Humidity in the coop and frostbite

[dacjohns]

I've been reading quite a few posts lately that say "high" humidity in a coop will contribute to/cause frostbite in chickens. I'm wondering where this idea comes from and if there is any evidence to support it.

I think that in warmer weather humidity can be a problem if the coop is not ventilated well enough because it might contribute to the buildup of ammonia.

In weather cold enough for frostbite I don't think humidity would be that much of a problem because in extreme cold air the humidity cannot get that high. The colder the amibient air temperature the lower the humidity. The water vapor freezes out of the air. You can't have high humidity in cold temperatures.

This is based on the amount of water in a given volume of air rather than the percentage value of relative humidity.

http://en.wikipedia.org/wiki/Relative_humidity

See the table about 3/4 down the page.

 

[Buck Creek Chickens]

if everything is 'wet' you will have high humidty in a cold coop, and that is what causes the problem

 

[dacjohns]

Quote:
I'm feeling dense tonight.

I'm looking for the relationship between "high humidity" and frostbite.

"High humidity" can not make the ambient air temperature any colder just like wind chill does not make the amibient air temperature colder. Wind chill is what the temperature feels like, not what it actually is.

Does "high humidity" cause a similar effect?

 

[Buck Creek Chickens]

high humidity might be the wrong word, its the amount of moisture in the air, it puts a thin layer of moisture on the comb which makes frostbite if the air is cold enough, like wet hands when its below freezing outside. where a coop that is wet/damp there is a higher amount of dampness around or if you have your waterer in the coop, do you understand what i'm trying to say


spelling

 

[elmo]

I think you may be forgetting the fact that every time a chicken exhales, she's putting out warm, moist air into the coop. If ventilation is inadequate, this moisture has to go somewhere...and it can't go into the very cold air as you rightly point out: cold air can't hold as much moisture as warmer air. The moisture ends up condensing on coop surfaces, including the chickens' combs and wattles which as other commenters have pointed out, can end up with frostbite.

 

[Buck Creek Chickens]

Quote:
that what i was trying to say, thank you

 

[dacjohns]

Quote:
I understand what you are saying. It's pretty much in line with what I have been able to come up with.

I guess maybe "high humidity" needs to be quantified now. And the amibient air temperature combined with humidity needs to be quantified.

So I guess what I'm now asking is at what temperature and what level of humidity (assuming still air) is frostbite a problem?

 

[Buck Creek Chickens]

anything below freezing,but the closer to 0 the easier it can happen, all depends on how 'wet' things are, and the draft in the coop, you know that roo's do not tuck there heads under there wing when sleeping so it make them more prone the frostbite

 

[elmo]

Have you read Patandchickens' page on winter coops?

https://www.backyardchickens.com/web/viewblog.php?id=1642-winter-coop-temperatures

Her suggestion is aim for 50 percent humidity or less. She mentions that chickens can get frostbite at temps barely below freezing when humidity is too high.

 

[Mac in Wisco]

I think you're right. As long as it isn't condensing on the ceiling and dripping on the birds, the high humidity doesn't make them colder. It actually makes it feel warmer.

I've spent weeks reading everything I could find on ventilating poultry barns.

We have 2500 hens in a 65 x 65 layer barn. I don't know how the previous owner did it, but he didn't use any heat in the winter and the smallest exhaust fan is 3500 CFM. Running the smallest fan in cool, not even cold, weather overventilated the barn and the birds were consuming way too much feed.

I did a couple of things. I put one of the 5000 CFM exhaust fans on a 5 minute interval timer. I can now customize the ventilation rate by changing the interval timer. e.g., If I run it for 2 minutes out of 5 I am ventilating at 2000 CFM.

I also installed a 80,000 BTU LP radiant heater. I put this in about 10 days ago and it's been a steep learning curve. I want to keep the barn at 65 degs and I figured if I adjusted the ventilation to keep the humidity at 70% in the coop I'd strike a balance between removing moisture and not burning too much fuel. Wrong! I burnt 100 gallons ($190) of propane in less than a week. The tank was refilled yesterday at $2.05 a gallon. I was really getting worried that this was altogether a bad idea to try to heat the barn, but I know it is fairly common in our area for these barns to be heated. Last night it got to -10 and I cut back the ventilation until the humidity reached 80%. That seemed to do the trick. The heater barely ran and I only burned a few gallons last night. The barn is nice and cozy. Ammonia levels are up a little as the moisture content of the litter has gone up, but nothing is wet in there, I wouldn't even call it damp. Just a little moister than usual.

Based on that, I'd say if you're ventilating to keep the humidity down you're probably losing most of the heat along with the moisture. I use a humidity sensor and can keep tabs on exactly what is going on. I have a feeling that those who walk into a cozy coop in the morning and feel a little bit of humidity increase the ventilation based on recommendations here, yet unless the birds are choking from ammonia I think that a little humidity is a sign that you are actually conserving some heat, even if that heat is only bird heat.