Wet House

Wayco Wayne_2

I looked at a house yesterday that has humidity problems. It has a moist crawlspace that needs work. sealing, insulation, not to mention some snake removal. (not me jack!!!) the landlords know it and are working a long term solution into the budget. I'm looking for a short term solution to buy time until the long term solution happens. They have 2 dehumidifiers going. One in the small basement that is only 25% of the footprint of the house, and another in an office on the main floor. I think an exhaust fan would help on some days to eject the moist air and bring in some drier air. Since it is a part time install I dont want to go HRV, but just use an in line duct fan drawing from the return of the FA furnace. Is there such a thing as a differential humidity control that would bring it on when it's drier outside and turn it off when it's more humid outside???? I will google and see what I can find.  

kcopp

Seal up all the outside.....

air first. Any outside air will condense on the inside of the foundation and cause more issues. Seal up the floor w/ Heavy duty plastic. Make sure there is no ground water and spray foam up the walls and floor joists to the outside. I will get an article to document....

http://www.buildingscience.com/documents/insights/bsi-009-new-light-in-crawlspaces?topic=resources/cond-crawlspaces

LarryC

Reduce sources of moisture

WW:



Immediate steps would include removing major sources of water.  Outside humid air getting drawn in, showering and bathing without using FUNCTIONING exhaust fans, excessive moisture from cooking, excessive moisture from lots of inside plants, improperly set or operating humidfiers, clothes dryer venting inside the living space, evaporation from standing water like uncovered drain sumps and open aquariums, clogged drains on dehumidifiers and air conditioning coil drain pans, moisture coming up thru the exposed dirt crawl space. 



Don't forget the goofy sources like a hot tub in a bedroom or basement, a leaking water bed, a wading pool in the garage, a hair dressing business in one of the bedrooms, a pot or mushroom grow room, etc.



If there wasn't moisture problem before, check for something that changed like exhaust lines that got broken, moved, or disconnected.  Did somebody install a laundry room upstairs and just vented the dryer into a wall cavity or the attic?  Does the stove exhaust hood actually vent outside?  Does the roof leak?  Perhaps the walls and ceilings are just drying out?



How about a lifting over pressure valve on the water heater or boiler system?



Good Luck.

Tim P._3

Humidity Differential

You can pick up a controller that will humidify/dehumidify from a setpoint for about $100.



If you wire them in series-- if humidity in crawlspace > 80, power second unit-- the second unit would be set  such that if humidity outside is less than 80, turn fan on.











Tim