In this video, This Old House general contractor Tom Silva helps a homeowner install an energy-efficient whole-house fan.
1. Identify an appropriate location in the attic to install the fan. It should be close to an electrical outlet, between two ceiling joists, and not near any pilot light.
2. Remove the insulation from between the joists in the fan's location.
3. Install solid blocking between the ceiling joists. Cut the blocking from the same 2x lumber as the joists.
4. Fasten the blocking by driving 3-inch drywall screws through the joists and into the ends of the blocking. Use a layout square to ensure the blocking is square; that is, perfectly straight up and down.
5. From the room below, use a drywall saw to cut the ceiling opening for the fan. Use a wet/dry vacuum to catch the dust while sawing.
6. From inside the attic, apply a continuous bead of acrylic latex caulk along the top of the joists and solid blocking.
7. Set an insulated isolator on top of the joists and press it down into the caulk.
8. Secure the isolator by screwing its metal tabs to the joists with 1¼-inch drywall screws.
9. Run a continuous bead of acrylic latex caulk around the top of the isolator, then set the whole-house fan on top.
10. Secure the fan by driving 1-inch sheet-metal screws down through the fan's flange and into the isolator.
11. Plug the fan's power cord into the nearby electrical outlet.
12. From the room below, screw the louvered vent to the fan to conceal the ceiling hole.
13. Use the handheld remote control to operate the fan.