• Last Updated:
  • Jul 13th, 2019 11:39 pm
Tags:
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes

Whole House Fan

Has anyone installed a whole house fan in their attic/ceiling to suck out the hot air especially from the upper floors of their home? Asking for Toronto summers... looking for info about cost and (ease of) installation?
20 replies
Deal Addict
User avatar
Oct 15, 2007
4774 posts
1971 upvotes
I’m sure the CFM requirement for this type of “system” to make any sort of impact would also require a make up air system to replenish the exhausted air, and the only place to get this air would be from outside which would defeat the purpose of what you’re trying to achieve. Without the Make Up air this would cause backdrafting
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide
Deal Fanatic
User avatar
Sep 1, 2005
8509 posts
3683 upvotes
Markham
I'm guessing these were a "thing" back in the early 60's because I used to have one in my current house until I took it out.

It had metal louvres on it. Thing was 3 ft x 3 ft and it moved a ton a air when I turned it on. In the summer, I could open up a few windows and turn that thing on and I could feel the draft of air going up the attic. It probably did wonders for cooling the hot air in the attic.

If OP wants to put one in, I think you also need to incorporate a very well insulated cover to prevent air from going thru there when you don't want air going thru there.
We're all bozos on the bus until we find a way to express ourselves...

Failure is always an option...just not the preferred one!
Deal Guru
User avatar
Feb 11, 2007
12983 posts
13111 upvotes
Oakville
OP, you should probably first look at improving your attic insulation, seal air leaks, shade windows, and look into growing greenery outside to provide shade. Also next time your replace your shingles go for a light colour.
If you get too much heat up stairs, run your HVAC fan constantly to even out the temps on all floors and close registers where you don't want the cooling.
Deal Fanatic
Jan 25, 2007
7445 posts
3557 upvotes
Paris
Whole house fans are a thing, even in cold climates. Have seen them on ask this old house. They are very very expensive.

My cousin had his old furnace taken out and I snagged the control board and fan before they scrapped it. We use it at the cottage so when the winter fire gets xx hot in the basement the fan turns on to push the hot air up a few floors. My other thought for it was to put in a draw system for when nights cooled and to draw in the colder air outside and push the hot out. I got the same effect at my place with a box fan in the front dining room, all other windows closed, and a window fan exhausting out our bedroom. Cools the place right down, but I’m only a raised bungalow.

I also run the furnace fan all night.
For sale: Ego 56V 5aH batteries, BNIB
https://forums.redflagdeals.com/ego-law ... h-2294293/
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes
TomLafinsky wrote: If I understand you correctly, you would like to have a fan installed in the ceiling of the second floor (or the attic) of your house so that in summer it could suck out the hot air inside your house. If that is correct, then you have a serious problem. In order to have air sucked out of your house you need to have air sucked in from the outside. And the air coming in would be hot/warm.

This could only work at night if outside temp is low and you wish to bring in cooler air inside. Though you better have some sort of air filtration where the air is allowed to enter the house otherwise your house will become dusty very quickly. I know because I experimented with a similar setup. Though in the end I gave up and instead let the a/c run all night when electricity is cheaper. Hope it helps.
Thanks, yes. That was the idea.... turn it on in the evenings when the outside air is cooler and leave the windows open so that the hot/stale air in the upper part of the house is flushed out through the attic vents and replaced with the cooler air through the windows.

Good point about the dust..... lots of construction in the area, so I suppose that would be a problem for me.
Last edited by barricuda on Jul 12th, 2019 9:00 am, edited 1 time in total.
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes
engineered wrote: OP, you should probably first look at improving your attic insulation, seal air leaks, shade windows, and look into growing greenery outside to provide shade. Also next time your replace your shingles go for a light colour.
If you get too much heat up stairs, run your HVAC fan constantly to even out the temps on all floors and close registers where you don't want the cooling.
For some reason my thermostat is wired in a way where I can't just run the fan. It turns on only with AC/heating (anyone else have this setup - I almost contemplated starting another thread for this question).... I wanted to experiment with closing/opening registers and cold air intake vents to somewhat simulate the effects of a whole house fan, but if I can run the fans only with the AC on then I don't have much to do except close registers in unused rooms like you said.
Deal Guru
User avatar
Feb 11, 2007
12983 posts
13111 upvotes
Oakville
barricuda wrote: For some reason my thermostat is wired in a way where I can't just run the fan. It turns on only with AC/heating (anyone else have this setup - I almost contemplated starting another thread for this question).... I wanted to experiment with closing/opening registers and cold air intake vents to somewhat simulate the effects of a whole house fan, but if I can run the fans only with the AC on then I don't have much to do except close registers in unused rooms like you said.
Definitely look into wiring it so you can run with the fan on. Makes for more clean air as well since it will be filtered.
With buying a new tstat if you have to.
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes
engineered wrote: Definitely look into wiring it so you can run with the fan on. Makes for more clean air as well since it will be filtered.
With buying a new tstat if you have to.
This is the video explaining thermostat I have -


At 0:12 and 2:44 it explains that the G wire (for the fan) will go into C terminal (for continuous power to the tstat?) which will deny me the option of running the fan by itself but "thats ok" because the fan will run with the AC and heating system.

Does this mean I need an extra wire in here to go to the G terminal to get back the ability to run my fan without the AC or heat? Or like you said replace the thermostat ?

Edit: Looked up some videos on how an existing 5th wire might be an option.... I'll take a look at the setup in my HVAC unit to see it if this is easily available for me and take it from there.
Jr. Member
Mar 31, 2013
176 posts
861 upvotes
Courtenay, BC
I have installed 3 whole house fans in 3 different houses, they work great if you know how to operate them, they are not a set and forget type of equipment. Two of the installs were in Medicine Hat, Alberta which can get damn hot in the summer.
Simply put, when it is cooler outside than in, open windows and turn the fan on.....it draws the cooler air thru the house and Forces it out thru the attic.....yes, it helps to cool off the living space (many times I would have to get up in the middle of the night and turn it off cause it got too cold), but to me the biggest advantage is it flushes all the hot air out of your attic, that is a huge heat sink, and if it never cools off your AC will run forever. In the "Hat", my neighbors house the AC would start at 10 am, mine wouldn't kick in till the late afternoon (exact same house)
A couple of crucial points, you must have enough venting in the attic, and never run it without open windows (it will create negative pressure, possibly blowing out gas appliance pilot lights).
Install is not that hard, but I am an electrician and have done plenty of carpentry work as well
See this website, my last two were the aircool classic model.....https://quietcoolsystems.com/whole-house-fan/ .....but I did have to get it shipped out of the US
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes
phantomfj wrote: ... but to me the biggest advantage is it flushes all the hot air out of your attic, that is a huge heat sink, and if it never cools off your AC will run forever. ...
Install is not that hard, but I am an electrician and have done plenty of carpentry work as well
See this website, my last two were the aircool classic model.....https://quietcoolsystems.com/whole-house-fan/ .....but I did have to get it shipped out of the US
Yes, this is exactly why I am looking into this.... all that air that get baked in the attic and the hot air that rises up and gets hotter in the upper floor because of the attic..... this seems like a nice solution to flush that out. I think there are enough Toronto summer nights/evenings that are cool and don't remain muggy/hot like the day to make this work. Just trying to determine if there is a rig/setup that makes it (relatively) easy to install at a reasonable cost.
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes
TomLafinsky wrote: Before you go to all this trouble you could experiment with this simple idea if feasible.
Thanks - I was exactly hoping for simpler rigs like this that would fit in the attic access space etc (I am a first time and new homeowner, lol). I think I have a friend who has tools and garage space to build a sturdier frame than the one in the video. I was also looking for fans with higher CFMs - so not maybe not an actual whole house fan, but something a little more industrial than the one in the video but would still fit the same size/frame to be a little more effective. The frame and fan would need to be joined as a unit to easily move it out of that space in the winter etc.
[OP]
Deal Addict
Jun 10, 2008
1075 posts
126 upvotes
TomLafinsky wrote: Of course you need to remove this contraption in the fall. I would suggest you measure the whole opening and go HD to buy a 1" piece of wood large enough to cover the whole attic opening. You could use an air mover similar to this one and let it hang from the piece of wood.

The drawback of opening the attic is that you will get more noise from outside. The advantage of using an air mover is that only a small hole in the piece of wood will be needed and therefore minimizing noise from the outside. The whole thing will not be pretty but if the access to the attic is in a closet then you shouldn't mind too much. Moreover there should be a light in the ceiling of the closet and you can connect your air mover to that.
Yeah, the attic access is in a closet, so that's great. Almost missed your link to the air mover :).... will definitely look into that... hopefully some good deals during prime day, lol
Deal Fanatic
User avatar
Sep 1, 2005
8509 posts
3683 upvotes
Markham
You have to seal the opening somehow during the winter or you'll get warm moist air going into the attic which is not a good thing.

There are days I wished I still had the whole house fan. I did what someone else said which is improve the insulation in the attic instead.

Hot air rises so it's always going to be hotter on that second floor unfortunately.

A cheap alternative to whole house fan is to buy a couple of box fans and run them in a window at night sucking air out of the second floor... It doesn't go thru the attic but it does exchange air.
We're all bozos on the bus until we find a way to express ourselves...

Failure is always an option...just not the preferred one!
Deal Guru
User avatar
Jun 12, 2007
14655 posts
3947 upvotes
London
barricuda wrote: ...,,I am a first time and new homeowner, lol). .. .
I would not do this.

Whole house fans date back to the 60s and the US. You are making assumptions based on how houses were built in the 60-70’s

Today, the energy standards mean that attics are much better insulated , especially in Canada. Isn’t it currently R60 minimum which is like 16-20” of fibreglass pink loose fill in the attic?

Not only that, but the attic air ventilation is much better today, especially with ridge line venting and continuous soffit air intakes. You don’t get really hot air trapped in the attic anymore
gr8dlr wrote: ..

A cheap alternative to whole house fan is to buy a couple of box fans and run them in a window at night sucking air out of the second floor... It doesn't go thru the attic but it does exchange air.
This is a better idea

Top