Proof Coop Insulation Does Nothing.

[Mac in Wisco]

Quote:
Exactly. That is about all you can do, observe the conditions and react accordingly. Even a hygrometer doesn't tell the whole story if you don't understand what it's measuring. 80% humidity at 20 degs in a coop is much different than 80% humidity at 60 degs in a coop. Those are two vastly different moisture levels.

I should probably take this over to the other thread... but in her case, her windows are part of her ventilation system and she has been opening and closing them as necessary, but is still concerned that she doesn't have enough fixed ventilation when they are closed and it's in the 30's at night. Why?

She should use the windows as she feels necessary and rely on the fixed venting when conditions call for for minimal ventilation. "It's been too warm, damp, or smelly in here, I'm going to crack the windows a little today."

If you didn't have heating or cooling in your house what would you do as the weather changes? Probably open and close windows as necessary?

 

[dsc6]

Would one of you ventilation experts please go to the pictures of my playhouse-turned-into-a-henhouse and talk about it's ventilation--pretty please???

There are 4 open windows on the bottom and 4 windows up above and inside there is a cathedral ceiling. It is elevated, not resting on the ground. I was thinking that maybe I should put plastic or something over some or all of the lower or upper windows when it starts to get really cold. I live in southwestern PA--not too much below zero days, except for wind chill.

The pictures are in the "coop' section and tiltled playhouse-into-coop, and from June, 2010. You can comment here or on that thread.

I would really appreciate it.

Deb in PA.

P.S. if you do an 'author' search and put it 'dsc6', you will see the list of my posts/threads, and it is easy to find the thread with the pictures.

 

[patandchickens]

Quote:
Hm, can I ask you to expand on this? I realize that obviously the total amount of water in the air at 80%rh/60F is going to be a lot greater than the total amount of water in the air at 80%rh/20F... but, could you talk more about how that matters in a practical sense?

I have been under the impression that effects on chickens (frostbite, respiratory risks) are basically just a matter of relative humidity, not absolute humidity. (R.h. being what the hygrometer's telling you)

But then you do this for a living and I don't, and I'd like to hear more.

Thanks,

Pat

 

[dsc6]

After reading Pat's ventilation page, I figure I have just about perfect ventilation. 8 windows that are each at least 12inX12in and 4 of them up high. I can't imagine how to ventilate as well as she says we should do AND avoid drafts. My winters arn't that cold. As it is, I keep the front door open all the time they are out of the hen-house, I use the deep litter method, and it has never smelled of ammonia at all. I'm worried about the 4 lower windows, though....

 

[Mac in Wisco]

Quote:
Hm, can I ask you to expand on this? I realize that obviously the total amount of water in the air at 80%rh/60F is going to be a lot greater than the total amount of water in the air at 80%rh/20F... but, could you talk more about how that matters in a practical sense?

I have been under the impression that effects on chickens (frostbite, respiratory risks) are basically just a matter of relative humidity, not absolute humidity. (R.h. being what the hygrometer's telling you)

But then you do this for a living and I don't, and I'd like to hear more.

Thanks,

Pat

The respiratory risks are associated with dry litter and dust that result from low humidity levels. I don't think that high relative humidity in itself poses any sort of respiratory risk, unless you consider that it could cause increased ammonia generation, which is very low anyway at the cold temperatures we are talking about. The absolute humidity governs the amount of moisture in the litter, but in practice the best you can do to keep the absolute humidity at a maximum in the coop is to keep the relative humidity in the coop at 80%. Beyond that you run into problems with condensation. 80% RH at low temperatures is still very dry air and 80% RH at higher temperatures would keep dust down better, as the absolute humidity is higher.

Trying to dehumidify a coop by increasing ventilation at the expense of heat can be problematic. What you will see is that as the temperature comes down from the increased ventilation, the relative humidity can roughly stay the same. One could start at 70 F and 80% RH and ventilate and ventilate to try to get the humidity down, and only see the temperature drop to 65 F and 80% RH. It's not so obvious to some that they have removed a lot of moisture from the coop, even though the hygrometer still reads 80%.

I'm still not too convinced that high RH values pose a cold stress risk to chickens, unless condensation is actually making things wet inside the coop. The higher RH can increase the conductivity of the air leading to greater convective losses, but at such low moisture levels does it really have that much of an effect, especially if you have reached an overall goal of increasing the temperature in the coop? At lower RH levels the birds lose more moisture to respiration which increases bird heat loss, especially with already very dry, cold air. It would seem to me that increased humidity levels would help them breath better.

 

[Rare Feathers Farm]

I just wanted to add that when I left for work this morning, it was 27 degrees outside and 42.7 in my coop. Oh and it's fully insulated.

No frozen waterers, happy, active chickens and I even had a few eggs (also not frozen but pre-chilled).

 

[LynneP]

-4C outside our coop today, +5C inside the insulated area, +1 in the main aisleway of the barn. Fair to say combination of hen heat and insulation keep the coop nicely warmed. Barn aisleway before insulation would have been only a degree or so over outdoor temps on a calm day.

 

[patandchickens]

Quote:
It seems to be sort of "common wisdom" among most commercial producers and extension service pamphlet-writers that high humidity (like, >80% r.h., -ish) is a real risk factor for respiratory disease outbreaks. This is also a traditional idea among many writers from the 1910-1930 era of large home flcoks and small commercial flocks.

The mechanisms commonly named to explain this are better microorganism survival outside the chicken's body in humid environments, and (in old-timey cold chicken barns, not modern 65 F ones) the cold humidity being a general stressor leading to poorer immunity. My experience of other animals in really really humid barns is that they are more apt to have respiratory problems (disease and allergies both).

I do not know of specific studies (have not looked very hard though, and considering how much ELSE has been formally studied by ag schools, I'm sure this has too), so do not have any independant measure of how real this is... but certainly people who I'd think *should* know seem to think so, for whatever that's worth. Anyone who wants to do a proper literature search on this, I'd really like to see the results of it!

There are also some studies I came across while (briefly but fruitlessly) looking for actual studies of the above, in which they show that broiler performance is reduced in high humdity, 'physiological stress and increased heat loss' being given as the explanation.

Trying to dehumidify a coop by increasing ventilation at the expense of heat can be problematic. What you will see is that as the temperature comes down from the increased ventilation, the relative humidity can roughly stay the same. One could start at 70 F and 80% RH and ventilate and ventilate to try to get the humidity down, and only see the temperature drop to 65 F and 80% RH.

That is not my experience in how things work in a backyard coop type situation -- since opening more ventilation does often cure condensation problems -- but it is still a valid and interesting point, perhaps quite relevant in situations with lower humidity to start with (i.e. *not* near saturation). I need to think about this more, and how it fits in with what i see happening. Thank you for making me think

I'm still not too convinced that high RH values pose a cold stress risk to chickens, unless condensation is actually making things wet inside the coop. The higher RH can increase the conductivity of the air leading to greater convective losses, but at such low moisture levels does it really have that much of an effect, especially if you have reached an overall goal of increasing the temperature in the coop?

Again I do not know about formal studies, but there is pretty good indirect and anecdotal evidence suggesting that when humidity approaches saturation you get more frostbite. This is not something of relevance to commercial chicken producers these days (although it *used* to be, in our grandfathers or great-grandfathers' day) but it definitely is to us backyarders

Sometime when I have more time, I really need to take another crack at finding studies on these two things (very high r.h. in regards to chicken health, and humidity in regards to comb/wattle frostbite). (Or even better, someone else want to? Or hey, I know, you can watch my kids while *I* do it... mind you it may take me a loooong time, I hope you like screamy little kids around... LOL)

Pat​

 

[Chickens-246]

Keep an eye out on who edits their posts after this one.

Quote:

 

[eKo_birdies]

non-insulated all the way for us here.... our coops are 6x16, have 25 hens... no problems whatsoever this year or any years in the past. i live at 8,000 feet in CO and the temps have consistently been getting in the single digits (or less) at night.