Cooling Garage Workshop in the Southeast on the Cheap

[Patrick Harper]

My situation is a bit unique and I'm unsure of how to tackle it. My current shop exists in a two car garage in a house that faces south-southwest. The heat in the afternoon is brutal this time a year. The rear wall and about 2/3rd's of one side wall on interior walls. All of the walls and garage doors are insulated. There is a small attic space above the front face of the house (5ft x 22ft). That is the only portion of the garage that is uninsulated.

I don't currently have the budget for a mini-split and, from what I understand, the small portable units don't work well in high humidity. I'm considering insulating and/or installing a gable fan in the small attic space, but I'm not sure which one I should try first. The gable area has a small window which would need to be replaced with a vent. If I insulate the attic area, should I insulate the wall, the attic floor, or both?

Thanks in advance.

[Jim Andrew]

Insulate, insulate, insulate. And with insulation you must have ventilation. Insulation tends to collect moisture if it is not ventilated well. Especially in the humid southeast. If you have flooring in your attic for storage, I would be tempted to take it up and insulate under it, with the possibility of putting it back down. If you cannot get your insulation thick enough under the flooring, consider stacking boards on top of the existing joists to get the proper amount of insulation.

[Robert Engel]

I'll give you my opinion take it FWIW.

I live in NE FL and I can relate. Lately where I live its been in the upper 90's in the shade. My shop is in an old horse barn and uninsulated, but there is no direct sun hitting the walls and that makes a huge diff. I've been able to work in the afternoons a bit but when it hits 98 its just too darn hot. I can't imagine if I had the sun beaming in.

1) If most of the heat is coming from direct sunlight, then adding more insulation probably won't help much.
2) Its also not going to help much to put a fan in the attic (if that's what you're talking about) especially with garage door open. There would be a benefit to the rest of the attic, though. I have 2 attic exhaust fans in my house, one at each gable end.

IMO shade + fans is the answer for you.

Something like an awning or one of those metal carports off front of your garage will help. Even one of those collapsable tents or better yet, a roll out awning like you put on an RV.

I recommend one big fan blowing out and something like a pedestal fan. I mounted a 3' fan in a window blowing out on the other end of my shop.

....last but not least a small fridge stocked with cold beverages of your choice.

[Kent Adams]

Insulate, insulate, insulate. And with insulation you must have ventilation. Insulation tends to collect moisture if it is not ventilated well. Especially in the humid southeast. If you have flooring in your attic for storage, I would be tempted to take it up and insulate under it, with the possibility of putting it back down. If you cannot get your insulation thick enough under the flooring, consider stacking boards on top of the existing joists to get the proper amount of insulation.

If the roof is sealed as well as the ceiling, you don't need ventilation, in fact ventilation can cause a lot of problems. My shop has a "hot roof". There is no condensation built up from conditioning the air below the ceiling. http://www.buildingscience.com/docum...-roof-systems/

[Patrick Harper]

Insulate, insulate, insulate. And with insulation you must have ventilation. Insulation tends to collect moisture if it is not ventilated well. Especially in the humid southeast. If you have flooring in your attic for storage, I would be tempted to take it up and insulate under it, with the possibility of putting it back down. If you cannot get your insulation thick enough under the flooring, consider stacking boards on top of the existing joists to get the proper amount of insulation.

I'm assuming I should insulate the exterior wall section in the attic as well as the floor. There isn't currently anything on the attic floor, so insulating shouldn't be difficult.

[Patrick Harper]

Robert, unfortunately due to HOA regulations I cannot add any shade to the front of the house. That's also cost prohibitive for me.

[Andrew Ulsher]

What about a retractable garage screen?

http://www.stoett.com/garage-retractable-screens/

[Patrick Harper]

Interesting idea, but I'm not sure it would be better than an insulated door.

[Andrew Ulsher]

Insulated door would not allow air flow where a screen that has sun blocking properties will allow air flow with a combination of fans should maybe make it bearable.

I'm in the same boat right now, trying to figure out what to do to cool a garage.

[Patrick Harper]

It's a bear. I'm really curious as to whether an exhaust fan in the small attic space or adding insulation to the small attic space would be more effective...or if either are worth trying.

[Thomas Wilson]

A lot of your heat has to be radiating down from the ceiling of the garage. A IR thermometer like this one http://www.thermoworks.com/products/ir/irgun.html would let you see what walls temperatures are. You can check before and after your modifications to see how much good you did, too.

I would try to lower the temperature of the attic and separate the attic and the garage thermally to reduce the heat entering the garage. To lower the temp of the attic, I would put a fan in the gable end. Size the fan by the square feet of roof. I am assuming you have soffet vents to let air into the attic. To separate the attic from the garage, I would insulate the floor of the attic space. 10" or so would be good. Blown in insulation is pretty cheap.

[Steve Kinnaird]

I just checked into the Stoett Screens.
The local screen shop dropped them because the constantly fail and fell apart.
Might just buy some screen and set it up like a roll-up shade, using a PVC pipe and pulleys.

[Steve Kinnaird]

Those are great for detecting where heat is coming in.
Harbor Freight usually has them on sale for around $25 to $30 and you can use the 20% off coupon too

[Patrick Harper]

Thanks guys. I just bought a temp gun from Amazon. $15 and prime eligible if anyone's interested. http://smile.amazon.com/BAFX-Product...rared+temp+gun

Not super high resolution or anything, but it seems to get good reviews.

[Andrew Ulsher]

Steve that is interesting about the Stoett Screens. I have not been able to go to a local shop to view any other options. I have seen a couple that are like a second garage door you can slide down as well.

Any idea what the cost was for the Stoett was? I'm debating a portable A/C unit by Whynter now. Might be able to get a used for $300, but I need to decide how to build a skirt for the garage or punch a hole in the exterior wall for the intake/exhaust.