Fermentation Closet Cooling Unit

So I am going down the path of turning my office closet into a temp controlled fermentation chamber. The closet is about 4ft x 9ft with a single door entrance. In the summer it is around 76 and winter down around 70. Not a huge swing throughout the year. I'd like to be able to keep the temp around the low 60s. I have gone around in circles on the best option to cool the closet. There is a small panel leading into the attic...perfect spot to run the exhaust hose on a portable ac unit. I've also thought about cutting and installing a window ac unit in the door. Any thoughts....what is the best option for cooling a closet.


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sgraham602 said:

So I am going down the path of turning my office closet into a temp controlled fermentation chamber. The closet is about 4ft x 9ft with a single door entrance. In the summer it is around 76 and winter down around 70. Not a huge swing throughout the year. I'd like to be able to keep the temp around the low 60s. I have gone around in circles on the best option to cool the closet. There is a small panel leading into the attic...perfect spot to run the exhaust hose on a portable ac unit. I've also thought about cutting and installing a window ac unit in the door. Any thoughts....what is the best option for cooling a closet.


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I don't have a perfect answer for you, but maybe some food for thought.

If you put a window AC in the door, that means all of the exhaust heat from the AC will be pumping into your office. Do you really want that??

That's a good point. In looking at positioning....a window unit in my door would ultimately mean I would not be able to open the door all the way, so a window A/C is out. If a portable AC unit will cool the closet enough, I'll go that route.

sgraham602 said:

That's a good point. In looking at positioning....a window unit in my door would ultimately mean I would not be able to open the door all the way, so a window A/C is out. If a portable AC unit will cool the closet enough, I'll go that route.

Click to expand...

I have to assume that most portable air conditioners could easily handle the 36 square feet of your closet.

Just a few other things to keep in mind though:

-Insulation: I have to assume that the closet is not well insulated and if yo stuck an AC in there, it would run a lot since it was not designed to keep cold air in.

-Condensation: I would think that the cold air in a confined space could cause a great deal of condensation, and water behind the drywall is a haven for mold.

If you are going to go this route, I would be sure to insulate the closet and cover the insulation with some kind of plastic. I have seen other threads where people use some sort of plastic board often found in restaurant kitchens.

A portable AC unit would work, but you need insulation. Don't forget that they need to be vented as well - same as a window unit. Before you just dump the AC vent into your attic space, remember that moisture has to be vented out. The last thing you want is all that moisture just sitting there growing mold and rot.

The issue I see is that condensation happens on the first cold surface that air vapor makes contact with. In this case, it will happen on the inside of the wall, regardless of the presence of insulation. The vapor barrier would actually need to be on the OUTSIDE of the insulation, which will be difficult on an interior closet, otherwise you will risk moldy walls. This is only an issue if you reach dewpoint. If the temp difference is only 15 degrees and humidity is low, you might not reach dewpoint. Below is a link to a dewpoint calculator. Put in the typical temp and humidity in your house. For instance, if your home is 71 degrees F and the humidity is 50%, then condensation will occur at 52 degrees. If your closet is at 55, then you won't have condensation. If it is at 48, then you will have moldy wet walls.

http://www.dpcalc.org/


I'm guessing unless you have a substantial dehumidifier in your home in North Carolina, you would see issues in the summer.