1、2009 ASHRAE 997ABSTRACTThe 2005 Energy Policy Act Requires that federal facilities be built to achieve at least a 30% energy savings over the 2004 ASHRAE Standard 90.1-2004. The Construction Engineering Research Laboratory of the U.S. Army Corps of Engineers, in collaboration with U.S. Army Corps of
2、 Engineers Headquar-ters and centers of standardization for respective building types, the U.S. Department of Energy (DOE), the National Renewable Energy Laboratory, and the ASHRAE Military Technology Group have developed design guides to achieve 30% energy savings over a baseline built to the minim
3、um requirements of ASHRAE Standard 90.1-2004 for new build-ings to be constructed under the Military Transformation Program. The building types included barracks, administra-tive buildings (e.g., a battalion headquarters and a company operation facility), a maintenance facility, a dining facility, a
4、 child development center, and an Army reserve center. This paper presents the results of the energy analysis for tactical equipment maintenance facilities (TEMFs). It provides a defi-nition of the baseline building selected for the analysis and the modeling assumptions. As a result of a computer an
5、alysis using EnergyPlus version 2.0, baseline and target energy budgets are clearly defined for all 15 DOE climate zones. Finally, a recom-mended set of energy efficiency solutions for each climate zone is presented that enable at least 30% energy savings in addition to improved and more productive
6、work environments that provide better thermal conditions and indoor air quality for soldiers and workers. Results of this study were implemented through the Armys standard design/build process in late 2007 by incorporating the target energy budgets by climate zone and the recommended sets of technol
7、ogies to meet these budgets into the Army standard Request for Proposal for TEMFs.INTRODUCTIONSection 109 of the Energy Policy Act of 2005 (EPAct 2005) states that, for new federal facilities, “the buildings be designed to achieve energy consumption levels that are at least 30 percent below the leve
8、ls established in the version of the American Society of Heating, Refrigerating and Air-Condi-tioning Engineers (ASHRAE) Standard or the International Energy Conservation Code, as appropriate” (NARA 2006). The energy-efficient designs must be life cycle cost effective; however, cost effective is not
9、 defined in the law; each federal agency is left to define it. The U.S. Department of Energy (DOE) issued additional guidance in the Federal Register(NARA 2006), which states that savings calculations should not include the plug loads and implies that the savings shall be determined through energy c
10、ost savings. The U.S. Army decided it would use site energy for the heating, ventilating, and air-conditioning (HVAC), lighting, and hot water loads to determine the energy savings.The U.S. Army constructs buildings across the country, and the Office of the Assistant Chief of Staff of the Installati
11、ons Management and the U.S. Army Corps of Engineers (USACE) decided to streamline the process of meeting the energy savings requirements. USACE and DOE collaborated with the National Renewable Energy Laboratory (NREL) and the ASHRAE Mili-tary Technology Group to develop baseline and target energy bu
12、dgets and design guides with one prescriptive path for achiev-ing 30% or greater energy savings. The project covers eight building types over all U.S. climate zones: basic training barracks, unaccompanied enlisted personal housing, battalion headquarters, tactical equipment maintenance facilities (T
13、EMFs), dining facilities, child development centers, Army reserve centers, and company operations. This paper focuses on Achieving Energy Efficiency and Improving Indoor Air Quality in Army Maintenance FacilitiesAlexander Zhivov, PhD Dale Herron Michael Deru, PhDMember ASHRAE Member ASHRAE Member AS
14、HRAEAlexander Zhivov is an operating agent of the IEA ECBCS Annex 46 and a program manager and Dale Herron is a mechanical engineer and project manager in the Energy Branch of the U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory, Champaign, IL. Michael
15、 Deru is senior engineer with the Center for Buildings and Thermal Systems at the National Renewable Energy Laboratory, Golden, CO. LO-09-094 2009, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions 2009, vol. 115, part
16、2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.998 ASHRAE TransactionsTEMFs; however, the process for developing all the design guides is similar.The concept for these design g
17、uides was adapted from the Advanced Energy Design Guides (AEDGs) from ASHRAE (2008). Each AEDG was developed for a specific building type and provides recommendation tables for each of the eight major climate zones and a “how-to” section on implementing the recommendations. The AEDGs do not provide
18、baseline and target energy budgets, which are used by the Army in its requests for proposals.APPROACHEnergy use baseline and target energy budgets were developed, and energy savings using different sets of technol-ogies were analyzed for a representative model of the TEMFs. For this study, the model
19、 was based on the information provided by the USACE Savannah District the TEMF Center of Standardization. Energy conservation technology candi-dates were selected based on previous Construction Engineer-ing Research Laboratory (CERL) studies of existing TEMFs (Zhivov et al. 2008), which outlined ene
20、rgy and indoor air quality related issues in existing facilities, and used research data from the IEA ECBCS (International Energy Agency Energy Conservation in Buildings and Community Systems) Annex 46 Holistic Assessment Tool-Kit on Energy Efficient Retrofit Measures for Government Buildings (EnERG
21、o) (IEA ECBCS Annex 46).All energy simulations for the TEMFs were carried out with EnergyPlus version 2.0 (DOE 2007). NREL is part of the EnergyPlus development team and has developed additional programs that work with EnergyPlus. These programs work together to create input files, manage simulation
22、s, provide optimization, and postprocess the results. The optimization engine, called Opt-E-Plus, is used to help optimize building designs based on energy performance, energy cost perfor-mance, or life cycle cost performance.The first step in this whole-building energy simulation project was to def
23、ine the baseline building model, which meets the requirements of ASHRAE Standard 90.1-2004 following the Appendix G guidelines (ASHRAE 2004a). We followed Appendix G with two exceptions, which were approved by DOE. We used site energy based on an Army decision, and developed baseline and target ener
24、gy budgets without plug loads as our metric for savings following EPAct 2005 guid-ance from DOE. Additionally, Standard 90.1-2004 does not contain requirements for building air leakage and infiltration levels. For TEMF office areas we defined a baseline air leak-age rate and an energy-efficient leak
25、age rate and included these factors in our energy efficiency analysis.EXISTING TEMF FACILITIES, THEIR SYSTEMS AND ISSUESTEMFs are used to shelter Army vehicles while they are being maintained or repaired. They are equipped with lifts, utility services, and tools that enable service people to effec-t
26、ively perform maintenance tasks, which include periodically changing fluids and components, replacing broken or damaged parts and subassemblies, and adding new compo-nents. The tasks are similar to those performed in an automo-tive repair garage. Tasks that require major rebuild of subassemblies are
27、 typically performed elsewhere.TEMFs come in a range of sizes. They are generally long buildings and consist of a number of bays that are 35 ft (10.7 m) wide and 60 ft to 80 ft (18.3 m to 24.4 m) long, which is long enough to accommodate two vehicles parked end to end. Also included in the TEMF are
28、administrative offices, rest-rooms, cribs for parts storage, and spaces for specialized main-tenance operations. Vehicle bays may form wings off a central core area where nonmaintenance activities occur. The building may also be rectangular with administrative, storage, and specialized spaces in bay
29、s similar to the maintenance bays.The common TEMF building is of masonry construction with a number of overhead doors on opposite sides of the building. These doors often do not fit tightly and thus enable outside air to enter the building. Windows are normally limited to a narrow band above the row
30、 of doors.Energy SystemsThe energy systems required in a TEMF provide power for tools, lighting, heating, and ventilation. Each bay has elec-trical power outlets and a compressed air piping system for electrical and pneumatic tools. The lighting system consists of high-wattage ceiling-hung ambient l
31、ights and lower wattage task lighting for close-up work. The heating system is required to maintain reasonable space temperatures in the winter. This is typically difficult to accomplish because of the large number of vehicle doors and the need to occasionally open them (Figure 1). The maintenance a
32、reas typically use radiant heat-ers or unit heaters.The administration spaces normally have forced air heat-ing units that burn natural gas or a building distribution system that uses hot water. The space is ventilated with an air handling unit that supplies outside air and an exhaust system that re
33、moves vehicle exhaust from the maintenance areas. The restrooms have their own exhaust system. Space cooling is provided for the administrative areas only.TEMFs contain a large amount of electrically powered equipment for working on vehicles such as air compressors, hydraulic pumps for lifts, overhe
34、ad cranes, various test equip-ment, welders, grinders, sanders, and other machine shop tools. Lights, ventilation fans, water distribution and waste pumps, door openers, and local water heaters also use electricity.Equipment and ProcessesA TEMF includes normal maintenance operations where lubricatin
35、g oils are changed, damaged body parts are replaced, brakes are changed and adjusted, engines are tuned, and trans-missions are adjusted. Also, a crane is used to pull and replace engines. Special maintenance bays handle large transport trucks, armored troop carrying vehicles, and tanks. Typically,
36、these special bays are found in a few TEMF facilities on a post. ASHRAE Transactions 999These facilities also have a location where welding is done and another location for painting.Concerns with Proper System OperationTEMFs have a number of challenges: They do not have a good temperature control sy
37、stem. In the summer, these buildings can become quite hot. The only relief is to open the doors to take advantage of breezes. At some locations, large roll-around evapora-tive cooling units are used to cool the air, but they are only marginally effective. During the heating season, these buildings c
38、an be quite cold. Outside air enters through open doors and the cracks around the doors. Warm air heaters have a difficult time heating the lower occupied zone.Radiant heaters can heat the floor, but they need to be placed where the people are located. Someone working under a vehicle does not benefi
39、t from the overhead radi-ant heaters. Radiant heaters are sometimes placed near the roof along the perimeter above the vehicle doors so as not to interfere with the overhead crane operation; however, they are away from the people in the space.The tailpipe exhaust systems are hard to use (Figure 2);
40、nozzles typically do not fit most vehicle tailpipes or exhaust grilles and the hoses tend to melt under the heat of exhaust gas. Also, most exhaust fumes are released when vehicles enter or exit the building. Only a few sys-tems can capture exhaust fumes from moving vehicles, but they are rarely spe
41、cified for TEMF operations. Thus, often no attempt is made to connect exhaust systems to the vehicles and take advantage of closed capture.Ventilation systems that consist of sidewall exhaust fans do not remove fumes that are heavier than air. Thus, general energy building ventilation should be prov
42、ided to dilute these fumes and maintain a healthy environ-ment. However, these systems require a lot of energy to move and heat high volumes of air during the winter. Many TEMF buildings have no or inadequate general ventilation.The high-level luminaries provide a good general “walk-around light” le
43、vel that is inadequate for close work. Often the doors are kept open, which increases the light-ing level in the work areas significantly. A good task lighting system in the repair bays is a necessity. Dark internal surfaces result in increased electrical energy consumption for lighting and in incre
44、ased heat radiation during the summer.Model Building DescriptionThe TEMF is a two-story structure (Figure 3a) with a total area of 49,920 ft2(4,638 m2). Table 1 lists description details; Table 2 lists the zones and internal loads. Figure 3a shows a rendered view of the energy simulation model, and
45、Figure 3b shows the floor plan. The building is nominally occupied from 8:00 a.m. to 5:00 p.m. Monday through Friday.LocationsPacific Northwest National Laboratory conducted energy analysis for the locations selected as representative cities for the 15 DOE climate zones (Briggs et al. 2003). For cli
46、mate zone 5B, Colorado Springs, Colorado was selected instead of Boise, Idaho to more closely align with the installations at Fort Carson. Table 3 lists the 15 climate zones and the cities used to represent the climate zones.ENERGY MODELINGEnergyPlus version 2.0 (DOE 2007) was used to complete the e
47、nergy simulations. All simulations were completed with the NREL analysis platform that manages EnergyPlus simulations. The approach to modeling the energy efficiency improvements was to add one improvement at a time starting with the envelope, then infiltration and HVAC. Figure 1 Typical Army mainte
48、nance facility.Figure 2 Tailpipe exhaust system (suspended above the vehicle) is hard to use.1000 ASHRAE TransactionsThe approach to modeling each area is presented in the follow-ing sections.Baseline EnvelopeThe baseline building envelope features are modeled as steel frame wall construction, roof
49、insulation entirely above deck, and door and fenestration types from ASHRAE Stan-dard 90.1-2004. The door, window, and skylight sizes and distribution are exactly the same in all building models. Skylights are included at 2% of the roof area in the repair bays, vehicle corridor, and office for daylighting. These metal build-ings have slightly different insulation requirements in Stan-dard 90.1-2004.InfiltrationThe infiltration for the baseline and energy-efficient building models was assumed to be 0.5 air changes per hour (ACH). The infiltration in all zones except the repair bays wa
