best way to lower humidity in home

brian2 · 01-23-2007, 12:47 PM

home in MN, outside temps in the teens.my RH is around 40% to high for this time of year. I've been thinking of having an air to air heat exchanger installed or possible DIY. Does any one think this would solve the proplem. Or any other ideas?

#CARRIERMAN · 01-23-2007, 02:24 PM

Hi brian2

Running the blower continuously is the best way to control humidity and comfort. No it will not hurt the blower running it all the time, and it will cost you somewhere aroud $120 to $150 dollars a year. Give it a try for about a week and see if it makes the difference you are looking for.

Good luck
Rusty

brian2 · 01-23-2007, 04:07 PM

not sure if my blower has a switch to run constant? Just moved in, I'll have to look into that. Carrierman, you think by running the fan constant it will drop the RH. I'll try it if my blower allows. thanks

concretemasonry · 01-23-2007, 05:06 PM

brian -

Is this a new home? As you probably know, getting the humidity up is usually what we want to do in Minnesota in the winter.

I run my fan constantly in the winter and when I am air conditioning and it certainly does seem to help with the humidity. It does a great job reducing the summer humity compared to my old furnace fan. Right now the humidity in my house is 20% (a little low). Outside it is 24 degrees and 67%.

I have a variable speed fan (D.C.) on my new furnace and it certainly is not near $100 per year. An older, non-variable speed would be higher.

brian2 · 01-23-2007, 05:43 PM

concretmasonry,
same outdoor conditions, but inside I have 48% even when it gets below zero. thats when I get condensation on the bottom of some windows. my house is 10 years old with 6 inch walls. I'm assuming the house is to air tight. when you say :variable speed does that mean 2 speeds or indefinate?

concretemasonry · 01-23-2007, 06:19 PM

A little condensation is not bad. You will always get some with shades and drapes the limit circulation.

You might have a house that is too tight. Mine has a fresh air intake that feeds the furnace room. It is not sealed so I don't know how it effects the inside humidity. From experience, I know that even outside cold air at a high humidity PERCENTAGE does not really have much moisture in it and can dry out the interior when it gets inside. - A far cry from the southern winter air.

My furnace (Bryant) is a new 80% (could not justify a 90% model even in Minnesota), but it does have what is advertised as a "variable speed" D.C. fan. It certainly has a mind of its own. I am so pleased with the temperature uniformity (2 story with open split entry) and summer humidity I get by running it 100%, I have not bothered with the details.

Dehumidifying below about 40% will cost you, plus you may have to bump up the thermostat a bit because of the dryness.

brian2 · 01-24-2007, 01:55 PM

concretemasonry,
It's supposed to get cold and low RH this weekend. Could you post your reading, so I got something to compare to. My furnace has a clean air intake, but that runs direct to the furnace. The room it self is not vented, laundry room. thanks