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HELP! What do I do about humidity?!

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by thegoldengirls, Dec 12, 2009.

  1. thegoldengirls

    thegoldengirls Songster

    Sep 12, 2009
    Central NY
    Just put a cheap thermometer in the coop which also measures humidity. I checked a few minutes ago and it says 80% humidity and it's going to drop to 20F or lower tonght. (Sun is going down now.) The chickens' door has been open all day and they have been in and out. And I have been in and out the walkthrough door. Not sure how the humidity can be so high..or, maybe it really is cheap. I have 9 birds that share a nice coop that is 8'x8'. And I just put down extra shavings. This is their first winter, as well as mine with the chickens.
    Am I just being a worry wart? (Which is what I tend to do with the animals.)
    Any thoughts?

  2. patandchickens

    patandchickens Flock Mistress

    Apr 20, 2007
    Ontario, Canada
    Have you checked the hygrometer using the salt method (see 'incubating and hatching eggs' section of BYC forum for directions how to do this -- it will tell you how inaccurate your hygrometer is, and thus what correction factor you need to be applying). It may very well be totally inaccurate, so I highly recommend checking it this way, even though it does take a day or so to do.

    Good luck, have fun,

  3. joebryant

    joebryant Crowing

    Quote:How to Calibrate a Hygrometer
    by Lianne McLeod, DVM
    for About.com
    *******To calibrate a hygrometer you will need:
    · 1/2 cup table salt
    · approximately 1/4 cup water
    · coffee cup
    · hygrometer
    · large re-sealable freezer bag
    1. Place 1/2 cup of salt in the coffee cup, and add the water. Stir for a bit to totally saturate the salt (the salt won't dissolve, it will be more like really wet sand).
    2. Place the salt/water mix in a re-sealable plastic bag, along with the hygrometer, and seal the bag. Note: make sure none of the salt/water mix comes in direct contact with the hygrometer.
    3. Set this bag aside at room temperature for 8-12 hours, in a location where the temperature is fairly constant.
    4. After 8-12 hours, check the reading of the hygrometer. It is best to read it while still in the bag.
    The relative humidity in the sealed bag with the salt/water mix should be 75 percent (mine read about 72 percent).
    5. For adjustable hygrometers, adjust to read 75 percent. You will have to do this very quickly, or remember how much you need to adjust the setting (e.g. mine read 72 percent rather than 75 percent, so I would need to adjust the dial up 3 percentage points).
    If yours is not adjustable (like mine), simply make a note of how "off" your hygrometer reads. If it reads below 75 percent, you will need to add the difference to your actual readings. If your hygrometer read above 75 percent on the calibration, you will need to subtract the difference from your actual reading.
    In my example: after sitting in the bag, my hygrometer read 72 percent, when it should have read 75 percent -- a difference of 3 percent. I now add 3 percent to the readings I take on the hygrometer (e.g. in a tank) to get the actual relative humidity.
    Remember: always give a hygrometer about 2 hours to stabilize before taking a reading, as changes in the relative humidity may take a while to register accurately on a hygrometer.

    Burbs (on byc) wrote:
    *Kosher salt is better because it is pure NaCl. Table salt has additives such as iodine and anticaking chemicals.
    Mine was off by 10 when calibrating with salt. I don't think it is that uncommon with the $20 digitals.
    When calculating at different humidity percentages keep in mind that it is not a direct addition. For example, mine read 65% when it should have read 75%. Thats a factor of 115% that needs to be added to the 65% reading. So if I am reading 35% on my meter the actaul is 40.25% (35 X 1.15 correction factor).
    From wikipedia:
    "The critical relative humidity (CRH) of a salt is defined as the relative humidity of the surrounding atmosphere (at a certain temperature) at which the material begins to absorb moisture from the atmosphere and below which it will not absorb atmospheric moisture.
    When the humidity of the atmosphere is equal to (or is greater than) the critical relative humidity of a sample of salt, the sample will take up water until all of the salt is dissolved to yield a saturated solution. All water-soluble salts and mixtures have characteristic critical humidities; it is a unique material property.
    I replied:
    Burbs, thanks for posting that. That could make a BIG difference in the original post. Mine was 70% rather than 75% so I was just quickly adding 5% as suggested in my post above, i.e., right now my hygrometer is reading 43% or 43+5=48% the old way. However, doing it correctly 75/70= 1.07 , so 43 x 1.07 = 46.01% NOT 48%. That incorrect difference of 2% could make an important difference when incubating eggs and deciding when/whether or not to add water.
    Also, when comparing my hygrometer's percentage to another that's known to be 100% correct, I could not see mine at 43% and the correct one at 46% and simply figure 3% difference at every percentage change, e.g., if mine only read 12% humidity, 12 x 1.07 = 12.84% not 15%. Thanks to you, I am going to keep a calculator next to my incubator and hygrometer from now on.
  4. chookchick

    chookchick Songster

    Aug 18, 2008
    Olympia WA
    Is there a lot of condensation on the windows? How does it "feel" to you? If it doesn't feel humid and the windows aren't wet, I wouldn't worry too much about it tonight. 20 degrees is not "too" awfully cold, and I'm sure your chickens heat it up some from there. Tomorrow you can figure out if that darned thing works or not.
  5. YonkFarm

    YonkFarm In the Brooder

    Feb 10, 2009
    Sutton, Nebraska
    I'm having the same issues....

    The humidity in my coop (12'x8' for 13 chickens, plus a 4'x12' storage area) went from 16% the past several days to 76% this afternoon! It's getting in the teens here tonight. Is there anything I should do? I've had their vent that's up at ceiling level closed for a few days and they haven't been outside much since we've had snow/wind/sub-zero temps, but today the vent was open as well as their pop door. We have an outdoor weather station and it says the humidity outside is 72%, so I'm thinking this is probably an accurate reading. It did feel quite humid outdoors today and our high temp was 33 degrees. Would the heat lamp help dry things out? I've only used it when our temps were getting well below zero. This is my first winter with chickens too.

    Thanks for any help!

    p.s. the Weather Channel says the humidity for our zip code is 93%????? Sometimes i wonder how accurate their readings are!
    Last edited: Dec 12, 2009
  6. chookchick

    chookchick Songster

    Aug 18, 2008
    Olympia WA
    76% is not awful, I would leave the vent open tonight unless it is huge (then maybe just part of it). I left a vent open even when the temps got down to 6 degrees. The chickens will warm up the air and you need a vent to carry off the moisture they produce. Gotta go but I'm sure they'll be fine!
  7. thegoldengirls

    thegoldengirls Songster

    Sep 12, 2009
    Central NY
    Thanks everyone. I'll pull the hygrometer tomorrow morning and test it. It was 3.99, so I guess I shouldn't put too much stock into it's accuracy.
    I had an infarad lamp on the past 2 nights because of the wind blowing through, but not tonight. I would really prefer not using it, although it only takes some of the nip out of the air rather than heating.
    Like I say, still pretty new at this and pretty hooked on my girls. I would hate to lose them out of my own ignorance.
    I appreciate all your feedback!

  8. wing it

    wing it Songster

    Aug 13, 2009
    long island
    what type of venting, if any, do you have in the coop?
  9. thegoldengirls

    thegoldengirls Songster

    Sep 12, 2009
    Central NY
    I have (2) 6"x12" vents in the soffits. one on each side of the building. I also leave at least one of the two double chicken doors open during the day. I'm heading out now to let them out and am going to see what is says before I open the doors.
  10. gsim

    gsim Songster

    Jun 18, 2009
    East Tennessee
    Quote:How much ventilation do you have besides the pop doors and the entrance door ? [​IMG]

    By way of comparison, I have 5 sq ft, independent of doors and windows. Including windows I total over 40 sq f not counting the entrance or pop doors. My coop is exactly twice the size of yours and houses 24 pullets of 6 mo age. [​IMG]

    Hang a pie tin or other piece of metal inside and up high. Then check later for condensation on it. If it is sweating, you are lacking ventilation. [​IMG]

    ( I keep my feed inside and my water for the chooks outside. When it freezes here, I close all 4 windows and let my overhead ventilation do all of the work keeping things dry. At those times, I will bring a small bucket of very warm water to them in the AM but it stays outside.) You may have a disfunctional piece of eqpt or you might just need ventilation added. Needs to be as high as possible if on walls, or maybe a turbine vent like I have in center of my coop. [​IMG]

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