Basic Overview: How to Install a Whole House Fan

It is fairly easy to install a Whole House Fan system by yourself, if you know how to use a drill, hammer and screw driver. I’ve done it myself and I would rate myself to be somewhat of a novice, when it comes to fixing and installing things around the house.

When it comes to the electrical hook up/wiring that may be a different story. If you have an outlet nearby you most likely could simply plug in the fan. Otherwise, you may want to hire an electrician. Definitely turn off the fuse in the electrical panel before doing any work on the circuits to avoid electrical shock. Use the following  general instruction at your own risk.

There are three main  types of WHF’s (Whole House Fans): direct, belt-driven and duct-fed. The first two are ceiling mounted fans and easier to install provided that they are small enough to fit between the roof joists. A duct-fed fan requires you to attach the motor/fan to the rafters of your roof.

Installing Unvented Ceiling Mounted Fans:

  • Location of rough opening for Whole House Fan

    Location of rough opening

    Choose the location of the fan. Usually a good place is a hallway somewhere in the center of your home. This way you provide a good flow of air throughout the entire living area. Avoid putting the fan close to an open window as the air will then only travel a very short distance which defeats the purpose of a WHF. Make sure the location you pick has good access from the attic with enough clearance and possibly a preexisting  electrical outlet nearby.

 

Use a cardboard cut-out template to determine the rough opening

Cardboard cut-out template

  •  Most WHF’s will come with a cardboard cut-out template that you can use to mark the rough opening in the ceiling. Go up into the ceiling and locate a good spot between the joists. You would need a keyhole or drywall saw for cutting a hole into the ceiling (size varies by type and model). A carpet knife or something similar will work in a pinch.

 

 

  • Use a drywall or keyhole saw to cut into the ceiling

    Use a drywall or keyhole saw to cut into the ceiling

    Ususally WHF’s come pre-assembled. Take the fan up into the attic and place it to fit the rough opening. Attach the fan to the joists, replace any insulation that was removed and screw in the grill from below.

  • Return to the attic to complete the electrical work. Again, this is the most dangerous part, so make sure you disconnect the electrical circuits before handling live wires. Use a volt meter to confirm that the circuit is indeed turned off. The electrical wiring for the fan requires 120 Volt grounded cable. Some models will actually come with a 6 ft. three prong plug that you could. DO NOT use an extension cord to get to an outlet beyond the 6ft. Novices should definitely consider hiring an electrician for any electrical work.
  •  SPECIAL CASE: Some WHF are too big to fit between your joists (16″ or even 24″ joists apart). Then you would have to cut one of the joists and reframe a box around the WHF. This requires structural changes to your home and you should definitely consider hiring a licensed contractor.

Installing Duct-Fed Whole House Fans

  1. All the steps from above apply…
  2. A duct-fed Whole House Fan keeps the noise away from the living space (QuietCool System)In addition a duct-fed fan requires you to hang the motor head of the fan from the rafters by fastening the metal strapping that is attached to the WHF. This is a fairly easy process but entails lifting a 15-30 lb heavy fan and keeping it in place while screwing it in. With a little ingenuity, you can find a way to keep it in position by propping it up with some boxes of sorts. That makes it easier and you can take your time attaching it securely.

Once the install is complete you can control the fan either by a wall switch, a digital or analog timer or simply by using a pull-line hanging directly from the fan. If you want to avoid complicated in-wall wiring, some models have the option to be controlled via wireless switches. See the Brand Comparison for the different options.

 

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