Exhaust Fans in Skylights--good or bad idea?

Old 10-27-18, 03:55 PM
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Exhaust Fans in Skylights--good or bad idea?

I have a 1600 sq. ft. warehouse with 3 solid walls and one wall that has two doors. Getting air to circulate in the space is nearly impossible. I have a plan but wanted to see if it was a good idea first.

I have 5 skylights that extend up from the roof of the warehouse. They are about 2 ft. x 4ft and extend up about 2ft. at the tall end. There are two at the back, one in the middle and two at the front.

I can't cut holes in the roof because it's a membrane roof and the homeowner's policy is very specific about it. However, if I cut holes in the highest part of my skylights and mounted exhaust fans, I should be able to circulate the air pretty easily.

Not only that but for more than half of the year so far, the temperature outside our loft has been lower than inside our loft. Often, we are running the AC unit when opening a window (which we don't have) would suffice.

By placing exhaust fans in the rear skylights, I think we can effectively draw air in from the doors. This could save us a ton of money and help avoid all of the noise that accompanies our 5 ton AC with too small ducts.

Will this work and if so, where can I get some decent, inexpensive exhaust fans for my skylights. Probably between 10 and 18 inches. Any other considerations?

Thanks in advance for any advice.
Old 10-27-18, 04:20 PM
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Cutting skylights doesn't sound like a good plan to me.
We'd at least need to know what they look like..... How-to-insert-pictures
Old 10-28-18, 07:55 AM
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I've got a 35' x 45' two-story barn converted from "attic storage" to office space,
it has two skylights with passive vents that do a good job of keeping the upper area comfortable.
The vents are comparatively small, just slots about ~24" x 1" however, they're quite effective.
Summer temperatures were well above 110, with vents open the loft generally stays about
10 degrees above outside air temperature, warm but generally tolerable.

I can keep the loft comfortable with one ceiling fan pushing warm air down so it is cooled by the concrete floor and masonry walls before circulating back up at the other side of the building.

I also let the stack effect pull cool air in through a north window that faces a shady shrubby area, At night a box fan in that window pushes cool evening air into the building to force warm air out the top, and to cool down the masonry walls and concrete floor again.

Last edited by Hal_S; 10-28-18 at 08:43 AM.

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