timb - I'm not sure what capacity my Whirlpool is. I got it at Lowes a few years ago (it was the only model they had in stock at the time) and it pretty much runs all the time, all seasons. My guess is that it costs $50/month. Our basement is 30' x 15' x 6' tall.

I just visited the Whirpool site and the one I have looks like either the 40 or 50 pint standard model. It does a good job of keeping the basement dry, as does having sill vents that allow for air movement. In the winter, I open the register that's on our forced hot air furnace to get drier air moving around.

The only problem I have had is in winter when basement temps drop a little which has caused the coils to freeze. Then I turn it off and let it thaw.