WHOLE BUILDING RETROFITS: A CONTRACTOR/SUPPLIER DEMONSTRATION

Transcription

1 1 WHOLE BUILDING RETROFITS: A CONTRACTOR/SUPPLIER DEMONSTRATION Professor Kirk Alter Purdue University Fast Management, Inc.

2 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! 2

3 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

4 ACHIEVING NET-ZERO BUILDINGS 4

5 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 well, and occupancy is stable. The owner, a family trust, has owned the building since 2003 and your firm has been managing it since 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 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. 5

6 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 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

7 BUILDING DETAILS The HVAC system at the building is a variable airvolume 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

8 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. 8

9 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. 9

10 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. 10

11 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. 11

12 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

13 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

14 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. 14

15 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: ggbp.shtml City and state (NYSERDA) incentives for energy efficiency or green renovation may apply. 15

16 NEW YORK CITY S GREENER, GREATER BUILDINGS PLAN 16

17 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. 17

18 FIGURE 1: ENERGY CONSUMPTION BY END USE 18

19 Savings ENERGY AUDIT / LEED GAP ANALYSIS No/Low Cost ECMs Cost kwh Therms $/year Simple payback (yrs) Replace OA Temperature / Humidity Sensor Insulate hot water pipes Utilize timer on DHW Circulator Pump Optimal Start Stop Control Lower hot water temperature from 125F to 120F Add Fitness Center Occupancy Sensor lighting controls Hot water heater schedule modification Install occupancy sensors in rooms Turn off extra lighting in stairwell Modifications to use air side economizer $ ,639 - $ 6, $ $ $ 150 2,440 - $ $ , $ 2, $ $ $ 500 5,766 - $ $ $ $ 40 2,523 - $ $ - 7,466 - $ $ - 68,253 - $

20 Capital Cost ECMs Savings ENERGY AUDIT / LEED GAP ANALYSIS Cost kwh Therms $/year Simple payback (yrs) Replace filters with higher efficiency models $ 3,500 11,086 - $ 2, Retrofit lighting in elevators to LED Supply Air Temperature Reset on Return/Outside Air Retrofit lighting in lobbies to CFLs Enable automatic chilled water temperature reset Replace older CHW/CW motors with efficient models Fitness center lighting retrofit Steam boiler to HW boiler VFD on CHW pump and variable bypass controls $ 1,800 6,377 - $ $ 8,200 3,800 3,229 $ 4, $ 6,480 16,617 - $ 1, $ 2,400 29,586 - $ 3, $ 3,800 1,627 - $ $ 1, $ $ 156,000-6,200 $ 9, $ 11,500 17,204 - $ 2, TOTAL $ 197, ,025 9,745 $ 37,

21 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. 21

22 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. 22

23 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. 23

24 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. 24

25 LOWER HOT WATER TEMPERATURES FROM 125 F TO 120 F Lower the hot water temperature from 125 to 120 F. 25

26 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. 26

27 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 27

28 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. 28

29 TURN OFF EXTRA LIGHTING IN STAIRWELL There is more lighting than needed in the stairwell, which is on Turn off the unnecessary lighting. 29

30 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. 30

31 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. 31

32 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. 32

33 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

34 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 34

35 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. 35

36 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 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

37 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. 37

38 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. 38

39 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

40 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 passedthrough 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. 40

41 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 Base Year % of Building Square Footage Base Rent Electricit y Rent Inclusion (per sf) Law Firm ,000 $75.00 N/A Tenant A ,000 $65.00 $2.75 Tenant B ,000 $63.50 $3.00 Tenant C ,000 $66.50 $2.90 Tenant D ,000 $73.00 $3.15 Open In negotiation 10 30,000 TBD TBD 41

42 KOHLER BUILT GREEN THE SOLAIRE 42

43 KOHLER BUILT GREEN HILLSIDE HOME 43

44 KOHLER BUILT GREEN CALIFORNIA ACADEMY OF SCIENCES 44

45 KOHLER EXTREME HOME MAKEOVER 45

46 VIEGA INTERNAL RECIRCULATION 46