy data from the subject building and, by applying the “typical” savings criteria outlined in the LBNL report, applying the lower 25 percentile, median and upper 25 percentile values for whole-building energy-savings (see Table A5) to the subject building, provide a dollar estimate of the potential energy savings and the corresponding retrocommissioning cost.

The following scenarios are to be considered:

Table A5

Energy savings Payback period Percentile

10% 0.5 Lower 25%

15% 1.0 Median value

30% 2.5 Upper 25%

Using the energy saving and payback periods above and the energy data sourced for your building calculate the potential energy savings and the associated (typical) retrocommissioning project costs for your building.

For example:Annual energy use = ‘W’ kWh/year

Potential annual energy savings = 10% of annual energy use (‘W’) = ‘X’ kWh/yearValue of energy saved = ‘X’ kWh/year x $/kWh = $’Y’/year

Cost of project = $’Y’/year x Payback period (0.5 in this case) = $’Z’This dollar figure $’Z’ represents the typical cost to achieve 10% energy savings for your building.Complete this exercise for all 3 scenarios listed below.

In addition calculate the energy intensity of the building, i.e. the energy use per square metre for your building (kWh/m2)



Scenario 1 10% energy savings/0.5 years payback



Energy intensity

Calculate the energy use per square metre for your building kWh/m2





Topic 17: Persistence Strategies

It is most important to see that retrocommissioning is an ongoing process, beyond the stage of handover. Most important is the need to continuously measure and verify the results of the retrocommissioning process.

The building and its systems performance are likely to deteriorate over time as tolerances slip and component wear and tear takes its toll on the system.

There are strategies however, which can be implemented by owners and facility managers to ensure that the benefits derived from retrocommissioning persist into the extended life of the building.

Strategies for persistence include:

Post occupancy evaluation Building documentation management Ongoing training NABERS ratings Automated monitoring and alarm Ongoing operational strategies Ongoing maintenance strategies Ongoing building tuning program System recommissioning program

Post occupancy evaluation

Post occupancy evaluation generally centres on two critical areas: the energy performance of the building, and the occupant satisfaction level.

Evaluation activities include checking occupant comfort and satisfaction and checking set points and schedules. Building operators, tenants, occupants, and maintenance providers should be interviewed. Periodic evaluation sheets can be issued to the tenants to determine if there are perceived or real issues within the building.

During the post occupancy period, it is important to maintain a log of tenant complaints to determine where problems exist. This can be monitored and addressed by the building tuning team

Building documentation management

Unauthorised and unrecorded changes to building operations are a primary cause of building performance degradation. Building documentation provides building operators and system maintenance contractors with the information they need to operate and maintain the building. If this information is inadequate or inaccurate, then building operations are likely to be sub optimal.

Procedures should be put in place to automatically and promptly update building documentation, including any changes to control strategies or set points that effect



system performance. Operation and Maintenance (O&M) manuals need to be upgraded with all system changes as they are implemented.

Changes might include tenancy fit-outs and the inclusion of supplementary ventilation, heating or cooling units. As-installed drawings should be updated and additional information included in the O&M manuals as necessary.

If everybody is responsible, no one is. Therefore, one person/position should be made responsible for the upkeep of the O & M Manuals and associated documentation and a formal system of change management and document control adopted

Ongoing training

Ongoing training of building management staff, building tenants and occupants helps to ensure that systems are understood and are operated correctly. This is particularly true of new staff and the original training materials should be made available to new staff when they join the team.

Building operators and system maintenance staff should be encouraged to increase their skills and knowledge through available and relevant industry courses and training. Well-informed and trained staff are more likely to maintain a high level of building performance into the future.

NABERS ratings

Where buildings need to maintain a NABERS rating, there will always be a sharp focus on building tuning and persistence strategies. This highlights the fact that all buildings must be carefully monitored to maintain performance and identify potential improvements. Verification of meter readings is an essential part of the NABERS process, so the calibration and accuracy of meters and temperature sensors (and reflective BMCS readings) should be closely monitored.

Automated monitoring and alarm

Most BMCS systems have functions which allow alarms to be sent out for various levels of faults. In the case of building tuning, key items should be highlighted that will initiate an alarm signal if the specified operating range or limits are exceeded.

Thus, if power consumption or run times are excessive, there will be a BMCS trend log and an alarm function which will highlight these issues. Refer to AIRAH DA28 Building Management and Control Systems (BMCS) for further details on automated monitoring and alarm strategies.

Operational strategies

Operational strategies that can be adopted to help the benefits of retrocommissioning persist into the long term building operational period include:

Systems monitoring and ongoing building tuning. System security and management. Formal system of change notification (to building manager).



Maintaining building documentation up to date including O&M manuals and as-installed drawings.

Maintaining availability of commissioning records. Setting targets for building performance. Staff training/Occupant training/Awareness campaigns. Monitoring and managing after hours usage. Enforcing building user guides and tenancy fitout guides. Displaying building daily/weekly monthly energy and water performance to

building occupants (engage occupants in the energy efficiency of the building).

Maintenance strategies

Enhancing current maintenance strategies to ensure that systems are maintained at their optimum performance, including the adoption of advanced maintenance strategies, refer AIRAH DA 19. Maintenance strategies that could be adopted include:

Development and document a formal Maintenance Policy or Plan. Adopt performance based maintenance contracts incorporating preventative

maintenance and condition based monitoring. Incentivise maintenance and service providers, linking incentives to

system/building performance improvements. Including the retuning of systems as part of the ongoing maintenance

contract.

Building tuning (ongoing)

Building tuning is an ongoing activity where efforts to maintain optimum performance are commencing directly after the commissioning, recommissioning or retrocommissioning programs have been completed.

Ongoing monitoring is used to establish the appropriate baseline of operation, either using the BMCS, or a dedicated monitoring system.

Operations are continuously monitored so that when deviations from the established baseline do occur, equipment repair or operational improvements can be rapidly instigated. Building tuning activities often concentrates on the operation of the system controls and the integration of systems operations.



Recommissioning

A recommissioning process should have already been planned and documented in the final commissioning report or at completion of the retrocommissioning phase. Recommissioning will be carried out periodically or after replacement, upgrading or changes to building equipment, services or use.

Periodic recommissioning will help to maintain system performance after retrocommissioning. Best practice is for the recommissioning plan to be developed with the original retrocommission project which is included in the building documentation at handover.

For this exercise note down answers and information from the discussion

EXERCISE 36 Note from the discussion what factors could impact on the performance results after the retrocommissioning process has completed.



Case Study 2 – Freshwater Place

Refer to the back of your learner guide for documentation on the Freshwater Place retrocommissioning Project.

Make notes on the Dr Paul Bannister audio presentation on “How a Melbourne building was retrocommissioned”.

Audio Presentation 1 Make notes on the following questions.

Why was this building suitable for retrocommissioning?

What was the first step?

What were the main interventions?

What is the difference between compliance control solutions?

What did widening the temperature deadband achieve?

What does service deprivation mean in retrocommissioning?

Other notes



Topic 18: Lessons learned

The training will conclude with a video presentation and a wrap up from the trainer. This is your opportunity to ask any questions about any part of the process or about any of the presentations you have seen during the training sessions.

VIDEO PRESENTATION - “Lessons learned in conducting retrocommissioning processes”.

Make notes on the video presentation from Davina Rooney on “Lessons learned in conducting retrocommissioning processes”.

Video Presentation Make notes on the following questions:

How has retrocommissioning developed as a process over the last few years?

Are capital expenditure investments always required in retrocommissioning?

How are buildings selected from a portfolio, how do you identify the best candidates for retrocommissioning?

How are retrocommissioning proposals approached from an owner’s perspective?

Have expectations exceeded outcomes, or vice versa, in your retrocommissioning experiences?

How do you assess the benefits and costs?

What are the red flags for retrocommissioning?

Overall, is retrocommissioning a beneficial practice for the building?

Does retrocommissioning ever end?



Wrap up

The trainer will provide an opportunity for you to ask questions about any part of the course that you wish to explore in more detail.



References

Evan Mills, Ph.D. (2009) Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions, Lawrence Berkeley National Laboratory, California Energy Commission, Public Interest Energy Research (PIER), California

AIRAH (2010) DA19 HVAC&R Maintenance

AIRAH (2011) DA27 Building Commissioning

AIRAH (2011) DA28 Building Management and Control Systems (BMCS)



Further resources

AIRAH

DA 26 Indoor Air QualityDA 24 Water system balancing

ASHRAE

ASHRAE Guideline 0, The Commissioning Process (2005)ASHRAE Guideline 1.1 (2008) HVAC&R Technical Requirements for the Commissioning ProcessASHRAE Standard 111 Measurement, Testing, Adjusting and Balancing of Building HVAC Systems

CIBSE

CIBSE (2003) Commissioning Code M: Commissioning managementCIBSE (1996) Commissioning Code A: Air Distribution SystemsCIBSE (2002) Commissioning Code B: BoilersCIBSE (2001) Commissioning Code C: Automatic ControlsCIBSE (2003) Commissioning Code L: LightingCIBSE (2002) Commissioning Code R: Refrigerating SystemsCIBSE (2003) Commissioning Code W: Water Distribution SystemsCIBSE (2009) Guide H - Building control systemsCIBSE (2009) TM 39 - Building energy metering

NABERS

NABERS (2010) Energy and Water for offices: Rules for collecting and using data Version 2.0NABERS (2010) Indoor Environment for offices - Data Collection Guidance DocumentNABERS (2008) Nabers Energy for offices – Validation Protocol for Thermal Energy exclusionsNABERS Validating non-utility meters for NABERS ratings

NEBB

NEBB (2009) Procedural Standards for Whole Building Systems Commissioning of new constructionNEBB (2005) Procedural Standards for Testing Adjusting and Balancing of Environmental SystemsNEBB (2007) Procedural Standards for Retrocommissioning of Existing Building



Commissioning

California Commissioning Collaborative (2006) California Commissioning Guide – New Buildings, California Commissioning Collaborative, CaliforniaUseable Buildings Trust (2009) SOFT LANDINGS FRAMEWORK for better briefing, design, handover and building performance in-use Building Services Research Industry Association BSRIA, BracknellNATSPEC Mechanical commissioning, NATSPEC Construction Information systems Ltd. Sydney

Retrocommissioning

California Commissioning Collaborative (2006) California Commissioning Guide – Existing Buildings, California Commissioning Collaborative, CaliforniaPECI (2007) A Retrocommissioning Guide for Building Owners, Portland Energy Conservation Inc. PortlandPECI (2009) A Study on Energy Savings and Measure Cost Effectiveness of Existing Building Commissioning, Lawrence Berkeley National Laboratory, California

Controls

Honeywell Inc (1997) Engineering manual of automatic control for commercial buildings, Honeywell Inc, Minneapolis

Measurement and verification

The Australasian Energy Performance Contracting Association (2004) A best practice guide to measurement and verification of energy savings, Commonwealth of Australia, Canberra

Websites

http://www.airah.org.au/http://www.ashrae.org/http://www.automatedbuildings.com/http://www.bacnet.org/http://www.bsria.co.ukhttp://www.bcxa.org/http:// www.cacx.org/http://www.cibse.org.au/http://www.csa.org.uk/http://www.ddc-online.org/default.htmlhttp://www.energy.ca.gov/http://btech.lbl.gov/http://www.lonmark.org/http://www.nabers.com.au/http:// www.nebb.org/http:www.newbuildings.orghttp://www.peci.org/



Additional material

PCA documentation for 66 Waterloo Road ProjectPaper from Dr Paul Bannister for Freshwater Place projectExtract from DA27 – Section 9 and Appendices B and C


Documents

Building retrocommissioning for energy efficiency€¦ · Web viewAlthough buildings with fully pneumatic controls can have good retrocommissioning opportunities, buildings with