Secondary Author(s)

Sherwin, John

Report Number




Attics; Buildings; Ducts; Residential; Air Quality; Ventilation


Florida Solar Energy Center (FSEC) has analyzed measured summer attic air temperature data taken for some 21 houses (three with two different roof configurations) over the last several years. The analysis is in support of the calculation within ASHRAE Special Project 152P which will be used to estimate duct system conductance gains which are exposed to the attic space. Knowledge of prevailing attic thermal conditions are critical to the duct heat transfer calculations for estimation of impacts on residential cooling system sizing.

The field data was from a variety of residential monitoring projects which were classified according to intrinsic differences in roofing configurations and characteristics. The sites were occupied homes spread around the state of Florida. There were a variety of different roofing construction types, roof colors and ventilation configurations. Data at each site were obtained from June 1st - September 30th according to the ASHRAE definition of summer. The attic air temperature and ambient air temperature were used for the data analysis. The attic air temperature was measured with a shielded type-T thermocouple at mid-attic height, halfway between the decking and insulation surface.

The ambient air temperature was obtained at each site by thermocouple located inside a shielded exterior enclosure at a 3-4m (10-12 foot) height. The summer 15-minute data from each site were sorted by the average ambient air temperature into the top 2.5% of the observations of the highest temperature. Within this limited group of observations, the average outside air temperature, attic air temperature and the coincident difference was reported.

Date Published



Reference Publication: Parker, D., Sherwin, J., "Monitored Summer Peak Attic Air Temperatures in Florida Residences," Presented at The 1998 ASHRAE Annual Meeting, Toronto, Canada, June 20­24, 1998.

Local Subjects

Buildings - Air Quality; Buildings - Attics; Buildings - Ducts; Buildings - Residential; Buildings - Ventilation


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