Posted By rykertest on 28 Mar 2010 05:33 PM
http://www.elementfour.com/home - I came across this product in a popular mechanics magazine at the gym today and it caught my eye. I looked on here and just found a thread with 1 post on it that just said what it was. I wonder if anyone has used this product or seen it? My first gut reaction is it's a fancy dehumidifier, but with some cool bells and whistles. I've seen prices of close to $1500 so it had better work good. lol
The idea is SWEET for third world countries or for remote areas, but for a typical residential area, I wonder if it is? If it doesn't use much power, it could reduce your electric bill from a reduced well useage.
Thoughts anyone?
Wringing water from the air takes at least an order of magnitude more energy than pumping the same volume of water from a well , even if your interior relative humidity is over 95% (in which case you're dying of fungal diseases. :-) )
The heat of vaporization of water is about 970BTU/lb.
At 8.34lbs/gallon you need to remove 8.34x 970-= ~8100BTU
from 100% relative humidity air to turn that vapor into a gallon of water.
Assuming that crummy li'l compressor & fan gizmo has a coefficient of performance of 3 (which might be a stretch), you'd need:
8100/3=2700BTUs of electricity to get that gallon of water out of vapor-saturated air.
1kwh=3412BTU
2700BTU is 2700/3412= 0.79kwh.
That's the same as running a 790 watt pump for a full HOUR, to get ONE GALLON. How deep is that well, again?
And at normal interior relative humidity, it'll take even more electricity to extract that gallon, since it has to bring the temp of the coil down well below the dew point of the air. In a 50% RH 70F room, that means you need to get it down to 45F or lower, since the dew point of that air is 55-ish. The lower you need to go, the lower the coefficient of performance, but you may be able to get a COP of 2.5 out of an optimized design.
If you live in a swamp and need to run a dehumidifier even when it's not very hot out to keep the interior humidity down to a healthful level, one of these gives you something to do with the condensate other than dumping it down the drain. That's the only value-added over any other mechanical dehumidifier.