The ever-popular VENTILATION question!

[Missuswayne]

I have read the detailed Patandchickens post about ventilation, but I want to ask about my coop specifically because I suspect I need more ventilation than I have. This is our first winter with our flock of 6 chickens and I built my coop. I'm in PA outside of Philadelphia -- so, hot, humid summers and cold winters but not super-New-England-cold. Not consistently, anyway.
Coop is 4'x8', raised, with windows on two sides (I usually keep the windows open during the day for circulation). Two 4"x32" vents are cut above the doors inside the run (circled in photo). I had two roost bars in there spanning the 8' but took out the higher one for the winter since it was at window level, only about 12" below the vents. Perfect for cross-breezes in the summer but I would think too drafty for winter cold?
The upper vents = 1.76 sq ft for my 32 sq ft coop. Am I correct in assuming I should have additional vents up by the peak (on the short sides)? It seems to me that opening the windows would cause drafts which is to be avoided?
On colder nights so far this month (low 30s) I've kept the windows and pop door closed at night and monitored the humidity and temp inside the coop with a remote hygrometer/thermometer. Humidity is always lower than outside and the temps are typically a couple degrees higher than outside at night.
Thanks in advance for any advice!

 

[PDXJULES]

Looks pretty good to me...as long bedding is dry, and you have no more than 6 large breed birds in there...and I assume they get out at dawn? Can @aart or another pro weigh in?

 

[azygous]

You want air flow, not drafts. To get the air flow, you'll have your coop chicken door to suck in outside air and you will have the high vents to exhaust the moist warmer indoor air. Ordinary convection automatically accomplishes this due to warmer air rising. Your front and rear vents appear entirely adequate as exhaust. Leaving open your chicken pop door will complete the ventilation. I see no need for more vents than you have.

 

[Folly's place]

See how it does this winter, and you'll know. For summer, it needs more openings. Do you keep those big doors to the run opened all the time then?
For winter, wrap the lower several feed of the run with clear (or nearly clear) sheet vinyl, so the entire structure is protected from winter winds and snow.
And your door latches are NOT raccoon proof!!!
Mary

 

[Missuswayne]

Looks pretty good to me...as long bedding is dry, and you have no more than 6 large breed birds in there...and I assume they get out at dawn? Can @aart or another pro weigh in?

I scoop the poop every day. Hemp bedding. Six different breeds, the largest of which are one blue orpington and one marans. Yes, the autodoor opens at dawn.

 

[Missuswayne]

You want air flow, not drafts. To get the air flow, you'll have your coop chicken door to suck in outside air and you will have the high vents to exhaust the moist warmer indoor air. Ordinary convection automatically accomplishes this due to warmer air rising. Your front and rear vents appear entirely adequate as exhaust. Leaving open your chicken pop door will complete the ventilation. I see no need for more vents than you have.

Thank you. So my question is, how would the pop door not be a draft...is it because it's working in tandem with the vents up top?
If my ventilation was inadequate what would be the signs? Humidity that's higher than outdoors? Ammonia stink?

 

[Missuswayne]

See how it does this winter, and you'll know. For summer, it needs more openings. Do you keep those big doors to the run opened all the time then?
For winter, wrap the lower several feed of the run with clear (or nearly clear) sheet vinyl, so the entire structure is protected from winter winds and snow.
And your door latches are NOT raccoon proof!!!
Mary

Yes, thank you! I am adding better latches on the inside doors this week. Those doors are inside the run, which is very secure -- I use gate latches secured with carabiners on the run door and the nest box door. I had a raccoon family crawling all over the outside of the run at night all autumn, they must have had a nest in the tree above! And yup, I'm getting my plastic wind break up this week as well. Totally last minute, as usual
For summer I was actually thinking about adding another window or two. I could keep the coop doors open to the run, I think they would be adequately protected. I may do that on the hottest nights (I do leave them open during the day on hot days.)

 

[Rldad1]

I see you have plastic roof sheets over purloins for your roof. Do you have anything else under those panels like wood? If not, do you have them blocked with HC? If not, that is a good way in for snakes and weasels. If they are open there is a lot more ventilation. As Mary says, your latches are not raccoon proof. It will take a raccoon about 5 minutes to figure out how to open them. You need some clevis' or locks on them.

 

[Missuswayne]

I see you have plastic roof sheets over purloins for your roof. Do you have anything else under those panels like wood? If not, do you have them blocked with HC? If not, that is a good way in for snakes and weasels. If they are open there is a lot more ventilation. As Mary says, your latches are not raccoon proof. It will take a raccoon about 5 minutes to figure out how to open them. You need some clevis' or locks on them.

Thank you! Yes the gate latches on the nest box and door of the run get secured with carabiners. And the ceiling is completely covered in HC, then there's a gap, then the plastic roofing panels (so there's airflow but protection from rain and predators.)

 

[aart]

So my question is, how would the pop door not be a draft...is it because it's working in tandem with the vents up top?
If my ventilation was inadequate what would be the signs? Humidity that's higher than outdoors? Ammonia stink?

It depends on if a direct wind can blow thru the pop door.
You might want to add wind blocks(clear plastic) to the run wall that faces the prevailing winds....or most the walls, leaving the top 6" open.

Coop vents look pretty good to me.
You may want more in summer.