My Shop is HOT!

R Q

R Q

Well-Known Member
Joined
Apr 4, 2005
Location
Charlotte
My shop gets so freaking hot it's sickening. It was 5 degrees hotter inside of it than it was outside yesterday. It is stick built, 30'x50', concrete slab floor, corrugated aluminum siding and roof. I have 3 whirlybirds and an exhaust fan at the far end. I have insulated the sides but there's no ceiling. I had plastic stapled as a ceiling but it finally deteriorated so I pulled it down. (It did help some.) I have a large garage door and two opposing windows. I run box fans in the windows blowing in and 3-4 high velocity floor fans when I'm Working in there but it's still very hot.
Give me some ideas to knock the temp down a few notches.
 
Insolation, the spray on, trim it type. Works really good. But if you are gonna run fans, best you can hope for is same temp as outside. Some type of AC will really help, after the insolation. I have also saw people use a garden waterer on the roof, if water isn't an issue.
 
R Q said:
My shop gets so freaking hot it's sickening. It was 5 degrees hotter inside of it than it was outside yesterday. It is stick built, 30'x50', concrete slab floor, corrugated aluminum siding and roof. I have 3 whirlybirds and an exhaust fan at the far end. I have insulated the sides but there's no ceiling. I had plastic stapled as a ceiling but it finally deteriorated so I pulled it down. (It did help some.) I have a large garage door and two opposing windows. I run box fans in the windows blowing in and 3-4 high velocity floor fans when I'm Working in there but it's still very hot.
Give me some ideas to knock the temp down a few notches.
Click to expand...

Without insulating in the roof, the rest if just fighting a loosing battle... Bring in a couple large trees to shade your building.
 
I fawking hate hot weather!!!!!!!!!!!!!!!!!!!!!

https://www.lowes.com/pd/Frigidaire-1900-sq-ft-Window-Air-Conditioner-230-Volt-28000-BTU/1000928488

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Insulation will probably be the cheapest rout for your shop.
My garage was at 80 degrees, about 1pm yesterday, by 5pm it was 83. Garage closed and you know above it is a conditioned bonus room and one wall on the side of house. But all walls are insulated.
I can maybe help with pricing on batt insulation for you.

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Mine is insulated on the roof (6", R19 I think) but not the walls, and it consistently stays noticeably cooler than outside. However, the still air sucks, so when I'm working, I just open the big door and turn a couple pedestal fans on.
 
We've got a ton of R-13 foil faced insulation at work. Can't return it and probably won't use it for some time. I can probably get it for you at a decent price. it is 16" on center though, not sure how you would install it.

Side note do you have a 36" long 1.5 diameter x.250 wall DOM?;)
can you text me where you got yours .
 
My 24x30 metal shop has just the bubble wrap stuff for insulation, the ceiling is open to the peak but it has the bubble wrap too. There's basically no shade either.

I have a 2 ton home package unit heat pump and a 2 ton window unit ac with electric strips that I run together on really hot or cold days. On moderate temp days (45-85) I can get by on one. They only run when I'm going out there, so I'll turn them on right after work then eat dinner to give them time to work. Highest electric bill ever was $150 for the shop on a separate meter. That was in January working 5 nights a week with them both running electric strips from 5 til 11pm for several weeks. Ac bill is usually less than $125 even in the heat of summer, that's with all the lights, welder, compressor, etc included. In about an hour they'll drop inside shop temp from 120+ to low 80s or bring it up from 30 or less to upper 50s, for the record I prefer mid 60s temp if I'm working.

I know insulation would help mine, but I'd have to move out to do it and I'd rather not, lol.

If you keep the doors down ac may be best bang for the buck, especially if you could enclose a smaller work area to use it in, just dropping the humidity makes a huge difference. Otherwise the swamp cooler is a good idea.
 
Insulation is your best bet. Going from a stick built, unisulated shop to a block shop with insulated ceiling was a dream come true.
 
I had some trees and shrubs too close to the shop but I cut them down last week! They were creating issues.
If I insulate the roof do I have to leave room between the metal and the insulation?
 
When you put plastic up did you have condensation?
That comes to be a problem sometimes, you can't have a double vapor barrier.
 
Look up the effective zones for swamp coolers. Unless you got an endless supply of cold water your wasting money.

They work on evaporative cooling....our humidity doesn't allow it to work well.

No temperature drop. So your gonna just get damp moving air.

Once the water equals the temps or near it your just adding humidity.
 
No fries said:
When you put plastic up did you have condensation?
That comes to be a problem sometimes, you can't have a double vapor barrier.
Click to expand...

Close but not 100%.

You will have condensation when you have a temperature difference and when a surface is below the dew point.

Portacool works ok but will raise the humidity and won’t do much in a humid environment.

Ideally insulate the air sealed ceiling and vent the roof. Insulate the air sealed walls. Find a used 2/3/4 ton package unit and attach. Run a/c in summer and gas/lp heat in winter. Can wire to run a/c and furnace at same time, to dehumidify in winter. Just look for a unit that has the evap coil before the furnace. Better to remove the moisture in the air before heating it.

Could do air sealed plastic ceiling with insulation above, vented roof, and hvac to condition the space. Least chance for condensation this way.

Or spray foam entire structure and condition the space.

Walls/doors/ceiling need to be airsealed .


If it were mine, I’d air seal the walls and insulate them.

Build ceiling of some type, plastic, Sheetrock, taped and staggered joint insulation board, and insulate ceiling.

Condition the space with used package unit, or ductless minisplit. May add 50 pint dehu to keep it dry when not in use and low load heating/cooling times in spring/fall.

Keep air gap with vented roof. Ridge vent and soffit vent. Soffit vent needs to exceed ridge vent area. Ideally some type on foil faced insulation board on top of ceiling insulation reflect radiant heat back upwards*. This must have air gap above it to roof to work properly.

I’d price each style and pick the cheapest ceiling option with most ROI.

My initial guess is two layers of 2” foil faced poly iso ceiling with joints staggered and taped and air sealed.

Have to compare that to Sheetrock/r19 or (r38) fiberglass batts covered with 1 layer of 1/2” foil polyiso.

Or plastic sheet ceiling/fiberglass batts/rolls/ 1/2” foil faced poly iso.

Each would require different ceiling framing to implement which affects total cost.

May be able to get away with polyiso layers attached on underside of roof truss/rafters, as long as the undersurface is taped, staggered, and sealed and you can get adequate venting from soffit to ridge.
 
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WARRIORWELDING said:
Look up the effective zones for swamp coolers. Unless you got an endless supply of cold water your wasting money.

They work on evaporative cooling....our humidity doesn't allow it to work well.

No temperature drop. So your gonna just get damp moving air.

Once the water equals the temps or near it your just adding humidity.
Click to expand...


This is exactly right, you'd be better off with a large fan. Or---for the price of a porta cool or spot cooler--install a regular split unit or package ac. The fact that I can leave machined pieces of steel laying around without oxidizing in a day is more than worth it for me.


This is how simple mine is, if I had a package unit laying around for nothing it would have been even easier.
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OP he wanted to knock it down a few degrees and there is no ceiling now and I'd be willing to bet there never will be.

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