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Thread: humidity

  1. #1
    Join Date
    Jun 2004
    Posts
    1
    I have an older(110+) home with very high humidity(my basement was at 90% before i turned on my dehumid...Its been humid here in north jersey, but i cant get a handle on it. The house is a small cottage(14oo sf excluding basemnt)with a stone basement(partial walkout). It smells musty throughout the house. A couple of questions: My basement is broken up in to 4 rooms with open door ways, whats the best aproach to lower the humid? Can anyone recomend an hvac contractor in north jersey that is helpful with these problems? I have called the few listed on april airs web site and cant get a call returned. I have also called 20 others out of the phone book, but no one is interested. My 14 month old daughter already has asthma and im thinking of selling the house. Sorry about the long post...any help is greatly appreciated.


  2. #2
    Join Date
    Mar 2004
    Location
    SE Michigan
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    17,601
    Do you have central heat/cooling?
    "The road to Hell is paved with progressive policies."

  3. #3
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,070
    Basics for humidity control, is all the earth in the basement/crwalspace covered by concrete or plastic? Close all vents to the outside, stop any water leakage, and remove water with sump. You need at a minimum 50 pints of dehumidification capacity at the normal temperature of the space per 1,200 sq.ft. of space. Residential dehumidifiers don't have significant capacity at cool basement temperatures. For tougher applications, check into units like Santa Fe. They will remove 60-70 pints per day in a cool basement and manintain 50%RH. This will stop all mold/must odors. Get a %RH meter and maintain <50%RH thoughout your to control mold and dust mites that can cause asthma

  4. #4
    Join Date
    Feb 2003
    Location
    Huntsville,AL
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    4,125
    HOWEVER, drying out to 50%RH may mean that the foundation will settle more! mine is, after one year of such! cracks showing at my steps from family rm slab to kit over crawl of trilevel.

    dammed if you do, dammed if you don't --

    I may go to 60%, since needing to sell, AND have no moisture evident -- visible nor smell.

  5. #5
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,070
    Originally posted by cem-bsee
    HOWEVER, drying out to 50%RH may mean that the foundation will settle more! mine is, after one year of such! cracks showing at my steps from family rm slab to kit over crawl of trilevel.

    dammed if you do, dammed if you don't --

    I may go to 60%, since needing to sell, AND have no moisture evident -- visible nor smell.
    Every winter the %RH in these type of basements is well below 50%RH. If you are concerned with maintaining a wet foundation, cover the surface with plastic. 60%RH may be ok, but marginal for mold control on cool surfaces. Sensitive people need dry space,<50%RH, or consider moving if unable to keep mold from growing.

  6. #6
    Join Date
    Mar 2003
    Location
    Houston
    Posts
    80
    Try mixing the air in the home more with basement air. This will make the home more comfortable and lesson the settling problem. Even dehumid Companies know that heat is your friend.


    "Pigs get fat, Hogs get slaughtered"

  7. #7
    Join Date
    Apr 2004
    Location
    STL
    Posts
    111
    Does anybody complain about humidity too _low_ in the cooling season? Is lower always better in the summer?
    ...and if those electronic humidity gauges aren't accurate, what can a _homeowner_ use to monitor indoor humidity?

    Electrajim

  8. #8
    Join Date
    Jun 2004
    Location
    4H: Hot, Humid Houston H.O.
    Posts
    3,304
    >>Does anybody complain about humidity too _low_ in the cooling season?

    I have never ever heard of that happening. But you might take into account that I live near the Gulf Coast, an inherently hot and humid climate. Maybe someone in the desert?

    >>Is lower always better in the summer?

    What I have heard is you want to be below 70% RH (relative humidity) if you want to avoid potential mold growth. And that you want to be below 60% RH or else you will have trouble feeling comfortable. In my experience getting down to 45-50% RH definitely feels better and for a given temperature, feels cooler.

    >>...and if those electronic humidity gauges aren't accurate, what can a _homeowner_ use to monitor indoor humidity?

    I think those $15 electronic gauges I buy from Wal-Mart, ARE reasonably accurate. One day I took a half dozen gauges, put them in the same spot, waited for them to equilibrate, and wrote down the results. Averaging the results, I figure is my best estimate of what the RH really is. The worst of the bunch was about 3% off at certain humidities, but under most conditions they were no more than 1-2% off from one another.

    You will me miles ahead of most homeowners in my opinion, if you buy two or three of these gadgets and place them in various places in your home.

    Hope this helps.

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