Underfloor Air: Rising Above a Checkered Past

It was a tough year for underfloor air distribution (UFAD) specialists. Touted for nearly a decade—including in EBN—as a radical breakthrough that would use far less energy and make occupants happier than conventional HVAC systems ever could, UFAD (which is closely associated with access or raised flooring systems) was suddenly banned by the U.S. General Services Administration (GSA) in 2007 because of outrageous air-leakage rates.

“That was a pretty big false alarm, in our view,” argues Tom Webster, P.E., a project scientist at the Center for the Built Environment (CBE) who works closely with industry practitioners to research comfort and building-science issues with UFAD. “The primary cause for that assessment at that particular time was that construction practices were really pretty poor. A lot of contractors were just starting out in the business and didn’t understand underfloor air well enough.”