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10-02-2011, 09:18 AM #1Regular Guest
- Join Date
- Apr 2008
- Upstate New York
help with lowering humidity levels in the winter
every winter I get condensation on the bottoms of my windows. I have all new windows ( vinyl ) live in a 1200 sf ranch with finished basement. I keep the basement dehumidifer at 50% year round. have very good attic insullation and ventelation. We heat with a 3 y old forced ar gas Rheem 95+ furnace.
It seems to stay around 50% indoors. Today it is 40 degs outside and raining and its 60% humidty inside....Its a pain in the winter with a 2" condensation on the bottom of my windows.
Is there a whole house dehumidifer that works well and doesnt cost a fortune to ru or install ?? Would turning my basement dehumidifer down to 45 help ??
My mothers house is 100 yrs old,forced air heat and her humdity runs 28%
10-09-2011, 02:37 AM #2
stupid question....do you have a humidifer on your furnace? if yes, turn the humidistat down...if no, outside make up air will solve this issue and give you healthier, fresher air.
10-09-2011, 07:05 AM #3
Condensation is simple.
Surface temperature drops below dewpoint. Water condenses.
There are 2 solutions:
#1. Raise the surface temperature
#2. Lower the humidity.
In winter, adding outside air to your home will help to lower the humidity because that outdoor air is dryer.
10-09-2011, 09:16 AM #4
You should have someone come out & do a blower door test to evaluate whether your home is getting enough fresh air changes. This is something included in an Energy Audit.
Getting enough fresh air changes in a home is very important. Indoor air pollution can be several times that of outdoor air pollution, even in big cities! Your humidity problem should be a wake up call.An answer without a question is meaningless.
Information without understanding is useless.
You can lead a horse to water............
10-09-2011, 08:06 PM #5Regular Guest
- Join Date
- Apr 2008
- Upstate New York
ok lowes replace the unit with a new Fridgidare 50 pint, it works but i have it set at 55%, it runs and then shuts off...5 minutes later its back on, this cant be normal or good for the unit..I have read others saying the same thing..is there a plug in dehumidstat that i could then set the unit at continuous run and plug it in to a dehumidstat that may work better than whatever is in the unit now ??
when it shuts off my portable humidity gage says it 43 %, the light on the unit says 55%
Again i really dont want to spen $ to keep my basement dry and who knows mayve that it will run the same way
Last edited by beenthere; 10-09-2011 at 10:31 PM. Reason: price
10-09-2011, 10:54 PM #6
The good news is it sounds like you have a good tight house. The bad news is it sounds like you have a good tight house. Without a blower door test, I am just shooting in the dark here, but it sounds like some outside ventilation could be in order here.Bad information is worse than no information at all.
There are three kinds of people in this world. Those who can count and those who can't!
10-10-2011, 12:04 PM #7
Another question is, how much moisture are the occupants and activities adding to the space? Occupants add about .5 lb. of moisture per hour. Fish tanks, high water tables around the home, and slow cooking will add additional moisture.
Two occupants adding 1 lbs. of moisture per hour to the air infiltrating the home at a specific outdoor dew point raise the indoor dew point.
If the outdoor dew point is 55^F with 100 cfm of fresh air, expect a 5^F rise in dew point. If your home is 70^F, with a 60^F dew point, the humidity will be about 70%RH. As the outdoor dew declines, the indoor %RH declines. With a 40^F outdoor dew point, expect 48%RH.
A dehumidifier is important until the outdoor dew point is <45^F. Then the amount of fresh air is critical for controlling indoor humidity. For lower dew points, more or less fresh air is more practical. Hope this helps.
Regards TBBear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"