Garage Workshop Cooling

[Marshall Harrison]

Like a lot of people I have my workshop in my 2 car garage and overflow into the driveway. I'm lucky in that I have a side entry garage so it makes this easy. What isn't easy is keeping the garage cool in the Florida heat. I can setup a canopy in the driveway but leaving the garage door open complicates cooling it. Also the homeowners association wont' allow me to put an AC unit in the window (two windows facing the street).

So I am curious about how you guys have solved the garage cooling problem. I would love to hear your solutions. Preferably as cheap as possible as wifey is getting uptight (as am I) about the startup expenses for the shop. Plus every dime spent on cooling is one less dime to spend on new tools.

[Roy Petersen]

I can setup a canopy in the driveway but leaving the garage door open complicates cooling it. Also the homeowners association wont' allow me to put an AC unit in the window (two windows facing the street).

They would allow woodworking under a canopy, but not an AC unit in a window? Odd.
Any chance you can make a new hole in a wall they'd be ok with, just for the AC unit?

[Art Mann]

Investigate installing a "mini split" air conditioner. It might satisfy the association.

[Marshall Harrison]

They would allow woodworking under a canopy, but not an AC unit in a window? Odd.
Any chance you can make a new hole in a wall they'd be ok with, just for the AC unit?

The canopy would be temporary while I was working but I would have to put it up and take it down each time.

Maybe I could use one of those indoor units that just vent through a window then keep the hedge high enough that they won't see it. The outside wall is brick up to about 4' then stucco the rest of the way.

My house is all metal studs even on exterior walls so framing something out or attaching something to the walls is a huge pain in the tush.

[Jim Becker]

An indoor, portable AC unit that vents though a window might be unobtrusive, both because of the hedge idea and because you can just pull the window insert out and close the window when it's not actually in use. It will look more or less like a removable window fan.

My solution was to install a mini-split like Art suggests and because the outdoor unit has some flexibility of positioning, it likely could easily be hidden or even placed next to the house AC condenser, depending on where it's located. Of course, that's a bigger investment....

[Marshall Harrison]

Thanks for the mini-split suggestion. I'll look into that.

I've used a portable AC before in my office but I'm not sure how well it would work in a garage. May look to insulate the garage door too. My wife does stained glass and it would fit in well with my Arts & Craft furniture interests. Got to get her back into that hobby so she will be interested in cooling the garage.

Its not too bad here yet but I know that summer is coming.

[Jim Becker]

Yes, you'll want to insulate the door. Do you know if they actually insulated the exterior wall(s) of the garage? All too often, builders skip that "because it's a garage" to save money. I had that situation in my previous home and even though I respectfully asked them not to sheetrock the exterior wall...they did anyway....and I had to rip it down.

[Joe Jensen]

When you insulate the garage door, use high R-value foam. Also, it works way better if you fill any gaps between the sheet foam and the door with spray foam. If you haven't used it before, tape off anything you don't want the spray foam on as it will expand and it's nearly impossible to remove. I put a minisplit in my 3 car garage in Arizona. I could only easily get a 20A 230V line to the mini split and I bought the most efficient unit I could. It's like 2 tons and rated at 23 SEER. You have to precool the night before as there is a lot of thermal mass to cool in the garage. I can get mine to 72 F in the heat of Arizona summer but once I start working the unit struggles to keep up. I do not have insulated side walls, just stucco and foam. Also the mini-split units reduce their output as the temp outside rises and most essentially no longer cool when above 110F. If you dig you will find the specs. In my shop the dust collector is 5HP, the saw, shaper, planer, etc are 5HP, and the lights contribute heat as well. In my experience as woodshop requires way more cooling than you might think. I am building a new shop and I will have a lot more cooling capacity and a much better insulated envelope

[Mark Blatter]

May look to insulate the garage door too. My wife does stained glass and it would fit in well with my Arts & Craft furniture interests. Got to get her back into that hobby so she will be interested in cooling the garage.

This is the most important. A couple of years ago we were having many days in a row above 100 here, at times hitting 105-108. My house faces west, so from mid-afternoon on the sun would shine into my garage. Shutting the door didn't help much as it was not insulated. I added insulation and it made a big difference. I love to work with the door open, but the difference is at least 25 degrees. The insulation was key in being able to work in the evenings.

[Marshall Harrison]

This is the most important. A couple of years ago we were having many days in a row above 100 here, at times hitting 105-108. My house faces west, so from mid-afternoon on the sun would shine into my garage. Shutting the door didn't help much as it was not insulated. I added insulation and it made a big difference. I love to work with the door open, but the difference is at least 25 degrees. The insulation was key in being able to work in the evenings.

What did you use for insulation Mark. I thought about using foam insulation sheets that are backed with something like tin foil. I'm guessing that it should be something lite so it doesn't interfere with the garage door opener.

My door faces south and the exterior walls face east and south with a partial wall is half north facing and half into the dining room. The fourth wall backs up to a bedroom and laundry room so no western facing issues.

[Mark Blatter]

What did you use for insulation Mark. I thought about using foam insulation sheets that are backed with something like tin foil. I'm guessing that it should be something lite so it doesn't interfere with the garage door opener.

My door faces south and the exterior walls face east and south with a partial wall is half north facing and half into the dining room. The fourth wall backs up to a bedroom and laundry room so no western facing issues.

I used solid foam insulation. I think it is 2" thick and I cut it to fill the rectangle open spots in the door. Added tape to hold them in place. After a few years the tape is peeling and I need to replace it all. I plan on using some pieces of metal and just screw them in place, so that they overlap the foam. It helped to keep it warm in the winter too, but that is more an issue here than you will have, though from my time living in Mayport I recall it can get cool there too.

[Robert Zschoche]

Marshall, A friend who is an HVAC contractor uses those portable "through the window" units to provide temporary cooling for customers in the summer while he is getting new equipment ordered for an installation. He says the units actually do OK. Maybe one of these would get you through the summer while you get ready for the more expensive mini-split option.....

My experience here in Virginia has been a good one with a high-quality insulated and properly installed garage door along with a Mitsubishi mini split. As long as I don't raise the door often my one ton unit does a fine job cooling and heating and it stays quite comfortable. For comparison, my door faces due west and one wall is to the south. The two other walls are common to living space in the house. The shop is a bout 380 sq feet with the ceiling at about 9'6" .

[Marshall Harrison]

I used solid foam insulation. I think it is 2" thick and I cut it to fill the rectangle open spots in the door. Added tape to hold them in place. After a few years the tape is peeling and I need to replace it all. I plan on using some pieces of metal and just screw them in place, so that they overlap the foam. It helped to keep it warm in the winter too, but that is more an issue here than you will have, though from my time living in Mayport I recall it can get cool there too.

Mayport? Must have been in the Navy.

Mayport is on the northeast side of Jacksonville. I', on the southeast side near where Julington Creek flows into the Saint Johns. I'm actually in the north west corner of Saint Johns county. Great place, all the benefits of Jacksonville but with better schools and none of the BS that Jax's government has.

Thanks for the tips on insulation.

Robert - that is probably what I'll do as I would like to move to the mountains of North Carolina in the next 5 years and I want to take my cooling solution with me.

[Scott McFarland]

Mayport? Must have been in the Navy.

Mayport is on the northeast side of Jacksonville. I', on the southeast side near where Julington Creek flows into the Saint Johns. I'm actually in the north west corner of Saint Johns county. Great place, all the benefits of Jacksonville but with better schools and none of the BS that Jax's government has.

Thanks for the tips on insulation.

Robert - that is probably what I'll do as I would like to move to the mountains of North Carolina in the next 5 years and I want to take my cooling solution with me.

I live in Houston, I have a 2ton Mitsubishi mini-split HVAC in my 550sq ft garage. It does a nice job. Really makes the summer woodworking months viable.

Be careful though, I received quotes ranging from $3500-9000 for the whole thing.

[Bill Dufour]

It may be worth about $200 more to get the mini split that is also a heat pump. Note that they have poor air filters so if you shop air has a lot of dust the coils will need cleaning often.
Bill D.
easy enough to install on a outside wall but you will need some tools. Around $200 used for hole saw, flaring kit, tubing bender(maybe) vacuum pump, manifold gauge set, adapter since mini splits use smaller then standard connectors. The gauge set is the same as used for car ac work with the old screw on connectors. I got all I needed at yard sales, ebay.
the vacuum pump is hardest to find but you do not care about horsepower or CFM.
Many here run all the wires and tubing then pay someone to flare and connect the lines, pull a vacuum and release the freon. They will charge around $100-200 for this service.