This is a draft document and does not represent a definitive view of the agency on the questions 

addressed. 

This and other guidance documents are accessible on the U.S. Department of Energy, Energy Efficiency & 

Renewable Energy web site at: http://www1.eere.energy.gov/guidance/default.aspx?pid=2&spid=1. 

Guidance Type: Test Procedures 

Category: Residential Products 

Product: Residential water heaters 

Guidance Version: DRAFT 

Issued: January 30, 2012 

Comment Period Closes: March 2, 2012 

Q: What operational-mode settings should be used when testing a residential storage-type heat pump 

water heater for the first-hour rating test and the simulated-use test? 

A: The following DOE draft guidance clarifies the appropriate settings for testing heat pump water 

heaters in accordance with DOE’s test procedures for residential storage-type water heaters. This 

guidance represents DOE’s interpretation of its existing regulations and is exempt from the notice and 

comment requirements of the Administrative Procedure Act. See 5 U.S.C. § 553(b)(A). Nevertheless, given 

that the Department has not previously expressed its views on this issue, we are interested in receiving 

feedback from the public. Therefore, the Department is accepting comments and suggestions from the 

public until March 2, 2012. Comments and suggestions should be provided in WordPerfect, Microsoft 

Word, PDF, or text file format by sending an email to HPWHTestingGuidance-2011-TP0074@ee.doe.gov. Please also include the docket number: EERE-2011-BT-TP-0074. At the end of the 

comment period, this draft guidance document may be adopted, revised, or withdrawn. 

SETTINGS USED FOR TESTING OF HEAT PUMP WATER HEATERS 

The test procedures for residential water heaters are found in 10 C.F.R. 430.23(e) and 10 C.F.R. Part 430, 

Subpart B, Appendix E. As part of these test procedures, DOE specifies testing conditions and a method 

of test for residential heat pump water heaters. DOE has received an inquiry regarding how to test a heat 

pump water heater since different models produced by various manufacturers may offer a variety of 

operational mode settings (e.g., heat pump only, electric resistance only, and some combination 

thereof). Appendix E to Subpart B to 10 CFR Part 430 specifies two different test methods for residential 

water heaters, including the first-hour rating test and the simulated-use test. DOE is clarifying for heat 

pump water heaters that the same operational mode should be used for conducting both the simulateduse test and the first-hour rating test. In addition, this operational mode should be the default mode or 

the suggested mode for normal operation as defined by the manufacturer in its product literature. When 

a default mode or suggested mode is not defined in the product literature, both tests should be 

conducted under an operational mode in which both the heat pump and any electric resistance backup 

heating element(s) are activated by the unit’s control scheme, and which can achieve the internal storage 

tank temperature specified in the DOE test procedure. If multiple operational modes meet these criteria, 

the water heater should be tested under the most energy-intensive mode. If the unit does not offer an 

operational mode that utilizes both the heat pump and the electric resistance backup heating element(s), 

the first-hour rating test and the simulated-use test should be tested in heat pump only mode. 

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