What is the difference between ventilation and a draft?

[Count Orloff]

I have a pretty run of the mill Amish-built coop, the type that has two windows and the five nest boxes in a covered overhang under the windows. My humidity levels are too high, so I'm considering adding a vent or two. What is the difference between a vent and a draft? Obviously an open window in the winter is going to provide ventilation, but it will also cause a strong draft. What should I aim for here?

 

[Dar]

you want to aim for a draft that is not directly on the birds....

when it gets windy out you dont want the direct air flow on the birds in winter .. the roof vents will allow the moisture to escape and not be drafty... same with those twirrly whirrly things on top..

 

[Fred's Hens]

It is where the bulk of the fresh air is entering. If it is down at the floor or through the wall at chicken height, it is merely a draft.
If the entering air is up higher (at eaves) and allowing to vent even higher up, (roof top or ridge) it whisks away the moisture laden air.

Chickens expel literally tons of water vapor over time.

As so many folks on BYC correctly state, it isn't low temperatures one needs to fear, but condensing and frost because of too much vapor.
Wild birds survive extremely low temperature just fine, in part because they are not enclosed in a frosty steam room.

 

[swimmer]

Fred's Hens :

It is where the bulk of the fresh air is entering. If it is down at the floor or through the wall at chicken height, it is merely a draft.
If the entering air is up higher (at eaves) and allowing to vent even higher up, (roof top or ridge) it whisks away the moisture laden air.

Chickens expel literally tons of water vapor over time.

As so many folks on BYC correctly state, it isn't low temperatures one needs to fear, but condensing and frost because of too much vapor.
Wild birds survive extremely low temperature just fine, in part because they are not enclosed in a frosty steam room.

Couldn't agree with you more. Once the cold weather hits, some people want to close everything up on their coops in fear of the cold temps. They are doing more harm than good by doing this.​

 

[patandchickens]

Draft (in a wintertime chicken coop sense) just means "enough direct air movement on the birds that it causes problems" (frostbite, hypothermia, annoyance). I realize that is kind of situation-dependant and therefore not something I can tell you "here, go measure <this> and if it's more than <this number> then it's a draft", but that is just the way it is

Basically try to keep the air movement as gentle and as far from the roosting chickens as possible.

For getting rid of humidity in wintertime, it's usually best to have the vents high up -- the main disadvantage of windows is that they typically open in about the *middle* of the wall.

For avoiding draft, you ideally want the vent(s) on the downwind side of the coop and as far as possible from the roost. This is more challenging in a, um, "very compact" coop like that style, but I would suggest that most likely a good solution would be to put as big a vent as you can in the upper triangular gable end that is facing E or S. "As big as you can" because it is real easy to close some of it down for less ventilation if circumstances require. I know this will put it over one end of the roost, at least with how most coops of that type are set up inside; but unless you have a whole big lot of chickens they should be fine just squooshing down towards the opposite end of the roost.

A droppings board, cleaned every morning, can also really help reduce coop humidity. If you have room for it (not all those coops do).

Good luck, have fun,

Pat

 

[elmo]

Since warmer air rises, a vent up at the top of the coop lets the air with the most moisture in it exit, which is what you're after to keep the humidity level in the coop down as much as possible. As others have noted, chickens exhale lots of moisture as they roost inside the coop all night, and the moisture from accumulated droppings can also add to the humidity.

In winter, you don't want cold wind blowing into your coop from vents that are positioned so that the air blows over your birds. I think about drafts in terms of wind chill. You can make hinged flaps over the vents to open or close as needed. A partially opened flap can also act as a sort of wind baffle to help block and divert incoming drafts.

 

[RoeDylanda]

Thanks for this thread, I've been feeling like the village idiot because I can't figure out where the draft might be in a 4 x 6 coop that's still in the design stages. I am hoping to do a simple front-wall-higher-than-the-back-wall design with 6" venting along the entire length of the top of the high wall (protected by the roof overhang) and triangular venting for the tops of the shorter walls, with the roost closer to the short wall (16 inches away to minimize wall splatter-- planning on full-size birds). There will be seasonal venting along the top of the short wall as well. I'm trying to save a Google sketch to my BYC page, but may not get it on there until tonight. When I get it there I will definitely be asking for input!

 

[ivan3]

Just a simple `template' for small coops: https://www.backyardchickens.com/forum/viewtopic.php?pid=914185#p914185

 

[bburn]

My window in the big coop is right at the roost. Tried to explain it to my DH but he says they are just chickens. So, while he was out of town I filfered through his stuff and found the big roll of stuff like they put on the outside of a house when they are building and cut myself a square of it and stapled it over the window and left a 2" gap at the top for ventilation. Works great. No breeze going through now. In the spring, once it warms up nicely, I will take it down. One of the advantages of our coop where it is, is that there is a wonderful cross breeze in the very hot summers we have. My chickens made it nicely through this last summer.

 

[Moxiechick]

We have vents along the top edges of two sides of our coop (along with a protected side vent in one wall). I was concerned about drafts, especially with the blizzards we get here in Maine, so I stuffed some blocks of foam into the vent openings. This way, air can be exchanged, yet the strong wind is diffused. So far, so good!