Secondary Author(s)

Chasar, David; Hoak, David; Chandra, Subrato

Report Number




Ventilation; Buildings; Residential


The addition of mechanical ventilation air to "tight" homes in hot and humid climates may adversely impact health, building durability, comfort and energy use by raising indoor humidity levels (RH) above 50%. High indoor humidity has been linked to microbial growth, building material decay, discomfort, and increased energy use (Moyer, et al, 2001). High indoor humidity in "tight" homes with mechanical ventilation has been documented in various Building America projects in hot humid locations (Rudd 2003).

The research described here quantifies the energy use, and humidity impacts of six mechanical ventilation strategies installed serially in a new, Energy Star Manufactured home laboratory (MHLab) with typical air tightness (5.4 ACH50) and simulated occupancy for a period of 14 days. Only one strategy (Case 4-Dehumidifier) provided ventilation meeting ASHRAE Standard 62 and maintained the indoor humidity lower than 50%.

Date Published


Local Subjects

Buildings - Residential; Buildings - Ventilation


FSEC Energy Research Center® Collection



Rights Statement

In Copyright