Ventilation

What ventilation do you have at night when the doors are closed?

 

I don't see any vents up high. Warm moist air rises so it needs a place to get out.

 

One square foot per ten of coop space. I'd open both of them halfway, they appear well above the roosting bar.

 

I would invest in a hygrometer. It'll make it much easier to keep an eye on things before a problem arises. I bought an inexpensive hygro/thermometer on Amazon.

 

You should have about 1 square foot of vent for every chicken. I have 6 square feet of vent area under the eaves on opposite sides of the coop. I have another 4 square feet in the clean out door in the back of the coop. My house is L shaped and the coop is placed in that L. The clean out door is only a few feet away from the house and gets no wind at all. There isn't a roost near that vent. The pop door is also open year round as 3 sides of the run are covered in clear vinyl during the winter so no breeze blows in from it.

You should probably place 2 vents up under your eaves on opposite sides of the coop. Neither vent should be on the side that gets the most wind. These vents never get closed so you only need hardware cloth on them. Now you need some lower vents. If your run is predator proof you could cover the sides in clear vinyl leaving the top foot not covered. Then you could leave your pop door open always and that would provide an area for air to enter the coop. If that won't work then a low vents can be cut near the floor, away from the birds, and away from the wind. You do not want wind blowing in. Perhaps louvered vents there. To help keep the chickens warmer at night you can use a 2 by 4 placed wide side for a roost. That way they can sit on their feet at night and keep them toasty warm.

So far this year I know of 2 coops that have burned to the ground due to using a heat lamp. Even if you have it hooked up so it can not fall, it can still cause a fire. Dust in the air of the coop can cause it to catch fire. Dust on the heat lamp can cause a fire. Please be extra careful. The lamp should be plugged into one of those ground fault outlets. I also read that they make special outlets for high dust areas. I haven't ever used a heat lamp yet. When it was -22 F my birds were in the run doing their normal stuff. They did not mind the cold at all.

 

To me, especially for OP, that's kind of like buying a pump rather than fixing a flat tire.

The coop has zero ventilation in it. Even in MN the birds will be fine with higher ventilation, especially with her heat lamp. I'm not going to opine on the safety of said lamp.

The easy thing would be to cut some louvered vents up top on either end.