S-EPA United States Environmental Protection Agency Air and Radiation (6202J) EPA 430-K-96-001 April 1996 ENERGY STAR Buildings Tech Tips BUILDINGS Sffi/iNGlhE EARTH. SAViNG^VbUR MONEY: Building Tune-Up Findings and Results Stage 2 ------- ENERGY STAR Buildings Tech Tips Building Tune-Up INTRODUCTION This Tech Tip was developed using results from the EPA Energy Star Buildings Program, a voluntary program that prevents pollution by encouraging enejgy efficiency in commercial buildings. Building on the successful Green Lights energy-efficient lighting program, Energy Star Buildings bases its success on proven technologies that are profitable investment opportunities. A central component of the program is a stage-by-stage implementation process that takes advantage of the system interactions and enables building owners to achieve additional energy savings while lowering capital expenditures. The stages of this process are summarized in the box below As many building owners entering the Energy Star Buildings program have already implemented Green Lights upgrades, a "tune-up" is often the first step. Even new buildings can use improved controls and operational strategies to reduce energy consumption. To . document and verify the Energy Star Buildings strategy, EPA signed an agreement with 24 organizations to become Showcase Partners and implement energy efficient upgrades in one building in one year. The Showcase buildings demonstrate that small investments in operational arid maintenance activities can provide a large return for buildings and benefit the environment by reducing greenhouse gas emissions. Stage 1 Stage 2 Stages Stag© 4 Stage 5 Green Building HVAC Load Improved Fans Lights Tune-Up Reductions and Air-Handling Systems Improved Heating and Cooling Plant ------- ENERGY STAR Buildings Tech Tips Building Tune-Up This can be accomplished through a comprehensive, structured energy survey of a facility where partners determine which energy-saving modifications and upgrades will be profitable. Based; on survey results, Partners start with low-cost adjustments and tune-ups to existing building systems. Partners also review and improve preventative maintenance programs and train building personnel on keeping the building's systems working at peak efficiency. EPA's experience has shown that these tune-up steps can save significant amounts of energy as well as significantly improve indoor air quality and occupant comfort ------- ENERGY STAR Buildings Tech Tips Building Tune-lip SHOWCASE SUCCESS Tune-up measures were successfully implemented in many Energy Star Showcase- buildings and in many cases tune-ups were able to provide immediate savings which aided in funding energy efficiency measures in later stages. Table 1 summarizes the key building characteristics (floor area and energy consumption) for Showcase buildings where tune-ups were implemented, and the level of costs and savings which were associated with the tune-up measures. The tune-up performed by Honeywell will be the focus of this report The tune-up measures performed by the other Showcase Partners are summarized in this section. Table 1. Summary of Showcase Buildings Tune-up Savings £XV< ^^^ "> s> fs">f > " ."Showcase, ' ',,,! >'" " 4 "* 's s $v> .** 2f\J>t&^*f "Partaer ^ ^ ?^- , -. ^w. ₯>s, '> xvt.. y-«- > Douglas County, OR Honeywell Inc. MN J.C Penney GA Louisville MSD KY Mobil Corp VA Mobil R&D TX Montgomery County, MD Warner Lambert NJ W*fV<, |3!F^"M Gov. Office Office Retail Office Office Off/Lab Gov. Office Office Sqiaaase 'i^eel^f -' "^ s ? f f 254,000 958,000 161,540 64,000 605,000 220,000 84,000 . 125,000 ..Annual v ^±'*xt<'- '?<--? - ^cm #,,/^ 5,343,800 16,993,000 9,105,000 1,816,000 6,178,000 15,500,000 3,722,000 2,726,000 \ ^Fmne^'ai)* i&QSt? < ' ',- $12,500 $108,785 $3,100 $10,400 $12,100 $69,000 $54,770 $2,410 Animal $37870 $62,560 $5,450 $3,409 $24,200 $16,000 $10,260 $4,250 .**-: - 31% 58% 176% 32% 200% 23% 19% 176% ------- ENERGY STAR Buildings Tech Tips Building Tune-Up Douglas County, Oregon: For this Showcase project, involving a courthouse and a jail, Douglas County replaced their old Energy Management System (EMS) with a newer system and added energy saving controls strategies. The new strategies included adding chilled water, condenser water and hot water resets, optimal start/stop, duty cycling and demand shaving, and pre-cool and pre-heat Chilled water and hot water temperatures are calculated based on complex formulas integrating outside air temperatures, space demands, and seasonal schedules. During simultaneous cooling/heating periods, the chillers are duty cycled between full load operation and off. Low temperature chilled water is provided for cooling while waste heat from the chiller is used to provide warm air to spaces that need heating. During the cooling season, the chiller provides a variable chilled water temperature based on outside air temperature and the previous day's load. During the heating season, the boilers shut down if the outside air rises above 55 °F and there is enough solar incidence (measured with ah insolator) to provide envelope heating. Additionally, Douglas County uses a card-access system to measure occupancy in specific zones and adjusts airflow and lighting provisions accordingly. This has not only minimized overheating and cooling, but has also decreased comfort complaints. Lessons Learned: Significant savings can be achieved without a major investment using an EMS and integrating controls. A strategy which uses ambient conditions and occupancy schedules to provide only the cooling and lieating necessary for individual zones maximizes energy reduction while maintaining comfort levels J.C. Penney This Showcase building is a department store in Atlanta, GA. The tune-up measures included coil cleaning and sensor replacements and additions. Thermocouples were relocated and humidity sensors were added to improve the comfort control. Some problems discovered during the tune-up survey were rectified as a result of HVAC equipment replacement associated with other Showcase upgrades. For instance, during the audit, the cooling tower was found to leak water, wasting about $1,000 per year. The Showcase upgrades included replacement of the cooling tower, which eliminated this problem. Lessons Learned: This building was very well operated, and therefore few improvements were identified. Tliefew measures implemented paid for themselves in less than a year. Improved operation is yet anotlier benefit of replacing old equipment with energy efficient equipment ------- ENERGY STAR Buildings Tech Tips Building Tune-Up Louisville Metropolitan Sewer District This Showcase building underwent complete renovation during the Showcase process. The building was converted from what was a bank to office space. During this renovation it had already been decided to convert operations from pneumatic controls to direct digital controls (DDC). Several additional strategies were added as a result of participation in the Showcase program, including winter night setback, optimal fan start-up mode, and outside air damper controls. Lessons Learned: Tune-up strategies are not limited to retrofits of existing buildings. Control strategies far buildings under renovation or new construction can also prove to be -profitable, . usually at little incremental cost. Mobil Corp. This Showcase building is a two-tower office complex in Reston, Virginia containing offices for Mobil Corporation. The facility was constructed in 1990-1991, and included a sophisticated EMS. Tune-up measures were identified in one of the tower buildings. Besides an air balancing and thermostat calibration/ during the Showcase process a supply air reset and optimal start/stop was added. After each Energy Star Buildings upgrade stage (starting with Green Lights) they experimented with reset to accommodate for the associated load reduction. Lessons Learned: Even newer, well maintained buildings can expect energy savings by following the staged strategy. Continuous monitoring and load measuring during the upgrade process and afterwards can be used to shift set points, which minimizes energy consumption while providing adequate comfort levels. MobilR&D This Showcase building is a research facility in Dallas, Texas. The tune-up involved several changes to the air handling units. A walk through revealed that water coils were piped incorrectly (providing parallel flow instead of counter-current flow), and that problems with the pneumatic system were resulting in excessive reheat Mobil organized a team of management, facilities operators, and outside consultants to maximize energy reduction with the tune-up while maintaining inside comfort levels. Two air handling units Were chosen, one supplying 100% outside air to lab spaces and the other supplying mixed air to office spaces, to test new procedures. A combination of air balancing and AHU redesign eliminated a lot of the reheat run-time and reduced the cooling load by 250 tons. In another tune-up measure, Mobil converted the lab supply units from constant 100% outside air to dual duct design where return air could be diverted to mix with outside air when possible. ------- ENERGY STAR Buildings Tech Tips Building Tune-Up Lessons learned: Because the entire cur handling system needed to be overhauled, forming a team including all potential players proved to be very effective. The AHU upgrades were able to reduce the cooling load by over 250 tons, and the dual duct design eliminated an additional 40 tons of cooling. As a result, Mobil was able to completely turn off one 250-ton chiller. Mobil had made an investment on the new CFC-free chillers prior to joining the Showcase program and conducting file tune-up. The new chillers were sized based on expected ^downsizing from lighting and other measures, however, the building tune-up led to an additional 290 tons reduction. By staging upgrades and completing a tune-up prior to committing capital for equipment, additional cost and energy savings are sometimes possible. '- ' ' Montgomery County, MD The Montgomery County office building is a seven-story building with one air handling unit and VAV boxes dedicated on each floor. By breaking down energy consumption by "end-use it was discovered that a large amount of annual energy was used for heating (31%). The tune-up process identified electric reheat coils in the VAV boxes that were operating nearly continuously during summer months. A combination of faulty sensors and inefficient controls Was causing substantial overcooling in combination with reheat. To solve the problem, Montgomery County demonstrated new DDC control systems and schedules to eliminate reheat for most of the cooling season. The demonstration showed significant savings which if applied to the total building would result in an annual reduction in heating energy of over 2 million kBtu (53%). As part of the Showcase upgrades/ Montgomery County initiated the new air supply schedules on all of the floors. Other measures included air balancing and thermostat calibration on all floors, and installation of controls on the chilled water valves. Lessons Learned: Measuring energy consumption by end-use before performing surveys can lead to identification of significant savings. Few comfort complaints do not necessarily imply an efficiently running system, especially when reheat is used. Thermostats must be calibrated regularly, especially if they provide input to the chiller. Example: a sensor in error by two degrees trying to maintain 65 F will cause the chiller to overwork to cool a space to 63 F (when the sensor'wouldread 65 F). The benefit of demonstrating energy efficiency measures on one or more floors was another valuable lesson. A small investment can show real energy savings, and can justify application of the measures to tlie remainder of the floors, as well as provide a more accurate estimate of overall energy savings ------- ENERGY STAR Buildings Tech Tips Building Tune-Up SHOWCASE ALL- STAR Honeywell Inc. The Honeywell Inc. Showcase facility is located at Honeywell Plaza in Minneapolis, MN. This project stands out because of the extensiveness of the upgrades while" maintaining a highTRR. Honeywell Plaza houses the corporate offices of Honeywell, Inc. and consists of three primary facilities known as Plaza South, Plaza East, and Plaza West. The gross square footage of this Showcase building complex is approximately 958,000 square feet The facility's average annual energy costs, excluding the mainframe computers, prior to joining the Showcase program was $967,580. The Plaza has been built in stages and has expanded with Honeywell's growth through the years. Plaza East consists of six smaller attached buildings ranging from 4 to 10 floors each. Plaza West consists of one independent stand-alone building with eight floors. Plaza South is the latest building constructed at the Honeywell facility and consists of one building with five floors. This building houses the main computer support systems for the overall company transactions. Building Control and Operation Plaza East Plaza South Plaza West The Honeywell facility is equipped with a Honeywell energy management system (EMS) known as the DeltaNet System. This system has a capacity of 20,000 control points. with about 600 points currently in use. The system ------- ENERGY STAR Buildings Tech Tips Building Tune-Up Overview of Lighting and HVAC Systems presently controls the operation of the air handling units, chillers, hot water pumps, chilled water pumps, condenser water pumps, boilers, and the overall building security systems. - The general facuity operational hours are Monday through Friday from 7:30 AM to 6:00 PM. The lighting and HVAC operational hours extend before and after the occupancy hours and are generally from about 5:30 AM to 8:30 PM with the exception of Mondays when the units are started at 4:00 AM for pre-warmup. The standard facility thermostat set point is 72° F on a year-round basis. Work orders for problems found in the building are executed based on a schedule developed by a sophisticated computer program. A brief description of the Honeywell Plaza lighting and HVAC systems prior to the tune-up measures is given below. Lighting. After Stage 1: Green Lights upgrades, the interior lighting fixtures for all of the three Plazas consisted of a variety of fluorescent fixtures with T8 lamps and electronic ballasts. There were also some incandescent and compact fluorescent fixtures throughout the facility. Several areas are equipped with occupancy sensors. ' Air Distribution. Most of the fan systems at the Honeywell Headquarters are variable air volume (VAV) systems. Most of the AHUs in the three Plazas are equipped with an economizer or a pre-heat coil. Fan operations are controlled by the building EMS. Existing supply and return fans are automatically turned on and off depending on their EMS operational set points. Cooling. The cooling systems consist of large chillers throughout the various Plazas. Plaza South has four chillers with a total capacity of 1625 tons, Plaza West has two 110-ton chillers, and Plaza East uses three chillers with a total capacity of 1110 tons. In the past, Plaza East ------- ENERGY STAR Buildings Tech Tips Building Tune-Up utilized well water to directly address the building's cooling requirements in favorable weather conditions. However, due to new state restrictions, Honeywell was required to abolish its use of well water by the end of 1995, Therefore, the capacity of the chiller plant in the adjacent Plaza South building will be expanded using thermal cold water storage to accommodate the cooling load requirements of Plaza East Heating. Two large steam boilers, installed in 1947 and located in the lower level of Plaza East, provide the heating requirements for all of Honeywell's three Plazas. Pre-Tune-Up Modeling Before implementation of any measures were completed, a DOE-2 model of Plaza West was performed to simulate energy consumption before and after upgrades. Building characteristics were entered, and the model was calibrated based on utility bills to increase accuracy. The tune up measures that were included in the simulation were winter night setback to 60 F (instead of 66 F) and a change in the minimum setting of the VAV boxes from 10 percent to 30 percent to increase comfort The model estimated the cost for these measures to be $1,800. As a result, the fan energy savings would be 39,300 kWh, and the annual cooling energy would increase by about 500 kWh (since the range of VAV control between 10% and 30% would now operate at 30%, consuming slightly more energy). The heating system would save 2,750 therms annually, and overall annual savings would be $2,450 (IRR136%). Building Tune-Up Measures The Outside Homes & Buildings division of Honeywell was used to investigate tune-up measures. Problems were identified using the Building Tune-Up survey form found in Appendix B in the Energy Star Buildings Manual. Table 2 is a listing of the major problems and tune-up actions taken as part of Stage 2 upgrades. It includes the savings and costs which can be expected for particular measures. A summary of highlighted measures follows the table. 10 ------- ENERGY STAR Buildings Tech Tips Building Tune-Up Table 2. Summary of Honeywell Tune-up Measures lisa&ls-m identified -\ , ; ; * v^S. -/.. ''"j f ~*"* "f-i "> --v>v» * * "&* Outdoor lights on South loading dock operate all day Space temperature not set back at night during winter Vending machines and water coolers operate constantly Heat exchangers and valves not insulated , Leaves in AHU coil Poor access to dampers in several AHUs Leaky AHU dampers Poor air filtration in several AHUs - Coil fins damaged in several AHUs Dirty bearings, fan wheels, and chambers in AHUs Loose fan belt Dirty chilled water coil Broken RA damper motor Faulty fan starter connection Tom supply canvas Worn out outside air . dampers Two uninsulated boilers jy />'-V*V"i V.V.V. > j v,>v.% .S. f :Ac:ti(pt Mecoieupaelideti."; ,*;/ , v ,--.??v, /< ,-^ ,v~ ' \^ '--, : ,*<: ^TOc^» - \ Repair photocell Program night setback into EMS Install time docks on coolers and vending machines containing non- perishable goods such as soda Insulate all exposed metal surfaces on the steam distribution system Repair screen Install access doors Repair/ adjust dampers Upgrade primary filters Straighten fins Clean AHUs Tighten belt Clean coil Replace motor Repair starter Repair canvas Replace dampers Insulate boilers tVtttyttyp -,' f jB$9t; :t%f , ; $150 $500 $3,465 $19,300 $50 $4,000 $1,000 $2,000 $150 $1,100 $20 $50 $200 $200 $100 $1,200 $16,500 :-Jb0d9^aJT''x.j $aTiegs*-i $40 $13,200* $6,000* $3,800 $100 $2,000 $1,000 $500 $50 $550 $20 $50 $200 $200 $200 $500 $4,500 $Enpie^ ! <«. ""ff » **j : rFay»a«%/'! 3.8 yr immediate 0.6 yr 5.0 yr 0.5 yr 2.0 yr 1.0 yr 4.0 yr 3.0 yr 2.0 yr 1.0 yr. 1.0 yr 1.0 yr 1.0 yr 0.5 yr 2.4 yr 3.7 yr 11 ------- ENERGY STAR Buildings Tech Tips Building Tune-Up Boilers need tune-up Over 400 defective steam traps Some fans running unnecessarily Frequent start-up of secondary chiller Dirty chilled water coil Test and tune-up boilers Repair-replace steam traps Minimize fan run times Adjust setpoints in EMS Clean coil $1,000 $57,400 $100 $200 $50 $500 $27,600* $500 $1,000 $50 2.0 yr 2.1 yr 0.2 yr 0.2 yr 1.0 yr Totals:, $108,785 $62,560 1.7 yr * Denotes savings which were measured and verified. All others are projected savings based on modeling Timers on vending machines. For several hours every night vending machines operate without anyone using them. The facilities engineers unplugged several machines during hours when it was expected that they wouldn't be used, and did not receive any complaints. By monitoring the energy consumption of machines left on during this period, they were able to determine that they could save $6,000 per year, with a simple payback of about 7 months, by installing timers. This strategy will work on machines serving non-perishable items, as well as display cases and other devices used only during occupied hours. Replacing steam traps. Ultrasonic testing of the steam traps along the distribution system identified over 400 defective traps, which were wasting over $27,000 per year in fuel costs. Winter night setback. Initially winter night and weekend setback was set at 66 degrees, which consumed a lot of energy during the particularly cold weather which could be expected in Minnesota. Significant savings at a small initial cost were achieved by lowering the space temperature set point to 60 degrees during the winter for night unoccupied hours. Lessons Learned: Even though tine Honeywell Plaza buildings were already very well maintained, before the Showcase -project commenced, the tuned building will save an estimated $62,560 per year, or 6.5% oftlie total operational costs. The net internal rate of return for the tune-up measures is about 58%. Using in-house personnel to survey and implement measures increases the profitability of many measures which otherwise would not have been implemented. 12 ------- ENERGY STAR Buildings Tech Tips Building Tune-lip CONCLUSION Tune-up measures provide significant savings, usually with a minimal investment A complete building audit can usually be performed by in-house personnel, or outside consultants can be hired if cost-effective. Measures as simple, as cleaning cooling coils save energy by allowing air handling systems to operate more efficiently. Other measures, such as updated EMS controls, provide larger savings by improving building operations. In many cases, performing a tune-up before approaching other upgrades provides a quick payback and savings which can be used to fund future upgrades. A newer building should expect to budget $0.01 - $0.10 per square foot for the tune-up. Older buildings and tune-ups involving significant purchases should budget $0.10 - $0.50 per square foot As was found in the Showcase projects, there are other advantages to tune-up measures besides direct energy savings. Cooling and heating loads can be reduced when the building is operating more efficiently. Indoor air quality problems can be prevented by a regular maintenance and cleaning schedule of air handling equipment Correcting faulty sensors and controls reduces the amount of comfort complaints in a building. Although quantifying these advantages in terms of costs and savings is hard to estimate, the functional improvements merit their consideration. By following the Energy Star Buildings staged strategy, the building tune-up should occur prior to investment in mechanical equipment upgrades and should be one of the first actions in an upgrade project A good tune-up procedure should include a full understanding of the energy profile of a building through an energy end-use breakdown, a comprehensive facility survey, and an examination of O&M procedures for improvements. Training of in-house staff for new equipment, and of new staff for existing equipment will prevent potential problems and ensure efficient operation. A comprehensive tune-up strategy plays a significant role in protecting the environment by reducing greenhouse gas emissions., 13 ------- ------- ------- ------- |