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House Fan Controls?

Patrick_North Member Posts: 249
Whole house fans sure have come a long way. Even before this recent heat wave i've been thinking about getting one of the newer models with built-in insulation panels that open up before the fan kicks on.

I'm wondering about controls, though. Most of these units just use a standard on/off switch but this sounds pretty inconvenient. I'm imagining something with dual thermostats to kick on when outside temps dip a set # of degrees below inside temps, and then shuts down when the inside and outside temp near equillibrium or some such scheme.

Sounds potentially complex. Anyone ever set up something like this? Suggestions?

Thanks all, and stay cool-



  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    Solar Control...

    What about using a solar air collector control. Place the collector sensor in the house, and the storage sensor in the OSA. When it is warmer inside than outside, the fan turns on, moving inside air out, replacing it with cooler OSA. When the differential in temperature approaches each other, it turns off. you will need a master low setting room temperature control to keep it from running during inclement weather.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Patrick_North
    Patrick_North Member Posts: 249
    Specific product?

    Cool, thanks!

    Is there some off the rack product I could buy like what you describe, or would this need to be cobbled together somehow? Brand/model reccommendations would be appreciated.


  • Patrick_North
    Patrick_North Member Posts: 249

    Well, I've looked into the solar hot air controls and all that I've seen seem to be identical to attic vent thermostatic controls with a simple on/off at a set point.

    So now I'm wondering about patching something together with two thermostats. something like this:
    1. Thermostat A is set to cooling mode and is placed inside. Once inside temps reach a max point (say, 80degrees) the thermostat clicks ON.
    2. Thermostat B is set to heating mode and has a sensor outside. Once outside temps dip below the same set point (or perhaps a bit cooler) it too clicks ON.
    3. The fan operates when boths controls are ON.
    Does this sound right? I'm just a homeowner, so if I wanted to contract a pro to set this up how would I phrase this? Are there better, more specific controls to use?

    Thanks all,

  • eluv8
    eluv8 Member Posts: 174
    Heat Timer Control

    You might be interested in this control for what you are doing. Perhaps overkill but maybe not if you go two stage. They also have a single stage.
  • Jack
    Jack Member Posts: 1,045
    My house has a whole house fan

    While you could make any number of controls for it, I prefer the manual mode. I kinda gauge when the sun has delined enough to bring the temp down by operating the fan. I may then go around and close some doors and/or windows to direct the air where I want it. 18yrs later, I've kinda got it down.
  • hot_rod
    hot_rod Member Posts: 14,785
    any solar

    differential control will do that. It kicks on when outside is so many degrees (adjustable) above inside, off when it cools the adjusted amount. Most only switch a 1 amp load so you would need an isolation relay.

    Depending on what you want to spend some have timer functions and yearly calendar.

    With some calculations you could even have the control track the amount of energy it removes in KWh.

    This one shows an optional remote readout, which you could build a new display window to show a blower :)

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
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