Unvented Attic Problems

More attic ventilation is good.

Unvented attic problems. Unvented conditioned attics were quite rare before the 1980s. Roof vents are for warmer climates. Areas with hot summers and cold winters can suffer the effects of both. Lots of gba readers have posted reports of this type of problem.

Among the early promoters of conditioned attics was joe lstiburek a principal of the building science corporation. Heat and moisture buildup in an attic cause predictable but different problems in hot and cold climates. Unvented attics do not experience such problems. The intent of this brief is to provide code related information about controlling moisture in unvented attics by installing a vapor diffusion port vent that would convey water vapor from an unvented attic to the outside when air permeable insulation materials are installed and can be verified as being in compliance with the related codes and standards for residential construction.

Attic ventilation myths that are off the charts 1. Here is a sampling. Heat is thus less likely to escape into an unvented attic from hvac equipment and if it does it will remain within the conditioned space. Unventilated attics can help to mitigate energy loss through leaky ducts or ceiling fittings.

However if moisture is able to enter the unvented attic space it may lead to roofing panel issues. Just like properly sizing your furnace and air conditioning unit you want precisely. When it s hot outside the sun beating down on the roof can increase the temperature in the attic.