dehumidifier or air conditioner in damp, unfinished basement??
Hi , I posted this question on the Home decorating forum, the conversation side, and this is one of the replies I got...Could you all with more experience than me on the subject weigh in your opinion on the subject? Thank you in advance!
We live in an almost 200 year old cape. The cellar gets damp in the summer, so we have a dehumidifier (which EATS electricity). The cellar only has 2 cellar windows, both on the same side, and a bulk head on the opposite side that we open on nice days. The windows have screens for the summer and glass for the winter that my husband has to screw off and on to exchange the two.
Now, my theory is that with the screens on and the dehumidifier on, when it rains or is very humid out, the dehumidifier will keep sucking all the moisture from outside to the inside. I think that we should keep the glass on in the summer and use the dehumidifier to try and keep the cellar dry. There is moisture that comes from the fieldstone foundation that has very little cement between the rocks.
My husband thinks that we should keep the screens on to allow for ventilation in a poorly ventilated space, even if it rains. He puts the screens on in spring and takes them off in late fall and these are times where it's not humid down there and the air is good. But in the summer it's humid and condensation occurs.
I don't know what is the best thing to do...What would you do?
(Old houses have their own set of issues......;-( "
Here was one of the replies and thanks to the poster of this info...
"Bear with me while I try and coherently regurgitate the thermo-dynamics lesson my engineer DH just gave me to explain what you should do, LOL!
First, he's assuming you do not have central air in your home. If by some chance your 200 year old home has been upgraded to have central air but does not have vents into the cellar, that's your solution. Get the conditioned air flowing into the cellar and shut the windows - not in that order. Moving on because you likely do not have central air ;-)
There are a couple of things to understand;
1) the warmer the air the more moisture it can hold
2) dehumidifiers put out a LOT of heat
3) because the dehumidifier is raising the temperature in your basement, the air has the ability to hold more moisture
4) because there is more moisture in the air, anything colder than the air (your stone walls, concrete or stone floor, cold water pipes) will sweat because the moisture in the warmer air condenses when it is in contact with these colder surfaces
5) the sweating surfaces add moisture to the environment which makes the dehumidifier work harder which makes the air warmer ........ and so on.
Your absolute most effective way to reduce moisture in your basement will be to go to Home Depot or whatever is cost effective for you, and buy a small, energy efficient window air conditioner and put it in one of your basement windows. It does not need to be set at the coldest setting, just make sure it can drain freely to the outside. Close the other cellar windows and block up the open area around the AC unit. You'll use less electricity to run a small window AC than the dehumidifier and you'll be using the right 'tool' for the job. A window AC takes the moisture out of the air and gets it outside, out of the space you are trying to cool and dehumidify. A dehumidifier heats up the air in the space you are trying to dehumidify, making the air able to hold more moisture, then keeps that moisture in a bucket in that same space.
I know your primary objective is to remove moisture, not to cool the air but they go hand in hand.
Funny thing is, I actually understand this. you live with an engineer long enough and eventually some of it has to make sense!!! "
So what should I do??? Thank you!