1、984 2009 ASHRAEABSTRACTThe 2005 Energy Policy Act requires that federal facilities be built to achieve at least 30% energy savings over the 2004 ASHRAE Standard 90.1-2004. The U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory of the U.S. Army Corps of E
2、ngineers (USACE) in collaboration with USACE Headquarters and centers of standardization for respective building types, the U.S. Department of Energys (DOE) National Renewable Energy Laboratory and the ad hoc ASHRAE Military Technol-ogy Group have developed design guides to achieve at least 30% ener
3、gy savings over a baseline built to the minimum requirements of the ASHRAE Standard 90.1-2004 for new buildings to be constructed under the Military Transformation Program. The building types included barracks (also called unaccompanied enlisted personnel housing or UEPH), trainee barracks, administ
4、rative buildings (e.g., a battalion headquar-ters, a company operation facility), a maintenance facility, a dining facility, a child development center, and an Army reserve center. All design guides were completed in 2007 and 2008. This paper presents the results of the energy analysis for standard
5、Army UEPH barracks. It provides a definition of the baseline building selected for the analysis and the modeling assumptions. As a result of a computer analysis using Ener-gyPlus version 2.0, baseline and target energy budgets are clearly defined for all 15 DOE climate zones. Finally, a recom-mended
6、 set of energy efficiency solutions for each climate zone is presented that result in at least 30% energy savings in addi-tion to an improved living environment that reduces the poten-tial for mold growth. Results of this study for UEPH barracks were implemented through the Armys standard design-bui
7、ld process in late 2007 by incorporating the target energy budgets and the recommended sets of technologies by climate zone to meet these budgets into the Army standard request for proposal for UEPH barracks.INTRODUCTIONSection 109 of the Energy Policy Act of 2005 (EPAct 2005) states that, for new f
8、ederal facilities, “the buildings be designed to achieve energy consumption levels that are at least 30 percent below the levels established in the version of the American Society of Heating, Refrigerating and Air-Condi-tioning Engineers (ASHRAE) Standard or the International Energy Conservation Cod
9、e, as appropriate” (NARA 2006). The energy-efficient designs must be life cycle cost effective; however, cost effective is not 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
10、 that savings calculations should not include the plug loads and implies that the savings shall be determined through energy cost 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 s
11、avings.The U.S. Army constructs buildings across the country, and the U.S. Army Office of the Assistant Chief of Staff of the Installations Management (OACSIM) and the U.S. Army Corps of Engineers (USACE) decided to streamline the process of meeting the energy savings requirements. USACE collaborate
12、d with DOEs National Renewable Energy Laboratory (NREL) and the ad hoc ASHRAE Military Technology Group (MTG) to develop baseline and target energy budgets and design guides with one prescriptive path for achieving 30% or more energy savings for each facility in each of the 15 DOE recommended Energy
13、 Design Guides for Army BarracksDale Herron Alexander Zhivov, PhD Michael Deru, PhDMember ASHRAE Member ASHRAE Member ASHRAEDale Herron is a mechanical engineer and project manager and Alexander Zhivov is an operating agent of the IEA ECBCS Annex 46 and a program manager in the Energy Branch of the
14、U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory, Champaign, IL. Michael Deru is senior engineer with the Center for Buildings and Thermal Systems at the National Renewable Energy Laboratory, Golden, CO. LO-09-093 2009, American Society of Heating, Ref
15、rigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions 2009, vol. 115, part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.ASHRAE Tr
16、ansactions 985U.S. climate zones. The project covers eight building types over all U.S. climate zones: Basic training barracksUnaccompanied enlisted personal housing (UEPH) or single soldier barracksBattalion headquartersTactical equipment maintenance facilitiesDining facilitiesChild development cen
17、tersArmy reserve centersCompany operations facilities. This paper focuses on the UEPH barracks; however, the process for developing all the design guides is similar.The concept for these design guides was adapted from the Advanced Energy Design Guides (AEDGs) from ASHRAE (2008). Each AEDG was develo
18、ped for a specific building type and provides recommendation tables for each of the eight major climate zones and a “how-to” section for implementing the recommendations. The AEDGs do not provide baseline and target energy budgets, which are used by the Army in its requests for proposals.APPROACHAn
19、energy 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 UEPH barracks building. For this study, the model was based on the information provided by the USACE Fort Worth District the Barracks
20、 Center of Standardization. Energy conservation technology candidates were selected based on previous CERL studies of existing Army facilities (Zhivov et al. 2008), which outlined energy and indoor air quality (IAQ) related issues in existing facilities, and used research data from the Interna-tiona
21、l Energy Agency 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 (EnERGo) (IEA ECBCS Annex 46).All energy simulations for the UEPH barracks were carried out
22、 with EnergyPlus version 2.0 (DOE 2008. NREL is part of the EnergyPlus development team and has developed additional programs to be used with EnergyPlus to optimize building energy performance. These programs work together to create input files, manage simulations, provide optimiza-tion, and postpro
23、cess the results. The optimization engine, called Opt-E-Plus, is used to help optimize building designs based on energy performance, energy cost performance, or life cycle cost performance.The first step in this whole-building energy simulation project was to define the baseline building model, whic
24、h 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. In this project analysis, we used site energy based on the Army decision, and developed baseline and target energy budgets
25、 without plug loads as our metric for savings following EPAct 2005 guidance from DOE. Finally, Standard 90.1-2004 does not contain requirements for building air leakage and infiltration levels. For UEPH barracks we defined a baseline air leakage rate and an energy-efficient leakage rate and included
26、 these factors in our energy efficiency analyses.EXISTING BARRACKS BUILDINGS ENERGY AND MOLD ISSUESThe U.S. Army has UEPH barracks at 26 installations in the United States and several in Europe, Japan, and Korea. The current standard design calls for the barracks module to house two soldiers. Each s
27、oldier is provided an individual lockable livingsleeping area, and the two soldiers share a bathroom and kitchenservice area. The floor area is 183 ft2(17 m2). Heating and cooling is provided to each room regardless of geographic location. Many Army UEPH barracks do not comply with the current stand
28、ard barracks module concept or space requirements.The designs of two Army barracks types have soldiers rooms with entrance doors that open directly to the outside. All other barrack types have two or more entrances into the build-ing and all soldiers rooms are accessible from central corri-dors. The
29、se buildings have less infiltration because, at the outside doors, there is often a vestibule and the corridor acts as a second vestibule for individual rooms.Studies of barracks conducted by the Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC/CERL) indic
30、ate multiple issues that should be addressed in new barracks construction, including:Mold growthTemperature control throughout the yearEnergy useWater useMaintenance costs.Mold growth is typical in most U.S. climate zones. Mold has been found not only in southern and eastern humid climates, but in m
31、any other climates where air-conditioning has a high usage in the barracks. To mitigate the health/IAQ issue from mold in barracks, the Army spends large amounts of money for mold remediation and clean-up operations. There are a number of causes for the mold problem and the following requirements sh
32、all be considered in a new design:Barracks living spaces need to be airtight to reduce moisture load infiltrating with outside air.The barracks air-conditioning system must be properly designed and sized to control the latent load in the spaces.The supply air flow rate must be designed to create a p
33、ositive room air pressure against the outside air to pre-vent moisture and unconditioned air penetration directly into the room.Heat gains need to be minimized to reduce the sensible cooling load on the air-conditioning system.986 ASHRAE TransactionsSpace temperature must be controlled within a reas
34、on-able range. Room temperature should not be lower than the outside dew point temperature.Supply air temperature should not exceed the outside dew point temperature to prevent condensation on air diffusers and surrounding cold surfaces.Cooling system piping, heat exchangers, and ducts must be prope
35、rly insulated to avoid condensation.Ventilation air must be dehumidified to absorb moisture (latent load) in the room air. In this case, air reheat after the cooling coil shall be designed and the use of waste heat for this purpose considered.STANDARD NEW UEPH BARRACK DESCRIPTIONUEPH barracks are si
36、milar to apartment buildings. The model used for this study contained 78 double-occupancy units for a total capacity of 156 personnel. Each apartment unit has two bedrooms with a storage area, a bathroom, and a kitchen (see Figure 1). The first floor has 24 units, a laundry room, a common area, a la
37、rge mechanical room, and a storage area. The second and third floors have 27 units and a laundry room. Each floor is 18,403 ft2(1710 m2) and the building is 55,209 ft2 (5088 m2). Figure 2 shows a rendering of the base-line computer model.CLIMATIC LOCATIONSFifteen locations were selected to represent
38、 15 climate zones in the United States (Briggs et al. 2003). We selected Colorado Springs, Colorado for climate zone 5B instead of Boise, Idaho, to more closely align with the installations at Fort Carson, Colorado. Table 1 lists the 15 climate zones and the cities used to represent the climate zone
39、s.ENERGY MODELINGEnergyPlus version 2.0 was used to complete the energy simulations (DOE 2008). All simulations were completed with the NREL analysis platform that manages EnergyPlus simulations. Table 2 lists the modeling assumptions used in the baseline and energy-efficient models.The approach to
40、modeling the energy efficiency improve-ments was to add one improvement at a time starting with the envelope, then infiltration and HVAC. The approach to model-ing each area is presented in the following sections.Figure 1 Section of the first floor plan for the UEPH barracks.ASHRAE Transactions 987E
41、NVELOPEAs stated in the Approach section, the Army decided to standardize the use the nonresidential ASHRAE Standard 90.1-2004 as the baseline for all barracks, even though the low-rise UEPH barracks used for this study might otherwise fall under the residential standard. The nonresidential enve-lop
42、e insulation levels are slightly lower than the residential ones. Simulations were completed that compare the residen-tial IECC-2004 requirements and Standard 90.1-2004 nonres-idential energy requirements for this building. Annual energy use in the nonresidential Standard 90.1-2004-compliant build-i
43、ng ranged from 2% lower in San Francisco to 15% higher in Duluth; the average difference over 14 locations was 7% more energy required in the Standard 90.1-2004-compliant building than in the IECC-2004-compliant building.The NREL optimization platform Opt-E-Plus was used to complete the first steps
44、to determine the optimal envelope improvements. The program finds the optimal solutions of a large set of selected envelope features based on initial capital costs, operational energy costs, and maintenance costs over a defined period. The capital and maintenance cost data are based on the informati
45、on used by ASHRAE for Standard 90.1 development. The utility costs are based on typical utility costs for each location, which are probably higher than the rates used by the Army; however, the Army rates for each location were not known. Higher energy costs would lead to more energy-efficient strate
46、gies, which was taken into account when reviewing the results. The analysis period was set to 30 years.Optimization runs for wall and roof insulation levels and window types were carried out for five locations for the UEPH barracks. Solutions were selected by location that produced high energy savin
47、gs and maintained low capital cost increases. Figures 3 and 4 show the optimization results for Houston. Each dot represents one simulation with a different combina-tion of features. The results are shown for the effects on the capital costs as well as the capital, energy, and maintenance costs over
48、 30 years. The minimum 30-year cost point provides about 5% energy savings; the optimal point provides more than 8% savings, but at a much higher first cost. Figure 4 shows how a group of near optimal solutions was selected that produced the highest savings and kept the increase in first costs to le
49、ss than 1.5%. The final solutions were manually selected from these near optimal solutions for each optimized location in a way that kept consistency in the insulation and windows across the climate zones. The results for these loca-tions were applied to the other locations based on similar heat-ing and cooling degree days and the need to keep the results simple and easy to implement.All optimization runs were completed with an attic roof construction and generic wall constructions that use an effective overall R-value. The final recommendations were determined from a review o
