Ac not cooling shop?

[American Locomotive]

How big are the doors in area? Nearly 100 degrees on the door surface is extremely hot. At 100 degrees, each square foot of door is going to be radiating about 50 btu/hr worth of heat into the room.

 

[Hobby_Man22]

10x10

 

[American Locomotive]

Okay, so that's 10,000+ BTU/hr worth of heat. Nearly 1 ton of your cooling gone just to your doors radiating heat into the room.

 

[Showkey]

That was reason for asking the temperature of the garage door ………in post 36

My daughter’s home in Texas has an uninsulated metal door……..the door can reach over 125-150* as the sun moves. One of the kids burned his hand on the inside of the door. She’s not trying to cool the garage but the inside temperature is over 110* in the heat of the day.

The slab is not the heat gain…..it might actually be the coolest part of the entire garage.

 

[Hobby_Man22]

I can put something like this on the doors and it supposedly stops heat transfer. This is the best I can do and still be able to use the doors.

Double Bubble Reflective Insulation (White/Foil) 4'x75' - 300 sq ft

Double bubble reflective foil insulation in your building ensures maximum insulation from radiant & conductive heating. White/foil for a finished look.

www.ecofoil.com

 

[Hobby_Man22]

I don't think we're too far off though. I mean it was holding at 77 when it was 95 outside. I actually didn't realize how hot it got. Until about 12pm it was running 15 minute cycles with 8 minutes in between.

 

[PoorUB]

It's finished. I have the door seals on too. I think I need to have the charge checked on the unit. Or I need more insulation.

How about the doors themselves, are they insulated?

I guess not!

What type of doors are they?
Can you not cut foam sheets and fit into the panels? If the sun is hitting those doors it will cook the place!

 

[Hobby_Man22]

How about the doors themselves, are they insulated?

I guess not!

What type of doors are they?
Can you not cut foam sheets and fit into the panels? If the sun is hitting those doors it will cook the place!

They aren't panel doors, theyre more like corrugated roll up doors. Nope they aren't insulated.

 

[Hobby_Man22]

Even with the sun beating down on them they aren't really hot to the touch. Although my hand is already 98.6 so......

 

[Hobby_Man22]

I measured today with black tape. 98 degrees on the doors.

 

[PoorUB]

Then you still have heat gain to deal with.

 

[Hobby_Man22]

Do you think that bubble insulation will work to keep the heat out? I'm skeptical.

 

[Hobby_Man22]

I got the hvac people coming out on Wednesday to check the charge. Let's make sure it's cooling like it should before I get too carried away with stuff. Seems like a few people here have bigger buildings than mine with half the insulation and don't have an issue.

 

[PoorUB]

Do you think that bubble insulation will work to keep the heat out? I'm skeptical.

I t would help, but how much? I don't know. It certainly can not hurt.

 

[Yankeefarmer]

I got the hvac people coming out on Wednesday to check the charge. Let's make sure it's cooling like it should before I get too carried away with stuff. Seems like a few people here have bigger buildings than mine with half the insulation and don't have an issue.

Is your building in full sun all day? That will make a difference between yours and buildings that get some or a lot of shade. Windows that let sun shine in matter. Also, I have found that the type of ceiling/roof arrangement can matter. A metal building with insulation under the roof panels will be warmer than a building with a ventilated space between the roof panels and insulation above a ceiling.

 

[Hobby_Man22]

Yeah pretty much in the sun all day. They went cheap on this building and didn't put those roof vents on.

 

[Terry D]

I don't think we're too far off though. I mean it was holding at 77 when it was 95 outside. I actually didn't realize how hot it got. Until about 12pm it was running 15 minute cycles with 8 minutes in between.

Almost sounds like it is short cycling. Its not running long enough to remove humidity. Possibly over sized.

 

[Hobby_Man22]

It's not short cycling because later in the afternoon it never shuts off and doesn't go to the set temperature.

 

[Hobby_Man22]

I mean if it starts off say at 75 early in the morning and you leave it there it may keep it through the rest of the day, but to try and drop it from 80 to 75 at 2:30 isn't going to happen. Lol

 

[slow]

dropping at the heat of the day, you would likely need twice the design capacity to do that. Once the slab and all of the items in the shop are heat soaked, you need to pull all of that heat out of the building. We had a similar issue at work, one small warehouse would get stupid hot and the team would try to drop the temp in the afternoon. Once we just lowered it a few degrees in the morning , it held a comfortable temperature all day. (but ran almost non stop)

 

[Hobby_Man22]

Mine seems to do okay as long as the sun isn't out. When the clouds roll in it seems like it catches up. I sure I hope I don't need more insulation. That was a pain just to do the R30. Lol Probably should have done R30 then an R15 on top of that. Then again something isn't adding up because guys on here have smaller a.c. units less insulation than I have and still seem to have an issue. I've left it running a few days already and it doesn't really matter.

 

[Hobby_Man22]

I mean I get the whole residual heat thing.

 

[Black Oak]

My neighbor and I have both installed "outer doors" to keep the sun of the primary big door . His is a slider , mine are bi-fold , like a closet door . HUGE , HUGE improvement , and not really a problem as I don't need that big door opened very often . One of the best things I've done .

 

[Hobby_Man22]

The tech came out and checked the charge. It was at the maximum amount and he liked how how the numbers looked and didn't want to change anything. He did find the thermostat was cooling the building 3-4 degrees cooler than what it showed on the thermostat. We set the offset for 3 degrees so at least what it says on the screen is what it is now. That's pretty good that it was at 72.5 degrees when it was 93 degrees outside. He said the system was putting out 52 degree temps with a return air temp of 72 so a 20 degree drop is excellent. So nothing is wrong with the system.

 

[Hobby_Man22]

He also said it's somewhat normal for the a.c. to run non stop in the heat of the day. That also makes a big difference having the thermostat cooling at the correct temp I think.

 

[930dreamer]

Good to hear your system is working correctly, are you planning on leaving it cooling all the time now?

 

[Showkey]

Good to hear your system is working correctly, are you planning on leaving it cooling all the time now?

At least until the first electric bill shows up.

 

[American Locomotive]

You probably should just replace your doors with insulated doors - or do the outer-door thing as someone else mentioned.

 

[Hobby_Man22]

At least until the first electric bill shows up.

I keep it at like 82 if I'm not in the shop. I don't think it runs much at that temp. Was thinking today, probably better than walking in when it's like 88 in the shop.

 

[Hobby_Man22]

It's been working better since he adjusted the thermostat offset. Remember when I used to complain that it would reach the target temp then just keep running? doesn't really do that anymore. Not sure what difference that would make if any honestly.