Admitting Air Into The Attic

Hot air exhaust vents located at the peak of the roof allow hot air to escape.

Admitting air into the attic.

In order to accomplish this an adequate venting system must be in place to vent the roof by allowing air flow to enter through soffit intake vents and out through ridge vents gable vents or louver vents. Gable end vents installed near the peak of a gable end this screened vent can allow hot air to leave the attic or fresh air to enter depending on prevailing breezes and temperature conditions. If you have air admittance valves in the attic and they fail to close then it is always possible that the air handler can draw in the sewer gases as they escape and distribute them through the house. In these rare cases plumbers use an air admittance valve.

Outlet vents allow the air to escape from your attic and are installed at a higher elevation. Air admittance valves aka studor vents are negative pressure activated one way mechanical valves. Roof vents ridge vents and gable vents are used as outlets in the attic. If this contaminated air gets sucked into the living space it can cause health problems for the occupants.

Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic. It may seem counterproductive to go to the trouble of improving attic insulation only to then add vents that admit outside air into the attic but fresh air plays a vital role in roof health. Cold air doesn t hold as much moisture so it condenses on the roof deck. This prevents cold outside air from traveling through the attic and into the living area of the home.

Air from the living space below can carry water vapor into the attic hitting a cold place in the attic and causing rot and mold growth. If a bath fan dumps into the attic that is very warm very moist air entering a cold space. Used most commonly at an island sink or vanity the vents are also located in the attic to prevent the roof penetrations as seen above on the front roof line elevation. These vents are installed directly into the blocking between the exposed rafters.

In texas the builders place the air handlers for the heating and cooling systems up in the attic.