ASHRAE Standard 90.1, Energy Standards for Buildings Except Low-Rise Residential Buildings provides the mini-mum requirements for the energy-efficient design of most buildings and offers, in detail, the minimum energy-efficient requirements for the design and construction of new buildings and their systems, new portions of buildings and their systems, and new systems and equipment in existing buildings as well as the criteria for determining compliance with these requirements. Due to the reliance that the Department of Energy places on the 90.1 standard to supply the requirements for energy-efficiency in buildings, the committee meets four times a year to expedite its work. Developing the revisions and acting on comments to the proposed revisions is ASHRAE’s 90.1 Special Standing Project Committee. The committee’s fall meeting was held on October 4-6 in Chicago.
Addressing the exterior of a building is the 90.1’s Envelope Subcommittee which meets in conjunction with the full 90.1 committee. This subcommittee had a very lengthy agenda of very complicated topics including thermal bridging, storm windows, new climate data, high speed commercial garage doors, and commissioning to mention just a few.
One of the more important actions was consideration of the public comments on providing an R Value for air cavities. Currently, ASHRAE 90.1 requires that this air space be at least one half inch and must be enclosed. At an earlier meeting, EIMA questioned whether this space had to be over ½ inch and sealed. Rushing in an attempt to finish its long agenda, the subcommittee agreed that air spaces just need to be enclosed on all sides and not sealed. This brings back the possibility that EIFS could claim its drainage plane as an enclosed space, particularly since, Dr. Dave Yarborough, formerly of Oak Ridge National Laboratory again cited a study that he did that shows that an enclosed space, no matter how small it is, can contribute to a wall’s R value. EIMA will continue to pursue this issue.