Ac for Garage

[roadrunner255]

Hello all,

Looking for suggestions/sizes for an ac unit for my metal Garage.

Dimensions are 40x36 , 12' walls, 1/2 roof pitch or 14'3" to perlin.

6" insulation in ceiling, 4" in the walls and gd' are also insulated.

Building 3 sides are 6" stone over metal.

Like to get a ductless mini split, not sure if they make one large enough. Not sure if going with two smaller units would be an idea.

I do have 2 60" ceiling fans on one side.

Any suggestions?

I have plenty of power.

Cheers

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[6768rogues]

Mine is 36'x48' with a 14' ceiling. I have two window air conditioners, one being 18,000 Btu and the other 12,000 Btu. If I am opening the doors and driving in cars that have been outside with hot engines, I have to run both. If I keep the doors closed and leave the AC on, the smaller one with keep up. I am not in TX, but it does get over 90 degrees and humid here.

 

[theoldwizard1]

Like to get a ductless mini split, not sure if they make one large enough. Not sure if going with two smaller units would be an idea.

I have no idea how big of a unit you need but I am pretty sure you can get a single compressor unit that would handle that.

I would recommend at least 2 interior air handler. They can be plumbed in the same compressor. Much cheaper.

 

[Marctrees]

Listen to 6768 and be done at about $1k.

Edit - Let me up that to about $1300 for two units, plus the wiring.

Opposite ends of building or roughly so. Marc

 

[Brian_WK]

Hello all,

Looking for suggestions/sizes for an ac unit for my metal Garage.

Dimensions are 40x36 , 12' walls, 1/2 roof pitch or 14'3" to perlin.

6" insulation in ceiling, 4" in the walls and gd' are also insulated.

Building 3 sides are 6" stone over metal.

Like to get a ductless mini split, not sure if they make one large enough. Not sure if going with two smaller units would be an idea.

I do have 2 60" ceiling fans on one side.

Any suggestions?

I have plenty of power.

Cheers

Sent from my SM-N900V using Tapatalk

Yes they make them large enough and I would go with a 2 head unit single condenser. Mount them 8-10 off the ground on opposite ends.

Mine is 36'x48' with a 14' ceiling. I have two window air conditioners, one being 18,000 Btu and the other 12,000 Btu. If I am opening the doors and driving in cars that have been outside with hot engines, I have to run both. If I keep the doors closed and leave the AC on, the smaller one with keep up. I am not in TX, but it does get over 90 degrees and humid here.

This is a cheap option but also noisier and less efficient.

Listen to 6768 and be done at about $1k.

Opposite ends of building or roughly so. Marc

It all depends on what you are trying to accomplish for your space. Finished, secure, quite, efficient, better coverage and more expensive = mini split.
The opposite of this but cheaper go with 2 window units.

Brian

 

[Falcon67]

Dual 12K units with the fans might do it in Austin. Might pay to have someone come and do a real heat load calc. I've got 7680 cu/ft in my shop with about 18K keeping it decent with the doors closed. You've got 17,280 cu/ft - 24K might be marginal.

 

[roadrunner255]

Thanks all,

I wonder if I could get by with one window 15K unit, just to knock the inside temp down a bit. Until I can decide whats best for the building, outside of prime HVAC season.

Temp now outside 90 (feels like 95) with 53% humidity and 70% dew point.

Currently with the dehumidifier going (20%) humidity and 91 in the building, I could live with 80 in there.

Any better/best 15K brand units that folks are using?

Cheers!

 

[Falcon67]

Not sure about "best" but the 8K LG I bought for the tool room two years ago works very well, compared to the cheap house brand 6K I got from Lowes the year before that - that only lasted one year. The other unit I have in the shop is a 10.5K Samsung. We've had that one 10~12 years now.

>Temp now outside 90 (feels like 95) with 53% humidity and 70% dew point.
We'll be at the drag strip all day tomorrow, heat index here is predicted at 110+. Right now it's 101.

 

[Marctrees]

15k for that volume?

Definately 24 25 .

Even then it will be limited benefit in the opposite end of building.

LG has good price seemingly decent quality in a sleeve mount at Walmart, free ship.

Better ratings if you believe them in other venues, best price total Walmart.

They have larger ones in same seeming product line.

I recently bought and installed an LG 12k for my Uncle, happy so far.

$340 for that size.

It was the sleeve mount also. Marc

https://www.walmart.com/ip/LG-LW121...-Air-Conditioner-with-Remote-Control/50703857

 

[Marctrees]

Sadly, there is not a single window ac made in US anymore.

Last hold out was Friedrich in TX, but that stopped ballpark 10 15 yr ago.

Marc

 

[Marctrees]

We are building a shop very similar size and insulation to what you have, and planning 2 X 24k LG's on opposite ends.

Marc

 

[6768rogues]

Mentioned my window units up this thread and a comment was made about noise. I don't sleep in the garage but I often have a TV mounted high on the wall on while I am working and I don't even notice the sound of the air conditioners. One cost about $400 and the other about $200. If one dies, I have the other to get me by and replacement is easy and cheap. On two occasions, our house central air died and I put the smaller barn unit in our bedroom window to limp along for a day or two until the central air was fixed. I put them in for the summer in about 15 minutes and it takes another 15 minutes to remove them in the fall, so they are not exposed to winter weather.
A couple of days ago it was 90 degrees and humid outside, but I was in the shop working in 67 degree comfort.

 

[Falcon67]

Neither of my units make much noise at all. Very low volume. No problems watching TV or listening to radio. There is a little surge in sound level when the compressors start up, but not much and goes down quick as they settle in. Not any worse than the house unit.

 

[Fueler]

My shop is similar to the OPs. I bought a 36K Klimaire split unit. That was 3 years ago. Works just right. Yesterday it was 90 with 47 percent humidity. Nasty stuff. Inside a cold 75 with machines running. I look to add even more insulation in the future.

The nice thing about AC is the more humid out the better they put out or so it seems.

The heater side isn't bad either. It will work down to around 36 degrees. Below that it is a bit iffy. I have used it alongside my propane tube heater and managed to cut my propane costs.

If one goes this big be aware it is a large unit. The outside wall brackets they try to sell you are woefully weak for this size unit. Had to build my own. Other than that, piece of cake.

Just installed a Mr Cool 12K on one end of my ranch and ditched the window units that generally had to be replaced every couple of years or so it seemed.

It is almost enough AC for the whole house. Going to install another one on the other end of the house to level it out.

Lordy, these things are quiet. The house is so quiet now at night it's unnerving.

 

[roadrunner255]

My shop is similar to the OPs. I bought a 36K Klimaire split unit. That was 3 years ago. Works just right. Yesterday it was 90 with 47 percent humidity. Nasty stuff. Inside a cold 75 with machines running. I look to add even more insulation in the future.

The nice thing about AC is the more humid out the better they put out or so it seems.

The heater side isn't bad either. It will work down to around 36 degrees. Below that it is a bit iffy. I have used it alongside my propane tube heater and managed to cut my propane costs.

If one goes this big be aware it is a large unit. The outside wall brackets they try to sell you are woefully weak for this size unit. Had to build my own. Other than that, piece of cake.

Just installed a Mr Cool 12K on one end of my ranch and ditched the window units that generally had to be replaced every couple of years or so it seemed.

It is almost enough AC for the whole house. Going to install another one on the other end of the house to level it out.

Lordy, these things are quiet. The house is so quiet now at night it's unnerving.

Thanks all, I will look into getting a dual mini split (two inside units) in the fall, with wi-fi, would be nice to lower the temp in the summer before I work in the building.

Other than the Kliamie are there other dual mini splits suggested?

Two inside units would probably be better than one large since I have a steel beam right at 20' in the front and back walls (40' length)?

I would like to go with one larger outside unit.

Cheers!

 

[James-W]

We are building a shop very similar size and insulation to what you have, and planning 2 X 24k LG's on opposite ends.

Marc

I am in agreement, if you are opening the large overhead doors quite a bit, then having two 24K BTU window units makes good sense. One 24K BTU window unit would probably do the trick if you keep the doors closed most of the time.

 

[Marctrees]

Well, we figure both AC units to do initial cooling, seeing as shop will be used NOT every day, and then, differing hours.

Doors will remain closed, as wanted.... NOT an in/ out shop... a Home shop.

So we figure barn exhaust fans for 30 minutes to get much heat out, while doors open... then both ac's for a couple hours or as needed, then shut one down or turn down both as needed for extended work hours. Marc

 

[James-W]

I am not sure you would need exhaust fans, but it certainly couldn't hurt. My thinking is that running the two 24K BTU A/C units you will have 48K BTU's and that is quite a bit of cooling capacity. Within a few minutes you should start to feel the cooling and within half an hour I think it will be half-way comfortable in the shop.

 

[Marctrees]

James - Very possibly true.

We're still putting in the output fans for any fumes, some dust, but mostly when it's time of year that air is cooler outside. Marc

 

[mpire]

Just keep in mind if your garage doors don't seal well then you will need to up the cooling capacity to compensate.

Ignore SEER or efficiency ratings, as they are useless in a garage AC that you won't be running every day. Any extra costs for more efficiency will not be recouped over the life of the system.

 

[Mike99]

Im in the process of drilling a 6 inch hole in the top of the wall 2 feet above the attached garage floor from the basement side. I plan on running one of the ducts from the laundry room imto the garage mostly for heat in the winter but with the added benefit of ac in the summer.Im installing 220ac unit heater as well so this setup should keep my hydro bill under control. $100 to drill a hole.

 

[CGKing]

Hello all,

Looking for suggestions/sizes for an ac unit for my metal Garage.

Dimensions are 40x36 , 12' walls, 1/2 roof pitch or 14'3" to perlin.

6" insulation in ceiling, 4" in the walls and gd' are also insulated.

Building 3 sides are 6" stone over metal.

Like to get a ductless mini split, not sure if they make one large enough. Not sure if going with two smaller units would be an idea.

I do have 2 60" ceiling fans on one side.


Any suggestions?

I have plenty of power.

Cheers

Sent from my SM-N900V using Tapatalk

I would like to discuss your insulation as I am not understanding "6" in Cieling and 4" in walls"...of a metal building? Like to know what you go with AC wie as well.
I am in Georgetown, we should go for a ride sometime. 2014 FLHXS.

 

[roadrunner255]

Yes they make them large enough and I would go with a 2 head unit single condenser. Mount them 8-10 off the ground on opposite ends.

This is a cheap option but also noisier and less efficient.

It all depends on what you are trying to accomplish for your space. Finished, secure, quite, efficient, better coverage and more expensive = mini split.
The opposite of this but cheaper go with 2 window units.

Brian

After reviewing the instructions for a Mitsubishi 2 zone mini split, can/should the lines exit the building in the same hole?

I could run the lines inside and exit the building in one hole then down to the condenser, instead of drilling 2 holes and running the lines over and down to the condenser.

Cheers!

 

[6768rogues]

Im in the process of drilling a 6 inch hole in the top of the wall 2 feet above the attached garage floor from the basement side. I plan on running one of the ducts from the laundry room imto the garage mostly for heat in the winter but with the added benefit of ac in the summer.Im installing 220ac unit heater as well so this setup should keep my hydro bill under control. $100 to drill a hole.

Here it is against code to share house and garage air. Are you doing it with no return? That would pressurize the garage, forcing air to escape or deadheading the duct. Then the house will be under negative pressure, since some of the air is going to the garage. The house will **** air through every crack from the outdoors. Not a very efficient setup.

 

[Mike99]

Here it is against code to share house and garage air. Are you doing it with no return? That would pressurize the garage, forcing air to escape or deadheading the duct. Then the house will be under negative pressure, since some of the air is going to the garage. The house will **** air through every crack from the outdoors. Not a very efficient setup.

The plan is to pressurize the garage to approximately 2 psi bringing the altitude down to 2000 feet bsl. Good for the health. Kinda like being on the shores of the dead sea. Of course I had to boost my furnace fan motor and install an out flow valve in the garage which I picked up cheap at an airplane scrap yard. Out flow valve is pressure controlled by vacuum which I can set from inside the house. Mounted pressure controller right beside the thermostat. And yes I did pressure test the garage. Its good to 4 psi before windows blow out. Dont need explosive decompression while your bbqing.

 

[AJ1978]

Mini-splits.... Pay now or Pay later. I have a 40x40 commercial shop well insulated with 2 garage doors. Had local AC contractor put mini split in this garage. Instant difference. My electric bill does not change summer to winter, winter I have a waste oil burner which requires more from compressor.

Side note, before the garage I had the same contractor place a mini split heat pump in my dads house, getting rid of the window unit.... My electric bill went down 40.00 a month from and 11,000 btu window unit..

 

[roadrunner255]

I would like to discuss your insulation as I am not understanding "6" in Cieling and 4" in walls"...of a metal building? Like to know what you go with AC wie as well.
I am in Georgetown, we should go for a ride sometime. 2014 FLHXS.

PM me

Thanks

 

[roadrunner255]

Update, returned the Window ac unit, unused decided to go with 2 1.5 ton mini splits.

Question about running the electric to the outside unit, are you allowed to run THHN without conduit in the speed channel along with the line set and drain hose?

I understand you have to have a disconnect, then a whip to the condenser from the disconnect.

Cheers!

 

[Double J]

Update, returned the Window ac unit, unused decided to go with 2 1.5 ton mini splits.

Subscribed. What units did you decide on?

 

[roadrunner255]

Subscribed. What units did you decide on?

Still trying to decide between Pioneer, blueridge, and Mitsubishi.

I'd like the Mitsubishi however, the cost is 2.5 times the others, I like the Pioneer over the Blueridge (better SEER and only requires a amp breaker vs 25 for the Blueridge).

Thanks

 

[ruidoso]

i have been using this supplier, www.thermospace.com

nice selection and free delivery, I have purchased and installed 3 units in 3 years. ( all new installs not replacements) am on my 3 year with a 24000 btu Air Con unit. if you take a close look at the pricing a 24000 is almost cheaper than a 18000. I currently just installed a 24000 btu in a 30x50 pole barn with min insulation (r-3) and open rafters. it was 103 degrees here last week and barn didn't get over 80 degrees with very low humidity.

 

[ruidoso]

Saw this today also, not a bad deal
http://breezzone.com/

they have a 24,000 btu air con for less than $1000

 

[Double J]

Still trying to decide between Pioneer, blueridge, and Mitsubishi.

I'd like the Mitsubishi however, the cost is 2.5 times the others, I like the Pioneer over the Blueridge (better SEER and only requires a amp breaker vs 25 for the Blueridge).

Thanks

Are you looking to go with two separate outdoor units or one outdoor unit that runs two indoor units (believe they refer to them as 2-zone units)? Just curious because I've been looking at something like this Mr. Cool 2-zone. I agree with you that its probably a better idea to have two indoor units with larger sqft garages.

 

[roadrunner255]

Are you looking to go with two separate outdoor units or one outdoor unit that runs two indoor units (believe they refer to them as 2-zone units)? Just curious because I've been looking at something like this Mr. Cool 2-zone. I agree with you that its probably a better idea to have two indoor units with larger sqft garages.

Less expensive and better reducancy going with 2 @ 1.5 ton single zone units since power is not an issue.

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[Black Oak]

A 36K comp. w/ 2 18K air handlers would be my choice down there in Texas. 12 ft. walls means lots of cu. ft. to keep cool. They can throttle back as needed.Also, poor install usually means trouble .Get a pro if you need to.

 

[Black Oak]

Two 18K single head units is also perfectly fine. For some guys it is a budget decision as much as anything else.

 

[Double J]

That's crazy that two separate units are cheaper that one with two handlers.

 

[ruidoso]

Looks like 2 24K are cheaper than a dual head 36K