The ever-popular VENTILATION question!

[Daisycar]

What a nice coop! Love the colour!!

 

[azygous]

@aart has pretty much explained how to avoid drafts.

I'll just add that by avoiding any openings or vents on the windward side of the coop, where wind or a breeze blows directly into the coop through an opening, you will avoid drafts. Air flow has more to do with temperature variation than air velocity. (Temperature variation on a very large scale is what causes wind, thus air movement on a very large scale.) You are creating air movement on a very small scale by allowing air coming in from a low point that is cool or freezing cold and it pushes the warmer air in the coop upward and out through the vents since warmer air wants to rise.

Frostbite occurs when condensation from the chickens' breathing settles on their combs and freezes. Just as in fruit orchards they avoid plant tissue freezing as respiration moisture from the trees settles on them by setting up huge fans to move the air so the moisture doesn't settle on the trees and freeze.