Garage too hot; Portacool versus mini-split A/C system?
 

Those evaporative coolers aren't real effective when the humidity is high. You didn't give a location, but the use of "heat index" says you are probably in a high humidity situation. AC is MUCH more effective in that situation.

If it's crazy hot, I just put a shop fan blowing directly on me and dampen my clothes with water, not dripping wet, but enough to know it's there. Only 100% cotton t shirts and jeans or work khakis. Same principle as the swamp cooler, but far more effective, as it is directly on your skin. Have to wet down every 30 mins or so.

Where are you located and what is the ambient humidity level? Look at the weather and see what the dew point is, that is the absolute minimum temperature that a swamp cooler can provide. High humidity (>40%) will make it useless or make the indoor temp WORSE (high humidity). You also need free flowing ventilation, preferably a cross draft for the swamp cooler to do its magic.

FWIW, in my area the humidity in the summer time is ~20-30%. On a 100˚+ day, the swamp coolers we have in our warehouse will blow in the mid 60s, keeps the overall temp in the warehouse in the upper 70s, lower 80s depending on the time of day and the humidity level. The key for successful operation is LOW HUMIDITY.

I'm in the same boat in Columbia, S.C. ...

Mini Split is the ticket. Less than a grand and it looks like something a DIYer could do. I've been talking about this for years and just maybe this month ...

Evaporative coolers will not do much for you this time of the year with the high humidity there. I used to do business in Charleston, went thru the same. A good ac is the way to go.

I agree .... mini-split is the ticket. HD sells them for around $900 and refrigerant will be around another $90 and the odds and ends needed probably another $100 So, for around $1,100 you can be chilled ...

Yup, humidity is too high for much effect, and as said above, added humidity in the shop will make it feel hotter unless you are standing in front of the cooler.

Is there a window in the garage? If so, a window unit from BLowe's or Home-Repo is a nice cheap solution. A 12K BTU should cool the garage down in a hurry and still be able to cope with the heat rejected from the cars.

A window unit will work just as well as a mini-split for the same BTU. A 12K BTU window unit is $200-250, a mini-split is more like $1200. Installation for the window unit is under 30 minutes, mini-split is several hours. If there's a window to slot a unit into, it's a no-brainer.

In order for a Portacool to work in high humidity, you will need additional wind speed to give effective evaporation. We're talking nearly a wind tunnel experience.

Back in lean times, I installed multiple whole-house fans to provide sufficient cooling. It won't lower the temperature that much but is more tolerable. You will need to lower the garage door to about 4-6".

I bought a mini split off eBay about 3 years ago for $550 delivered. My garage is 2.5 car detached with 10 ft ceiling- insulated and drywall. 12k btu unit keeps me toasty warm in winter and is more than capable at cooling.

It’s also nearly silent which is a big deal to me.

I have been having the same thought, sort of, except I am contemplating how to cool my 40x60 shop with 16' ceilings. It is insulated but thought about getting a 5 ton unit, run a line of ducting down the center with vents. It might not make it cold but surely it would cool it to a tolerable level for the few hours on the weekends I am out there.

Is your garage walls and/or ceiling insulated? If not, most any refrigerant type cooling unit will be working extra hard just to keep up. If the garage is insulated, you should be happy with a mini split or window unit. However, even though you have no windows in your garage, it is not a big deal to cut and frame out a hole for a window A/C unit to fit into. The advantage here, is you can put it up high where it will take in the most heat. The mini split units like to be mounted up high as well. Of course being high is not as good for winter when you need heat, but the cooling aspect of these systems is where they really do well.

If your shop has insulation you should be ok. Our shop at work is metal construction 25x50' with 14' ceilings and currently cooled with a 2 1/2 ton Rheem unit from '96 that's on its last legs. When new it could keep it 75 on the hottest days, now it struggles to keep it at 78-80 when it's 100+ outside. When it gets replaced this fall we're considering upgrading to a 5-ton and adding a currently un-conditioned 25 x 25 production room to the system.

That was exactly my thought. For $1000 savings, I'm cutting a hole in the wall.

There are window unit heat pumps too, which will heat as well. Make sure they're actually a heat pump, many are just a normal AC with a built in electric resistance heater. Fine if that's what you want, but way more spendy to run than a heat pump.

If you have no insulation and you're selling the house anyway, skip installing an A/C, it won't really help anyway. Open the door and park a drum fan out there to move some air.

I just installed an 18k btu minisplit unit. I had done a 12k in my kitchen a few years back. Amongst the best decisions Ive ever made regarding climate control,in a building. Super efficient, quiet, and the ability to throttle the compressor means you can always get the right mix of cooling and dehumidification.

A decent unit, all in, is $1200-2000 depending upon size and capacity. Avoid fly by night units. If you can work on old cars, you can do the flaring and vacuum to get the system ready. Really not a lot to it...

With no insulation in the garage, any heating/cooling system effectiveness is going to be seriously compromised.

Depending on your timeline and the value added to the property by having an insulated and climate controlled garage, I'd consider doing it anyway. You could very well wind up making money on the improvement.

I just insulated my 30x30 two story tin-wall shop. R7.7 foam panels on the walls and R21 fiberglass on the ceiling, as well as a goodly amount of caulking and expanding foam. ENORMOUS difference. Absolutely enormous. Looking forward to seeing how it does this coming winter - last year I was thrilled when I was able to get the snow I'd tracked in to melt.

True, but this isn’t a situation where the unit will run 16-24hours per day, every day. Not to speak for OP, but garage service is more like a few hours, a few days a week, if that. Often ultimate comfort isn’t a necessity compared to taking the edge off.

Isolation is the key.
 

I like not having windows. No one can see what is inside and windows are a source for heat transfer.

R40 in the attic, a good window unit mounted high and a low electric bill for cooling. Blown in insulation is the best especially if batts were used first.

The sweetness of doing it cheap will be long gone when the bitterness of high cooling/heating cost are realized then endured.

Lol

Material is less than $1k.

Rule#1: if any company sends a salesman to your house for a quote I guarantee they are overcharging you.

The insulation is kind of a big deal if you want to do anything more than take the humidity out of the air. Insulation is cheap and effective, which is why it’s not recommended by your ac installer. Just buy a bigger (more expensive) unit!

With this statement alone I'd have told him to get lost. He's either completely ignorant of HVAC, or he's a liar trying to sell you a bigger system. Either way, gone.

Obviously get multiple quotes, research insulation, and look at DIY mini split or hacking a hole in a wall to install a window unit.

A window unit is totally a viable option. Basically cut a hole in the wall and you can have heat and air in a half a day.

Mini splits can be bought on eBay. I bought mine 2 or 3 years ago and has been working flawlessly since. It was $550. It took me a full day to install, it was my first time installing a split system.

I had a real struggle trying to get my flares right, I didn’t have the correct flaring tool. I ended up brazing the line. Looking back I should have left the line in tact and just installed it. I wanted it to be super tidy so I went through the extra effort.

Don’t over think it. If you plan on being there another year or so I would definitely do it. Insulation and drywall will make your garage more like living space than, well, a garage.

I’d show you a picture of my garage but this forum is from the 90’s and can’t handle anything bigger than a thumbnail.

Garage

I didn't realize they were that inexpensive. That'll change some of my plans.

That is a very nice man cave!

Invest a few hours and $25 and get your EPA license so you can legally buy refrigerant. You will need a vacuum pump and a set of gauages too.

Good to have the cert but not needed with a split. The unit is precharged. Vacuum pump is a must however

some are and some are not. Plus, clumbsy folks like me may have a spill. Getting mine soon. Tired of sweating ...

I've owned two mini split Mitsubishi units. They are easy to install and provide good efficiency. Replacement parts can be expensive. Insulation and air tight sealing is the best investment long term. Our current home heating and cooling bills seldom exceed $100 a month. Our neighbors without good insulation and sealing spend up to $500 a month for about the same living space.

If it were my garage and I planned to move, I would not spend money on insulation and AC. I would use either the self contained water misting units or make my own with a misting system and fans. I could then take them with me when I moved. Misting systems appear to drop the temperature about 20 degrees. The old swamp coolers produced air that was about 15-20 degrees cooler then outside air.

The work space needing cooling can be reduced by plastic sheets or tarps. This space reduction technique is used sometimes in larger buildings that are not insulated. If I made the work space smaller with this method then the small portable ac units could be used and the heat exhausted outside with a 4" flexible hose. I've seen those discounted to less than $400.

Fix your lack of filtration. The dust comes from the return air. You either have a leaking duct or you're using really crappy filters. A/C units don't make dust. They air they supply is only as clean as the air they take in.

+1 on that.
There are filters that (used to) cost less than $1 and you can see through them, and filters that cost $15 and have ratings as to minimum particle sizes, etc.
3M Filtrete and similar are good for those of us with allergies.

Eugene's Garage / Man Cave
 

? How do you fit the cars / tools / p[arts / etc. in there ? .

I love that :D .

All the tools are stored in my tool chest, in the cabinets, or on the peg board on the other (not pictured) wall.

I only pull a car in there for repair. I don’t park cars in there as my garage has morphed in to a bit of an outdoor living space for the family. I simply move the wicker furniture and straighten out the ever growing pile of kids toys.

I don’t really save car parts anymore, only some nos stuff that is hard to find, specifically for the 4matic part of my car.

I’ll snap some more photos later. That picture is 2 years old.

Ok
I am a licensed HVAC/Electrician
Get a good one unless you just want a quickie system.
Mitsubishi is best
All others are clones
Gree is cheap
I can get a 3 ton 22 seer mini condenser for $600 but the distribution head is 2K
I can get 2 ton units all day long for 1600 full systems
A garage really needs 2ton or 24,000 btuh
A far cheaper option is a PTAC
Lowe’s has a 18,000 btuh heat pump ptac for 799
Cut an 18x22 hole in the wall and run 30 amps of 220 to the outlet and you are done

Two nice things about minis
1. They are SILENT inside
2. They are extremely efficient, inverter drive variable capacity

Also, they only need a 2” hole in the wall to operate.

I effectively cool/heat my 24x24 garage with a 12,000btu unit (240v). Granted my space is insulated (r12/walls, r19 ceiling) and relatively air tight. Ceiling is around 10ft.

I agree Mitsubishi is the best but for a garage I think it’s a bit overkill. Like I said previously my unit was about $550 delivered from eBay and is called something I’ve never heard of. I think ultimately it boils down to the install whether you will have a long lasting system or not.

https://youtu.be/iX3kxAA2L4Q

:D

I have a 24k btu split system from Friedrich in my garage. Its also a heat pump so it will crank out serious heat in the winter months too. The other day I worked all afternoon on a car that was hot when it pulled into the garage, in 95 degree weather, and it had it down to 69 and maintained it all afternoon. :D I like it cold!

Not so easy as 220 VAC is not available in the US, you would need a step down transformer. Better to go with a 240 VAC unit :D

"220, 240, whatever it takes" (reminds me of the line in Mr. Mom)

Oh, its available, but most often on 3 phase...

Yes, most homes have 240, but the equipment is often rated for 197-250v... most call it 220.

208v 240v, 277v... in Charlotte, there are a lot of areas with 200v... really dims the lights when ac comes on.


(I think the Mr. Mom quote was 220, 221, whatever it takes...)
https://youtu.be/iX3kxAA2L4Q