Attic Air Flow Diagram

Whole house fans powered attic fans.

Attic air flow diagram.

An outdoor unit which houses the fan condenser and compressor and an indoor unit which holds the evaporator and fan. Attic hvac systems save space. Your home is a heated conditioned area that is designed to keep air in. Increased ventilation will make the entire roof cold and reduce or eliminate ice dams.

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. Hot air exhaust vents located at the peak of the roof allow hot air to escape. The ice traps water behind it allowing the water to seep back under the shingles and leak through the roof. We insulate moisture proof and throw up every barrier to heat and cold.

Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic. 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. 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. Most updated central air conditioned homes have a new air conditioner split system meaning the ac is broken up into parts.

Water is insulation s enemy. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. In winter the natural convection air flow through the attic prevents ice. The insulation will resist heat transfer into the house.

The super heated air inside the attic can warp and damage roof shingles if not forced out through gable or roof vents. 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. Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be. Proper insulation and air sealing also keeps attics cold in winter by blocking the entry of heat and moist air from below.

A different animal first think of your attic and roof as a separate entity from your home. Box out light fixtures. If your attic is well insulated the insulation might be plugging the spaces between rafters just above exterior walls. Well mainly it s a way to save space.

The solution is to add baffles which allow air to flow past the insulation photo 9. Misconceptions about the air flow in your attic can lead to thousands of dollars in damage and repair costs.