In their research paper they summarized data collected from 2001 to 2006 specifically analyzing the impact balanced attic ventilation has on moisture control in attics in hot, humid climates. In the study, Air Vent’s ShingleVent® II ridge vent (a copolymer, shingle-over ridge vent) was used for exhaust and Air Vent’s aluminum continuous soffit vents were used for intake. The research paper focused on data collected in 2006:
“A ventilated attic possesses many advantages for a hot, humid climate,” Porter and Mooney write. In particular the paper points out:
- Relative humidity remains well below that of the external environment
- Condensation on roofing members is rare
- Moisture is removed quickly
The researchers write: “A ventilated attic supports cost effective, energy efficient climate control of unconditioned spaces in hot, humid regions. …The resulting data describes a climate that maintains a steady resistance to saturation providing a solid barrier to the elements. This climate serves to remove moisture at a rate consistent with the prevention of mold and mildew growth, and in the event of moisture intrusion can alleviate damage to insulation and prevent seepage into the conditioned space. …It is possible that sealing the attic spaces entirely and insulating the structure would reduce the thermal heat transfer from an attic, but this would provide no outlet for moisture transported through porous roofing materials or past the ceiling plane. …This investigation concludes the conditions in a ventilated attic are stable through seasonal changes and promotes cost effective, energy efficient climate control of unconditioned spaces in hot, humid regions.”
Read the entire research paper: pdf Internal Microclimate Resulting from Ventilated Attics in Hot Humid Regions (404 KB)
Read our condensed version of the U of FL research: pdf Balanced Attic Ventilation Reduces Moisture Buildup in Hot, Humid Climates (1.16 MB)
