You keep reading about not letting drafts hit chickens in the winter. These “drafts” are not like the little bit of air movement you might need a candle to see near a window in your house. These drafts are more like breezes that ruffle the feathers.
Just like the wild birds you see outside in the dead of winter, chickens trap tiny pockets of air in their down and feathers. This trapped air is what keeps them warm and provides insulation. It’s not really the down but is the trapped air. Their body heat warms that air and that keeps them warm. Chickens and wild birds can keep themselves warm as long as they stay out of a wind strong enough to ruffle their feathers and let that trapped air escape. You’ll see wild birds at your feeder all winter, even in really low temperatures, but not when a cold wind is blowing. Then they are hiding somewhere out of the wind.
You need ventilation in the winter for two reasons. Ammonia is produced by their poop decomposing. If the poop is frozen it is not going to decompose, but watch out when it thaws. Ammonia is hard on their respiratory system but ammonia is lighter than air. To keep ammonia from building up to dangerous concentrations you just need a hole above their heads. It doesn’t take a huge hole as gravity will provide the energy to remove that lighter than air ammonia out of there.
Water vapor or humidity is the other risk and is a bit harder to come up with the right amount of ventilation you need. Moisture can come from their poop before it freezes but also their breath has a lot of moisture in it. High moisture can lead to frostbite. Warm air like their breath holds more moisture than cold air and also rises. Before it freezes their poop is warmer than frozen air too. It doesn’t seem like much but the warmer (compared to the outside air) more moist air at the top of the coop is what you want to get rid of. Gravity does not provide nearly as much energy to this warm lighter air as it does to that lighter ammonia so you need more ventilation to get rid of it. How much more? That’s hard to answer. It’s going to depend on you ventilate, how many chickens you have, how big your coop is, and how you provide that ventilation.
Roof vents and gable vents can move a lot of air. Ridge vents do too but may become blocked by snow. For these to work best you need an opening down lower to let heavier colder air in which forces the warmer air at the top out. It doesn’t take a lot of difference but the more difference in elevation you have the more air movement you will have. The risk here is that you will create a breeze blowing on the chickens in a strong wind so you have to be a bit careful where you put that opening if it is below the chickens.
Another very popular way to provide a lot of ventilation is to leave the top of the walls open under the overhang to keep rain out and cover those openings with hardware cloth to keep predators out. These provide a way for air to get in so the roof or gable vents work better. If you have two of these or maybe in conjunction with gable vents you can get a breeze blowing across, but as long as this breeze does not hit the chickens on the roost their feathers will not get ruffled and let those air pockets out.
To me, having all the openings above their heads when they are on the roosts is the easiest way to do this, but all you need to do is to create a dead air space where the chickens are. There is an open air coop design that JackE really likes that has one side of the coop open well below where the chickens roost that is used way up in Canada. You create a dead air space back where the roosts are but leave the front open for great ventilation. There are many different ways to do this.
Heat is a much greater danger to chickens than cold as long as you give them a minimum amount of protection from breezes yet provide enough ventilation in winter. I’ve seen chickens sleep in protected spots in trees in weather below zero Fahrenheit with no problems, no frostbite or anything else. One poster on this forum that I really trust talked about chickens spending the winter in trees in northern Michigan. As long as they can get out of breezes they really can keep themselves warm, just like the wild birds.
In the summer with the heat you need lots of ventilation. Openings above and below them or even right at their level on the roosts are good. A breeze doesn’t hurt them when it is warm, it feels good. Having ways to close off that lower ventilation gives you a lot of flexibility.
Good luck!
Just like the wild birds you see outside in the dead of winter, chickens trap tiny pockets of air in their down and feathers. This trapped air is what keeps them warm and provides insulation. It’s not really the down but is the trapped air. Their body heat warms that air and that keeps them warm. Chickens and wild birds can keep themselves warm as long as they stay out of a wind strong enough to ruffle their feathers and let that trapped air escape. You’ll see wild birds at your feeder all winter, even in really low temperatures, but not when a cold wind is blowing. Then they are hiding somewhere out of the wind.
You need ventilation in the winter for two reasons. Ammonia is produced by their poop decomposing. If the poop is frozen it is not going to decompose, but watch out when it thaws. Ammonia is hard on their respiratory system but ammonia is lighter than air. To keep ammonia from building up to dangerous concentrations you just need a hole above their heads. It doesn’t take a huge hole as gravity will provide the energy to remove that lighter than air ammonia out of there.
Water vapor or humidity is the other risk and is a bit harder to come up with the right amount of ventilation you need. Moisture can come from their poop before it freezes but also their breath has a lot of moisture in it. High moisture can lead to frostbite. Warm air like their breath holds more moisture than cold air and also rises. Before it freezes their poop is warmer than frozen air too. It doesn’t seem like much but the warmer (compared to the outside air) more moist air at the top of the coop is what you want to get rid of. Gravity does not provide nearly as much energy to this warm lighter air as it does to that lighter ammonia so you need more ventilation to get rid of it. How much more? That’s hard to answer. It’s going to depend on you ventilate, how many chickens you have, how big your coop is, and how you provide that ventilation.
Roof vents and gable vents can move a lot of air. Ridge vents do too but may become blocked by snow. For these to work best you need an opening down lower to let heavier colder air in which forces the warmer air at the top out. It doesn’t take a lot of difference but the more difference in elevation you have the more air movement you will have. The risk here is that you will create a breeze blowing on the chickens in a strong wind so you have to be a bit careful where you put that opening if it is below the chickens.
Another very popular way to provide a lot of ventilation is to leave the top of the walls open under the overhang to keep rain out and cover those openings with hardware cloth to keep predators out. These provide a way for air to get in so the roof or gable vents work better. If you have two of these or maybe in conjunction with gable vents you can get a breeze blowing across, but as long as this breeze does not hit the chickens on the roost their feathers will not get ruffled and let those air pockets out.
To me, having all the openings above their heads when they are on the roosts is the easiest way to do this, but all you need to do is to create a dead air space where the chickens are. There is an open air coop design that JackE really likes that has one side of the coop open well below where the chickens roost that is used way up in Canada. You create a dead air space back where the roosts are but leave the front open for great ventilation. There are many different ways to do this.
Heat is a much greater danger to chickens than cold as long as you give them a minimum amount of protection from breezes yet provide enough ventilation in winter. I’ve seen chickens sleep in protected spots in trees in weather below zero Fahrenheit with no problems, no frostbite or anything else. One poster on this forum that I really trust talked about chickens spending the winter in trees in northern Michigan. As long as they can get out of breezes they really can keep themselves warm, just like the wild birds.
In the summer with the heat you need lots of ventilation. Openings above and below them or even right at their level on the roosts are good. A breeze doesn’t hurt them when it is warm, it feels good. Having ways to close off that lower ventilation gives you a lot of flexibility.
Good luck!
