I need to size a dehumidifier for a basement that's about 1,050 sq ft. The
space is irregular but open, and there is a floor drain available. I don't
know how to specify one, and am probably asking the wrong questions on
google. Is there a chart somewhere that will help me size a unit.
This is a damp basement, and for the first time it's smelling moldy (or
maybe just crappy). We rarely go down there, so is a dehumidifier even our
Nope. It depends of how the water is getting in, and how much of it
there is. So the depth of the water table, how leaky the walls
doors, and windows are, and whether there's water against the
foundations, the presence or absence of open sumps, and whether
the blowoff valve on your water heater is venting all affect the
question more than how big the space is.
That is likely about as good a chart as you are going to get. The only
thing likely better might be an experienced professional from your local
area to make a judgment call based on a good amount of experience with like
homes in like conditions.
Thanks for the replies, and especially the chart. Our basement is damp, not
really wet. There are no windows or doors to the outside, and it's very
rarely used, thus the musky smell down there. We get some white fluff on
the exposed concrete wall, so I expect the dampness is from a minimal
seepage thru the front wall.
Is it good to oversize? From the chart, a 25 pt unit would take care of a
'very wet' basement the size of ours. Should it be plenty for a slightly
damp space of the same size, or is it a better idea to just buy a big
Just remember that once you have a dehumidifier running for a while you
won't need it as much.
So smaller units (25-30 pint/day) will often work fine. and after the first
week you may even be able to go without it for days at a time once the
humidity is reduced
Also as a general rule higher capacity means, more expensive to buy, more
noise and power consumption.
I have a floor drain in the right place, or believe me, I wouldn't be asking
these questions. I've just learned from the net that there are
dehumidifiers - low temp units - made specifically for basements. I'll pick
up a 50 pt one tomorrow. Lowes has one with a hose connection, energy star
and all that, two speed and 50 pt capacity. That seems to be about the
minimum basement size available, and it's 200 bucks. I thought I was
looking at more money, so I'm just going to buy one.
Thanks for all the good advice.
Good point. I made the mistake of getting one not marked low temp and
ended up getting a new one so designed for basements. As it turned out
after about three recalls of the old one the finally came up with one last
recall which I installed myself and now the original ones functions just
fine in the basement. I use it as a backup.
Well oversize will work better than undersized, but it will be more
expensive to buy and a little less efficient so it will cost a little more
to run. If you are on the edge, I would go larger. If you go too small you
may find you need a second one. BTW the efficiency rating of the larger one
MAY be better than the smaller so it may end up being cheaper. I really
don't know what the likelihood of that is.
On Fri, 30 Sep 2005 15:12:33 GMT, "Joseph Meehan"
A cupla years ago I was looking for a DH also.
I believe it was the Consumer's mag that said to get the largest one
you can afford. I did that and it worked fine.
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