Coop humidity: How high is too high?

[CatWhisperer]

I have 3 coops. Yesterday I put temp/humidity sensors in each. The top sensor measures our garage on top and the 3 coops below.
The bottom sensor is older and measures our old coop(the middle reading on top) and our garage on the bottom. The readings don’t match but still give a general idea what’s going on. The photo was taken at 4:30 am this morning.
My question is, what is a safe range in the winter? Wondering how to adjust ventilation as the numbers rise out of a safe range.

 

[Fairview01]

Any humidity above ambient i would consider to high. Humidity in the coop is always bad summer or winter. Humidity encourages higher concentrations of ammonia leading to respiratory issues.

Shoot for max vetilation without drafts.

 

[Mrs. K]

It is the combination of cold and humidity. So if your coldest temperatures are above 20 degrees, I would not worry about this too much.

Good ventilation above their heads can really help. My roof slants to the south, lower on the north side, and that soffit remains open year round.

Adding dry bedding deeply. Weekly spread that with scratch, and mine with stir the bedding up, breaking apart the manure so it dries out.

I assume you are worried about frostbite. When mine have been most prone to frostbite is after a bitter cold spell, then warmth during the day hours, and cold hard freeze at night. The warmth in the day, releases the frozen moisture.

If you are dealing with severe cold and high outdoor humidity, or have a pretty small coop it gets more tricky. A lot of people then have a poop board, and daily remove the poop.

There really is a limit on what you can do, however, the birds themselves produce a great deal of moisture, so more space in the coop, and I think vertical space is important, reduces the moisture confined. Ventilation is imperative in a small coop, and so much ventilation is needed in a small coop, that people often don't have enough, thinking the birds will be too cold. In a small coop, I would have nearly one whole side open.

Mrs K

 

[aart]

Any humidity above ambient i would consider to high

Yep, this^^^.
You can't make it less humid inside the coop than it is outside the coop.
If humidity is ~10% higher inside the coop than outside, you need more ventilation.