Whole House Fan

Other Devices & Integrations Climate Control & Temperature Sensors
1

I am relatively new to Zwave. I have a garage door tilt sensor, a lock, and some light switches (with more on the way).

We have a 30 year old house that has an old whole house fan in the attic that works great to help cool the place. There are two different 1 gang panels that control it. One controls fan speed (which we’ve set once and never changed) and the other is supposed to be a timer and also controls on/off. That switch works fine to go from on to off (or vice versa), but the timing function on it hasn’t worked since we’ve moved into the place a couple months ago. You can set it to one minute or 4 hours and it never counts down or shuts off on its own.

That being said, I would love to replace the timer with something zwave, so that I can turn it on/off remotely and actually set a timer on it. I’m a little confused by the myriad of choices out there and wondered if anyone had any recommendations by exactly what to put there?

Thanks!

2

You can replace your timer switch with an Appliance (On/Of) switch.

See my post:
http://forum.micasaverde.com/index.php/topic,31398.msg226668.html#msg226668

I control my Fan by looking at:
Window Sensors (Need some windows open)
Thermostat (Temp Setting - Turn Off Fan at this inside temp)
Outdoor Temp (Do not want fan on if Outside Temp > Inside Temp_

3

I’ve never heard of a whole-house attic fan… but is it safe to assume it’s run on a 120V (and not a 240V) motor? If so, definitely an appliance switch or even a universal module.

If not… you could use a 240V contactor with a universal module/Fibaro module.

4

So can you send me a link to what you’re suggesting? All the appliance switches I can find seem to be the ones you plug into the wall and pass a plug thru from your appliance. I was hoping to replace the timer module in the wall with something directly. (see attached)

I assume with those I can no longer manually control the timer? It would all have to be done thru the Vera? Unless I just wanted on/off.

@delta, yeah, whole house fans are nice. If you open a couple windows they create a vaccuum and suck all the hot air out of your house and pull in the cooler air from outside. Supposed to radically reduce AC costs. AFAIK, it’s 120.

5

If it’s 110V use something like:

6

These were popular in Florida pre A/C days. When I was house hunting I saw several ones in houses built before mid 70’s.
Not for use in the heat of summer but great if it’s low 70’s or less outside.

Not zwave but this would replace your existing broken one.
[url=http://www.homedepot.com/p/Master-Flow-12-Hour-Timer-for-Whole-House-Fans-WHT36/100097793]http://www.homedepot.com/p/Master-Flow-12-Hour-Timer-for-Whole-House-Fans-WHT36/100097793[/url]

The only Zwave option is a standard Z-Wave On/Off switch that you control from Vera with Scenes that determine how long the fan will be on. There is no Zwave compatible equivalent of this.

7

Thanks to you both!

Yeah, BOFH, that’s where I started, and then I began to think… “Hmm. controlling this from my phone sure would be nice.”

Richard, that looks great. Just one question because I’m relatively new to this. Is there a reason that a normal dimmer switch (like I’ve used on my light switches) wouldn’t work? Is it just the power draw? I don’t mind spending the extra $$ for this one, but just curious.

8

A dimmer switch will work not for this as they are not made for this kind of loads. It has to be a on/off switch like eg the one Richard posted or this one. [url=http://www.lowes.com/pd_339577-1353-45637_0__?productId=3707736]http://www.lowes.com/pd_339577-1353-45637_0__?productId=3707736[/url] (Don’t let Iris fool you, this is a zwave switch)

You could have your cake and eat it too you know. Replace the existing timer and place a Zwave on/off switch next to it in parallel. Then you could have it both ways. Or perhaps use one of the below in parallel with the timer? I’m pretty sure that should work and is a nice and clean look.

[url=http://www.amazon.com/Aeon-Labs-DSC26103-ZWUS–Wall-Controller/dp/B008VWBNAU]http://www.amazon.com/Aeon-Labs-DSC26103-ZWUS--Wall-Controller/dp/B008VWBNAU[/url]

9

Hmm. I think I really like that idea. I thought about doing something like that but wasn’t sure. I might have to give it a shot!

10

Make sure you check the power ratings of the fan compared to the Z-Wave switch.
The AEON device will not likely be able to handle your hole house fan load.

In particular pay attention to startup and full load amps of the motor.

11

Rather than try to find a Zwave device that will handle the Amps and surges related to whole house fans, you can avoid all that with a simple beefy relay. Power the relay with your Zwave device :-).

I did this years ago for my whole house fan when I wanted to control the fan with a simple thermostat. Worked a treat!

12

^this would be my suggestion. I actually have the unused hardware you need to do this, if you’re interested. One 40A, 240V contactor–which would work just as well for 120V–and a universal module. I had planned to use it to control my water heater, but ended up moving to a place with a gas water heater.

13

Thanks for the help! I already ordered what I think I’ll need. So we’ll see how it goes!

14

I added my code to this forum message. It’s a good start for putting logic into running a whole house fan rather than the AC.
http://forum.micasaverde.com/index.php?topic=25707.0

15

I have a similar setup with the whole house fan in my old house. The power wires that go to the speed switch went to a plug and outlet so I just used a lamp module. Worked great. You guys that don’t know what a whf is make me laugh. They are widely used in California where the temp at night cools down significantly.

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