Instructables

Cooling Your House - Whole Housefan & Attic Fan Combo

Picture of Cooling Your House - Whole Housefan & Attic Fan Combo
I am never home. I have to many thinks to do, hobbies, work, family, a small business we run. we all know it as life. I have the oldest A/C system in the universe. It cost to much to run and it dosent cool the house. I can leave it on all day and I will come home and find it is 84 degrees inside 73 degrees outside. So the A/C is not worth it. We pulled out the fans out of the closet. 2 in each bedroom one in the sliding glass door one in the front door (pushing in or pulling out of the window) and 4 just moving air in the condo. just attempting to bring the cool night air in to our for lack of better words Sweat Lodge. It was time for a change after having to get up in the middle of the night to shower with cool water just to fall back asleep.
 
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Step 1: Attic Fan

We have great isolation in our attic. R40 is no joke (yes, the access pannel is insolated with R40 as well). Yet as I pushed the access to the attic up I was met with a slap in the face of 100+ degree air. This was just insult to injury. It was only 80 somthing outside and I would have thought the new roof and 6 extra turtle vents would have helped but it didn't. We will get to that in part B of this solution.

Step 2: Measure Attic Access Opening

Picture of Measure Attic Access Opening
This is important to select the proper materials for this project. My measurements where 24" x 30". The side to side is the most important. I need at least 3 inches on each side for the fan assembly to rest.

Step 3: Choosing Proper Fan For Square Footage

The math is actually quite simple. its your square footage x ceiling height. My dimentions where 800sqft x 8 foot celings. A 800 square foot house with an 8 foot high ceilings has 6,400 cubic feet of space (800 sq/ft area * 8 ft = 6,400 cubic feet). A good rule of thumb is 3 to 4 times an hour.
SinAmos11 months ago
And? You should add the temperature differences, so you can share how effective your fans are at cooling the house.
12141214 (author)  SinAmos11 months ago
I thought about doing this but I decided against it. Mainly due to the fact that the inside of the house will be the same temperature as outside when the fan is on. Those nights when I made this the house was 91 degrees and the outside air temperature was 86 degrees so it wasn't much of a difference at the time. It defiantly would be now considering its 60 degrees out, but the fan is not necessary on night's like this. What did cool us down on those hot nights was the consistently moving air. The light breeze made those 86 degree nights feel like 70 degrees. I just wasn't sure how to show this aspect. I did a smoke test that worked great but it wasn't that visible in the pictures.

If you have any ideas let me know. I will defiantly modify this post.