Pat’s Big Ol' Ventilation Page
https://www.backyardchickens.com/web/viewblog.php?id=1642-VENTILATION
Pat’s Cold Coop (winter design) page:
https://www.backyardchickens.com/web/viewblog.php?id=1642-winter-coop-temperatures
A couple of articles for you. The lady that wrote these was in Ontario.
The danger from cold is not so much that they will freeze to death. If the chicken is sick, weak, or in bad shape the stress from extreme cold might be enough to send it over the edge, but it’s really rare to lose a healthy chicken to cold. The biggest danger is frostbite. They can get frostbite any temperature below freezing, but other things have to be right for them to get it. Higher humidity in the coop is a danger that can lead to frostbite. Where dos the humidity come from? Their poop and their breathing. If the poop is frozen, it is not giving off any moisture. That leaves heir breathi9ng, which is still some but less of a worry compared to poop. A little ventilation can help with that, especially over their heads. Warm air holds more moisture than cold air and warm air rises. I know it’ll cool off pretty quickly but it will still be up higher.
Wind chill is real. You don’t want a breeze hitting them when they are on the roost. If all the ventilation is over their heads, they are not going to be caught in any cross-drafts. Those cross-drafts will be over their heads, taking out that moist air that rose.
Another risk is ammonia that develops from their poop when it is wet. Ammonia is real hard on their respiratory system. If the poop is frozen it’s not going to be giving off any ammonia but watch out when it thaws. Ammonia is lighter than air. If there is a hole higher than their heads, the ammonia will keep rising right out of the coop. Do you see a trend here? Maybe the ventilation should be over their heads when they are on the roost. If the poop is frozen, it really doesn’t need to be that much but beware when it thaws and freezes, thaws and freezes. It can get tricky when it’s going through that cycle
All that to get to insulation. There are two basic types of heat movement, convection and radiation. I’m lumping conduction with radiation for this. Convection is air movement. The warm air rising will move the warm air out of the coop. How fast? Well, how big is your coop and how much ventilation do you have? Anyway, insulation will not help you with this as long as you don’t have leaks in your wall.
Radiation/conduction is where insulation can help. It’s especially good in the summer right under your roof. That can keep it a lot cooler. It can make a difference in south and west walls too with the sun. In the winter insulation will reduce the heat lost through the walls and maybe roof. But you need to have heat before you can lose it. Where are you getting heat? The chickens themselves give off a reasonable amount. If your coop is on the ground the ground itself just might be warmer than the air and warm things up a bit, especially in those really bad cold snaps. Insulation is not going to heat up your coop but it can help keep the coop warmer. How much? That depends on how your coop is built and where it might be getting heat.
It’s not a clear-cut answer. There is a lot of “it depends” involved.