The 2004 standard contains changes made via two addenda. The standard no longer contains combustion appliance backdrafting test requirements. The test included in the 2003 standard was based on the best industry-accepted method found in the National Fuel Gas Code but questions arose about its application to solid-fuel burning appliances, according to David Grimsrud, chair of the committee that wrote the standard.

There also was concern about it not being possible to perform the test until the home is completed, opening the potential for having to perform remedial balancing at a difficult stage of construction and sale, he said.

While the test requirements have been eliminated, the standard sets an upper limit of exhaust flow to 15 cfm/100 square feet when natural-draft combustion appliances are present.

The standard also contains a change in climate zone terminology from "severe cold climate" to "very cold," which is now defined as one that has more than 9,000 65 degree F degree-days.

This makes the standard's climate definitions consistent with proposed revisions to the International Code Council climate zone definitions, which will simplify implementation of Standard 62.2 into code, said Grimsrud. ASHRAE has proposed that the standard be included in the 2006 International Residential Code.

The cost of Standard 62.2-2004 is $37 ($29 for ASHRAE members). To order, contact ASHRAE Customer Service at 800-527-4723 (United States and Canada) or 404-636-8400 (worldwide), by mail at 1791 Tullie Circle NE, Atlanta, GA 30329, or visit ASHRAE's online bookstore at www.ashrae.org.

Publication date: 12/27/2004