ASHRAE Standards & Guidelines for Building Energy Audits · PDF fileASHRAE Standards & Guidelines for Building Energy Audits ... 2 ASHRAE Handbook Fundamentals Chapter 19 Energy

ASHRAE Standards & Guidelines for Building Energy Audits 6/5/2017

Konstantinos Laskos Civil Engineer, BEMP, BEAP Energy Planning & Savings Consultant

Triantafyllos Triantafyllopoulos Mech. Engineer @ Menerga ASHRAE Hellenic Chapter President Elect 2016-2017

ASHRAE and other entities have defined energy audits as processes in which engineering service providers identify and recommend efficiency opportunities to clients. The objectives of an energy audit are to identify and develop measures that: 1.  will reduce the energy use and/or cost of operating a building 1.  and/or will improve the indoor environmental quality experience by the

occupants.

Definition

What is Energy Audit ?


In a Nutshell

1.  How much energy are they using?

2.  Where are they using it?

3.  Are they using it effectively?

4.  How can they use it more effectively?


Basic Steps

1.  Collect and analyze historical energy use.

2.  Study the building and gather data on its operational characteristics and indoor environmental quality.

3.  Identify potential measures that will reduce the energy use and/or cost and/or will improve the occupants’ indoor environmental quality.

4.  Perform an engineering and economic analysis of potential modifications.

5.  Prepare a list of appropriate measures and group measures into bundles that will capitalize on potential synergies and cost reductions.

6.  Prepare a report to document the analysis process and results.

energyaudit

Energy Audit vs Energy Labeling

Basic Differences

predefinedopera/on realopera/on

energylabeling

vs

Energy Audit vs Energy Labeling

Basic Differences

energyusefor“condi/oned”spacesfor:

hea/ng

cooling

ven/la/on

DHW

ligh/ng

energylabeling energyaudit

vshea/ng

cooling

ven/la/on

DHW

interiorligh/ng

energyusefor:

exteriorligh/ng

plug-loads

motors

refrigera/on

etc

ASHRAE Standard 211P: Standard for Commercial Building Energy Audit


This standard applies to all buildings except: •  single-family houses,

•  multifamily structures of three stories or fewer above grade,

•  manufactured houses (mobile homes), and

•  manufactured houses (modular).

Scope


Levels of Energy Audits

Level1:

Walk-ThroughAnalysis

Level2:EnergySurveyAnalysis

Level3:DetailedAnalysisofCapitalIntensiveModificaEons

ASHRAE Standard 211P Preliminary Energy Use Analysis (PEA)

•  Calculate the total annual building energy use, and divide by the gross floor area to obtain the Energy Use Intensity (EUI) i.e. kWh/m2.

•  Calculate total annual building energy cost and divide by gross floor area to obtain the Energy Cost Index (ECI) i.e. €/m2.

•  Benchmark the building’s normalized energy consumption relative to that of similar (peer) buildings for a minimum of 12 consecutive months (up to three consecutive years shall be used as available).

Benchmarking

ASHRAE Standard 211P Level 1 Energy Audit

Facility Site Survey

•  Conduct a walk-through survey of the facility to accompanied by the building operator or maintenance staff member. Become familiar with its construction, equipment, operation, equipment schedules and maintenance.

•  Identify major energy-using systems, processes, and equipment. Gather

control strategies and equipment information of major components from nameplates, as-built drawings, or other means.

•  Identify operating problems, malfunctioning equipment, maintenance costs, and maintenance needs.

•  Interview the owner and/or operator and occupants to identify current space usage, special problems (especially relating to thermal comfort or indoor air quality).


Identify Low-Cost & No-Cost Energy Efficiency Measure Recommendations

•  Changes to lighting and HVAC (e.g., thermostats) controls, to reduce lighting and HVAC in areas that are unoccupied or unused for substantial periods of time.

•  Implementation of routines (and logs) to improve the efficiency of operations, or maintenance of such improvements after tune-ups.

•  Education of building operators and/or occupants.


Identify Potential EEM Capital Recommendations

Identify potential capital-expensed EEMs including a preliminary qualitative estimate of the level of potential costs and energy cost savings.

Review EEMs with Owner’s Representative

Provide to the owner or their appropriate representative a list of identified measures, their brief descriptions, their qualitative impact, and approximate level of economic return. Receive feedback.


The Level 2 audit shall follow upon, and take into consideration the findings of, a Level 1 audit and also incudes the following additional steps*:

Breakdown of the annual total energy cost by component

*If no separate Level 1 audit has been conducted, shall comply with all the procedural requirements for a Level 1 audit.


Facility Site Survey - Determine key operating parameters Determine Operations: Setpoints

•  Space temperature

•  Space humidity

•  Space lighting levels

•  Hot water supply setpoint controls

•  Chilled water supply setpoint controls

•  Supply air temperature setpoint controls

•  DHW storage and delivery temperatures

•  Fan system flow controls

•  Economizer controls

•  Minimum outdoor airflow rates

•  Carbon dioxide levels


Facility Site Survey - Determine key operating parameters Determine Operating: Schedules

•  Occupied or unoccupied hours in controlled zones

•  Space temperature setpoint schedules

•  Lighting occupancy schedules and controls

•  Warm-up and cool-down periods

Equipment efficiencies*:

*Equipmentperformancecharacteris/csshalltakeintoaccountpart-loadorseasonalefficiencies

•  Combustion efficiency

•  Cooling equipment efficiency

•  Energy recovery efficiency

•  Pump efficiency

•  Fan efficiency


Conduct end-use breakdown Based on:

1.  A calculated method that estimates energy use according to the size, load, method of control and efficiency of equipment, and its operating hours 1.

2.  A building energy model 2.

3.  Sub-metered energy use in the building.

1 Assumptions used in this analysis must be the same as those used for calculations of energy and demand savings. 2 The same simulation must be used as is used for calculation of energy and demand savings.


List Energy Efficiency Measures and Group Interactive Measures*

•  Opaque Elements Insulation, Roof Painting •  Windows Replacement, Glazing Replacement

•  Reduce Distribution Losses (Insulation, VSD, Economizers)

•  Replace HVAC

•  Low Water Use Devices •  Solar Systems

Envelope:

Lighting :

HVAC Systems:

DHW Water Heating

•  Replace Fixtures, Replace Lamps •  Daylighting Utilization •  Occupancy Sensors

*Avoidthepoten/alforoversta/ngenergysavingsduetosavingsoverlapbetweenindividualmeasures


Calculate Savings (energy, demand)

Calculation Methods1,2,3: Stipulated values, engineering calculations, building energy model. Calculate before EEM & after EEM.

Interactions: Analysis of measures and/or measure groups shall include interactions

Weather data: Shall be long-term average data.

Equipment performance: Shall take into account part-load or seasonal efficiencies where applicable

1 The U.S. Department of Energy maintains a directory of building energy software tools on its Web site

2 ASHRAE Handbook Fundamentals Chapter 19 Energy Estimating and modeling methods

3 ASHRAE Guideline 14 (2014): Annex E Retrofit Isolation approach techniques


Estimate EEM Costs

•  Material costs

•  Labor costs

•  Design fees

•  Construction management

•  Site-specific installation factors

•  Permits

•  Temporary services

•  Test and Balancing

•  Commissioning


Conduct Economic Analysis

𝑆𝑃𝑃= 𝐼𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡/𝐴𝑛𝑛𝑢𝑎𝑙 𝑆𝑎𝑣𝑖𝑛𝑔𝑠 

𝑅𝑂𝐼= 𝐴𝑛𝑛𝑢𝑎𝑙 𝑆𝑎𝑣𝑖𝑛𝑔𝑠/𝐼𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡 x100

Simple Payback :

Return of Investment :

•  Identify the measures that meet the owner’s economic or other criteria, whether individually, or in aggregate.

•  Note the ancillary benefits of each measure or group.


Quality Assurance Review

•  Evaluate the feasibility and appropriateness of identified measures, as well as the reasonableness of energy savings projections, implementation cost estimates, and all observations and findings of the energy audit report.

•  Compare the energy savings, cost savings, costs, and ROIs for each measure to expected ranges for the type of measure specified to verify reasonableness.

•  Validate savings by calculating the percent savings of each measure in relation to total energy use of the relevant end-use category.


Review EEMs with Owner’s Representative

•  Provide to the owner or their appropriate representative a list of identified measures, their brief descriptions, energy, energy cost, and non-energy cost savings, available incentives, simple ROI, and simple paybacks.

•  Obtain from the owner or owner’s representative their comments about which measures are preferred for implementation or further study.

•  After the review with the owner or owner’s representative, the audit shall be revised to show the recommended measures, measure groups, and measures identified but not recommended.


Schematic diagram of each of the recommended EEMs

*If no separate Level 1 & 2 audit has been conducted, shall comply with all the procedural requirements for a Level 1 & 2 audit.

The Level 3 audit shall follow upon, and take into consideration the findings of, a Level 2 audit and also incudes the following additional steps*: Review the accepted EEMs considering system interactions to create bundle of measures


The simulation software shall meet the requirements of ASHRAE Standard 140. Indicative software:

Annual building energy modeling is required for envelope measure analysis


The model shall be calibrated with respect to the building’s actual energy use per the methodology in ASHRAE Guideline 14.

𝐶𝑉(𝑅𝑀𝑆𝐸)=100×√∑↑▒(𝑦𝑖− 𝑦𝑖 )2 /𝑛−1  /𝑦  

𝑁𝑀𝐵𝐸=100×∑↑▒(𝑦𝑖− 𝑦𝑖  )/(𝑛−1)× 𝑦  

CVRMSE = coefficient of variation of the root mean square error NMBE = normalized mean bias error

𝑦 = measured value 𝑦  = model predicted value 𝑦  = mean value of the measured data n = number of data points in sample

data CVRMSEmax NMBEmax

Monthly 15% 5%

Hourly 30% 10%


Lifecycle Cost Analysis (LCCA)

CashFlows

Out-lows

InitialInvestmentReplacement

CostsMaintenance

Costs

Taxes

EnergyAuditCosts

M&VCosts

In-lows

EnergyCostSavings

DemandCostSavings

WaterCosts

Procedures for Commercial Building Energy Audits 2nd Edition (2011) – Best Practices

Procedures for Commercial Building Energy Audits 2nd Edition (2011) – Best Practices

The energy assessment provider may be one person or a team with several members depending on the complexity of the site. The team usually includes the following:

• A building envelope expert or construction engineer • A mechanical engineer • An electrical systems expert • A control systems expert • An energy modeler

Performance Measurement Protocol for Commercial Buildings & Best Practices

ASHRAE Guideline 14 (2014): Measurement of Energy, Demand & Water Savings

The purpose of this document is to provide guidelines for reliably measuring the energy, demand, and water savings achieved in conservation projects.

Relevant ASHRAE Guidelines and Standards

•  Standard105-2014:StandardMethodsOfDetermining,Expressing,AndComparingBuildingEnergyPerformanceandGreenhouseGasEmissions

•  Standard180-2012:StandardPrac/ceForInspec/onAndMaintenanceOfCommercialBuildingHVACSystems

•  Standard189.1--2014:StandardforDesignofHigh--PerformanceGreenBuildings

•  Standard62.1--2016:Ven/la/onforAcceptableIndoorAirQuality

•  Standard90.1-2016:EnergyStandardforBuildings

•  Guideline11-2009:FieldTes/ngofHVACControlComponents

•  Guideline22-2012:Instrumenta/onforMonitoringCentralChilled-WaterPlantEfficiency

Konstantinos Laskos [email protected]

Triantafyllos Triantafyllopoulos [email protected]

Q&A

ASHRAE Standards & Guidelines for Building Energy Audits 6/5/2017

Documents

ASHRAE Standards & Guidelines for Building Energy Audits · PDF fileASHRAE Standards & Guidelines for Building Energy Audits ... 2 ASHRAE Handbook Fundamentals Chapter 19 Energy