ATLANTA - Changes intended to make requirements easier to use in home retrofits are covered in the newly published 2010 residential ventilation standard from ASHRAE. ANSI/ASHRAE Standard 62.2-2010, “Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings,” defines the roles of, and minimum requirements for, mechanical and natural ventilation systems and the building envelope, in order to provide acceptable IAQ in low-rise residential buildings.

The 2010 standard encourages home retrofits to improve IAQ by allowing alternative methods for meeting the standard’s requirements regarding kitchen and bathroom exhaust fans. The standard currently requires fans in those rooms. “This change makes the standard much easier to use in home retrofits, which is very important considering massive federal and state government efforts in this area,” said Steven Emmerich, committee chair. “For example, installation of new equipment in some existing homes can be a barrier in terms of expense and practicality. Under the alternative compliance path, the overall whole-house ventilation rate can be increased to compensate for insufficient or nonexistent bathroom exhaust.”

The overall approach to residential ventilation in the standard has not changed since the 2007 version was published, such as whole-house mechanical for most houses, local exhaust in baths and kitchens, and some source-control measures.

Additional improvements to the standard include more accurate factors for intermittent whole-house systems; changes to better limit unintended (potentially contaminated) air transfer from garages, leaky ducts, adjacent housing units, and other such spaces; and deletion of an exception for certain climates that had allowed the use of windows instead of fans, given that studies have shown that windows are not used enough and are unreliable for ventilation.

The cost of Standard 62.2-2010 is $54 ($46 for ASHRAE members). To order, contact ASHRAE at 800-527-4723 or visit www.ashrae.org/bookstore.

Publication date: 08/02/2010