ideas for cooling shop

[Mark Lawrence]

Just moved into new home with 3 car garage, about 750 sq feet. I moved from NY to southwest florida. In need of some ideas to make shop cool enough to work comfortably without spending a fortune. I bought a large commercial pedestal fan, but it just isnt enough. Ceiling fans? commeicial floor fans?

[Von Bickley]

When you find out, let me know.

[Doug Dawson]

Just moved into new home with 3 car garage, about 750 sq feet. I moved from NY to southwest florida. In need of some ideas to make shop cool enough to work comfortably without spending a fortune. I bought a large commercial pedestal fan, but it just isnt enough. Ceiling fans? commeicial floor fans?

For starters, get a decent dehumidifier, and run it continuously. It will stop your cast iron from rusting away to nothing.

Then, when that's not enough, install a mini-split. You can put one in for as little as a grand, if you're handy (and another few hundred to have it charged.)

[Lee Schierer]

Unless you are dedicating the entire garage to your work shop or partitioning off one bay, any time you open the garage doors you will pretty much negate any efforts to cool or dehumidfy your shop area. You will also need to close off the ceiling area and insulate the walls and ceiling. Each time a vehicle backs out an equivalent amount of outside air will be drawn in, not counting the cooler inside air draining out for the whole time the door(s) are open.

The good news is your body will acclimate to the warmer/humid weather after a year or so.

[Marc Jeske]

Is the garage insulated or not?

Vented, or not?
Various + and - on this issue, depending on what you do overall.
If you're gonna AC you want NOT vented.. EVEN if your insul is at ceiling level.

First, insulate the roof, easiest to do at ceiling level.

Insulate the walls.
Make sure your overhead doors are as tight sealing as possible.

Then buy a $800 24kbtu "window" AC and place in side of building you will spend most time in.

Has worked well for me in previous shop, and doing it again building new shop.

Marc

Marc

[Doug Dawson]

Unless you are dedicating the entire garage to your work shop or partitioning off one bay, any time you open the garage doors you will pretty much negate any efforts to cool or dehumidfy your shop area. You will also need to close off the ceiling area and insulate the walls and ceiling. Each time a vehicle backs out an equivalent amount of outside air will be drawn in, not counting the cooler inside air draining out for the whole time the door(s) are open.

The good news is your body will acclimate to the warmer/humid weather after a year or so.

Trying to be more comfortable in your garage in Florida is a tremendous incentive to never open the garage doors. ;^) Your body might acclimate eventually, but your tools won't.

I have this picture in my mind of rock drumming at its finest, with sweat spraying everywhere. (Yes I also live in a climate like that.)

[Greg Parrish]

I’m in Florida and have a 22 x 20 garage dedicated to my shop attached to our house. Still has the double car roll up door on one wall. One wall shared with house.

I had had a company come in and pump foamdown the walls not connected to house. Two walls and area over garage door. 54 holes worth that I had to patch. They also put insulation above the ceiling and radiant foil in rafters to match what we had in the house. Lastly installed foam insulation into inside panels of the garage door.

From there I had a Mitsubishi 18k btu mini split installed and I also run a portable dehumidifier full time. My current dehumidifier has a pump and sends water out a small aquarium filter sized tube to our washing machine drain pipe when the tank is full.

Long story short, I keep the air around 72 degrees and humidity around 45 to 50 percent year round and rust and issues seem to be under control. We limit usage of the big door to rare occasions so that helps too. But given the insulation and the size of our mini split and dehumidifier it only takes about 30 to 60 mins to overcome having the big door open for any length of time.

I wipe my my cast iron tops a few times a year with a spray of boeshield and a wipe with a blue shop paper towel.

[Jim Becker]

Insulate regardless, if it's not already thoroughly done. You choices for cooling from there in include window AC, portable AC or a MiniSplit. (I recently installed the latter and am totally, totally pleased with it. You could also do the swamp cooler thing which is traditional in many southern areas, but this evaporative cooling method isn't the same as AC will be for lowering temperatures and more importantly, lowering humidity.

[Marc Jeske]

Ya, swamp cooler may work in SantaFe, not so much in Hot/Humid.

We have a local Lumberyard that has a swamp cooler running in the AC'd showroom.

People walk by and it feels SO nice.

Ya, wait till they get it home.

Pretty silly.

Gonna be some unhappy customers.

Absolutely no humidity reduction, in fact the opposite.

Kinda like Lowe's Garden area selling plants only long term suitable for way different zones.

Caveat emptor.

Marc

[Bill Dufour]

If you go mini split pay a few hundred extra and get the heat pump version. First step is make sure the roof is white. I wonder if dark solar panels with air flow gaps under cool or heat the attic below?
Bill D.

[Brice Rogers]

Bill, it the solar panels are for a swimming pool, then they would cool the attic below. But more importantly, they would keep the sun from beating down directly on the roof.

If the solar panels are photovoltaic (producing electricity), they will shade the roof from the direct rays of the sun. The panels get warm in the sun and they would re-radiate a little heat from the backside. The panels that I've seen are white on the back so they would re-radiate less. Not sure if that is standard across the industry. So, while they won't cool the attic, they will reduce the heat gain from the sun.

On outdoor video surveillance cameras in the sun, they often have a solar shield. It is nothing but a piece of aluminum spaced about 1/2" to 1" above the primary housing. But it helps a whole lot.

[Greg Parrish]

.
On outdoor video surveillance cameras in the sun, they often have a solar shield. It is nothing but a piece of aluminum spaced about 1/2" to 1" above the primary housing. But it helps a whole lot.

thats pretty much what the foil on inside of our rafters does. Blocks solar radiation and creates an air barrier gap.

[Mark Lawrence]

If you go mini split pay a few hundred extra and get the heat pump version. First step is make sure the roof is white. I wonder if dark solar panels with air flow gaps under cool or heat the attic below?
Bill D.
What is the advantage of the heat pump version? Obviously, I don't need to heat the space.

[Jim Becker]

What is the advantage of the heat pump version? Obviously, I don't need to heat the space.

Honestly...a lot more selection. There are very few AC only MiniSplits on the market compared to the "full" versions that go both ways.

[Robert Engel]

Humidity is probably a bigger problem because of rust issues and wood movement problems.

AC is the only real solution here. I wouldn't insulate unless you are going with AC. I live in FL & from personal experience when its 90°+ outside with 80%+ humidity it won't make that much difference. You'll open the garage door & turn fans on and it will be as cool as it will get in a about 10 minutes.

I think you have to look at insulating and installing AC if you want to have a bearable work environment. Choices are standard heat pump or mini split. I wouldn't recommend a window ac.

It will add to the value of the house, too.

[Osvaldo Cristo]

Just moved into new home with 3 car garage, about 750 sq feet. I moved from NY to southwest florida. In need of some ideas to make shop cool enough to work comfortably without spending a fortune. I bought a large commercial pedestal fan, but it just isnt enough. Ceiling fans? commeicial floor fans?

White external walls and ceilings. Concrete floor and lots of natural ventilation. For the humidity, oil pot always available near you for constant use for your tools.

I live in a tropical area, actually our home is only 10 km South of Tropic of Capricorn. My shop is in the basement, so semi buried. Concrete walls, ceiling and floor... great thermal inertia. Good natural ventilation. I can work year around comfortably there.

[Carlos Alvarez]

A swamp cooler definitely won't work there. It becomes useless (makes things worse) around 50%. It's phenomenally good in Phoenix right now with sub-10% humidity. Feels like a 20 degree drop or maybe more.

[Alan Lightstone]

I converted my garage in SW Florida to a workshop. Best investment ever was a split A/C unit.

I have a rule to never open the garage door, unless I truly have no choice, when it rains. The cast iron tries to rust immediately after that.

Spray your cast iron tops with CRC 3-36 (available on Amazon, one of the woodworking magazines rated it the highest for preventing rust a few years ago, and, IMHO, I feel it works far better than Boeshield).

You'll love the working conditions. Don't forget to clean the cheap filter on the A/C often. I added blown insulation in the ceiling, which did noticeably help.

Where in SW FL are you located?

[Mark Lawrence]

I converted my garage in SW Florida to a workshop. Best investment ever was a split A/C unit.

I have a rule to never open the garage door, unless I truly have no choice, when it rains. The cast iron tries to rust immediately after that.

Spray your cast iron tops with CRC 3-36 (available on Amazon, one of the woodworking magazines rated it the highest for preventing rust a few years ago, and, IMHO, I feel it works far better than Boeshield).

You'll love the working conditions. Don't forget to clean the cheap filter on the A/C often. I added blown insulation in the ceiling, which did noticeably help.

Where in SW FL are you located?

Just moved to Cape Coral.

I put 70 pint dehumidifer in and pump the water out under the garage door. My exterior walls are concrete block and the house is painted a light beige color both in and out. I doubt there is any insulation in the concrete wall of the living space, but the AC in the house is great (new home) so I'm thinking I won't need to insulate the garage walls. I will insulate the garage doors, however.

I had 2 insulation contractors give me estimates for the attic. ONe recommended spray foam for the underside of the roof (R20- saying it performed much better than blown in). Estimate was $1100. The other estimate came through HD for blown in R30, @ $1650. Opinions, please.

As for the split AC, any recommendations on size of unit? Brand? Is this something I should buy from Amazon, install the unit myself and just pay an HVAC guys to do the hook ups?

[Bill Dufour]

For the humidity, oil pot always available near you for constant use for your tools.

I never heard of this idea but it might stain wood. I have heard of a bucket of water to keep tools in when working outside in summer sun. Mostly for mechanics tools which have lots of oil and grease on them already. I suppose now mechanics wear gloves instead.
Bil lD

[Mark Lawrence]

So I got the garage attic insulated, and I'm having a 24,000 btu, 19 Seer split unit installed this week. I'll also insulate the garage doors.

I purchased a 70 pint dehumidify as well. Is the dehumidifier still necessary once I put in the A/C?

[Van Huskey]

I purchased a 70 pint dehumidify as well. Is the dehumidifier still necessary once I put in the A/C?

No, as long as the mini-split is properly sized (runs often enough) the humidity should stay in the low to mid 40% range.

[Jim Dwight]

My 14x24 shop garage is walled off from my 20x24 car garage. The walls and ceiling are insulated as is the single garage door in one end. If I run the AC in the bedroom above my shop, the shop is comfortable. But the bedroom is rarely occupied these days so I turn the temperature up to 90 F. That lets the shop get pretty hot. In the morning, if I open the doors on both ends of the shop, it is OK. But in the afternoon, when it is 90+ and the humidity is 80-90%, it is not a lot of fun to work in the shop. I sanded for a couple hours on two different evenings to get my grandsons blocks done before his visit this week and was dripping by the time I quit. I may have to do something. With my level of insulation and only a little over 300 ft2, I think a small window unit will make the shop OK. I don't want it 72, I would be cold, but I think I can get it under 80 where I will be fine. I keep the house at 78. My son has a unit I could probably borrow to try out my theory.

The only time I had an issue with rust on the tools was when water came down the driveway and was a couple inches deep briefly in the shop. Since the road was paved (and the slope changed) I've had no flooding and the tools don't rust, with no AC or dehumidifier. You will get condensation if you let humid air come into contact with tools below the dew point of the air. But if the shop is as hot as the outside and don't have a water source, you won't have condensation. If you lower the temperature with AC, you will also reduce the dew point and should be fine. When I run the AC above the shop and the temperature goes down in the shop, I am at some risk but have noticed no issues. Long way of saying I still am not thinking of a dehumidifier. I do not see a problem it would solve.

I'm in central South Carolina. It may not be as hot and humid as FL but it's close.

[Mark Lawrence]

Got the split installed yesterday. Wow, it's incredible! Now all that's left is the garage door insulation.

No more excuses. Got to figure out most effective floor plan and do the lighting and electric.

[Todd Mason-Darnell]

Got the split installed yesterday. Wow, it's incredible! Now all that's left is the garage door insulation.

No more excuses. Got to figure out most effective floor plan and do the lighting and electric.


Congratulations...you will love it. The best thing I did was to decide to condition my shop full time, not just when I was in it.

[Jim Becker]

Got the split installed yesterday. Wow, it's incredible! Now all that's left is the garage door insulation.



I am continually amazed and pleased at how efficient my MiniSplit is in the shop...our electric bill has barely budged, too. I guess the 20 SEER rating of my unit isn't a terrible thing! It's also very comfortable to work in there now because of the humidity reduction and air movement. I run it at 74ºF and it takes mere minutes to "get there" after I turn it on, even in the middle of a hot day.

[Ben Rivel]

Jealous! I cant wait to put a mini split in my garage! Hope youre enjoying it!

[Doug Landphair]

While it's not Florida, the humidity and heat in Tennessee are similar - it just doesn't last as long as it does in Florida. I have a detached 24 x 24 shop. My contractor installed a heat pump wall unit just like you'd find in a hotel room. As I recall, it was about $800 10 years ago. No idea what it would cost now but it works well enough to keep the shop cool during the hottest part of the summer and warm enough during the coldest part of winter. It might be something worth looking into.

[Stew Hagerty]

Like you, I have my shop in a 3-car garage. Unlike you, I am most definitely NOT in Florida. I live in NE Indiana, where it still gets into the 90's for days at a time, and with humidity levels also in the 90's. But it doesn't stay like that for 9 or 10 months out of the year. That said, I still wanted my garage to be cooler. It was already well insulated and had 5/8" fire code sheet rock on the walls. I also have 2" thick insulated steel "sandwich" style overhead doors. So it stays comparatively warm in the winter and cool in the summer. The first thing I did was to install a vent in the duct that runs up the side of my HVAC unit (aka furnace) which, since it is an attached garage and my home is on a slab, just happens to be in my garage. The duct runs from the plenum to the humidifier. Adding that vent provided the perfect amount of additional heat to make the shop comfortable all winter, but didn't quite do enough in the cooling department to suit me. So I started looking at mini-splits and I really liked the features and amount of cooling they could provide. Then I looked at the prices and stopped looking at mini-splits.

As I was browsing for alternatives, I found this: https://smile.amazon.com/gp/product/B0028AYQDC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

390505
(https://smile.amazon.com/gp/product/B0028AYQDC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)

Instead of mounting the intake & exhaust hoses though a window (I don't have windows in my garage), I cut back the siding and installed a mount like the ones used to put exterior lights on. Then I cut holes in the wall and ran the ports through the mounting block. Since the ports come with caps, I now have a permanent installation. That extra 14k BTU's of cooling make all the difference. I can work out there in total comfort on all but the 1 or 2 hottest days of the year. And since it also works as a self draining dehumidifier I have never had any problems with my tools rusting.

If anyone is interested, I would be happy to share photos of my setup.