Any cheap / free ideas to cool a garage?

[clinebarger]

I tried this one. Supposed to cool 4x the size of the garage and it won't do anything. I put it in our bedroom window and it's still not a good cooler at all

You have to put it directly on you like I already stated & it needs to be larger (More CFM), Your location is dryer than mine & should work better for you.

I'm just far enough away from the Gulf & just far enough West for evaporative coolers to work on hot days after the morning humidity burns off.

I don't think A/C will work without insulating the walls!!

 

[PandaBear]

So, no neighbor near you right?

Can you buy some patio umbrella and put them all around your exterior? If not, can you put up a bunch of aluminum foil or metal "fence" around? I think most of the heat you get is from the sun light and if you block off the sun hitting your house it would significantly cool it down.

Or follow the Greeks and paint your house white and baby blue.

 

[4WD]

So, no neighbor near you right?

Can you buy some patio umbrella and put them all around your exterior? If not, can you put up a bunch of aluminum foil or metal "fence" around? I think most of the heat you get is from the sun light and if you block off the sun hitting your house it would significantly cool it down.

Or follow the Greeks and paint your house white and baby blue.

If there is just one side taking intense sun - astrofoil is easy to put up. It’s a good radiant barrier - plus a bit of insulation …

 

[JimPghPA]

Instal a heat-pump water-heater in that garage and you get hot water and a cooled off garage.

 

[ArrestMeRedZ]

FWIW I've lived on George AFB around the corner from you and in Apple Valley and the weather was the same. At George the base housing only had a roof mounted swamp cooler. It worked just fine except for the few monsoon days out of the year when the humidity was way up.
A properly set up and sized swamp cooler with a downdraft from the roof and an exit vent should provide the solution.

 

[ecotourist]

A doctor I used to work with said that 30 years ago in India they sprinkled water on their roofs so the evaporation would cool their buildings. There is a good theoretical basis for that, so it wouldn't hurt to try it. You could start by manually spraying water from the ground or from a ladder. If it helps you could set up a micro-drip system along the ridge line (like people use in gardening) to minimize water usage.

I expect that you have an insulated ceiling in your garage. In near desert heat, that attic space must get fantastically hot. Simply ventilating that space would help quite a bit.

As the next step after those two, I think you will need to insulate the walls, which isn't free but still pretty cheap. In Edmonton I insulated the stud spaces using R12 insulation with a 6 mil poly cover, in that case insulation against the cold. It would have been more elegant to drywall over it but functionally it worked fine.

And white paint would help too.

 

[Snagglefoot]

For the OP, how is the interior finished? Are the studs visible? I am guessing you get a massive solar load on the south wall late in the afternoon.

If you have studs visible, you can pull back all your equipment away from the wall, rent a do it yourself foam spraying system, and spray purple closed cell foam between the studs. It’s R7 per inch so even 2x4 studs have room for R24. Then, put up drywall or plywood. To cheapen things up you don’t have to finish the drywall. Doing just the south wall would make a difference.

Edit. I just saw the south side only has 3 ft exposed. Get those 3 ft insulated with closed cell spray foam. Better than nothing.

 

[dlundblad]

Have a heat gain calculation done and get a mini split sized accordingly

I’ve often wondered when it comes to sizing a mini split, is the ceiling height taken into consideration?

800 square feet with say a 9’ ceiling is different than 800 square feet with a cathedral ceiling.

 

[burbguy82]

My garage is 20ftx24ft. We put insulation on the roof when we reroofed it. No insulation in the walls.

It gets unbearably hot in there during the summer. A few years ago I put an evaporative cooler in a window which only pushed the cool air out the whirly bird on the roof without effecting the inside temp.

Anyone have any ideas I may not be aware of? Adding insulation to the walls would be a serious job and not something I'd want to do in the summer.

I have a similar situation. Fans are the only thing that I have found to make the space tolerable. I have an exhaust fan in the rear wall, and when hot, I roll a big fan in the roll up door and let it rip.

Air movement is the only answer I see.

 

[Lubener]

There are contractors that can inject foam insulation between the wall studs.

 

[SOUNDMAN5000]

My 25' X 25' garage is detached and is unfinished so stud walls and open exposed beam ceiling.
When it came time to re-roof I went metal roof ( Over top of my existing shingles with a ridge vent ) with the silver tin color thats popular in my area ( Coastal beach town in the HOT South )
The temp drop from shingles to the tin roof was drastic. The garage is not cool but its cooler than than being outside in the sun now after the tin roof. Its still too hot to do anything in the garage so I hope to buy one of those belt driven $399, 42" shop fans from Home depot as that would be all I need.

IMO the only other option is to sheetrock, insulation and a HVAC...
I'm old, when I was in was in school each class room had a wall mounted belt drive fan about the same size as that Home depot big round belt drive shop fan so if it cooled a classroom one would cool a garage is my thinking?

In Jr High the Choir room, the band room and the library and office was the only AC cooled rooms.
I can still feel that wonderful cold air hitting my face walking into my 6th period band class.

IMO things were better back in 1979 but lack of AC was NOT one if them!

 

[barbersurgeon]

So, no neighbor near you right?

Or follow the Greeks and paint your house white and baby blue.

DIY whitewash has some radiant cooling effect.

Rig a shade tarp on the highest exposure side.

Could be tax credits available for insulating or cooling assistance program from state?

 

[SOUNDMAN5000]

I just ordered this from Costco, $289. Tried it yesterday, lowered my insulated garage from 79 to 75 in 2 hours and also dropped the humidity from 63% to 43%. It was 93 outside and the garage is below a living space that is cooled to 85 when nobody is there. It really doesn’t get very hot being somewhat below grade and well insulated.

The portion I was cooling is 930SF and has 10.5’ ceilings which is asking a lot of a 12k btu unit. I don’t doubt it could get it to be 70 or less when 93 outside so I’m thrilled.

It’s hotter where you live and no insulation will make it tough though.
No idea why the image is turned 90 degrees.

View attachment 294680

I have that same window AC. After so many years of clunky, loud window units its nice to find a virtually silent window unit, I have been using my unit a few Summer seasons! I love it! FYI, You may want to check as I received a recall notice a few weeks ago that my specific unit has a possible mold issue so I'm being offered a new replacement unit!

 

[SC Maintenance]

I have the same issue in Florida with the heat. It is a 'wet' humid heat. I tried one of those "Portacool" machines, the one you fill with water and a fan blows over a stream of water yada yada.... No dice. The Portacool is an evaporative cooler, and in the Florida humidity nothing evaporates. Wound up giving it to my parents for their patio, and my father threw it out with the garbage one day.

PERHAPS it would work in a very dry environment, like the OP in California. But it was worthless in the humidity. And they are not free lol.

For a swamp cooler to work you need humidity below 30% - which in Florida is never. The temperature drop has to do with how fast the water will evaporate.

In the desert it stays well below that likely all summer - probably down below 15% on a hot day. They still use them in commercial and industrial out west.

 

[RhondaHonda]

I have that same window AC. After so many years of clunky, loud window units its nice to find a virtually silent window unit, I have been using my unit a few Summer seasons! I love it! FYI, You may want to check as I received a recall notice a few weeks ago that my specific unit has a possible mold issue so I'm being offered a new replacement unit!

Thanks, they added some different drain plugs to the carton that let water drip slowly instead of possibly keeping it in the unit. It’s a very nice unit and will hold me over til I get a mini split.

 

[skyactiv]

You need a radiant barrier stapled to the top cords of the roof trusses with an air gap between the sheathing and the radiant barrier. Insulation shouldn't touch the radiant barrier. It's not expensive if you buy it from a builder supply.

 

[Egg_Head]

Paint a portion of the southern facing exterior wall white, then test the inside temp of the painted wall side vs. the non-painted with a IR temp gun and see how much that moves the needle for temp drop.

 

[skyactiv]

Sold here and under $200 for a roll. I'd be interesting to see the live temp later in the day if it's legit.

https://radiantguard.com/products/radiant-barrier-xtreme?variant=45696317456623

 

[Boomer]

Even using fans and getting high rates of air exchange with the outside, you will never get the actual temperature below the outside temperature. You need to well insulate the walls and get an air conditioning unit. That is the only way you can really get the inside cool in a timely and effective manner.

 

[SC Maintenance]

Even using fans and getting high rates of air exchange with the outside, you will never get the actual temperature below the outside temperature. You need to well insulate the walls and get an air conditioning unit. That is the only way you can really get the inside cool in a timely and effective manner.

Correct, the only benefit of a fan is if it blows on you, allowing your perspiration to evaporate faster and providing a cooling affect to your body.

The only way to get below ambient is some sort of mechanical cooler whether it be DX or evaporation.