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Idea for a dehumidifier

I've been trying to find a solution for my crawlspace and I just don't have the money for a dehumidifier. I do, however, have the idea to go to Hobby Lobby and get a 5 lb bag of Silica Gel and/or maybe some rock salt (probably the ice melt type since I can get it cheap right now).

3 comments

Aug 25, 2011. 6:24 AMmagiko says:

I think that it would be more productive to pull air through the box rather than push air into a box. Pulling air causes a vacuum (negative air pressure) and the outside air would rush in the vents in an even/predictable way to fill the vacuum - much more efficient since the entire atmosphere does the work. Pushing the air into a box puts positive pressure in the box, and that pressure has to do the work to get out, and it'll do it, but probably not evenly, and I'm wanting to say less energy-efficient (electricity used to cubic feet per minute of air moved).

It's hard to picture how big this unit is. I imagine that fan is a box fan. The green circle isn't labeled.

I won't weigh the pros and cons of a 2 stage system with gel and salt both (but I do wonder why the gel is at a 90 degree angle hanging off the box).

Anyway - long story short, consider turning the fan around.

Oct 10, 2011. 4:28 PMAndale_The_Great (author) says:

idea for size was an 18 gallon storage tote

can't just turn the fan around cuz then it would be on the side where the water would accumulate
i could just design it differently so it pulls. I will consider that when actually building

I'd like to find more information on the amount of moisture removed by rock salt or desiccant

Sep 8, 2011. 6:44 PMjholcomb-1 says:

The navy's main reduction gear dehumidifier uses one fan to pull the moisture from the mrg casing to the atmosphere of the space. So using your design, forcing the crawl space air into the dehumidifier would work. I would either have the exhaust guided to the outside or use 2 fans one for intake and one for exhaust. The reason being leaving the "crawl space" air inside the dehumidifier will either cause your desiccant to expire faster or ruin the motor of the fan, depending on the amount of moisture, might want to use a barometer. Also the desiccant should be close to the intake but not too close to impede the flow of air.