Timothy Markus wrote:Hi Pierre-Luc, and welcome to Permies.
First, you know you get down to -40C at times. It's OK, you can admit it. ;) I know we get down to that most winters in SW ON, sometimes for a week or two.
Timothy Markus wrote:Insulation and ventilation are pretty much mutually exclusive. It's nice to insulate the floor of the coop, but the deep litter takes care of that. Also, they'll happily roam around in the snow, so it's usually not a big deal. The window doesn't need to be double glazed as any heat in the coop will go right out the top. You also don't need a fancy cupola, just know that you need to get rid of the excess moisture and, as you know, keep the drafts off them.
Timothy Markus wrote:I built a 4x6' coop out of 2x3 frame on 2' centers and 1/2" ply sides and roof. I slanted the roof from 7' to 5' and kept my roosts at 2.5-3' so there was about 18" above the roosting hen to the 2" gap around the roof. I just ran 2x3" joists on top of the coop frame for the gap and used 1/2" hardware cloth to keep out rats, weasels and opossums. I had a couple of open cut outs that I covered with hardware cloth for more ventilation in the summer that I covered in the winter.
Chickens come with a down coat, so they can stay pretty warm in winter. I chose breeds with small combs, pea combs for preference. I had a number of Chanteclers, our only Canadian breed, and they do very well in winter, as you'd expect. I did end up with a couple of hens with big combs and they did get a little frostbite, but not bad. In winter, they'll crowd together on the roost for warmth, squat down on their feet and tuck they're heads under their wings. If you heat the coop and then lose power, they can't handle the abrupt change, so that'll kill them. I took my girls through several winters like that without any issues except frozen water and eggs.
I built a cookie tin waterer heater for underneath the plastic waterer, though I had to use 2 75W bulbs when it got down below -20C. If you do use a cupola, make your air intake the same gaps just below the roof. That way you'll have air stratification and it will come in under the roof and out the cupola, but the cupola should be at least 2' tall to get the right stack effect. I've done a lot of attic ventilation analyses and stratification is normally a bad thing, but good for livestock. Like I said, though, it's needlessly complicated as a 2" gap 18" above chicken height (2-2.5' above the roost) works just fine.
edit: I just wanted to add that you pretty much need to supplement light in our winters as they like 14 hours to lay well, even the Chanteclers, whatever anyone tells you. If you get them this year as ready to lay or pullets, you don't have to let them moult in the fall but next year let them moult naturally as the light wanes, then add light back gradually in the morning to get to 14 hours. You want them to experience natural dusk as they'll naturally go home to roost and the light won't shut off all of a sudden, leaving them on the floor.
Dan Boone wrote:My family had chickens in the 1970s in a log coop on the upper Yukon in Alaska, where it would get down below -50F and stay there for a couple of weeks at a time in January. Under those conditions at least, ventilation was the enemy. The goal was to seal that coop up as tightly as possible. It was about six feet by eight feet, just tall enough for a person to stand inside, flat roof, made of about six inch logs, chinked with moss, plywood and tarpaper flat roof insulated with several inches of moss with Visqueen (plastic) vapor barrier. There was sawdust on the floor of the coop but there was a screened bin under the perch to catch droppings. Ammonia in the air was a definite issue, but never so much that it seemed to affect the health of the chickens. I'm not saying any of this was a good way to do things, I'm just saying it was a way that worked and (mostly) kept chickens alive -- probably based on drawings/designs my parents saw in Mother Earth News magazine or Foxfire or a Rodale Press book.
In the very coldest temperatures they would hang an old fashioned barn lantern (kerosine-fueled, metal lantern, wires protecting the glass chimney) from a nail just inside the door, well away from the perch. It would provide a slight boost to the air temp in the coop.
Chickens were a mix of "spent" factory egg layers (white leghorns with trimmed beaks and claws, very stupid birds, barely able to walk or scratch or feed themselves, apparently sold cheap in those days after their egg production would start to drop) and Rhode Island Reds that we raised from chicks bought as chicks. The Reds had much larger combs and they did get a little bit of comb frostbite, but the Leghorns were much older birds. My recollection is that we did get some mortality (one or two dead birds) among the leghorns the first winter when it got really cold.
Trace Oswald wrote:I'm a huge fan of open air coops. In my opinion, ventilation is far more important than temperature. Woods' open air chicken coop book is fantastic.
Chickens in very cold weather get frostbite. They get frostbite far worse if there is any moisture at all in their coop. I kept chickens one year in a 3 sided coop i built from straw bales. It didn't have a front at all. It was narrow and pretty deep, I believe it was about 4 feet wide and 12 feet or so deep. I built the roof from old doors stacked across and resting on the side walls. I put more bales on top of them for insulation. I used tree branches at the very back for roosts. Since the front was entirely open and i never water my chickens in their coop, it stayed perfectly dry. With the roosts in the very back, they didn't get drafts. The opening was facing south and our really cold winds come from the north east. We had temps -15 to -20 regularly, and a low as -30f . The chickens were fine and the rooster had almost no frostbite on his comb. The rooster in my traditional coop got worse frostbite.
Woods' book talks about the minimum depth the coop can be to keep the chickens away from drafts with a completely open air coop.
Other people mentioned snow. My chickens won't walk in snow. They don't mind the cold but none of the breeds I have raised would walk in snow. I build open ended greenhouse type structures to give mine areas to walk without snow in the winter. That is also where their water is, never in the coop.
Pierre-Luc Drouin wrote:
Thanks for sharing your experience. -50F in Alaska is definitely more extreme than here. If you say that ammonia was an issue, do you think they were also affected by moisture as well under these conditions?
Pierre-Luc Drouin wrote:
Thanks for all the helpful information. I want to stay away from active heating. Regarding what you are saying about air stratification, do you mean that it would be better, if I have a design that involves a cupola, that the air intakes be located right under the roof instead of lower in the coop? Even if the intakes do not cause the coop to be drafty due to the air moving only through a controlled stack effect? The 4" pipe that would go to my cupola would be about 4' tall...
I intend to bring power to the coop to supplement light, warm up water, control doors, the ceiling vent and to monitor the temperature/humidity. The roof will have a 45 degree pitch and face south so it is ideal for solar panels in the future.
You want the air intake above the chickens, not below, as that would cause drafts from bottom to top. I like air intake to be about 18" above the chickens when roosting. I never bothered to calculate air changes, I just gave them enough ventilation to make sure it was fresh air. If your roof only has a single slope, you need your air egress at the top of the slope. If you put a cupola in the middle, the ammonia can pool in the upslope of the ceiling.
An idea I have is to create vertical air intakes under the coop, which will sit 2' above the ground, and introduce that air in the coop about 1.5' above the floor (about 0.5' under the roost bars).