Router Forums banner

Garage/Workshop Cooling

1 reading
13K views 41 replies 27 participants last post by  MikeSibley  
#1 ·
I live in Phoenix, AZ. Summers get real hot (100+). Would welcome any ideas on how to cool down my garage/workshop so that I can get some work done in the summer months. Central airconditioning is not an option.
 
#3 ·
Well, if you want AC & heat + a major investment, a mini-split is what we selected for a porch remodel - the Mitsubishi Mr. Slim shown below; the smaller unit is on the brick wall of the porch as shown; the conduit goes below the floor to the main unit under the porch floor - with a studded wall the conduit contents could be hidden. The porch is about the same size as your shop but w/ a standard height ceiling.

Image
Image
 
#4 ·
#5 ·
Yes, the correct name is Evaporative Cooler and one problem with the Portable Evaporative Cooler is they are often used in a space with the windows closed and as they operate the humidity percent increases and the unit becomes , well , not so Evaporative with the air becoming more saturated and uncomfortable in many instances.

If one or two of the portables were to be installed in window openings for outdoor air intake then they may very well work in the Phoenix climate.
 
#6 · (Edited)
I live in Texas and yesterday was 108*. I just bought a 110V, 13k BTU portable AC/heater/dehumidifier combo unit for around $500 for my 400 sq. ft. shop/garage. I looked at the split minis but I could have, literally, built a new shop for what those things cost (around $4K installed). I have only had it for about a week, but it seems to make a huge difference. The key is insulation. I also added extra insulation to the attic over the garage as well as putting weather stripping around the garage doors. All of this will pretty much seal off your shop, so you will need some kind of air filtration to keep the dangerous sawdust down as well as circulating the air. As I said it was 108* yesterday and the shop was a "comfortable?" 85 to 90*.
Edited: I should have said that the shop was 85 to 90 without the AC unit being turned on due to the insulation and weather stripping. That is a significant amount compared to outside temp.
 
#9 · (Edited)
I'm also thinking insulation. Most people don't think about needing much insulation in a desert region... but it also helps to keep "hot" out and "cold" in.

From and my parents still live in Eastern Washington, a little thought of desert region, where temps are not uncommon to get above 120 degrees. I can still remember putting insulation in a building when it was 128 degrees outside (never measured it inside). Not a real pleasure when you're sweating and all those loose insulation fibers stick to you. ::scratch::scratch::
 
#8 ·
I live in Northwest Phoenix and I understand your pain. Evaporative coolers would not work too well in the summer months as our humidity is up. I had the same problem as you and got a Koolfront air conditioner, which is on wheels and vents through a four inch hose which you put out your window. You will also need an air filter to remove all of the sawdust that will fly around. If you do not get an air filtration system, the air conditioning coils will quickly get plugged up. I got an air filtration system that hangs from the ceiling so it does not take up any of my limited floor space.
 
#11 ·
I use a side draft cooler in my workshop in the Mojave. 107 here yesterday and the cooler only drops temps by 20-25 degrees, so it is still warm inside. I have partially insulated the shed, especially the ceiling, which helps a little, but I think full insulation would really make the difference I also lined the shed walls first with aluminum coated bubble wrap before putting in the block foam insulation I used. Do the insulating BEFORE you put up shelves and cabinets, it is a massive chore to go back to insulate later. I had water just outside the workshop (shed) so it was easy to run 1/4 inch copper line to the cooler. Be sure to get a flaring tool for the copper fittings or they can easily break loose and spill a lot of expensive water before you notice. Every exterior faucet has cut off valves at the base, same with the cooler source. Amazing how often these puppies break. Find a store where you can get schedule 80 pipe for any runs above ground--all it takes is one freezing night to have your pipes burst. I also used a threaded T at the lowest point in the 1/4 inch run. Water goes straight through from source, into the T, with a 1/4 fitting on the other side. The third outlet has a threaded stopper that lets me drain the system before winter. Finally, I also have a fan that directs some of the cool air to the far reaches of the shop, which is where I have my workbench.
 
#12 ·
I would like to put my 2 cents in here if I may I live in Winnemucca, NV and it runs right around 100 to 100+ and I am using a swamp cooler in a 12x20 shop with cast iron table saw, band saw and jointer and no rust, works great. Just stuck it in a window.
 
#16 ·
The first money I would spend would be on as much insulation your walls and ceiling can handle. Then with the size of your shop, it should keep it usable. I am fortunate to have 10" walls and have that much insulation in them. I have 16" to 20" in the ceiling. In the summer when it reaches 95 degrees the shop will stay a comfy 75 degrees with a small window AC unit. In the winter I run a 110 volt ceramic heater that keeps the shop at 70 dehrees even when it gets down to 0 degrees. The shop is 480 sq ft. That is the benefit of having plenty of insulation.
 
#17 ·
Joe, I live in LA where we not only get the heat but huge amounts of humidity (LA=Lower Alabama). We have been using the portable units on wheels on our job sites for years. These are the ones that Scott suggested, that discharge through a 4" hose. We solved the sawdust problem by building a filter box for the intake. it is a frame covered with blue filter cloth. The cloth is held in place by staples and can be easily changed when dirty. You can also prolong the life of the cloth if you periodically blow it clean with a leaf blower from the back side.
 
#18 ·
I suggest you to load some of your gears and put it on a backpack. Google finest natural/nature pools in America. Pick your best bet and prepare yourself for a couple of miles hike. Of course, you should have the bucks for it. If you reach your destination or the pool you chose, for sure you’ll never know what hot means. Opps! Am I on the wrong thread? My mind came up with a summer getaway. :sold:
 
#21 ·
I think my garage (shop) fits in with what a lot of you guys have. It is a one car garage about 13 x 25 with lots of stuff in it besides my woodworking tools.

I have opted for a split system air conditioner. The reason is simply the home owners assoc. wouldn't tolerate a window unit stuck through the outside wall. Period.

Two years ago we had the original siding on our house replaced with Hardi plank. while the siding was off, I asked the contractor to insulate the garage wall. Good move on my part. :) Then I had my garage door replaced with an insulated energy efficient door.

Fast forward to this week. I bought a Fedders 12K unit w/heat pump from Heat and Cool dot com...$845 delivered. I hired an electrician to do some elect work around the house and part of it was to run power to the condenser (located behind the privacy fence) and to the inside unit. The required running conduit along the soffit and into the wall where he installed a receptacle. Tomorrow, my son, the HVAC guy, will be here to run the refrigeration lines and charge it all up. Hope to be a lot cooler in the shop than the 100 deg F today.

I bought the plastic shroud like that pictured in the porch conversion from a local refrigeration outfit (United Refrigeration). It is Plastiduct and can be bought over the internet, but since I bought local, it was half price of the online prices. It is paintable so I will be painting it to match the house and thus fade away and not be an eyesore. The shroud covers the lineset thus hiding it from prying eyes.

Costs do add up. Monday a company will be here to insulate the garage and the bedroom/bath adjacent to it. $600 for R38 blown in insulation.

Yippeee! Hard to stay calm after having temps in the garage as high as 102 at times. Tough on an old retired guy like me.

Why did I spend so much? Well, I have retired as a pro sports photographer, and selling just one lens (Canon 300 f/2.8) netted me $3500 so some of that is going into the house to make things more comfortable. Selling another lens was more than enough to buy a new Grizzly 14 inch band saw. :)
 
#22 ·
New member and good place to say hello. I live near Texas coast and it does get hot.
First of the summer I converted an attached garage, about 400sq ft , into a "play" room
for my drums. Insulated the inside of the garage doors and installed a window unit for ac
and heat. Frigidaire 18,500 ac and 16,ooo heat, bought from amazon for about $600,00
Works great. I admit I did have one window so installation was easy, also wired 220 for
an outlet directly under unit. Would do it again. Maybe an option for ya.
 
#24 ·
While the previous posts on this thread are about 7 years old, this is a good thread!

NicoT: I'm in the Houston, TX area -- temps and humidity run about equal (90/90). In my 400ish s.f. uninsulated, drafty garage I put a 24000 btu wall unit in, which can cool the space fairly well to the mid- to upper-70s. I have a small heater that I use for the "winter" months if needed. Usually I just put on a heavy shirt. :)

Ive just embarked on a project which will include insulating the space which should help a LOT. Eventually, if the universe chooses to smile upon me, I will put in a 2+ ton split unit to replace the wall unit -- while not a priority, it would solve a few problems.

I bought my 24k unit at Sam's club for about $400. I paid someone a couple hours labor and a few beers to put it in the wall for me. Wiring was easy -- I overtook a circuit that fed the (previously filled in) pool pumps.
 
#25 ·
Old but good string. I had an evaporative cooler for some time in my 12x24 shop/shed. Later swapped it for a 6K AC window unit that goes through the outside wall. But I also have a lot of insulation in place in the ceiling and walls. What has really helped a lot is laying in a layer of radiant barrier (aluminized bubble wrap), then the insulaiton. When we insulated the garage, we measured the heat difference between the uninsulated roof and the spot next to it with the radiant barrier. The covered roof was 35 degrees lower. Good stuff, have it in the garage door too.

With all the insulation, about R20 in the walls, a ceramic heater holds the temp nicely, but it takes two heaters to bring the temp up.

If I had it to do over again in my 2x4 walls, I'd have added 2x2s on the studs so I could have put R30+ in the walls. In other words, I come down on the insulate like mad and use a decent sized AC. You could probably find a used AC unit if you searched a bit.

BTW, I live in the high, dry desert, and didn't have much rust problem, but then I also use boeshield rust inhibitor on all my cast iron. With the AC, I don't have to concern myself with condensation.
 
#26 ·
I am now on my second mini split AC/heat. The old one developed a small Freon leak in the evaporator. This go around, I installed a MRCool DIY 12K model. did it all by myself with a little help from my son, who is in his mid 40's. No HVAC guy needed, or electrical because the electrical was already there.

As you can see from the screenshot of my home automation program, the outside temp is 91.7F, and it is 79.5 in the shop. The unit is running cooling the shop back down. We have just unloaded the groceries, so the temp went up some while the garage door was open. Yep, fully insulated walls and ceiling.
 

Attachments

#32 ·
I tried one of these before we put the mini-split in and it was just about useless. Granted, it was a 10k unit and our mini-split is a 12k but even at that when I let it run all night it still only felt cool in the morning if it was blowing on you. Plus, you need a window open 4" or the garage door up 4" to vent the unit and that just lets more hot air in. I built a small adapter for the window so I could attach the hose and block the rest of the window but it didn't make much difference. Then we had to also connect a hose for the condensate drain.

All in all it was in the way every time I turned around, performed very poorly, and was a nuisance to connect each time I used it.

My $0.02

David
 
#28 ·
MT Stringer,

How do you like the 12K Mr Cool DIY unit, now that you have had it a while?

I am planning on partitioning off about 500 sq ft of my basement garage to use as a woodshop, and I am looking at the same unit. I think it's a 3rd generation now, and not sure what the difference is, if any. I will have 3 walls completely underground, and I am planning on putting 1 inch styrofoam insulation panels on them. The partition wall will have r12 insulation, and a 4 foot double hung French patio door. I've not decided whether or not to go with an inside or outside door unit. I'm wanting to use this type of door for the width opening and insulating factor. The double interior doors with without glass are usually hollow, unless they are solid wood.

The temperature here is usually 90+ in the summer, and averages 30 in the winter. so it shouldn't run much being underground. But I may have to use a sump pump for the condensation. I'm not sure yet if there will be enough of a drop for the drain hose to work without one.
 
#29 ·
It is working well except the thermostat control appears to be a little wonky. There is a 3 degree swing but overall I like it. I have ti set on 80, but it runs about 77. And that is with mid 90's outside.
 
#33 ·
Alot of these kind of units have a built in 2-5 degree dead band tied into into the programming. Basically designed to prevent the units from turning on/off every time there is a 1 degree swing in temp. With a 4 degree dead band, set to 76, unit will cool down to 76 shut off and not turn back on until temps hit 80. then the cycle repeats over and over. Same with heating. Set to 76, unit will heat to 76 then turn off, drop down to 72 before it turns back on.....some are adjustable.

with short deadbands, units start/stop more often but run for shorter periods of time. With long deadbands, units dont' start/stop as often but run for longer periods of time to read desired temps. IMHO its the start/stop cycle that is hardest on HVAC systems.
 
#34 ·
I'm in South Mississippi near the Gulf Coast where the humidity usually equals the temperature, well at least when it's above 90! In my location the humidity is as much of a problem as the temperature.

I had a 12K BTU window unit and my shop is in my detached garage where there is no insulation. It could keep up when I didn't let it get above 80-85 but above that temp, it just couldn't keep up. So I replaced that unit with a 24K BTU unit and it works, but takes a while to cool it down. My next project is to remove the ceiling (floor of attic floored for storage) and install insulation. Ceiling is drywall and almost thinking it would be better to put plywood back up rather than drywall. That would give me a lot more strength for hanging things like dust collection pipes etc.
 
#41 ·
I put OSB on my shop ceiling but it was because I knew that sooner or later I would be swinging something end for end and smack it into the ceiling. The OSB doesn't mind that and I painted it white so it reflects light almost as well as painted drywall does. With the price of drywall these days I don't think there would be much price difference.
 
  • Like
Reactions: Nickp
#35 ·
The only issue with running a unit that is substantially larger than the space for which it is designed is that it doesn't run long enough to dehumidify. It can pull the temp down just fine but a properly sized unit will dehumidify more efficiently.

Be sure you get plenty of help or a lift if you're going to put anything on the ceiling, even if you go back with drywall. Lifting anything overhead will wear you out quickly!

David
 
#36 ·
woefully misunderstood by most!!!! Excellent point made David!!!

Especially of interest to those who live in areas with prolonged high temp/high humidity levels. not to mention how it plays havoc on tools