What size BTU mini-split for high ceiling garage?

[maximus20895]

Hello,

Building a garage and I am getting different results on BTU calculators, mainly because of the high ceiling garage. I tried to give as much info as I could in the picture. Planning on putting a mini split in the garage so it doesn't get too hot when I work out there. I would like to maintain a temp of ~90 year around and 75 or so when I'm working for a few hours.

I also don't really know how high to place the mini split since it's such a high ceiling; I was thinking around 7" or so since I do not want to cool the ceiling. All walls are insulated ( don't know R-value sorry) as well as the garage door. The pink box is where I would like to attach the mini splits.

If anyone could help me get a ball park figure on the BTU size that would be really helpful.

Thank you so much.

 

[PoorUB]

2 to 3 tons should do it assuming proper insulation. 2 probably will do it, 3 will for sure do it.

What are your calculators telling you?

 

[u3b3rg33k]

Minisplits can adjust their BTU to the load, so oversizing a bit is not the problem you have when you oversize a single-stage unit. if 3T isn't out of budget, it'll just pull down to the setpoint that much faster. I'd vote 3 ton.

 

[maximus20895]

2 to 3 tons should do it assuming proper insulation. 2 probably will do it, 3 will for sure do it.

What are your calculators telling you?

Around 18k to 36k, but it wasn't really consistent. I really appreciate your help!

Minisplits can adjust their BTU to the load, so oversizing a bit is not the problem you have when you oversize a single-stage unit. if 3T isn't out of budget, it'll just pull down to the setpoint that much faster. I'd vote 3 ton.

OH, okay I didn't know that. Thanks very much!


Would it be advantageous to install to head units that are 18k each in the garage or would one be just fine? My thinking was more cfm of cool air? May be way off here, just a thought.

Again thanks so much to you both!

 

[kelpaso1]

2 to 3 tons should do it assuming proper insulation. 2 probably will do it, 3 will for sure do it.

What are your calculators telling you?

Why do people still use the "tons" measurment for BTU's. Stuck in the old days I guess

 

[u3b3rg33k]

if you can do math, the units don't matter. they sell equipment sized in tons, so that's what everyone else uses to do their math?

Around 18k to 36k, but it wasn't really consistent. I really appreciate your help!



OH, okay I didn't know that. Thanks very much!


Would it be advantageous to install to head units that are 18k each in the garage or would one be just fine? My thinking was more cfm of cool air? May be way off here, just a thought.

Again thanks so much to you both!

I prefer single headed minisplits for the better turndown ratio, and it's less confusing for installers/techs that aren't well versed. your layout would seem to strongly prefer a two head system due to the odd shape.

 

[PoorUB]

Why do people still use the "tons" measurment for BTU's. Stuck in the old days I guess

We had this discussion a while back. It is a regional thing would be my guess.

Just let it go. You didn't win last time you brought it up, although you probably think you did.

We even posted links to manufacturers web sites using tons to describe sizes. I suppose the manufacturers are out of line too.

12,000 BTU = a ton, always has, always will. It is not very difficult math.

Some people drink soda, some people drink pop,

 

[PoorUB]

I would go two heads in you case too with the odd shaped building.

There can be some benefit to two separate units. If one fails, you still have the other so you have some cooling. There is not much more money involved with two units over a multi head.

 

[kelpaso1]

We had this discussion a while back. It is a regional thing would be my guess.

Just let it go. You didn't win last time you brought it up, although you probably think you did.

We even posted links to manufacturers web sites using tons to describe sizes. I suppose the manufacturers are out of line too.

12,000 BTU = a ton, always has, always will. It is not very difficult math.

Some people drink soda, some people drink pop,

Heheh, Ya I guess. Here in Canada you never hear anyone say tons, it's always BTU's.

 

[vavet]

I'm happy with my 18k for a 768 sq ft building in Virginia. My highs aren't as high as yours...but I have a lot more humidity.
In Phoenix, you're not getting the cooling effect by pulling moisture out of the air.
I know you're just looking for an answer, but I'd like to understand how the humidity affects the BTU/sq ft.

 

[u3b3rg33k]

We had this discussion a while back. It is a regional thing would be my guess.

Just let it go. You didn't win last time you brought it up, although you probably think you did.

We even posted links to manufacturers web sites using tons to describe sizes. I suppose the manufacturers are out of line too.

12,000 BTU = a ton, always has, always will. It is not very difficult math.

Some people drink soda, some people drink pop,

well...
12,000BTU/hr = 1 ton (per day)
288,000BTU = 1 ton (per day)

because 1 ton of cooling came from the cooling you got per ton of ice, delivered, daily.

anyways my point is time matters

 

[ace10]

Two heads better than one.
Ceiling fan in the taller section.
Blockout window coverings, even if they're just heavy roller shades will help.

But IMO, you're going to be asking a lot for a system to drop temps by 15F on demand.

 

[PoorUB]

well...
12,000BTU/hr = 1 ton (per day)
288,000BTU = 1 ton (per day)

because 1 ton of cooling came from the cooling you got per ton of ice, delivered, daily.

anyways my point is time matters

Sure, but in this case I am pretty confident everyone knows what is going on

If you told someone in the USA you were running 80 down the interstate they would assume MPH, not FPS. I can see where KPH might get confused instead of MPH say in Canada, but a ton is 12,000 BTU all over the world.

 

[maximus20895]

Thanks everyone! I really appreciate it!

I probably will look into a 2 head unit.

I just have to find a good brand what what fits my needs now.

Again, thanks so much for the help!

 

[Jim greengo]

Why do people still use the "tons" measurment for BTU's. Stuck in the old days I guess

Because most of us are in America.

 

[Jim greengo]

Around 18k to 36k, but it wasn't really consistent. I really appreciate your help!



OH, okay I didn't know that. Thanks very much!


Would it be advantageous to install to head units that are 18k each in the garage or would one be just fine? My thinking was more cfm of cool air? May be way off here, just a thought.

Again thanks so much to you both!

I'd use 1 on each end of the long part of garage,and a 3rd for the smaller part if you can get a 3 head system.

 

[maximus20895]

I'd use 1 on each end of the long part of garage,and a 3rd for the smaller part if you can get a 3 head system.

Hmmm. The small part of the garage would be a long run, but worth thinking about!


Thanks!

 

[Jim greengo]

Hmmm. The small part of the garage would be a long run, but worth thinking about!


Thanks!

I was thinking length wise. Hahaha
Just did the math again,the 20x20 is the smaller part of the garage sq footage wise.
So I'll stick with my origional story and say 1 head there,and 1 on each end of the 45'section of garage.

 

[u3b3rg33k]

Sure, but in this case I am pretty confident everyone knows what is going on

If you told someone in the USA you were running 80 down the interstate they would assume MPH, not FPS. I can see where KPH might get confused instead of MPH say in Canada, but a ton is 12,000 BTU/hr all over the world.

fixed that for you.

 

[maximus20895]

I was thinking length wise. Hahaha
Just did the math again,the 20x20 is the smaller part of the garage sq footage wise.
So I'll stick with my origional story and say 1 head there,and 1 on each end of the 45'section of garage.

Not sure what you mean length wise? All I'm saying is to run the ac lines, I would have to go up 10 or so feet, across 15 ft and down 10 or so feet at the minimum if I wanted to instead a head in the small section :/

 

[PoorUB]

fixed that for you.

I bet you are a blast at a party!

 

[JunkBonds]

Heheh, Ya I guess. Here in Canada you never hear anyone say tons, it's always BTU's.

Not in southern Ontario. A/C is always tons and furnaces btu's.

 

[Jim greengo]

Not sure what you mean length wise? All I'm saying is to run the ac lines, I would have to go up 10 or so feet, across 15 ft and down 10 or so feet at the minimum if I wanted to instead a head in the small section :/

Well 1 area is 45' front to back,the other is 22' according to your drawing.
I cant explain it much plainer than that,but do it however ya want.

 

[maximus20895]

Sorry, I didn't mean to offend you.

All I was saying is any wall other than the long 45 will be long run for the ac lines.

Again, I'm sorry and thanks for the help!