The Great Winter Coop Humidity/Ventilation Experiment! Post Your Results Here!

[mobius]

Hi Everyone!

I live, with six chickens, in what I like to call Deep Northwest Montana. This is my first winter with chickens. I have had quite a bit of concern over humidity and ventilation in the coop as winter approached. So on good advice on this forum, I purchased a hygrometer/thermometer that does remote readings. I tested it using the salt water test. It was 5% below, so I add 5 to my readings. I put the remote in the chicken coop at beak level where my girls roost. They are winter-hardy breeds.

So the (tested) hygrometer is my new best friend at the moment. Last night it was predicted to get to -12F here, and ya know what? It DID. So I was rather concerned. In advance. I decided to take readings every half hour last night (and this morning). I am starting this thread to post the results. I encourage any of you who would like, to post your results here also, in the interest of sharing and tweaking.

Last Night:

10:30 p.m
Outside: -8F. RH 71%
Coop Pop Door Open: 8F RH 64%

AS the chickens seem to keep the 4x5x5 coop about 10 to 16 degrees warmer, I was starting to get concerned about the -12F. So I called it, and closed the pop door at this point.

11:30 p.m.
Outside -9F RH 78%
Coop 7F RH 64%

So far so good. It stabilized until:

1:30 a.m. (Don't tease me about staying up please! Or do, it's ok!)

Outside -12F RH 74%
Coop 5F RH 65%

Today:

8 a.m.
Outside -12F RH 83%
Coop 4F RH 67%

9 a.m.
Outside -8F RH 78%
Coop 6F RH 67%

Whew! Okay it is not going to get above zero until noon. While I usually take warm food out to them in the a.m. and usually the pop door remains open, I am going to leave them closed up til about noon and then give them lots of yummy things.

Other points of note:

They have food and water in the coop. The water is horizontal nipples on a covered 4 gallon bucket with a stock tank de-icer.
I slathered their combs with castor oil.
I put PILES of straw (over regular pine shavings)in their run AND coop yesterday, which they began to distribute.

I hope this helps folks worried about deep cold! I have had a LOT of good advice on this forum, which seems to be paying off. These results are very reassuring to me (and I hope they may help you)! Please DO post any data you collect!

I will continue to post readings here myself. Obviously I like to keep track!

HERE is the level we are shooting for and more info about hygrometers (humidity measurers):

From @patandchickens :

Yes, you CAN get indoor humidity lower than outdoors, if your indoor is warmer (I am not advocating electric heating necessarily -- there are LOTS of things that can act to make your coop warmer than the outdoors, esp. at night. See 'cold coop' page in .sig below for that subject). What matters in terms of frostbite is relative humidity. For a given amount of water vapor in the air, relative humidity is lower at warmer temperatures.

Also, in terms of temporary weather 'blips', it sure seems to me like having your coop start out pretty dry -- dry wood, dry shavings, nonpooey, nonhumid -- seems to create a sort of 'humidity sponge' that can even out temporary swings in the weather.

Commercial chicken barns seem to aim for around 50-70% humidity. IMO for backyard flock purposes it's when you get to 75-80% that you start getting a bit iffy, and I'd say above 85-90% humidity is really courting trouble.

HYGROMETERS ARE NOT USUALLY ACCURATE right out of the package; you need to use something like the salt method (see 'incubating and brooding eggs' section of BYC forum for instructions) to figure out how wrong yours is so you know how much to add or subtract to its reading. I would not suggest believing a hygrometer reading otherwise

Cracking the doors is probably not enough ventilation, and is not a good location for it in wintertime. See my ventilation page (link in .sig below -- sorry to keep doing that, but the whole reason I did those pages was so I don't have to type all this stuff over and over and over

) for details as to construction, location, size, and management of vents.

Good luck, have fun,

Pat

From @aart

Hygrometer is easily tested:
Hygrometers can be tested by putting 1/2 cup salt and 1/4 cup water in a dish or jar and mixing it to a slurry.
Put the salt slurry jar and the hygrometer next to each other in a large sealed plastic bag.
After 8-12 hours the hygrometer should read 75%... note any differences and you're set.

From me:

The hygrometer was 5 Percent below 75% for outside and 4 percent below 75% for inside. I marked the weather station with a sharpie.

Here is a recent link to which hygrometer people use!

https://www.backyardchickens.com/t/...tion-do-you-use-to-monitor-coop-conditions/10

 

[Beekissed]

Just an interesting side note to the DL providing warmth in the coop. When I dumped 15 cartloads of green material from the garden into both my coops in October, I realized that was the most green material I'd placed there so late in the season and it contained 25-30 ft. vines that couldn't be flipped if need be, so I capped that green matter with some brown(leaves, straw, etc.) and hoped for the best. Was worrying that it wouldn't compost as well with all those woody vines in there, but I must admit they created great air pockets in the mass. They've sunk downward in the mass by 2 ft. or more, so they are indeed decomposing, but it's taking awhile.

Anyhoo, the spare pen doesn't get the share of manure that the main coop does, but it still got a good bit this year in one way or another that also isn't the norm here...usually that spare pen is rarely used in the fall and just briefly when it is. But, I had various juveniles that wanted to roost there and I let them, got a flock of birds from my sister that I held there until butchering, etc. So, that added some good nitrogen to the spare pen.

Flash forward to dog housing. I build a hay bunker house in the spare pen in the winter for my LGD, who doesn't like the confines of a dog house in cold weather for sleeping but still appreciates warm digs when temps hit below zero. I got curious about any warmth from the DL under his thick layer of hay bed and stuck my hand under there yesterday (note, he only lies in there at night) and was pleased to feel a warmth being generated in the DL under his bed! The spare pen is even more open air than my hoop coop, so it's got great ventilation and I don't worry he'll get chilled at all from the humidity in the DL, but I'm mighty pleased that he has a heated dog bed for the winter. A cool and unplanned side effect of the composting DL.

Ben's hay house bunker



Materials that went into the coop from the garden....15 of these...





The spare pen...it doesn't have as deep of DL as the main pen digester...only about a foot of DL here.



The main coop's roosting section where most of the mass is accumulated and managed.




Sorry...didn't mean to derail the OPs thread topic but felt it germane to the topic to mention that some of us are intentionally creating humidity in our coops for a purpose but are also allowing and adapting ventilation for the added humidity generated and how that all goes down, the whys and hows and how it all looks.

Sorry, Mobius!

 

[Mrs. K]

I am no expert, but following this and thinking about the following points:

• I think the day time temperature/humidity is not a big deal because chickens are more active, moving around. The weather may be cold, but the bird is warmer do to movement, although when it is severely cold, mine are not nearly as active as in nicer weather. However, still more active than when roosted up.
• Daytime movement also puts more space between birds. At night ming are roosting pretty close together I assume for warmth, but this would also concentrate humidity in that region.
• Exposure to cold can cause frost bite, I agree, however, it is almost always due to exposure to the elements, most coops would be enough protection? This is why weather people talk about wind chill, when exposed to the wind, it is much colder and harder on your skin. If you are out in it, and step behind a building, it is always surprising how much more comfortable being out of the wind is.
• The parts of the chickens that seem liable to frostbit are the wattle and mostly the comb. This area has no feathers, I have seen these areas looking damp. I am assuming that with the cold, these contract to restrict blood flow to that region, which would make them more susceptible to frostbite. This time of year, they tend to be a bit more pale and wrinkly anyway.
• I have never seen it on the feet at all, but in biology, I did learn about birds feet and their blood and temperature. Wild birds walk on ice and snow all the time, and so do my chickens. With little or no effect that I can see. Many on here have proposed flat roosts, I have at different times provided both types of roosts to my birds, to have them seem to prefer a rounder perch, I have compromise, and mine roost on old fence posts.

Very interesting topic.

Mrs K

 

[mobius]

Oh my, everyone, I realized it has been nearly a month of posting results with fairly varied winter weather conditions! The results appear solid. I am thinking this is enough data from me for the moment. Whew!

I may do some testing of temps at different levels in the coop, as previously suggested.

But let's keep this thread open, and please post your findings and questions here!

I think the most important take-away for me (being inexperienced at flock management) is that is is completely worthwhile to make a small purchase of a hygrometer/thermometer and test your conditions, and then adjust and tweak accordingly. Otherwise watch the window glass and conditions and/or your rooster's comb for indications. Secondly, keep an eye on your birds and their set-up when you provide routine management.

And my deep thank you to everyone who has contributed!

 

[Howard E]

I am in the process of putting together a piece on cold weather chickens. One of the resources I'm using is a book I got from BYC member and Publisher Robert P, called "Poultry Production". It was first published in 1961 and the author was a professor of poultry husbandry at University of Illinois.

Anyway, long story short, what Mobius is seeing is pretty much exactly what should happen, as per the book. Chickens do crank out enough heat all by themselves to drive up the temperature in the building enough to lower the relative humidity inside, which helps dry the building out. A chicken's body temp is about 107F +/-, and they shed heat constantly, so the birds do have to eat enough high caloric feed to maintain that level of body temp. The feed is the fuel for their furnace. How it all works is a complex (very complex) interaction of birds and their housing, the latter of which involves balancing ventilation, insulation, plus deep or built up litter, or at least that is what the book says.

I think there is another thread on this topic from Wesley in MN who found his coop at 0F when outside temps were -24F. He has somewhere around 24 birds in his. But he is finding similar results. All good to know!

 

[lazy gardener]

IMO, this is one of the most important threads on the BYC site. Agreed with Bee, the woe is me attitude, often stating a problem without the desire to actually implement the necessary changes to actually fix the problem gets old fast. I want to run to town to pick up a hygrometer, and at least one more outdoor thermometer, so I can have a better idea what is going on in my coop as it relates to temp/humidity/frost bite/and egg laying. I did an exhaustive search, and found nothing in the commercial arena that even vaguely relates to the issues that we as back yard flock keepers encounter with our small coops and flocks in a frigid winter.

 

[WesleyBeal]

I wouldn't be surprised to learn from someone in meteorology that RH is always really high right at 32 degrees. All the water that was trapped as ice is now changing to liquid, making it available to change again to gas.

My degree is in English, so my conclusions are automatically not great, but seems to me that I'd suspect the worst temperature for RH to be 32.1 degrees. That would result in the slowest melt possible, keeping some liquid water available for the maximum amount of time.

Like I said though, my degree is in English.

 

[bullets]

If you get get a chance I would place both of your thermometers outside for an hour or two and see if they are giving you the same reading. It's a likely possibility one of them is reading differently than the other. Even if they are both off a few degrees on accuracy it's okay for this experiment as long as they both show the same readings on humidity accuracy and temp in the same environment.

 

[Beekissed]

I think that's a good idea. Seems I have more trouble with frost bite issues~if I have them at all~at those temps rather than subzero temps, due to the excess moisture that is already in the air both outside and in at those temps, particularly after a snow or rain.

Here's my own kind of report, though not exactly on humidity, as I don't measure that...would be interesting if I did. It's warmer than normal here right now, so will repeat these measurements when we get some sustained cold temps in the single digits or below zero to see just how much the DL cooks at those temps.

Today is a 45* day with occasional slight breezes but not much. Here is the temp at roost height at that temp....




For the first time ever, I just thought I'd shove my hand back in the DL litter mass under the roosts and was pleasantly surprised to find it much hotter than I had supposed it would be....here are readings from two depths in the litter.... and, keep in mind, this is not too deep, as my thermometer probe won't go any deeper than 5 in.





At the most shallow spot under the roosts it was a mere 85*.

I'll add some water to the mass today and that will really heat it up in there....these readings are without any added moisture beyond the feces and humidity from the materials, the ground and the air.

Like I said, I'll take further readings when the temps are truly cold for a sustained period of time to see just how dormant that biomass heater goes in colder temps and will post them then....should be awhile, as we are having an unseasonably warm winter right now. Got up to 70 degrees yesterday!

Might be pertinent to add that this is in a hoop coop with a LOT of ventilation at all levels.....right next to this mass is an open pop door and the tarp is pulled back, open vents under the roof over the mass and 8 ft. away is the front of the coop with a half door open, small windows and roof vents open and another pop door open, not to mention various large cracks and gaps along the floor and further up the coop.

 

[Howard E]

Yes, I agree. Dry chips and droppings by themselves are going nowhere as far as composting and generating heat are concerned, no matter how deep. To get compost heating up, it has to be managed, including the Carbon, Nitrogen, Air and Water. A fifth element is heat.

In order for composting material to generate that level (or greater) of heat, there has to be what some refer to as a "critical mass". A large enough mass of material assembled in such as way as to trap the heat the compost generates. My guess is you could take the same material you have now and spread it over 3X to 4X the surface or floor area you have now and once thinned out, the heat would go way down if not dissipate completely. That would be cold composting or "rot". Or, you could pile it up deeper to 3' or more and it would take off and get really hot. Once you get to the level where the material starts trapping the heat in, you could be at 120 to 140 or so, aka, "hot composting". Good in a compost pile, but something to be avoided inside a chicken house.

My guess is at your 12" to 24" of depth of a managed blend, you are right on the cusp of this taking off and right where you want to be. Good info!

BTW, as part of this equation, one of the stated benefits of deep litter systems in chicken houses is the ability of the litter to 'soak up" or absorb short term spikes in humidity and moisture. On days when the RH is way up there both inside and out, the deep litter gives it a place to go. It is later released when the weather changes and things start to dry out. Yet another benefit is it insulates the ground and floor beneath it, both of which continue to give up some radiant heat into the house.