controlling humidity in the shop

Re: controlling humidity in the shop

Ed Mulligan, Cape Cod

>I don't think humidity caused your cabinet collapse. Sounds more like poor workmanship or design (or both). On Cape Cod (eastern MA) the outside humidity is at present the same as yours. Inside it's ~ 35%. Nothing is falling apart here :)

Heating your shop will lower the humidity, all else remaining unchanged.

When it's too dry in my shop, which has an unsealed concrete floor, I just throw a bucket of water on the floor. For humid weather which is June thru October here,I run a small dehumidifier. Ambient humidity in summer runs 80% or so. With the dehumidifier I can bring ot down to 60%. It adds a lot to the electric bill but is worth it IMO.

Ed

Re: controlling humidity in the shop

Brian F Philipp

>Agree with your other posting. The failure was workmanship related. Go to Sears or Lowes and get a 40 pint dehumidifier (w/casters)and an auto cutoff feature. During the humid summertime run it twice a week for 6-8 hrs. I have a basement shop in the humid St Louis area, it works great for me.

Re: controlling humidity in the shop

Mike From MN

>I agree that humidity was not the cause of the shelving collapse. It is very hard to control humidity in a garage unless you have a good vapor barrier on the walls and ceiling, and some very good weather srtipping around the doors. Heating the space does as much as anything to reduce the Relative Humidity % a dehumidifier does remove water vapor from the space it is in however it also adds heat to the space and I believe the heat is what changes the RH% as much or more than the small amount of water that is removed. In a typical garage there is so much leakage that I doubt that any small dehumidifier wouldn't keep up with the leakage. What does change is the space temperature increases and that in effect reduces the RH%. So I would say don't spend the money on a dehumidifier use a heater, gas or electric and just raise the space temperature above the outdoor conditions by at least 5 degrees and you will see a reduction of RH. The dehumidifier is like a heatpump in this application and would be more energy efficent Watts or BTU's output is generally more than the input by a factor of 1.5 to 2, and electric heater is 100% efficent however you only get a Watt out for every Watt of input.

By raising the space temperature 10 degrees, lets say from 50 degrees and 40%RH to 60 degrees you will reduce the RH% by 10% if you raise the temperature from 50 to 70 degrees in the space the RH% reduction is very close to 20%. If the garage is at 90% RH and 50 degrees and you heat the garage to 70 degrees the RH would be very close to 45% and this isn't removing any water, just adding heat.

Sorry for getting so longwinded.