Blowing Air In The Attic

Air sealing air leaks are a major cause of losing warm air.

Blowing air in the attic.

Of clearance above the fan. If you have a complex attic with lots of ductwork bathroom fans and ceiling fixtures more air sealing will need to be done. Whether it s 110 f or 130 f there s not much difference in the amount of heat flowing from the attic to the living space below. Hot air exhaust vents located at the peak of the roof allow hot air to escape.

Just make sure the ceiling is airtight and fully insulated and the temperature in the attic doesn t matter much. I went up into the attic to investigate and i did notice that in 2 places labeled with red arrows there is ice cold air simply blowing out from the air handler into the attic. Handy homeowners can install blown in insulation in the attic. As the air leaves it creates negative pressure behind it sucking in cool air from below into the soffits and creating a self repeating ventilation process.

1 the first is out of a white pvc pipe that has an odd section sticking straight up but it s completely open so the cold air is coming out of the top of that. This sends hot air up and out cooling your house and your attic. Even if your roof already has ridge vents and plenty of ventilation built in it s a good idea to install gable fans or roof fans to help blow hot humid air out of the attic. And you can blow it easily and quickly into odd shaped spaces in an attic where access is limited and dragging up batts is tough.

Attic ventilation fans also tend to be quite energy efficient in terms of their own operation. Put it in an attic full of blown insulation. These fans are commonly mounted in an upstairs stairwell or hallway ceiling where there s at least 3 ft. Typically the cost for air sealing runs from 350 to 1 500.

Use expanding foam or caulking to seal any air leaks in your attic. Blowing insulation into walls is best left to the pros because it involves drilling into stud spaces that may contain electrical. Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic. Blown in cellulose has a higher r rating and is less expensive than either blown insulation like fiberglass attic insulation or fiberglass batts.

Cellulose blown in ceiling insulation is a good choice for diyers. However with that understanding that creating negative pressure in the attic can cause all kinds of problems sucking out air from the conditioned space possible back drafting of combustion appliances etc he has come up with the idea to blow air into the attic instead i e creating positive pressure to force the hot air out.