I live in a community near Venice Florida. The garage temperatures will get excessively hot. Is there a way to vent a garage in Florida to at least cool it down to the ambient temperature?
I have a large bathroom exhaust in my garage set with a hi/lo honeywell stat. In the summer when it heats up, the stat turns the fan on for awhile. Works up here in Canada and Im sure my garage can get just as hot as Florida
A standard bath fan is 50 cfm. If you have a small garage, say 10 by 22 by 10 high, you have 2200 cubic feet of air inside. With a 50 cfm fan, you will get one air change every 44 minutes. I suggest that you measure the garage and get a fan that will change the air at least 4 times per hour. Then you need an adequate opening for makeup air or the fan won't do its job. Put the makeup air opening in the shade in the coolest place you can find.
Is your garage detached or attached to house. Is the garage finished inside, drywall, etc. This makes a difference in the solution. You could use a thru-wall exhaust fan or a power roof vent.
I'm thinking very seriously about a whole house fan in the shop, to save on AC bills in the summer. I have a lot of roof venting, so there would be no back pressure problem here. YMMV.
My exhaust fan is 200 cfm (home depot). I added a table saw dust collector adaptor to the bottom for the cigar smoke when someone stands underneath. Not sure how many air changes I get per hour but 200 cfm works fine for my double car garage.
If your garage has a gable, you can mount a gable exhaust fan. I lived in a typical ranch home and installed one and it really moved some hot air out of my attic. Easy to install, getting power to it was the hardest part of the install. Lowe's has a couple to choose from.