New Life for ASHRAE 90.2?
Not So Fast
by Jeff Inks

If right about now you’re saying to yourself, “ASHRAE 90.2?” you’re definitely not alone. Actually, ASHRAE 90.2 - Energy-Efficient Design of Low-Rise Residential Buildings—which is developed and maintained by the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE), has been around and available for adoption as a one- and two-family and low-rise residential energy code since 1993—but with no takers. Nonetheless, ASHRAE has kept it sitting quietly on the sidelines updating it in 2001, 2004, 2007, and tentatively for 2012. But the “sitting quietly” part may be over.

"Additionally, having four different sets of energy performance requirements in each climate zone could cause problems for fenestration manufacturers."

Waking Up
Unlike its prominent companion, ASHRAE 90.1, which covers most other construction, 90.2 has been a sleeper and not adopted by any state or local jurisdiction, so it has not garnered much attention or concern. But with growing concerns by some in the residential construction industry that the International Code Council’s (ICC) predominant International Energy Conservation Code (IECC) is becoming too stringent or difficult to reasonably build to, some are looking to 90.2 as a possible alternative. However, it is viewed by ASHRAE (and most others familiar with it) as needing an overhaul first, which ASHRAE is attempting to do, but the effort is causing a stir.

ASHRAE has been working to overhaul 90.2 through a comprehensive rewrite for about the last 18 months. Up to this point, a primary intent has been to develop what some stakeholders consider a more practical or reasonable approach to energy efficiency requirements for low-rise residential construction including single-family homes. With that objective in mind, a revised draft of the standard has been developed by the ASHRAE 90.2 committee.

Among other provisions included in the draft is a new approach to the prescriptive path that offers four different combinations of prescriptive requirements as alternatives for each climate zone. Some of these allow for controversial equipment trade-offs. They also put limits on allowable fenestration area, which is a significant concern to WDMA and others in the fenestration industry.

Draft Under Scrutiny
The first complete draft of the “new” 90.2 was released by the ASHRAE 90.2 committee for an advisory public review in May. The purpose of ASHRAE’s advisory public review is “to seek suggestions for new, unusual, or potentially controversial elements of the proposed guideline that the project committee believes would benefit from increased public scrutiny prior to finalizing the draft for its first formal public review.” That’s exactly what the committee got.

In response to the review, the 90.2 committee received a number of comments expressing major concern that the direction the rewrite of 90.2 is taking is wrong, asserting it is too lenient and does not sufficiently advance energy efficiency in residential construction. Several stakeholders also feel strongly that the “new” 90.2 should be a leader among energy codes and standards by providing more stringent energy-efficient requirements than the IECC, and not be “just another energy code.”

Also expressed were concerns about the proposed multiple prescriptive paths, including comments by WDMA because of the limitations put on allowable fenestration area and the proposed allowance of equipment trade-offs. Additionally, having four different sets of energy performance requirements in each climate zone could cause problems for fenestration manufacturers. Debate over the need and burden of another residential energy code is also in play.

Advisory Panel Convenes
Deciding some special attention to the project is warranted, ASHRAE’s board directed that a special advisory panel be appointed to provide “strategic” direction to the overhaul effort. That decision has in effect put development of 90.2 in a temporary state of limbo.

Currently there is no specific timeline for the panel to complete its work and provide recommendations, but it could very well be back to the drawing board for much of the document.

Jeff Inks serves as vice president, codes and regulatory affairs, for the Window and Door Manufacturers Association.

DWM
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