June 5, 1998


A residential attic model, contained in the finite element computer program FSEC 3.0, was empirically aligned with measured attic data from three roof research facilities in Florida and Illinois. This model was then used to simulate hourly space conditioning energy use, and roof and attic temperatures, for peak cooling days and annual weather, for Orlando, Florida and Las Vegas, Nevada. Results showed that, when compared to typically vented attics with the air distribution ducts present, sealed cathedralized attics (i.e. unvented attic with the air barrier and insulation at the sloped roof plane) can be constructed without an associated energy penalty in hot climates.