Report Number




Cooling; Buildings; Ventilation


An experimental study was carried out in the summer of 1991 to investigate the natural cooling potential of use of a whole house fan in Central Florida's hot and humid climate. The residential building, in Cocoa Beach, FL, is typical of much of the existing housing stock in Florida: a concrete block structure with R-11 ceiling insulation. The building was ventilated with all windows open during the three month summer test period (June-August). Air temperatures and relative humidity inside the home interior along with exterior meteorological conditions (insolation, wind speed, air temperature, relative humidity) were scanned every five seconds with integrated averages recorded on a multi-channel data logger every 15-minutes. The house was naturally ventilated during the first half of summer. After a significant period of pre-retrofit summer data had been collected characterizing the building's thermal response, a 24" whole house fan was installed. The house was then force ventilated during evening hours for the remainder of the summer to establish potential of whole-house fans to improve interior comfort conditions. The electrical consumption of the fan was measured at both available fan speeds.

Measurements revealed that the building interior was 3 - 6°F cooler during the evening hours after the whole house fan was operated. However, data also showed that nighttime humidity levels rose: relative humidity increased from 74% to 83% during the nighttime period where fan-powered ventilation was used. Using the data results, an analysis was performed using Orlando, Florida TMY data to see how limits to whole house ventilation based on humidity and temperature conditions would affect the potential of such a cooling strategy.

Date Published



Buildings - Cooling; Buildings - Ventilation



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