How to Mount an Exhaust Fan

Getting rid of attic heat keeps things cool in the rest of the house, too.

Stagnant air in the attic can reach over 150 degrees during the warm months, and the higher the attic temperature rises, the quicker the bordering rooms below heat up. To keep your home at a desirable temperature, install a powered exhaust ventilation fan. Here’s how:

Materials and Tools:

exhaust fan
thermostat
tape measure
drill
reciprocating saw
putty knife
flexible roof patching
roofing nails
caulk

Steps:

  1. Determine the location for a gable vent. The ideal location is about 2 to 3 feet from the roof ridge and 14 feet from the side of the house. Use a tape measure to find this location inside the attic. If the location is on or close to the roof rafters, adjust the location to fall between the two roof rafters and mark with a pencil. Drill a hole up through the interior ceiling out through the exterior roof.
  2. Trace the 14-foot-diameter template for the exhaust-fan hole about 1 inch below the lower edge of a roofing shingle with a marker.
  3. Use a reciprocating saw to follow the template design and cut an opening through the roof.
  4. Loosen the shingles along the top edge of the hole with a putty knife to slide the edge of the fan beneath.
  5. Apply flexible roof patching along the top underside edge of the fan with a putty knife to prevent rain from entering. However, don’t patch along the bottom edge. If moisture were to enter the fan, leaving the bottom edge open will allow the moisture to be released.
  6. Nail the fan in place with roofing nails, and use caulking to seal the nails. Then attach the fan’s housing unit.
  7. Turn off the main breaker panel and connect the power wires, matching the corresponding colors together. Run the wires to a thermostat to automatically control the fan. Test the thermostat to make sure the system is wired correctly. An incorrectly wired thermostat can run up your bill by running the fan constantly.

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