1、196 2008 ASHRAE ABSTRACT Building energy performance rating protocols provide away to compare the energy consumption of one building withthose of other similar buildings. A search found 47 protocolsfor commercial buildings, five of which were chosen for in-depth evaluation in this paper. The most co
2、mmon methodologyused by the protocols chosen was to compare the building toa database of surveyed buildings. The comparison could be assimple as a graphical comparison of energy intensity, or itcould be a complex procedure to compute an index. To comparethe selected protocols, data on 29 buildings w
3、ere gatheredusing a short survey. While some exceptionally good buildingsare consistently rated well across different rating methods,most buildings could be considered “good” by some ratingmethods but not others. INTRODUCTIONEvery day we use ratings to help us make purchasing deci-sions. For example
4、, we would not purchase a car withoutunderstanding how many miles it can go on a gallon of gas, anda computer printer would not be considered for purchase with-out understanding the number of pages per minute it can print.Most expensive items have been rated by some measure toallow us to choose the
5、item and understand its level of func-tionality. We also use ratings to inform us on how we are doingcompared to others. Children receive grades and test scores oneach subject in school to understand how they are doing.Adults are concerned with their credit scores and cholesterollevels as measures o
6、f borrowing power and health. Thesescores or ratings help make the complexity of comparing itemswithin a category simpler to understand. No rating or scoringsystem is perfect, but they do provide an overall indicator thatmay be used to start making decisions or perhaps to beginfocusing on the detail
7、s of a few choices. Building energy performance rating methods may beused for existing or new buildings to determine how theirenergy usages compare with a group of similar buildings. Likethose for other products, rating methods for buildings are usedto help make purchasing decisions related to those
8、 buildings.For existing buildings, a rating method may spur investment inan energy-conservation improvement to the building or, atleast, prompt an energy audit to understand how to reduceenergy use in the building. For new construction, buildingenergy performance rating methods can help guide the de
9、signprocess by providing an energy-consumption goal or simplythe examination of energy use during the design process.Rating methods become even more useful when only onemethod is commonly used. Under a single common ratingsystem, discussion of the measure becomes even easier sinceeveryone shares a c
10、ommon understanding of the overall mean-ing of the rating. In addition, a product that is sold that has notbeen rated under a single common rating system is unlikely tobe purchased, which encourages the widespread use of therating system. This empowers consumers and business deci-sion makers with a
11、common basis of comparison for all itemsin a product category. Many different building energy performance rating meth-ods are available, so the advantage of having a single commonrating method for consumers and business decision makersdoes not exist for building energy performance. Someonetrying to
12、decide which building to rent for his or her businesswould not expect to have a common building energy perfor-mance rating available for each choice. Instead, a buildingenergy performance rating method could be chosen and ratingcalculated for each building if sufficient information wasEvaluation of
13、Building Energy Performance Rating ProtocolsJason Glazer, PEMember ASHRAEJason Glazer is president of GARD Analytics, Inc., Park Ridge, IL.NY-08-026 (RP-1286)2008, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions, Volu
14、me 114, Part 1. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.ASHRAE Transactions 197available. More likely, the utility bills of previous tenants, ifavailable, may be compared w
15、ith each other. Decisions basedon this could lead to erroneous conclusions concerning whichbuilding would minimize energy use or expenditure.ASHRAE, the sponsor of this research, helps to establishstandards for the building sector covering many differentHVAC products and for overall efficient buildi
16、ng design andoperation. It would be a natural fit for ASHRAE to establisha standard method of rating the energy performance of build-ings. This research project may be considered one preliminarystep to such an effort by providing close examination of someexisting building energy performance methods.
17、 Even if an ASHRAE standard on building energy perfor-mance rating is never developed, this paper may help thosetrying to choose between different rating methods. If one ormore of the rating methods under consideration are examined,the details can help consumers decide between the differentsystems.
18、If a chosen rating method is not included in thispaper, the methodologies described and information gatheredmay still form the basis of a deeper understanding of ratingmethods in general and facilitate choosing a method.The benefits of commercial building rating include: An owner of multiple buildin
19、gs can easily determinewhich building justifies further investment in energy-efficient retrofits.Building developers can legitimately claim a project tobe “high performance.”Tenants can be attracted to buildings that demonstratelower energy usage.Program developers for stimulating the construction o
20、fhigh-performance buildings need a metric to quantify“high performance.”Energy efficiency contributes to overall building perfor-mance that includes sustainability issues, including landuse, water use, and material use.Search and Selection By a formal literature search and an informal Internetsearch
21、, many different rating methods were uncovered,including 47 protocols for commercial buildings and 31 thatapplied to residences. Most of the residential protocols werebased on point systems that have achieved a high degree ofmarket penetration in the home-building industry. Ratingmethods that apply
22、to commercial buildings were the mainfocus of this research; five were selected for in-depth investi-gation based on a range of criteria, including the use ofASHRAE documents, the approach used, the range of build-ing types, the perceived number of users, and the amount oftechnical documentation ava
23、ilable. The five methods selectedwere ENERGY STAR Label for Buildings, Arch/Cal-Arch,LEED-NC/LEED-EB, BREEAM, and ENERGYguide. References to ASHRAE DocumentsOf the 47 commercial building energy performance ratingprotocols found, nine had references to ASHRAE publicationssuch as standards, guidelines
24、, and the ASHRAE HandbookFundamentals. Many of the point-based systems have refer-ences to ASHRAE documents because point-based systemsare likely to reference specific requirements, almost like astandard. ASHRAE publications referenced by the protocolsfound during the search were:ANSI/ASHRAE Standar
25、d 29-1988, Methods of TestingAutomatic Ice Makers (ASHRAE 2005)ANSI/ASHRAE Standard 52.1-1992, Gravimetric andDust-Spot Procedures for Testing Air-Cleaning DevicesUsed in General Ventilation for Removing ParticulateMatter (ASHRAE 1992b)ANSI/ASHRAE Standard 52.2-1999, Method of TestingGeneral Ventila
26、tion Air-Cleaning Devices for RemovalEfficiency by Particle Size (ASHRAE 1999)ANSI/ASHRAE Standard 55-1992, Thermal Environmen-tal Conditions for Human Occupancy (ASHRAE 1992a)ANSI/ASHRAE Standard 62-2001, Ventilation forAcceptable Indoor Air Quality (ASHRAE 2001)ANSI/ASHRAE/IESNA Standard 90.1-2001
27、, EnergyStandard for Buildings Except Low-Rise ResidentialBuildings (ASHRAE 2001c)ANSI/ASHRAE Standard 117-2002, Method of TestingClosed Refrigerators (ASHRAE 2002a)ANSI/ASHRAE Standard 129-1997, Measuring AirChange Effectiveness (ASHRAE 2002b)ASHRAE Guideline 1-1996, The HVAC CommissioningProcess (
28、ASHRAE 1996)ASHRAE Guideline 4-1993, Preparation of Operatingand Maintenance Documentation for Building Systems(ASHRAE 1993)2001 ASHRAE HandbookFundamentals (ASHRAE2001b)Test BuildingsIn order to test and understand the ratings from theseprotocols, data from actual buildings were gathered. Thedetail
29、ed questions that are part of the LEED and BREEAMrating methods made contacting building operator or facilitymanagers necessary. Public information from buildings thathave been rated under the ENERGY STAR Label for Build-ings program and the LEED program included contact infor-mation. A subset of pe
30、ople were contacted and asked tocomplete a questionnaire about their buildings. Data on 29buildings, including 15 office buildings, 9 schools, 4 hospitals,and 1 hotel, were gathered and used for testing the ratingprotocols. The data for these 29 buildings are summarized inTable 1.ENERGY STAR Label f
31、or BuildingsThe ENERGY STAR Label for Buildings (EPA 1999)program by the U.S. Environmental Protection Agencyincludes a building energy performance rating protocol basedon matching the actual energy use of a building against a statis-198 ASHRAE Transactionstical distribution of buildings. The rating
32、 is described on ascale of 1 to 100, and a score of 75 or greater for a facility maymake it eligible to receive the ENERGY STAR Label forBuildings. The score (EPA 2001a, 2001b, 2003a, 2003b) isbased on where the building fits in the distribution of energyuse for similar buildings based on source ene
33、rgy. The ratingindicates the percentage of comparable facilities nationwidethat are less efficient. For most building types, the data arefrom the U.S. Department of Energy/Energy InformationAdministrations (EIA) Commercial Building EnergyConsumption Survey, CBECS (DOE 2002), but data sets fromElectr
34、ic Power Research Institute, EPRI (EPRI 1997), and theHospitality Research Group, HRG (HRG 2004), are used forhospitals and hotels, respectively.A regression model is applied to the filtered records fromthe CBECS, EPRI, or HRG database to calculate the predictedsource energy consumption for each rec
35、ord. This is done tonormalize the data and smooth the results so they dont showas much random variation at the individual record level. Thenormalized data are then put into a histogram and values thatcorrespond to the thresholds for each percentage point (1%,2%, 3%, ., 100%) are computed. These valu
36、es are then fit toa gamma distribution to further smooth out the values, keepingTable 1. Selected BuildingsType Census Division Size, ft2*(m2) Decade Built Energy CodeHospital East North Central 250,000 (25,000) 1940s NoneHospital West South Central 150,000 (15,000) 1990s UnknownHospital West North
37、Central 450,000 (45,000) 1980s UnknownHospital Pacific 700,000 (70,000) 1970s UnknownHotel Mountain 50,000 (5000) 1990s UnknownOffice South Atlantic 250,000 (25,000) 1960s UnknownOffice West North Central 150,000 (15,000) 1990s UnknownOffice East South Central 100,000 (10,000) 1960s UnknownOffice Mo
38、untain 250,000 (25,000) 1990s 90.1-99Office West South Central 300,000 (30,000) 2000s 90.1-89Office West South Central 250,000 (25,000) 1990s 90.1-89Office West South Central 650,000 (65,000) 2000s 90.1-89Office Mountain 750,000 (75,000) 1960s UnknownOffice Middle Atlantic 10,000 (1000) 1990s Local
39、Energy CodeOffice Mountain 800,000 (80,000) 1980s UnknownOffice Pacific 300,000 (30,000) 1990s Local Energy CodeOffice Pacific 950,000 (95,000) 2000s Local Energy CodeOffice Pacific 450,000 (45,000) 1990s 90.1-89Office Middle Atlantic 750,000 (75,000) 1960s UnknownOffice Mountain 10,000 (1000) 1990s
40、 Local Energy CodeSchool West North Central 150,000 (15,000) 1990s UnknownSchool Middle Atlantic 50,000 (5000) 1950s NoneSchool Middle Atlantic 50,000 (5000) 1960s NoneSchool West North Central 50,000 (5000) 1920s UnknownSchool West North Central 50,000 (5000) 1950s UnknownSchool West North Central
41、150,000 (15,000) 1950s UnknownSchool West North Central 50,000 (5000) 1960s UnknownSchool West North Central 50,000 (5000) 1950s UnknownSchool East North Central 500,000 (50,000) 1960s None*Sizes rounded to nearest 50,000 ft2to keep data anonymous.ASHRAE Transactions 199the 75% value constant during
42、 the fitting so that it does notaffect who is eligible to receive the ENERGY STAR Label.The reason for this step of fitting the data to a gamma distri-bution is to reduce the clustering of results that may lead to asmall change in source energy, making a multiple point changein score. This step remo
43、ves any “jaggies” that can result froma model that is based on a limited number of data points. Thethresholds after gamma distribution are still in the form ofvalues corresponding to 1%, 2%, 3%, all the way to 100%, in1% increments. The increments correspond to the EnergyPerformance Rating values of
44、 1 to 100.The user inputs monthly electricity and fuel consumptionfrom utility bills. The energy consumption is then normalizedfor weather to make the energy use reflect a 30-year average.This is because the same building may experience signifi-cantly different weather from year to year, and the lab
45、el shouldapply to its expected typical performance. The actualconsumption normalized for typical weather is then comparedto each adjusted energy threshold value (1% to 100%). Thelowest threshold that is smaller than actual consumptionnormalized for typical weather is the Energy PerformanceRating of
46、the building. Arch/Cal-ArchLawrence Berkeley National Laboratory (LBNL) has twobuilding energy rating protocols that are closely related. Archand Cal-Arch (Piette et al. 2001; Piette and Kinney 2002) areboth protocols based on statistically valid datasets. CBECS isthe basis of the national tool Arch
47、, and Cal-Arch, which isfocused on buildings in California, uses the Commercial EndUse Survey, CEUS (PG it has a large number of build-ings represented and has a shape that seems somewhat like anormal distribution. Unfortunately, the number of buildingsrepresented in many of the evaluations is small
48、. The histogramon the right is much more common; just a scattering of build-ings is shown after choosing the building type and entering thebuilding area and zip code. These histogram results with onlya few buildings are a challenge to interpret. They lack a largenumber of buildings, which leads to q
49、uestioning just how typi-cal the buildings shown are. For Cal-Arch, the “higher than Xpercent of comparison buildings shown” is used as the bench-mark value for the building. For Arch, this value is not shown;instead, the histogram itself was analyzed. LEEDThe U.S. Green Building Council publishes severaldifferent variations of Leadership in Energy and Environmen-tal Design (LEED), including LEED for existing buildings,LEED-EB (USGBC 2004b). The energy and atmosphere (EA)prerequisites and credits are:Prerequisite 1Existing Building CommissioningPrerequisite 2Minimum Energy Performanc
