Originally Posted by gpeters3
Humidity is a warm air thing. Cold air doesnt hold moisture so if the vents are near the top the heat and humidity should move out. OTOH, cold air sinks and if the vents are in the floor what ever is in tne air should move out as temps drop. Why do commercial coops have exhaust fans? They obviously want to control how and when air moves.
I put my windows above the roost height primarily to keep the coop cooler in warm weather. I have cross ventilation above the nest boxes and roosts. If you want the hot air out you have to have air movement but if it is not in line with the birds then its not a draft, is it? Drafts are air currents that affect living things, right? Im thinking you need vents above and below where the chickens hang out but then what will prevent air moving between lower and upper vents creating a draft......im thinking we need a wind tunnel with smoke to test out these theories.
Keep too many chickens, in too small a coop, with too little ventilation/fresh air flow, and you WILL see humidity in the wintertime. You will see it as frost on the inside of the coop, and the chickens themselves. Then, you will see frostbite, and most likely, respiratory issues. I've read on this forum, where somebody had the great idea, of shutting up the coop, to....... wait for it, "KeepThemWarm". They wondered why they could not get the coop's door open because it had frozen shut, from the inside.
Commercial coops have exhaust fans, because they cram far too many chickens in those industrial coops, and passive ventilation won't work. Square foot per bird, doesn't mean anything to them. They HAVE to force ventilate, otherwise they will have a bunch of dead birds. If you have a properly designed backyard coop, you should have no need for forced air.
Drafts are not a problem in the warmer months. You WANT air movement in the summer. In the winter, you want max air exchange, without the felt air movement/drafts.