AC Benefit?
- Thread starter FL Guy
- Start date
mike93lx
ALLIANCE MEMBER
If your garage is warmer than you want it to be, your garage will benefit from an air conditioning unit
I understand that.
At what point do you know if your garage is insulated enough to accommodate a AC unit without wasting $$ on one?
mike93lx
ALLIANCE MEMBER
I guess wasting money is relative.
When you need cooling, is it a waste? If you are already insulated, it's unlikely you will pay back on adding more. A load calc will tell you what size and you can adjust insulation values to see how the sizing will change.
If you have been getting by without cooling, I would bet that means you are pretty well insulated
Shiftless
Well-known member
One time expense of insulation vs. monthly expense of electricity… your choice
Some guys run AC with no insulation at all.
Other guys have excellent insulation and no climate control at all.
More than a few live in harsh climates and have an uninsulated building with no climate control and either “tough it out” or just stay out of the garage until the weather gets better.
Without knowing any of your particulars, no one can answer your question with any authority. If your walls are open, and you are considering finishing your garage, I would say that installing normal levels of insulation in the stud cavities is a good idea. Like R-13 in a 2x4 framed wall. The ceiling/roof needs more. Also, pay attention to air leaks. If you have a lot of gaps around the garage door for example, you are losing heat in the winter and gaining unwanted heat in the summer.
Where are you located? How big is your garage? Any windows?
Some guys run AC with no insulation at all.
Other guys have excellent insulation and no climate control at all.
More than a few live in harsh climates and have an uninsulated building with no climate control and either “tough it out” or just stay out of the garage until the weather gets better.
Without knowing any of your particulars, no one can answer your question with any authority. If your walls are open, and you are considering finishing your garage, I would say that installing normal levels of insulation in the stud cavities is a good idea. Like R-13 in a 2x4 framed wall. The ceiling/roof needs more. Also, pay attention to air leaks. If you have a lot of gaps around the garage door for example, you are losing heat in the winter and gaining unwanted heat in the summer.
Where are you located? How big is your garage? Any windows?
Firebrick43
Well-known member
Are you wanting to AC all the time or just when your out there. If the latter you good. If the former you might want to add some more.
R value standards for climate zone 2 which I assume your in is R38 for the ceiling and R13 for the walls. you definately don't have that for the ceiling
R value standards for climate zone 2 which I assume your in is R38 for the ceiling and R13 for the walls. you definately don't have that for the ceiling
Just when I’m out there.
If I can keep it 75-80°, I’d be happy.
I just hate to cut a hole in my siding and install a 24k btu window unit and it not do anything worth a damn.
Firebrick43
Well-known member
I think a 24k might struggle if you go out in the afternoon on a hot day and want to work out there in an hour or two. Especially with a slab that has absorbed some heat. If you start it earlier it probably would be ok.
Is your insulation covering the steel post to the inside or just in between them? I personally would add another 2 inches to the ceiling but that can come later if needed.
A 24k is rated for 1500 square feet but that is a room that is insulated to code.
Is your insulation covering the steel post to the inside or just in between them? I personally would add another 2 inches to the ceiling but that can come later if needed.
A 24k is rated for 1500 square feet but that is a room that is insulated to code.
I installed a radiant barrier directly over the frame rails. This gives me a 2.5” air gap and a little more of a gap on the ceiling. I then screwed 2” foam over the radiant barrier.
A mini split will run me north of $2500.
Window unit, same size as mini will run me about $7-800.
Jinks
Well-known member
When was the last time you couldn't benefit from air conditioning in central Florida? I'm in central Florida & have a mini split in my shop. I don't use it every day, but when I'm working on something for a few hours on a 97* - 99* day with 98 to 100% humidity I benefit from my air conditioning. If you don't think you will benefit from the added expense don't bother. Work out there this summer, & get back to us with your feelings on the subject later..............
What type of insulation do you have?When was the last time you couldn't benefit from air conditioning in central Florida? I'm in central Florida & have a mini split in my shop. I don't use it every day, but when I'm working on something for a few hours on a 97* - 99* day with 98 to 100% humidity I benefit from my air conditioning. If you don't think you will benefit from the added expense don't bother. Work out there this summer, & get back to us with your feelings on the subject later..............
Size of mini split?
When it’s 99° outside, how cool is your garage?
shade
Well-known member
Window units are mostly ****.
Warranty support if they have issues in the first year...good luck.
Minis are amazing! Well worth the money
Jinks
Well-known member
None on the south side or east side. Minimal garage door insulation on west side, & up against the house on the north.
Mitsubishi 12000BTU.
Usually about 78* or 79*, but what ever I want it. Removing humidity is more important than cooling, but the mini split does both...........
Innovate1
Well-known member
Lots of good points in the replies but... I gotta say that your original question makes no sense. Ambient temp means the temp around something. So if your garage maintains what the ambient temp is outside you basically have the windows wide open or a carport.
Insulation is one thing. Air sealing is another to lower the cooling needed.
racecougar
Well-known member
An uninsulated building will maintain outdoor ambient temp.
I just installed a Gree Vireo Gen 3 24k mini-split. Including the cost of adding 50' of 3/4" EMT, 50' x 3 10ga THHN, 8 x 80# bags of concrete mix for the pad, and all the new tools (5 cfm vacuum pump, eccentric flaring tool, metric crowsfoot wrenches, valve core remover/installer tool, R410a adapters, and so on, my all-in cost was $2504. Well worth it to get rid of the noisy, inefficient, window AC units that I've used the past three years.
fitter30
Well-known member
The more mass (stuff) in a building especially metal (tools and cars) the longer it will take to heat or cool to make it comfortable like a house. It's easy to cool the air humidity is the hard part.
dcg9381
Well-known member
This is all about how much you want HVAC. The bottom line is you can cool an uninsulated garage. It'll just cost more in HVAC capacity and costs more to keep cool. I'm too old to work in a metal building in Texas without HVAC.
I "split the difference" - our climate zone is 3. The cost to spray foam R30-R60 on the shop roof deck was fairly tremendous... Probably $20k. Instead, I opted for about R12 and installed 4 tons of HVAC. I do not cool the shop full time, so it makes sense to spend $2k more on HVAC equipment and a little more on power as I probably would never see $20k savings in my life time on a part-time shop.
