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Tony Sade
03-20-2004, 8:28 PM
I need to figure out the proper size window air conditioner to put in my garage before the heat of summer hits. (No more sweat running down my nose onto my projects or cast iron.)

I've googled ac calculators and I've come up with anywhere between 9,000 and 15,400 Btu!. So much for that approach. It's a 500 sq. ft. garage that's incorporated into the house, has two good vertical casement windows, faces south, is reasonably well insulated, and will only be occupied by me and the wife's car when I can't get rid of it. Any idea how to accurately calculate the size I need?

Anyone have any recommendations for a unit for this type of window? I'll probably be taking it out of the window during the winter, so I'd like to err on the side of a lighter weight ac.

Finally-are these type of windows (Anderson) tough to get apart? I figure I'll have to get rid of one of the windows to fit the AC. Thanks, Tony

Jim Becker
03-20-2004, 9:03 PM
I can tell you that my 8000 BTU unit is about half what my 600 sq ft needs! It was purchased when the shop was still 350 sq ft. If I were you, I'd stick to the higher end of that calculated range and buy a unit with a thermostat (and a timer). IMHO, of course.

Dennis Peacock
03-20-2004, 9:05 PM
I need to figure out the proper size window air conditioner to put in my garage before the heat of summer hits. (No more sweat running down my nose onto my projects or cast iron.)

I've googled ac calculators and I've come up with anywhere between 9,000 and 15,400 Btu!. So much for that approach. It's a 500 sq. ft. garage that's incorporated into the house, has two good vertical casement windows, faces south, is reasonably well insulated, and will only be occupied by me and the wife's car when I can't get rid of it. Any idea how to accurately calculate the size I need?

Anyone have any recommendations for a unit for this type of window? I'll probably be taking it out of the window during the winter, so I'd like to err on the side of a lighter weight ac.

Finally-are these type of windows (Anderson) tough to get apart? I figure I'll have to get rid of one of the windows to fit the AC. Thanks, Tony

That's an easy one....just went through that this past summer.

600 Sq Ft per 1 Ton of A/C needed.....which works out to 12,000 BTU needed for 600 Sq Ft. You can get my with a 10,000 BTU unit but it your garage is not insulated, you need the extra 2,000 BTU which would bring it back up to 12,000......

In short?

600 Sq Ft per 1 Ton of A/C
1 Ton of A/C is about 12,000 BTU

I cool 1,200 Sq Ft with a 10,000BTU AND an 8,000BTU unit. In the heat of the summer....it's all they can do to keep the temp under 84 Degrees.

Bill Turpin
03-20-2004, 9:15 PM
Since the AC is going to be constantly fighting a filter with more dust load, than heat loads figured with house dust, you should figure on using the higher capacity. The efficiency will always be be less than optimal. Clean often, DIRTY FILTERS KILL 92% OF AC COMPRESSORS, NOT LIGHTNING. If you are not going to run constantly, you need to figure draw down load.

Bill Turpin NC Refrigeration License #2821