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

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A: The following DOE draft guidance clarifies the appropriate settings for testing heat pump water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

0074@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 At the end of the comment period, this draft guidance document may be adopted, revised, or withdrawn.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 heatpump 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 c ontrol 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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