1. Whole house fans work really good if/when there is cooler air outside which can be drawn into windows. If the air outside is hot the whole house fan will do little to cool things down.

2. Have you considered evaluating your current insulation system and determining if more/better insulation in the walls or attic might be a more effective solution?

3. Whole house fans can actually work fine without a powered gable vent. If there is sufficient vented space (gable vents, soffit vents, ridge vents) then the differential pressure caused by the fan will force that air out.

4. My feeling is that the gable vent is not likely working well BECAUSE you have other vents.

I live on the highest (3rd floor) level of a condo building. I have the 3rd floor AND the attic, triangular-shaped like the letter A. I have a non-working attic gable-mounted roof fan, which I’m considering replacing. The highest CFM that I see on the market is 1600 cfm. Is there any other HIGHER cfm Gable-Mounted fan with a thermostat?

Secondly, it gets extremely hot in my 3rd floor. I’m very interested in installing a Whole House Fan, but the smallest one I found is 4500 cfm. My square area of my home is roughly 1300 sq. ft., or so.

Here’s the BIG question for the expert(s): If I install a Whole House Fan of 4500 cfm, and replace my non-working attic fan with the 1600 cfm Gable mounted fan, then WILL THAT BE SUFFICIENT to move the hot air out of my attic AND cool down my 3rd floor and attic?
I have approx. 7 openings/vents in my attic, but most of them are only 12″x12″ vents/openings. The only biggest vent/opening is one, 16″x16″ just for one Gable-mounted attic fan.

I understand that 4500 cfm coming from the hallway into the attic is 3-times more pressure coming into the attic than what’s coming out of the attic (1600 cfm), BUT I have 5-6 other vents for air to come out of them: so would the excess 2900 cfm be able to get out of the rest of the vents of the attic?
If not, then what do you suggest? Are there any smaller Whole House Fans, less than 4500 cfm? Is it really worth getting a smaller fan: because it may not cool my place with as forceful “wind-power” as a 4500 cfm fan? Are there smaller gable fans that will fit the 12″x12″ openings that I have? And what is the strongest fans (in cfm) that fit those dimentions?

When answering, please provide as much information as possible: SKU numbers, full barcodes, manufacturer names and complete title of fan(s). Thanx Aug 27, 2010

I like in the Midwest. Summers often include two months hovering around 100F!

A friend of mine living in a vintage bungalow home showed me what an efficient Whole House Fan can do. The only thing he uses his AC for is to control humidity sometimes.

It is common to have basements where I live. My friend draws his air from his nice cool basement. It’s like free AC!

I just bought a 4500 sq ft two-story, with full basement. I will be installing a Whole House Fan and hope to limit my use of AC to very little.

My basement is a full basement and keeps to a nice cool 68F even on days over 100F. I will be drawing air from the furthest location (in the basement) from my stairs through a basement window drawing from a shady part of the house.

Be smart folks, and save yourself a fortune! With a little engineering you can eliminate those high summer energy bills almost completely!

Last… Whole House Fans can also help keep upper floors cool when your AC below isn’t adequate. You have to be smart about how much pressure you are drawing, but even a small pressure will help add cooler air upstairs without adding a window unit. In order to not be wasteful, you must make sure your vented air source going in to your house is relatively cool. You don’t want to be trading cool air for warm air!

Thanks