This is the Secret to the Coldest Portable Garage Air Conditioner, and in this guide you will learn the one gigantic trick that I use to get the most from my garage air conditioner.
If You Like My Posts, You'll Love My Books
Portable Garage Air Conditioner
I live in the Arizona desert, and as I am writing this, we are in the middle of breaking a record for the most consecutive days of 110 degree of higher temperatures. Also, my woodworking shop is actually a fancy way of saying my garage, which is hot, especially when it reaches 118 degrees outside.
After talking to a friend, he gave me an idea that literally turned my portable air conditioner into the best garage air conditioner that I have ever had. The trick is not expensive, and you can knock out the entire project in a couple hours.
I’ll show you everything you need to know to take your portable air conditioner and make it perform better than it should, and if it works in my shop when it’s over 110 degrees outside, it will surely work for your shop too. Even if you need an air conditioner for a garage with no windows, this will work. Enjoy.
Portable Air Conditioners and Woodworkers
When you buy an air conditioner for your woodworking shop, or for your garage no matter what you make, the first thing you do is look at the rating on the box. Specifically, the number of square feet that the unit can handle.
Come See What I'm Making on Etsy!
That right there is the start of making your air conditioner work well. Pick something that is rated for as many square feet as you can. For reference, mine is rated for 450 square feet, and my shop is 240 square feet, so I’m already off to a good start by getting a unit that is more powerful than needed.
After that, you want a unit that you can move around, so a portable garage air conditioner is the best choice. If you haven’t bought one yet, get one. If you already have an air conditioner that you use in your garage, don’t worry, this will still work for you.
See Also: 7 Tips for Using a Portable Air Conditioner for the Garage
How Much Space Do You Need
The next step is to think about how much space you need, and specifically how much of your workshop do you actually work in. If you are like most craftsmen, you only work in a small area of your shop, normally right near your bench.
Well, if you only work in a small section of your garage, why would you need to air condition the entire area? It makes no sense, because not only will it take longer to cool down a larger space, it will not be as comfortable, because garages are notoriously hard to cool.
That’s the first part of the solution. Define where you do the majority of your work, and think of how you can place the air conditioner in that area, or change your hop layout to be closer to your air conditioner assuming it’s a window unit that is not as easy to move around.
Separating the Garage for an Air Conditioner
The next step, and truly the secret to the coldest portable garage air conditioner possible is to cut off a section of your shop that you will work in primarily, and seal it so you only have to cool one small area rather than the whole space.
For me, I work almost exclusively at my lathe, and my bench, which are right next to each other. This actual space is about 10 feet by 12 feet, or 120 square feet total. It is much easier, and faster to cool down a space that is 120 square feet than my shole area of 240 square feet, so the air conditioner works so much better.
Come See What I'm Making on Etsy!
Not only is it easer for the unit to work, it cools the area faster, and works less than running the unit to try and cool the entire garage. You can also open the garage door if you like, and not ruin your precious cold air.
See Also: 12 Tips for the Best Garage Lighting Layout
How to Partition Your Garage for an AC Unit
The next question is how to partition the shop and trap that awesome cold air. That is the second part of the secret, and it involves moving blankets. Yes, simple moving blankets that you can get from any hardware store, or moving company.
For most single car garages, four blankets will do the trick. You sew two of them together to form a large curtain, and then hang them from hooks in the ceiling.
There is a mall gap at the top where the hot air can escape, and the blankets go all the way to the floor so the heavier, cold air doesn’t escape.
Use a set of small hooks that screw directly into the ceiling and some metal grommets to hang the moving blankets much like a shower curtain. Place the hooks every four to six inches and even though they are only good for a couple pounds of weight, collectively they will hold well.
If You Like My Posts, You'll Love My Books
Also, overlap your curtain by a couple feet, so that you thoroughly seal the gap between the two drapes, holding that air conditioned air inside.
See Also: 16 Great Tips for Setting Up a Workshop in the Garage
Ducting Your Portable Air Conditioner
Once your garage area has been partitioned, now you need to place your new air conditioner in a spot where you can vent it outside, and get the most cool air for your space. I recommend a corner, and somewhere that is close enough that you can blow it at yourself while you are in the shop.
For my shop, there was one outside wall, so I ucted it through the wall using HVAC parts that you can find at any home improvement store. They were not expensive, and if you can make a hole through your wall, you can install the rest of the parts.
In the end, it looks similar to a dryer vent that goes through the wall, just a larger version, since most portable garage air conditioners run a six inch vent. Also, the closer you can leave your air conditioner to that vent, the better, because the shorter the vent hose, the more efficient the unit.
Putting it All Together
Now, if your numbers are similar to mine, you have around 100 square feet to cool, and a unit that is capable of cooling about five times that space. You also have a moving blanket partition that has some insulating properties to it, and that will keep your section of the garage cooler.
When you turn on your garage AC unit, you will notice that it cools much faster than ever before, and that your area becomes more comfortable, faster. You will also notice that the unit doesn’t work as hard, and the temperature comes down faster.
You might even have to point the unit away from you, because after a while of running in a space that is a fifth of the space that your portable garage air conditioner is capable of cooling, it’s going to get very cold, and that should make you smile.
Come See What I'm Making on Etsy!
People Also Ask
Are portable air conditioners good for a garage? Yes, portable air conditioners are a great solution for a garage, as they offer easy installation, and quick cooling. You can also move the unit around, making it easy to direct the cool air exactly where you need it.
How do you vent a portable air conditioner in a garage without a window? You can vent a portable air conditioner in a couple ways, even if you don’t have a window. You can duct it through a wall, or you can use a long piece of foam panel that you place under your partially closed garage door, which you duct the hot air through.
Is it worth putting AC in the garage? It’s definitely worth putting a portable air conditioner in the garage, and it will make the space more livable, easier to use, and more fun to work in. They are not very expensive compared to larger units, and they move right where you need them.
What type of air conditioner is best for a garage? The best type of air conditioner for the garage is a portable unit, because you can put it where you need it, and make yourself feel cooler faster.
Portable Garage Air Conditioner Wrap Up
Now that you know everything you need to get the coldest air possible in your garage shop, it’s time to take action. I waited and waited on getting a garage air conditioner because I thought it was not going to work very well. Don’t do that.
Instead, get the darn thing, and install it. Then, partition off the area so that you can maximize the cooling power and decrease the time it takes to become comfortable in the shop.
As you know from earlier, I live in Arizona, and we just finished breaking a heat record set all the way back in the 70’s. If this works in my shop, it should work in yours, because unless you are my neighbor, you probably live in a cooler place than I do.
If you have any questions about getting a portable ac unit, please contact me and I will do my best to help you.
Post Author-

- More than 20 Years Woodworking Experience
- 7 Woodworking Books Available on Amazon
- Over 1 Million Words Published About Woodworking
- Bachelor of Arts Degree from Arizona State University
I receive Commissions for Purchases Made Through the Links in This Post.
Come See What I'm Making on Etsy!
You Can Find My Books on Amazon!
