Review of International Methods of Test to Rate the Efficiency of Water Heaters

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The American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standards Project Committee (SPC) 118.2, Method of Testing for Rating Residential Water Heaters, is seeking to improve the test procedure used for measuring the energy efficiency of residential gas and electric water heaters. ASHRAE is seeking to develop an improved test procedure in part to support the U.S. Department of Energy's (DOE's) desire to update and amend the water heater test procedure underlying the minimum energy efficiency standards for water heaters. DOE's test procedures are often based on or reference ASHRAE standards.DOE's most recent minimum energy performance standards (MEPS) for residential water heaters were promulgated in 2010.[1] The associated test procedures are stipulated in the Code of Federal Regulations (CFR).[2] Although DOE currently is conducting a rulemaking to review and possibly amend the test procedures for residential water heaters, that rulemaking pertains to accounting for energy consumed during standby and off modes. In its notice of proposed rulemaking published in the Federal Register on August 30, 2010, DOE tentatively concluded that the test procedure for water heaters already fully accounts for and incorporates the energy consumed during standby and off modes [3].

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This work was sponsored by the Gas Technology Institute (GTI) which is funded by the California Energy Commission, Public Interest Energy Research (PIER) Program, under Residential Water Heating Program Contract No. 500-08-060. This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, State, and Community Programs, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.


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