How much ventilation?

Hi there,
I was just curious on how many vents you really need. Also, what should the humidity level be. I am just making sure I'm ready for winter!
Thanks

It depends on how many birds you have. Where the vents are located and how effective they work is also a factor on the size they need to be.

In general an uncaulked construction will pull air in with vents at top pushing air out. This action of mixing air inside the coop without drafts and venting out the top exits the excess moisture from poop and breathing along with ammonia. With a one slant roof more than enough venting is achieved by using 2x4's or 2x3's on side for rafters. That leaves an 1 1/2" gap along top and bottom of slant. Cover the openings with hardware cloth. This pulls air in from bottom of roof slant and mixes with hot air rising before exiting top of slant.

Here's a basic coop design showing what I mean (click on the thumbnail image at bottom of page):

http://www.mansfieldfeed.com/news-updates/build-your-own-chicken-coop-2014-02-3056

My advice on vents is to make more than will ever be needed and make them so you can close them if the wind is whipping.
I have a ton of vents in my coop. There are 11 windows that can open and one 14 foot long by 16 inch wide soffit vent. Last winter I found the wind during a bad storm blowing snow up into the soffit vent. I still need to make closable shutters for that. I was out there in -16 degree temps with whipping wind stapling plastic as an emergency measure.
I strongly recommend making shutters or a method for closing them off that you can do quickly and easily for every vent. That way whichever way the wind is coming from you have options.

For each hen one square foot of open vent is recommended. I find with my group I did not need that much. I did still have a lot of vents open but not one square foot per hen.

Now as to humidity......
You will not be able to lower the humidity without vents and even with them if it is humid outside it will be higher inside. I try to not let mine rise much more then the outside humidity. If it starts to go up I open a vent or two.

Side note but important. With the vents.... Keep them up high. The higher the better. No hen will be comfy with a draft blowing up her skirt. Drafts are bad vents are good. Fine line I know.

Good articles.

https://www.backyardchickens.com/a/winter-coop-temperatures

https://www.backyardchickens.com/a/...-go-out-there-and-cut-more-holes-in-your-coop

21hens-incharge said:

My advice on vents is to make more than will ever be needed and make them so you can close them if the wind is whipping.
I have a ton of vents in my coop. There are 11 windows that can open and one 14 foot long by 16 inch wide soffit vent. Last winter I found the wind during a bad storm blowing snow up into the soffit vent. I still need to make closable shutters for that. I was out there in -16 degree temps with whipping wind stapling plastic as an emergency measure.
I strongly recommend making shutters or a method for closing them off that you can do quickly and easily for every vent. That way whichever way the wind is coming from you have options.

For each hen one square foot of open vent is recommended. I find with my group I did not need that much. I did still have a lot of vents open but not one square foot per hen.

Now as to humidity......
You will not be able to lower the humidity without vents and even with them if it is humid outside it will be higher inside. I try to not let mine rise much more then the outside humidity. If it starts to go up I open a vent or two.

Side note but important. With the vents.... Keep them up high. The higher the better. No hen will be comfy with a draft blowing up her skirt. Drafts are bad vents are good. Fine line I know.

Good articles.

https://www.backyardchickens.com/a/winter-coop-temperatures

https://www.backyardchickens.com/a/...-go-out-there-and-cut-more-holes-in-your-coop

Click to expand...

Ditto Da Bolded above.

....my ventilation. The first picture is the front of the coop the second picture is the sides exactly the same on the other side

....my old coop then my new coop. See the ventilation