How to Wire the Wall Switch

NOTE: This post does not apply to the Kohilo 2.8

All AirScape models, except the Kohilo 2.8, use low voltage controls (24 volt) to turn the unit on/off and switch between high and low speed. Never wire line voltage to your wall switch.

Run 18-22 gauge wire (x3) from the WHF to the wall switch location. Attach the 3 wires to the control board at the screw terminals COM RED, START BLK, and HI SPD BLU/WHT.

Connect the 3 wires to the wall switch (see below). We have pre-wired wire leads to the wall switch to indicate the wire locations. The wire leads correspond to the control board as follows: RED to COM RED, BLACK to START BLK, and WHITE to HI SPD BLU/WHT.


TOP 5 – Things to consider before installing your WHF

(1) Sizing – Size is important when it comes to a whole house fan since air movement is what will be cooling your home. You want to move just enough cool air to grab heat as it radiates out of the building materials. If you don’t move enough air the heat will radiate faster than it can be removed. Check out our Sizing Calculator to determine which WHF is right for your home

(2) Attic venting – The whole house fan will be forcing air into the attic….. it needs a way to escape. If you don’t have enough attic venting the performance of your WHF will be reduced. This is because the majority of its work will be put towards pushing air out of the attic instead of pulling fresh air in through your open windows. Each AirScape model has a certain amount of venting required so it can operate optimally. Use our Attic Venting Calculator to determine how much venting you have.

(3) Location – Is important. Ideally you would install the WHF at the center of the house at the highest point. If your home was a two-story square building with equal window distribution you would mount the unit in center of the attic floor, enabling you to open all windows equally to achieve even cooling. Offsetting the unit one direction or another will change how you open windows. This is not an exact science and will take some trial and error to determine how best to open windows to optimize the cooling in your home.

(4) Attic clearance – Not all attics are created equally. It is a good idea to determine the amount of attic clearance before purchasing an AirScape. All of our models have different clearance requirement. Check out the installation manuals for exact install dimensions.

(5) Power – Is there power in your attic? Every AirScape model comes with a ten foot power cord which we recommend plugging into an outlet instead of hard wiring. You should also take into consideration the amp requirements for the AirScape you are installing.

Unique and Challenging Installs – introduction

Did you find your install particularly challenging because of your attic configuration? Did you have a unique install that went beyond the traditional install method? Or are you just proud of your DIY project? If you answered yes to any of these questions we would love to see your installation photos. Hopefully, your unique or challenging install will help someone overcome an obstacle in their installation or just show them what’s possible beyond the norm. With that being said, we are starting an ongoing blog series on unique and/or challenging installs. This series is open to both home owners and installers.

So, if you feel that your installation could be helpful, please send your photos and answers to the questions below to:

What was the most challenging part of the installation?

On a scale of 1 to 5 how difficult would you rate this installation? (1 easy – 5 difficult)

What advice would you give to someone doing this installation?

How much of a “Do-it-yourselfer” are you? ( 1 what’s a hammer? – 5 fix everything myself)

Sound Reduction part 4 – Ducted Models

The final step on our journey of sound reduction brings us to ducted AirScape models. As you already know the ducted design of the 2.5 WHF, 2.5e WHF, 4.4e WHF, 4.5 WHF, and the Kohilo 2.8 allow for maximum airflow with a minimum of noise. Improper installation of these models can increase their sound levels. We touched on this subject earlier in the blog “4.5 Installation – Maximize Airflow, Minimize Noise.” There are a few things you need to consider when installing a ducted model.

90 DEGREE BEND –  The 90 degree bend should be as smooth as possible to maintain the 20″ diameter of the ductwork. Kinking the ductwork will increase the sound level and reduce airflow because the air does not have a smooth path to the fan.

EXTENSION –  It is important to extend the ductwork as far as possible away from the damper box. This needs to be done without distorting the 90 degree bend in the ductwork. Extending the ductwork fully moves the sound source (the fan) to the farthest point from the living space.

D-RINGS –  The 2.5, 2.5e, and 4.4e fans have D-rings which are used to hang the fan from the attic rafters. Only 4 of the 8 D-rings are used in the installation. The unused D-rings should be taped down to avoid excess rattling.

PART 1 / PART 2 / PART 3 / PART 4

Sound Reduction part 3 – Raised Frame w/ Ductboard

The next logical step for sound reduction is to combine the raised frame concept and add the duct board mentioned in part 1. In the following steps we’ll show you how to do this type of install.

STEP 1:  First we created two frames with inside dimensions of 14.5″x22.5″ using 2×4’s.

STEP 2:  Next we made a box using the two frames from step 1 and 3/8″ plywood. For this example we made our raised frame 17″ tall using (2) 25.5″ x 17″ and (2) 18.25″x17″ pieces of plywood. The vertical clearance of your attic will determine how tall of a box you can create. The picture shown is with one side removed.

STEP 3:  Position the box over the framed opening and secure. Caulk all of the seams and gaps of the newly constructed raised frame. Attach the provided gasket to the upper frame of the box. Line the box between the 2×4 frames with duct board. In this example we used (2) 24″x10.75″ and (2) 16″x10.75″ sections of duct board. We decided to go with a friction fit, but adhesive or screws with flat washers would work as well.

STEP 4:  Position the unit on top of the raised frame (1.7 shown). Secure using the provided screws. From the living space caulk all the gaps between the unit and the framing. You can now follow the remaining steps in the installation and operation manual to finish your install.

PART 1 / PART 2 / PART 3