Attic Air Flows

Whole house fans powered attic fans.

Attic air flows.

Air flows in through the soffit vents and out through the roof vents. Fans and vents may be installed on the roof system that will draw the air out of the attic space and exhaust it to the exterior. Soffit vents may leave air trapped at the top of your attic. The biggest chore is adjusting the air flow valves known as dampers in the ductwork.

For the best results place roof ventilation near the roof s peak and soffit vents in the eaves. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Static roof line vents are effective for ventilation but generally aren t recommended due to issues with leaks. Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Intake exhaust airflow in a house attic square footage 2 square inches of exhaust and square inches of intake net free area nfa needed. And when the ductwork is in an attic fine tuning the process can be a system of trial and error demanding time. The most common mistake homeowners make when installing insulation is to block the flow of air at the eaves.

The ice traps water behind it allowing the water to seep back under the shingles and leak through the roof. Grab a flashlight and inspect your attic during the winter. Make sure there is air flow from the eaves. Vents come in various styles.

These ice dams form when warm attic air melts the snow on the roof and the water refreezes along the colder edge of the roof. If you see dampness or frost you need better roof ventilation and some attic vents. If the soffit of your home isn t perforated to allow air movement either replace it with perforated soffit or install round air vents under the eaves to allow air flow. In the summer natural air flow in a well vented attic moves super heated air out of the attic protecting roof shingles and removing moisture.

These fans may be controlled by a switch or a thermostat which detects heat build up in the attic space and automatically exhausts the attic space. The insulation will resist heat transfer into the house. One common problem is caused by ice buildup along the edges of a roof. Gable vents may circulate air through only a small percentage of your attic.