First winter with our first chickens. Thanks for confirming what I thought: the heat lamp I was considering is not only unnecessary, but could be dangerous in the tiny coop my 3 girls share! But I'm worried our home built coop isn't ventilated enough. Worried about Predators, we put one small A/C floor vent on both the east and west side of the coop, up high near the eves.Their run is as secure as fort Knox, so we've been leaving the trap door open as well. How do i know They're getting enough air without drafts? If I close the trap door will the little vents be enough? Thanks!
Probably could use more ventilation but it depends on how big or little your coop is relative to the number of birds inside. I leave windows open and now my eaves are open air as well (covered in stapled on 1/2" hardware cloth) because my previous roof had rotted due to poor ventilation (ac vents on the eaves). The main coop is 5x10 and has held up to 22 various sized/aged birds at one time.