Dehumidification for shop.....

[redhawknc1]

I have taken over my 3 car garage and am turning it into a workshop. I also store quite a bit of wood in there(12% or less for final acclimation to shop). Never had any rusting problems with machinery or tools, but only heat the shop during the times I'm in there. Will be adding a 220V electric ceiling mount forced air heater soon, now that I have 220 wired. Hopefully on a thermostat. Was thinking of adding a dehumidifier to help keep the air drier. I know quite a few of you use them. Any recommendations on what I should be looking for. The shop is split into a 440 sq. ft area with a wall and door, then about a 220 sq. ft area. Will I need 2 dehumidifiers?

[Bas]

The answer is: It depends.

My basement is ~900 sq.ft., with about 400 of that for the shop. I have a small dehumidifier, from Sears. It's the size of one of those mini fridges. It does great most of the year, the only time it has a hard time is keeping up in the summer when the A/C is off. But, this basement is insulated and heated/ cooled year round. At 440 sq.ft., your garage is quite a bit smaller, but you'll probably have more humidity.

I suggest you buy one, hook it up, and see how it does. If it runs continuously without getting the moisture down sufficiently, buy a second one. All you need is an outlet (which you should have plenty of....) and a small hole in the wall to run a drainage tube out. Two smaller ones are bound to be cheaper than one big one.

As for what to look for - don't buy the cheapest or most expensive unit, don't get the biggest model, don't get the smallest model. Make sure it has a hose, you don't want to have to empty containers all the time. You can look at the specs, but those are usually for living spaces, not garages, so that won't help much with the sizing.

[DaveO]

In my basement/daylight garage shop ~500 sq. ft. I run a Kenmore unit. It is pretty large sized for the space. My shop is kinda climate controlled, as best as you can do with a garage door. I pull off of the house system, with the thermostat upstairs. Right now the humidity in my shop is at 40%. The dehumidifier cycles on and off in 6 hour shifts. It actually adds to the heat in the winter. In the summer that's not the best deal, but it's a dry heat. In summer my shop stays around 76º and 60% humidity. Winter time it's generally around 70º and 40% humidity. I have fans moving the air around at all times. I have air dried lumber down to 8-10% by storing it in my shop.
I highly recommend piping it out instead of dealing with emptying the bucket.

MTCW,
Dave

[DaveO]

Here's a guide on sizing the unit(s) -

*A rough guide for sizing a dehumidifier for the “average” basement:
Less than 350 square feet: 25-30 pint @ saturation
Less than 700 square feet: 40 pint @ saturation
Less than 900 square feet: 50 pint @ saturation
Less than 1200 square feet: 65 pint @ saturation
Less than 2500 square feet 100 pint @ AHAM
Less than 3000 square feet 135 pint @ AHAM

**AHAM (80% relative humidity, 60 degrees F)

Dave