Worried about humidity in the coop this winter

[3cravns]

My family and I are new to raising chickens this year. We have 13 hens. Our coop is 8 x 8 plywood with cedar lap siding. The walls are 2 x 4 with fiberglass insulation and plywood on the inside walls too. We had the coop wired with electricity, there is an outside "porch light", one inside light is wired to a sensor so that it comes on automatically at dark and there is another inside light that we just turn on and off the old fashioned way with a switch We had the electrician install an exhaust fan in the peak of the roof and that is also wired to a timer so that in the warmer months it comes on twice per day to pull all of the warm, stale air out of the coop. We currently have the fan door pulled tight closed and the timer is off. The ceiling of the coop we did in fourths. 3 of the 4ths are covered in plywood and the last one is framed in and covered in just screen(screen door screen) to keep the bugs out in the summer but to allow the heat to escape out the exhaust fan. The ceiling is insulated with fiberglass as well except over the screen, that is still open to the peak.
We are in Northern Minnesota so winter is long and cold. This week our high temps are expected to be in the low teens with our overnight lows expected in the single digits. We have gotten about 6 inches of snow so far today and the outside humidity today is 81%. Here is my concern...the windows of the coop are completely frosted today. We have the chicken door shut at night but open that up during the day so that the girls can get out to the chicken yard which we have made considerably smaller for the winter using bales of straw and plywood with a couple of pieces of plexiglass to let in what little sunlight we get this time of year. Prior to reading some of the posts here about getting ready for winter my main concern was the cold but the more I read I see that my main concern should be, and is now, humidity. We would appreciate any and all advice we can get, especially from anyone in a similar climate. I'll attempt to attach a picture of the outside of the coop and one of my favorite girls (ok, my favorite)

 

[ADozenGirlz]

Have you read "Pat's Big Ol' Ventilation Page"? That may be of some assistance to you. The link is here: https://www.backyardchickens.com/web/viewblog.php?id=1642-VENTILATION

Another thread that may interest you:
https://www.backyardchickens.com/forum/viewtopic.php?id=347589

Adorable coop, btw!!!

 

[True Grit]

I love your coop. Just for comparison, the temp here is about 16, humidity high 70's and pretty windy outside. Inside the coop it is 24 degrees and 65 % humidity. I went and checked the single pane window and it is not frosted so I'm guessing it is not too humid in there. I don't have very much ventilation open tonight either but I only have 5 hens. I'm curious how much of your ventilation is open now. Do you have a min/max thermometer/hygrometer that has a remote readout? I think the new lithium batteries will keep it going in the cold. Then you know what you're dealing with. It's a learning experience for me..

 

[3cravns]

Good to hear from someone in Minnesota! We are up in Walker (shores of Leech Lake). We do have a little minimum/maximum thermometer/hygrometer out in the coop. It seems to freeze up or something. Like I said, I think the temperature is accurate but it says the humidity is 16% right now so I'm sure that is wrong. If I bring it in the house for a while it seems to reset itself. I really don't have any true ventilation open right now. I was wondering if enough of the heat/humidity would rise to the peak and keep the girls comfortable. This is a complete learning experience for me. My husband did raise chickens as a kid growing up in southern MN but they lived on a farm with sheep and a barn as well and on the really cold nights the chickens would sleep in the barn ON the sheep! Lucky chickens!
I don't mind learning but hate to do it at the expense of the chickens health. I will stop tomorrow on my way home from work and get a lithium battery for the thermometer and see if that will keep it working.
Do you have problems with your eggs freezing this time of year? So far ours have been ok but I wonder about when it gets really cold, Minnesota style cold!!

 

[elmo]

Quote:
First of all, it isn't a good idea to have any opening to your coop secured only with "screen door screen." A raccoon can tear through that stuff in a second. I used hardware cloth with 1/2 inch wire spacing to cover all the openings to my coop, plus insect screen to keep out mosquitoes.

Secondly, I'm a little confused about your description. It sounds like you've got a screened "skylight" in your roof? Doesn't the rain pour through that? I must be misunderstanding what you wrote...

 

[Mac in Wisco]

You need to have an air inlet in conjunction with the fan opening so that the warm, humid air can still escape to some extent. Yes, you will lose some heat, but not all of it. It may be a matter of just cracking a window to get the air moving up and out.

When you say the fan is on a timer, do you mean a cycle timer? Depending on the fan size, you could set it to come on 15 or 30 seconds every five minutes. If it's too large of a fan though, it may be better to just rely on natural ventilation.

 

[Intheswamp]

Neat looking coop.

But, of course, I've got a couple of comments...

Screen-door wire isn't going to keep a predator out...most anything could rip through it. 1/4" hardware cloth would be much better.

That big opening under the roof...don't ya'll get snow up there that could possibly blow inside there and cause problems?

Best wishes,
Ed

 

[LynneP]

Gosh it's a lovely coop and well-designed. So if you need to flush the air, you can flip a switch? Another option is to install a vent with a closeable feature operated by a lever high on the wall, above the roosts but reachable, so you can have it open or shut as humidity demands.

And Ed is right- that screen door can easily be enhanced with hardware cloth (1/2" gauge) firmly attached outside the screening. It would be nice to have both to discourage bugs, so be sure you can access the screening by unscrewing a frame or something...

 

[jim s]

Hi 3cravns. I live in Duluth MN. Winters are cold, especially with winds off Lake Superior. I have kept chickens over one winter now. I have two coops, yours looks great by the way, one of mine is unisulated, 4'x8', and about a dozen birds stay there. I don't heat it and the birds do fine until about 20 below zero. I learned the hard way last year when a rooster got frostbite on his crown. I keep a window cracked about an inch and that is enough for ventilation at night though during the day the door is open. As others have intimated, it is trial and error. The colder it gets, the less you have to worry about humidity. I have found that any temp above zero the birds can handle just fine so I leave plenty of ventilation. I think for your sake, with a very insulated coop you can get away with more ventilation. Humidity does hurt the birds more than the cold. When it is going to be below zero, I turn on a heat lamp in one side of the coop and leave more ventilation. Hope that is helpful, just my experience.

 

[Nostalchic]

That is a beautiful, well thought out little coop, 3cravns! And I see that you have a solid door to back up the screen door at night (as do I - if a predator manages to get into the chicken run during the day - which they can't - they won't have to tear thru any screen, they can just go in the chickens' little door, or pick them up in the run). I do have hardware cloth and screening over the long ventilation openings at the tops of my north and south walls - about 4 inches wide. The north openings I can and do close thru the winter, but the south vents, which are at the top of an 8 foot wall of our shed-roof coop, are open all the time. Granted that we have much less humidity than you do, but this has worked well. I also clean the coop every day, scooping it up every morning, and it is bedded with coarse sawdust, so that removes one source of moisture. It also helps to have cold tolerant breeds, which means larger birds with smaller combs. My EE's have had no trouble with the cold.