AirScape Engineer's Blog

The newest version of our control board has a master override or interlock. The interlock, which is now required by some building codes, effectively disables the WHF by closing the damper doors and turning off the fans. It is often used in conjunction with smoke detectors or mechanical systems located in the attic. The idea is that if the furnace turns on or the smoke detector goes off the WHF will shut down. This could slow down the spread of a fire or save $$$ if the furnace was accidentally turned on.

The interlock is integrated into our 24v digital controls on V4 of our control board. To use the interlock simply remove the two-pin shunt and run low voltage wire from the interlock screw terminals to the relay on the device that will disable the WHF. To activate the interlock the relay should interrupt the 24v current. Do not wire 120v to the interlock.

When activated a solid red LED will illuminate on the WHF control board. The fans will turn off and the damper doors will close. Once the interlock is disengaged, the LED will go out. The WHF can be restarted by flipping the wall switch off and on again or by using your remote.

When you call in with a tech support issue we will want to know which version of our control board is controlling your unit. This is important because it will help us properly diagnose what is going on with your WHF. In most cases we can determine the control board version if you give us the model information for your AirScape. The model is listed on a sticker found on the unit (near the junction box on the 1.7, 2.5, 4.5 and on the damper door of the 1.0). Occasionally the model sticker isn’t enough. If you are already going into the attic to write down the model information you might as well take a look at the control board as well.

The control board has had several different incarnations over the years. Please take a look at the photos below and identify your control board before you call tech support.

My control board looks most like: 1, 2, 3, 4, or 5 (Differences between 3 and 4 circled in red)

1 2

3 4

56

This summer we came out with the newest version of our WHF control board. The new control board has several new features which improve on the previous versions. It is now being phased into all AirScape models in production. The following are some of the improvements/changes made to the control board:

One of the biggest changes is how the actuator is controlled. The actuator(s) will now cycle the damper doors open before the fans turn on. We have also added LED indicators which indicate operation of actuator(s) and fan speeds. Programming your optional remote has become even easier with the new control board. Now all you have to do to mate your remote transmitter to the WHF is to turn the main power to the unit on and off by unplugging and plugging in the damper box power cord or turning the circuit breaker off and on at the electrical panel. We also added the ability to reset the remote programming as well.

Now, for all of the contractors or advanced users out there we added something for you too. The control board now has a master override or interlock. This is a safety switch that when enabled will turn off the fan(s) and close the damper doors. The interlock is now required by some community building codes to disable the whole house fan if for example a furnace turns on or a fire alarm is triggered. Please see future tech support blogs or give us a call for more information on the interlock.