This fall I noticed something I had not seen before; the dreaded black spots, this time on cabin carpeting. Clearly, better humidity control was in order for the cooler season.
A large compressor unit would be a beast on a small boat. Though I have a 30-pint unit at home, the downsides are major:
- A lot of amps on the shore power cord.
- A back injury waiting to happen; the unit is huge and awkward.
- In the way.
- More capacity than I needed.
So I looked around and found this. The principle is elegant, with very few moving parts. The size and weight appropriate. They are prone to icing (found this while testing in the garden shed in cool temperatures) but deicing by running it off a light timer is simple; 10 hours on and 14 hours off. A photo cell lamp switch would work just as well. I needed a drain so that the tank did not fill and potentially freeze, something easily provided with a few fittings, some aquarium tubing, and a gallon jug on the floor (it could go into the sink, but I'm taking measurements). What if it stays below freezing a few days and does not melt? There is no problem with the tank or hose freeing because there is no water flow. There is little bother with excess ice build up, because at those temperatures there is little water in the air. So far--2 months--the units is removing a few ounces per day and keeping the relative humidity at 65% at 40-50F temperatures. I can reasonably project that it will remove 5 gallons (42 pounds) during the November-March season. Bear in mind that all dehumidifiers are very inefficient at low temperatures; this unit would pull 20 ounces per day in a typical basement running 24 hours.
Cold plate thawed.
Cold plate frosted. If below 55F this will occur in 3-8 hours. Upon melting, roughly the daily water removal capacity. Can the ice grow to a damaging extent? I left it on in icing conditions for 3 weeks once and the ice had not reached the screen. The ice provides so much insulation it simply stops working.
Perhaps I'll run it all year. The mattress and bedding are already noticeably drier and more pleasant.
Notes 2-14-2013: So far? In 3 1/2 months the CaCl2 bag has removed about 1 pint of water to the dehumidifier's 16 pints. Not even competition. And the bedding smells fresher than it ever has. The relative humidity has been holding at about 65%.
Notes 9-20-2013: Still running fine. If I set the timer on a shortish cycle the solar panels replace the drain just fine.
Notes 4-19-2014: I've been running it all-year for over 2 years. Still quietly purring along. I started running a Perfect Home 2 pint unit a year ago in another boat. No problems.