Physics Question Time!

[penk]

So I'm running a dehumidifier in my basement due to the ridiculous humidity levels in the last week or so. In an hour of running, it extracted about a half gallon of water from the air.

Which got me thinking.

Given:
1) Basement air volume of approximately 4500 cubic feet (20x30 basement with an 7.5' ceiling)
2) A relative humidity of between 50 and 60% (based on current forecasts. It's occasonally spiking up to 80%)
3) Ambient temperature at the start of this process at 84 degrees fahrenheit. Current indoor temperature is 76 degrees.

How much water is actually IN the air now?

If I cool down to 72 degrees, how much water will be extracted - ie, how often do I have to change the tank out?

I've been S'ingTFW, and have gotten a lot of physics chattering, but haven't been able to suss out the actual values.

Any ideas?

Comments

[penk.livejournal.com]

Thanks for all the answers... here's a few details...

The unit i'm using is a combination AC / dehumidifer. It's venting to the outside now (though it's a craptastic install - it'll be done better shortly). So the temperature change is because it's running as an AC now.

Air infiltration is happening, but not a lot. Super-insulated housing and all that :) but I know the inerface to the outside for the vent is full of holes (I just needed to get things started and cooled- and it's absolutely done that).

Half a gallon sounds about right... the container I've emptied I misjudged... it's probably about 1/3 of a gallon. so I've pulled a half gallon so far in about 6-7 hours. I'm probably down to 40% humidity in here now - it's noticeably dryer.

The goal here is to prevent mustyness/mold int he basement during these days. I think this'll do it.

Thanks :)

[metahacker.livejournal.com]

You'll also pull a lot of humidity out of the walls/floor/etc. to start with. That'll taper off eventually.