Attic Air Circulation

That said venting an attic is not always a complete energy efficient solution.

Attic air circulation.

As the attic space warms up from the irradiation of the sun the ventilation port opens wider to allow the solar fan to move more warm stale air out of the attic area. Baffles are available at home centers. Most solar attic fans are surface mounted meaning that they are installed directly through the roof surface where they are most efficient. That means air can t flow from the soffit vents to the roof vents.

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. Whole house fans powered attic fans. Soffit vents may leave air trapped at the top of your attic.

Proper air circulation in the attic is all about preventing moisture buildup. If your attic is well insulated the insulation might be plugging the spaces between rafters just above exterior walls. 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. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Solar attic fans do just that. Intake vents located at the lowest part of the roof under the eaves allow cool. Increased ventilation will make the entire roof cold and reduce or eliminate ice dams. Gable vents may circulate air through only a small percentage of your attic.

During the summer soffit and gable vents draw cooler air from outside the house to replace hot air that collects in. The insulation will resist heat transfer into the house. If the attic is insulated with fiberglass batts just pull back any that are blocking the flow of air. Attic ventilation works best in mild to cold climates.

The ice traps water behind it allowing the water to seep back under the shingles and leak through the roof. In hot humid climates ventilation will not keep an attic cool although air circulation combined with an attic fan can help reduce cooling costs. 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. Static roof line vents are effective for ventilation but generally aren t recommended due to issues with leaks.