ARLINGTON, Va. — An internal review by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) revealed an aspect of the current U.S. Department of Energy (DOE) efficiency test procedure for residential furnaces and boilers that may result in an inaccurate AFUE measurement for two-stage or modulating condensing residential boilers. The problem in the test procedure is in the calculations used to determine the AFUE when selecting the option of skipping the heat-up and cool-down tests.

These ratings were based on the current DOE efficiency test procedure, and the error is due to an inconsistency in those procedures rather than a failure to properly conduct the DOE test. All the involved models are highly efficient and exceed the current federal minimum AFUE for these products, so there is no issue with their compliance with federal minimum-efficiency standards.

“As soon as we discovered this test procedure inconsistency, we moved expeditiously not only to ensure accurate equipment ratings for consumers and in the AHRI Directory, but also to work with DOE officials to ensure the issue is corrected for all products,” said Stephen Yurek, president and CEO, AHRI.

He said that AHRI has implemented the following actions:

• Requiring all new model certifications and AHRI certification tests of all currently listed models for the subcategory of boilers to include heat-up and cool-down tests;

• Requiring the manufacturers of existing models in this subcategory of boilers listed in AHRI’s directory to immediately do one of the following: (1) drop the rating to 90 percent; (2) discontinue the model; or (3) provide test results that include the heat-up and cool-down tests that support a higher rating; and

• Developing appropriate calculations to determine the correct AFUE for two-stage and modulating condensing boilers.

Yurek, AHRI general counsel David Calabrese, and other AHRI staff briefed DOE officials in November about the issue and urged DOE officials to expeditiously notify manufacturers that are not participating in AHRI’s certification program of the issue so that the DOE can take steps to ensure proper AFUE ratings for their affected products.

Publication date: 12/17/2012