Hi there, I have a fully insulated 12' by 8' coop. I use straw for extra heat, and have nesting boxes off the ground. I also have a 2' by 4' insulated box inside of this coop. How many hens do I need to make sure I have enough heat. I don't want to use a heater, and I only have winter hardy breeds. Thanks
About 20 to 24 should be a good number. The biggest threat to chickens in really cold weather is frostbite. A well ventilated coop is essential to prevent frostbite. Lots and lots of ventilation, as high up as you can possibly get is best. You'll need roosts wide enough for them to cover up their feet completely. 2x4s wide side up are a perfect way to achieve that.
Chickens don't heat the coop, they heat themselves, and do it quite efficiently, I wouldn't add chickens just for heat, crowding is a way worse offense. Feed them correctly, proper roosts, warm water, good ventilation, access to sunshine, protection from winds, and stuff to do so they aren't bored.
