# AC ???



## shawnmasterson (Jan 24, 2013)

I was recently given a nice window ac. My thoughts are to cut it into the wall. My shop always has this musty smell unless I open the overhead, then it seems like everything sweats. For those that use window ac do you just leave it run or turn it on and off when coming and going. My shop time is very up and down at best. I hate to leave it run up the bill if I'm not out there. I was considering setting it up on a thermostat of sorts so the whole unit would come on and off. I just wondered what you guys do. as always thanks


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## TheFridge (May 1, 2014)

I wouldn't leave it running if I wasn't there. If I had an AC.


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## wapakfred (Jul 29, 2011)

I only run mine when I'm in there and when the temps are high enough. To be honest, a dehumidifier might help you with the musty smell, but the ones I've had cost as much to run as the window unit (mine's an 8K BTU model). The thing is running the AC all the time may make it a little too cool, but it still might be worth trying.


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## CharlieM1958 (Nov 7, 2006)

Are you sure the window unit doesn't have a built-in thermostat? It may cut off and on by itself.


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## shawnmasterson (Jan 24, 2013)

It does have a digital thermostat that kicks the compressor on and off, but the blower and what not are running all the time.


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## English (May 10, 2014)

Does it have a energy saver cycle. If it does this will shut the unit down, and restart the fan every now and then to pull air across the thermostat to see if cooling is required.

Mine has this and I set my stat at 78 and leave it on. It maintains humidity and keeps my wood closer to the humidity in the house where my projects end up.


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## gop1ayoutside (Jul 12, 2013)

I live on the gulf coast where it is hotter than you know what and 100% humidity for about half the year. I recently installed a window a/c in my detached garage and insulated it so I can make my woodworking a year-round hobby (thread linked here).

My strategy so far is to leave it running all the time set at a pretty high temp (I use 81) which keeps the humidity down significantly but doesn't run the compressor near as much as if it's set in the low 70s which is what I turn it down to when I am in there to work. The shop is not yet fully up and running so I have not completed any projects yet and I can't speak to how well this controls wood moisture but I am sure being acclimated to the air conditioned shop is much closer to the humidity level in a living space than being acclimated to the raw conditions of a gulf coast summer.


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## Crank50 (Jan 31, 2014)

Two questions. 
Is the BTU of the AC correct for the Sq. Ft area of the shop?
- you should have about 25 to 30 BTU per Sq. Ft.
- example: my shop is 384 Sq.Ft. X 30 BTU = 11,500 BTU so I bought a 12,000 BTU AC.

Is your shop insulated? 
- If it is not insulated it will be very expensive to run the AC all the time.
- Ventilation will help keep the space somewhat cooler during "OFF Time" for the AC.
- When I get my insulation done I'll leave my AC on with the thermostat at 78 to 80 degrees.


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## shawnmasterson (Jan 24, 2013)

the shop is fair sized @ 780 sf. The shop is well insulated with about r45 in ceiling r15 walls, and shaded most of the day by neighbors pine trees. the unit is 12k btu, undersized but free. I live in northern Indiana. Right now we have 60 at night and 80 during the day with varying humidity, but normally high. I have no real experience with window ac, I have always had central air (CA) or no air in the house. It sounds like the energy saver cycle will make it act like CA witch is what I am looking for. My major concern is the ambient dust and the blower running all the time.


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## English (May 10, 2014)

My shop is 672 sf, my unit is heat and cool 12,000 btu. It handles my shop, I have seen 103 degree days and 10 degree days handled with no problem, my shop is insulated but not as well as yours.

The one you have should be big enough.


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## mudflap4869 (May 28, 2014)

Cross ventilation is important to reduce moisture. Gable vents and an automatic fan might be your least expensive answer. Seasoning lumber is accomplished by air swipe; air curent moving across the surface draws the moisture out. Think dehydrator. Stick and stack your lumber and place a simple box fan above it to move the air past it and save the A/C for your shop office/mancave.


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## MT_Stringer (Jul 21, 2009)

I put in a 12K split system AC w/heat pump. It has no problem keeping the set point temp (77). Ceiling is R38, four inch insulation all four walls. We replaced the siding on our house a couple of years ago and I had the contractor insulate the outside wall.

Much better than the 100 deg days outside of the past. 

Go for it. You could even put it on a timer if you like.


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## wapakfred (Jul 29, 2011)

Shawn, I doubt that unit is undersized for the way you're set up. To compare, I have a 768 sq. ft. shop in more or less the same climate, and I have R45 ceiling with R19 walls (and a 16' ft. OH door, one entry door) but no shade. The 8K btu window unit I use is taxed on really hot days (90º+), but otherwise adequate. The equipment (especially the DC) can over power it when run a lot, but it's actually not as bad as I thought it would be. I had to go with that size because the one I wanted (a 12K) wouldn't fit on the smallish windows the builder put in. You don't always hear folks mention the heat load from a DC, but mine seems considerable…..wish I could vent it outside. I guess that air movement comes with a price in heat load. I'm not contesting Crank's numbers, just offering my experience.


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## firefighterontheside (Apr 26, 2013)

I turn it on when it's hot out there. If I'm gonna be out there several days in a row, I'll leave it on overnight but at a higher temp and then set it back down in the morning. Works great for me.


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## shawnmasterson (Jan 24, 2013)

Right on thanks guys. I will update you when I do it. If I remember I will try to video and blog it.


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## todd1962 (Oct 23, 2013)

I have exactly the same numbers as Crank.

Mine has an energy saver cycle. I raise the thermostat when I'm not working so it doesn't run so much while still keeping the humidity in my shop in check.


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## Crank50 (Jan 31, 2014)

I'll admit I went to the high side of my capacity range, but I'll only have R11 walls and R19 ceiling, not the greatest but it was left over from a remodel of my house and free, and I have 9ft ceilings and an upstairs storage area of about 100 sq.ft. I wanted to divert a little cooling capacity to as well. The box my unit came in said it was good for 575 Sq.Ft.

An under sized AC will still work most of the time, it just has to run more and might not be able to keep up on really bad days.

An over size unit is just as bad, because it won't run enough and will not control the humidity as well.


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## bigblockyeti (Sep 9, 2013)

The guy I bought my shop from used it as a gym and ran the AC all the time, said it added about $15/month (kept at 69 degrees) to the electric bill. I didn't like the look of a window unit hanging off the outside so I removed it. I now run a dehumidifier that is controlled by a humidistat and it adds about $5/month, the dry air makes the temperature much more tolerable. Air drying wood in my shop takes far less time now too.


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