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I am hoping to get a deal on a mini split air conditioning unit for my shop this time of year. I do not know how to size the unit. Can someone run the calculation for me?
I live in Northern Illinois (Chicago area).
Shop is 30X32 with 11 foot ceilings.
I have a single car garage door, factory insulated.
1 have a man door leading outside. It is insulated fiberglass with a window in the door.
I have a second man door leading to an unheated garage.
I have 2 windows, both thermal pane glass.
Ceiling has 10 inches of fiberglass batts, walls have 3 1/2 with vapor barrier.
Flooring is raw concrete.
Is there anything else needed?
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Location: Regina Saskatchewan Canada
Are you going to set the temp and leave it? Turn on when in use or run a set back program of hold and turn down when in use? A/C or heat pump?
Blackhat
Bad experiences come from poor decisions. So do good stories.
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I have a Hot Dawg heater to provide winter heat, so I'm only looking for air conditioning. I use a window unit now that I'd like to replace. I typically turn off the AC unit when I'm not in the shop. The insulation is good enough that it never gets more than 82 degrees or so in the shop without the AC as long as I keep the doors and window closed.
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Right now, Daikin has the best warranty- up to 12 years parts and compressor. This is a VERY important feature to look for. Average warranties can be 5 years parts and compressor (7 year compressor- Mitsubishi).
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I'd go with a 2 ton and aim the head at the area you use most. A hanging dust cleaner will help circulate air, that's a pretty good size space for a single head to throw air around. Watch Daikin as I'm not sure their reboxed Goodman's have the same warranty as their own product.
Blackhat
Bad experiences come from poor decisions. So do good stories.
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I installed a 2 ton mini split unit in my garage near Houston. 3 garage doors, none insulated. 600 sq ft. 10 in of insulation in the attic. No insulation in the walls, but walls are finished with paneling (dead air between inside and out, helps a bit). One insulated door, one single pane window. My unit will drop the garage to 80 degrees, even on the hottest days.
I can't imagine you would need more than this in northern IL.
Mark
Mark in Sugar Land, TX
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It won't hurt to oversize a bit when using a variable drive mini split. You'll have enough for the hottest days and all lights and tools running and it will just slow down when the load is small and humid. They run about 80% of the time anyway.
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I just built the exact same size shop.. 12 foot ceilings. Mine is 968 sf. I just installed a Daikin 1.5 Ton unit.
Its literally not running yet but in place, the fella is coming Tuesday to complete installation.
The unit was spec'd by the company I bought it from. The climate here never really gets too hot .. 90 is a scorching day.. and rarely below freezing..
Achieving life is not the equivalent of avoiding death.
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Looks like a 1.5 to 2 ton unit will be on my shopping list. Thanks for all the help.
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(09-04-2016, 09:27 PM)Rick F Wrote: I just built the exact same size shop.. 12 foot ceilings. Mine is 968 sf. I just installed a Daikin 1.5 Ton unit.
Its literally not running yet but in place, the fella is coming Tuesday to complete installation.
The unit was spec'd by the company I bought it from. The climate here never really gets too hot .. 90 is a scorching day.. and rarely below freezing..
OK that's where I want to live....
As for six I'd go with a 3 like mentioned in the post above mine. Remember you won't be running it all the time so you need more btus to get a quicker cool down and also in a wood shop if you have an air cleaner that will increase your required cooling. How? Its because you are on the bottom part of the shop and the ceiling gets much hotter than where you are. So you don't feel that hot air. So when the air cleaner is running it's throwing all that hot air around breaking up the air stratification. Makes the building more comfortable overall if the ac can keep up.
If it were a regular split system always make sure to have high returns for cooling. Makes a huge didifference in the comfort of houses as well.
