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WHOLE BUILDING RETROFITS:
A CONTRACTOR/SUPPLIER
DEMONSTRATION Professor Kirk Alter
Purdue University
Fast Management, Inc.
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SESSION DESCRIPTION
Whole Building Retrofits: A Contractor/Supplier Demonstration
You’ve heard for years now that…you must look at the whole building…that there are more and more opportunities to expand your expertise beyond the traditional scope of your trade… You’ve come to seminars and heard what you need to do…but it never just came together for you, so you don’t do it. Come to this session and watch a demonstration of a contractor and a group of suppliers partnering to develop the scope, provide multiple options for the customer, evaluate the costs, and deliver a fully integrated energy & water efficient solution for the building. You won’t leave thinking about what you offer in the same way!
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THE CASE – AN OFFICE BUILDING
You are a favored PHCC member who provides services to the company that manages a multi-tenant Class A office building in the Chelsea neighborhood of Manhattan. In response to a recent municipal regulation, the building has undergone an energy audit, which shows that this building has a significant opportunity to reduce energy consumption; lower operating costs and brings additional benefits to the property. However, there are barriers that are preventing the owner from agreeing to fund and implement the project.
You are presenting to the owners of the building in order to convince them to approve the project. Your suggestion should include implementation, technical, financial, phasing, leasing/contracting or other solutions that address the barriers that the owner can use to pay for and implement the most effective package of energy efficiency measures in the optimal way.
Solutions will be judged on the demonstration of:
• Understanding of the barriers and motivations of multiple stakeholders
• Realism and ability to be implemented
• Effectiveness in achieving the goals
• Strength and accuracy of analysis supporting the recommendations
• Creativity 3
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ACHIEVING NET-ZERO BUILDINGS
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OVERVIEW
This property is a stable, multi-tenant Class A office building in the Chelsea neighborhood of Manhattan, New York City. This property weathered the downturn of 2008-2009 well, and occupancy is stable. The owner, a family trust, has owned the building since 2003 and your firm has been managing it since 2004.
In response to the New York City Greener, Greater Buildings regulation and its requirement to audit, disclose, and upgrade energy performance, the owner tasked you—the management firm– with undertaking an energy audit and US Green Building Council’s LEED for Existing Buildings: Operations & Maintenance (EBOM) gap analysis. An ASHRAE Level I & II Energy Audit for LEED-EBOM Energy and Atmosphere (EA) Credits 2.1-2.2 was completed, and showed that some capital investments would improve the energy performance of the building, lower operating costs, and help the building achieve LEED and ENERGY STAR certification.
With these promising technical and financial results, the owner would like to proceed with the project. However, the recommendations require investment to achieve the results and the owner wants to ensure that whatever capital is invested in the project meets their business goals –
providing competitive financial returns. With the current lease arrangements, the owner does not see a path forward to implement the projects in a way that the owner would be able to participate in the benefits. As the management company, you have been tasked with proposing a solution.
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BUILDING DETAILS
The building is a 12-story commercial high-rise building consisting of 300,0001 square feet located in the Chelsea neighborhood of Manhattan. The building is a brick, concrete facade and glass structure originally built in 1963. The building underwent an $8 million interior and exterior renovation in 2004, which involved a mechanical system renovation, but did not focus on energy efficiency or LEED certification.
The building has five tenants – a law firm which occupies 65% of the space, and four retail tenants and one empty space that comprise the other 35%, on the first and second floors. The building has a daily occupancy of approximately 500 workers. The building operates on a typical 55 hours/week schedule, from 7am-6pm Mon-Fri with most occupants arriving at 8am. 6
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BUILDING DETAILS
The HVAC system at the building is a variable air-
volume fan-powered perimeter terminal box with hot
water reheat and core terminal boxes with no fan or
reheat. The primary cooling/heating is manifested by
a 4-pipe hot water/chilled water fan coil air handler
delivery. A central plant creates the chilled water and
hot water is converted from steam generated by
steam boilers, both of which are located in the
basement. Air handlers that serve each floor are
equipped with variable frequency drives that allow
them to adjust their fan speed, based on a static
pressure sensor and set point, to meet the airflow
needs of each floor and the terminal boxes. 7
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BUILDING DETAILS
The central cooling plant located in the basement
is served by three, 176 ton forced draft BAC
cooling towers, a 300 ton York centrifugal chiller,
and a 200 ton Trane screw-driven chiller. Air
handlers that serve each floor are equipped with
variable frequency drives that allow them to
adjust their fan speed—based on a static
pressure sensor and set point—to meet the
airflow needs of each floor and the terminal
boxes.
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BUILDING DETAILS
The building has a hot water reheat system along
the perimeter. This hot water system functions to
serve the variable air volume (VAV) boxes on
each floor by four climate-control zones, one for
each side of the building. Hot water for the air
handler fan coils and VAV reheat system is
supplied by two 100 hp Superior boilers. The
boilers generate steam, which is converted to hot
water for the reheat system. A VAV system
supplies conditioned air to the tenant space on
each floor.
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BUILDING DETAILS
The building’s entire HVAC system is controlled
by an energy management system (EMS) via
building computer and off-site modem access.
The EMS is capable of monitoring and adjusting
set points, alarms, start up and shut down of
equipment, and optimizing performance of the
system.
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BUILDING DETAILS
The building is wired with a single master
connection to Con Ed. From there, the landlord
distributes electricity to the tenants and records
their usage, in the case of the law firm, with
submeters.
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BUILDING DETAILS
Lighting in the building consists of approximately
10% fluorescent (T8s and T5s), 85% dimmable
incandescent, and 5% high intensity discharge metal
halide. The tenant spaces primarily consist of T8 and
T5 mixes with fluorescent biaxial can lights. The
elevator lobby and hallway areas are primarily high
intensity metal halide augmented by can lights and 2’
x 2’ fluorescent fixtures that are controlled by switch.
Office spaces have overhead lighting and most
individual tenants’ workstations have task lighting to
control the light at their workspace to adjust for the
task being performed. Building common areas, such
as hallways, are controlled by the EMS. 12
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OWNERSHIP STRUCTURE
The owner is a family trust. They acquired the building in 2003 and plan to hold the building for the foreseeable future. The family has no particular interest in sustainability or green buildings, but realize the need to comply with the New York City regulation could be an opportunity to differentiate the building in the market by achieving ENERGY STAR or LEED certification as there are few office buildings in the Chelsea area of Manhattan with these certifications and this would differentiate their building. However, the owners will not pursue this path if it does not make financial sense.
The building has been managed by the same company since 2004, and has been tasked with compliance with the regulation as well as exploring the opportunity for ENERGY STAR or LEED certification. 13
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LEASING DETAILS
This multi-tenant office building is almost fully occupied. Of the rentable square feet, a law firm occupies 65%, and the other 35% is occupied by four small retail tenants and one vacant space. Lease negotiations for a fifth retail tenant are just beginning. The law firm is twelve years into a lease with a 15-year term, while the other tenants use the same lease structure and are at different points on leases with rolling five-year terms.
The law firm is twelve years into a lease with a 15-year term, while the other tenants use the same lease structure and are at different points on leases with rolling five-year terms.
The law firm has expressed interest in being in a LEED and/or ENERGY STAR certified building. The retail tenants have been silent on the issue.
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NEW YORK CITY CONTEXT
The building is subject to New York City’s
Greener, Greater Buildings Plan, including the
requirements for benchmarking and disclosure of
energy use, auditing, and retro-commissioning.
More information about this regulation can be
found at:
http://www.nyc.gov/html/planyc2030/html/about/
ggbp.shtml
City and state (NYSERDA) incentives for energy
efficiency or green renovation may apply. 15
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NEW YORK CITY’S GREENER, GREATER
BUILDINGS PLAN
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ENERGY EFFICIENCY OPPORTUNITY
Currently, the building has an energy use intensity (EUI) of 104 kBtu per square foot. The current building ENERGY STAR score is 62 out of 100.
HVAC components and lighting dominate the majority of the energy use and cost in the building, with elevators, data/server rooms, plug loads, and other equipment that are intermittent or difficult to quantify comprising the rest of the use.
The main building utilities are electricity and steam. The total Annual Utility Spend equates to
$3.77 per square foot per year to run the building. This breaks down into: Electricity $3.55
Steam $0.22
In the course of the audit, 19 energy conservation measures (ECMs) were identified with implementation costs and annual savings estimates. The annualized savings estimations of all recommendations total $37,653 (at 2011 energy prices) with an average simple payback period of 5.3 years. All of these measures should yield worthwhile energy savings and foster better operational control of the building.
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FIGURE 1: ENERGY CONSUMPTION BY END USE
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ENERGY AUDIT / LEED GAP ANALYSIS No/Low Cost
ECMs
Savings
Cost kWh Therms $/year Simple payback
(yrs)
Replace OA
Temperature /
Humidity Sensor
$ 550 56,639 - $ 6,798 0.1
Insulate hot water
pipes
$ 80 508 28 $ 96 0.8
Utilize timer on
DHW Circulator
Pump
$ 150 2,440 - $ 294 0.5
Optimal Start
Stop Control
$ 900 37,323 233 $ 2,270 0.4
Lower hot water
temperature from
125F to 120F
$ 10 - 24 $ 25 0.4
Add Fitness
Center Occupancy
Sensor lighting
controls
$ 500 5,766 - $ 693 0.7
Hot water heater
schedule
modification
$ - - 31 $ 32 0.0
Install occupancy
sensors in rooms
$ 40 2,523 - $ 304 0.1
Turn off extra
lighting in
stairwell
$ - 7,466 - $ 895 0.0
Modifications to
use air side
economizer
$ - 68,253 - $ 819 0.0
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ENERGY AUDIT / LEED GAP ANALYSIS Capital Cost
ECMs
Savings
Cost kWh Therms $/year Simple payback
(yrs)
Replace filters with
higher efficiency
models
$ 3,500 11,086 - $ 2,612 1.3
Retrofit lighting in
elevators to LED
$ 1,800 6,377 - $767 2.3
Supply Air
Temperature Reset
on Return/Outside
Air
$ 8,200 3,800 3,229 $ 4,492 1.8
Retrofit lighting in
lobbies to CFLs
$ 6,480 16,617 - $ 1,995 3.2
Enable automatic
chilled water
temperature reset
$ 2,400 29,586 - $ 3,550 0.7
Replace older
CHW/CW motors
with efficient
models
$ 3,800 1,627 - $ 435 8.7
Fitness center
lighting retrofit
$ 1,900 830 - $ 161 11.8
Steam boiler to HW
boiler
$ 156,000 - 6,200 $ 9,349 16.7
VFD on CHW pump
and variable bypass
controls
$ 11,500 17,204 - $ 2,066 5.6
TOTAL $ 197,810 268,025 9,745 $ 37,653 5.3
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REPLACE OA TEMPERATURE/
HUMIDITY SENSOR
The automation system utilizes this temperature/humidity sensor for many energy management and automatic energy savings programs such as the waterside economizer, airside economizer control, and cooling tower control. Currently, the sensor is incorrectly reading the ambient temperature and humidity. This sensor should be replaced and relocated so that it does not pick up solar load or radiant heat from the wall it is mounted on. This should allow these systems to function properly. It should also allow for more hours of free waterside and airside cooling instead of mechanical cooling. The best location for this critical sensor is a weather-protected shaded area. Another good strategy to ensure proper system operation is to install two sensors and compare them against each other, generating an alarm when there is any significant variation. The calibration of this sensor should be verified at least every 6 months to ensure proper operation of all energy saving systems.
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INSULATE HOT WATER PIPES
There are two portions of copper hot water
circulation pipe that are not insulated. One
section is located in the engineering office and
the other in the fitness center. Apply 3”
insulation to the pipes. This should reduce
cooling loads slightly and save natural gas at the
hot water heater.
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UTILIZE TIMER ON DHW CIRCULATOR
PUMP
The hot water heater circulation pump is in
operation continuously. Install timers that limit
operation and consumption of these devices to
occupied hours.
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OPTIMAL START
The floor-by-floor AHUs and rest of system that
support them start between 5:00 and 5:30 am.
Program to automatically set the start time so
that adequate space temperatures are achieved
right before occupants arrive. Alternatively
manually program shorter lead start times and
observe the time for the space to reach
temperature. This will reduce the total number of
hours and thereby consumption of the overall
system.
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LOWER HOT WATER TEMPERATURES FROM
125°F TO 120°F
Lower the hot water temperature from 125 to
120°F.
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FITNESS CENTER OCCUPANCY SENSOR TO
CONTROL THE HVAC AND LIGHTING
Lighting in the fitness center is controlled by
switch, and HVAC is controlled by wall-mounted
thermostat and enabled by the control system.
Install an occupancy sensor to control the
lighting and set the delay to 30 minutes.
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HOT WATER HEATER SCHEDULE MODIFIED
FROM 6AM-6PM TO 7:30-1:30
Hot water heater schedule modified from 6am-
6pm to 7:30-1:30
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INSTALL OCCUPANCY SENSORS IN ROOMS
B1 AND B2
The lighting control for the basement elevator
lobbies are controlled by switch. Installed dual
technology occupancy sensors to control elevator
lobby lighting and set for 10 minute delay.
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TURN OFF EXTRA LIGHTING IN
STAIRWELL
There is more lighting than needed in the
stairwell, which is on 24-7. Turn off the
unnecessary lighting.
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MODIFICATIONS TO USE AIRSIDE ECONOMIZER
INSTEAD OF WATERSIDE/MECHANICAL
Repair the airside economizer dampers &
controls to allow for less mechanical cooling.
Complications with dampers and controls
settings had waterside economizer operating
along with mechanical cooling and no airside
economizer. Correcting damper installation
issues and changing the control methodology to
take advantage of free airside cooling allows for
other mechanical equipment to be turned off.
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REPLACE FILTERS WITH HIGH EFFICIENCY
DUAL 2” MERV-13
The air handlers utilized at 2” MERV 11 pleated
pre filter and a final bank of 4” pleated final
filters. The filter configuration was changed from
two banks of filters to one bank of dual 2” MERV
13 filters. The total static drop across the new
configuration is less than the original, resulting
in fan energy savings. New AHU filter bank in
place.
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RETROFIT (52) MR-16S IN ELEVATORS TO
LED
The elevators are outfitted with 20W halogen
MR-16s that are operational continuously.
Replace elevator lighting with 6W LEDs, which
consume less and last longer.
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SUPPLY AIR TEMPERATURE RESET ON
RETURN/OUTSIDE AIR TEMPERATURE
Reset the supply air temperature from 55F-62F
based on return 70F-74F or outside air
temperature 30F-60F. The supply air
temperature delivered by the air handlers is
maintained at a constant 55°F unless manually
adjusted. Employ new programming and sensors
to reset the supply air temperature from 55°F-
62°F based on 70°F-74°F or outside air
temperatures from 30°F-60°F. Resetting the
supply air temperature should reduce the
amount of reheat needed on the perimeter zones
and allow the chilled water and cooling load to be
reduced at other times. 33
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RETROFIT 70W MH TO 23W CF IN
LOBBIES & HALLWAYS
The building has 83 high intensity discharge
70W lights used in the lobby, elevator lobbies,
and hallways. Remove the ballasts and replace
these lights with 23W compact fluorescents
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CHILLED WATER TEMPERATURE RESET
Enable automatic chilled water supply temperature reset 44°F-54°F based on outside air temperatures. The operational chilled water temperature is normally 45°F and is manually reset by the engineer at times to 55°F. While a manual temperature reset is an excellent energy conservation procedure in the winter, calibrated automatic reset has been shown to nearly double the energy savings.
Recommendation: The Trane 200 ton helical rotary chiller has an automatic chilled water reset program existing but currently disabled. To implement this ECM, this programming needs to be enabled and adjusted to the desired parameters. For this analysis, a variety of reset range settings were examined. After several iterations, a reset range of 44°F to 54°F relative to outdoor temps of 50°F to 85°F produced the best results. Similar results may be achieved with 45°F to 55°F relative outdoor temps 40°F to 90°F, which is built into the chiller controls. Since the outside air temperature is not a direct indicator of building load, this range may require adjustment, or the reset can be driven on building load driven chilled water return temp. This can also be accomplished through the chiller controls. The annual hourly analysis graphic below shows the chiller consumption with and without the reset strategy. The green that can be seen is displayed as the energy savings.
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REPLACE 2 OLDER CHW/CW MOTORS
WITH NEW HIGHER EFFICIENCY MOTORS
Replace CHW and CW pump motors nearing failure with higher efficiency motors. The chilled water and condenser water pump motors P1 and P3 appear to be 15-20 years old and 91% efficient. During operation they are running hotter than normal, above 145°F, which may be an indicator of imminent complications or failure. These motors should be replaced regardless of financial energy savings. Replacing these motors with new, reliable, high efficiency equipment is worth the incremental cost difference of several hundred dollars. New 93% efficient motors will save energy during operation, provide lower maintenance costs, and enhanced reliability. Impact on Equipment Service Life: Replacing the
equipment will mean a longer service life.
Impact on Health, Comfort, & Safety: No anticipated impact on health, comfort, and safety. 36
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FITNESS CENTER RETROFIT (19) MR-16S
20W TO 6W TO LED
The building has 19 halogen 20W MR-16s for
lighting the fitness center. Replace the halogen
MR-16s with 6W LEDs.
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RETROFIT STEAM BOILER SYSTEM TO HIGH
EFFICIENCY HOT WATER BOILERS WITH
TEMPERATURE RESET
The building heating is generated by two, 1962
steam boilers with newer burners. The steam is
transmitted from the basement to the penthouse
where it is converted to hot water for AHU
fancoil heating and VAV reheat system. Replace
the current steam boilers with several 97%
efficient modulating condensing boilers with
variable turndown and outside air reset.
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VFD ON CHW PUMP 3 & VARIABLE
PRIMARY BYPASS CONTROLS
Utilize a VFD on CHW pump 3 & variable primary bypass controls to reduce pump consumption. The chilled water is delivered from the chiller to the air handlers by a constant speed pump. The Trane 200 ton helical rotary chiller has a CH530 controller. This controller allows the chiller to handle variable primary flow up to a limit of 70% of rated. The system currently operates with two-way valves at the air handlers and a bypass in the mechanical room to maintain a constant flow through the chiller. To implement this ECM, precise valve control and flow sensors would need to be put into place at the bypass and on the return line prior to the bypass. As the two-way valves at the air handlers close the primary chilled water pump would be able to slow down in response. Once the lower flow limit to the chiller is reached the pump speed would need to be maintained. The bypass would be allowed to open in this lower range to ensure that the chiller minimum flow (70% of design) is steadily maintained. 39
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CRITICAL LEASE TERMS
Law Firm Start Year: 2000
Term: 15 years
Base rent: $75 per rentable square foot (net of electric)
Square Feet: 195,000 (65% of total)
Operating Expense Pass-Through/Escalation: The lease stipulates that the only expenses that can be passed-through are utilities (non-electrical), maintenance, cleaning, and security. The lease also contains a protocol through which the cost increases can be audited.
Electricity: The law firm’s space is submetered. The management company reads the submeters monthly and bills the firm, adding an increase of 12%, which is the negotiated maximum in the lease.
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CRITICAL LEASE TERMS Retail Tenants (4) and Vacant Space (1)
Start Year: various (see table below)
Term: 5 year, renewable
Operating Expense Pass-Through/Escalation: These leases use a fixed index formula with a fixed percentage of
3% each year.
Electricity: all of these leases use a Rent Inclusion
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Base Year % of
Building
Square
Footage
Base Rent Electricit
y Rent
Inclusion
(per sf)
Law Firm 2000 65 195,000 $75.00 N/A
Tenant A 2008 5 15,000 $65.00 $2.75
Tenant B 2008 5 15,000 $63.50 $3.00
Tenant C 2010 7 21,000 $66.50 $2.90
Tenant D 2012 8 24,000 $73.00 $3.15
Open In
negotiation
10 30,000 TBD TBD
KOHLER – BUILT GREEN – THE SOLAIRE
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KOHLER – BUILT GREEN – HILLSIDE
HOME
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KOHLER – BUILT GREEN –
CALIFORNIA ACADEMY OF SCIENCES
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KOHLER EXTREME HOME MAKEOVER
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VIEGA INTERNAL RECIRCULATION
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