Starting a coop build, it is my first build and first chickens so feedback is very welcome

[3KillerBs]

I noticed the snow on the roof will melt along the opening line of the ridge vent before it melts above/below that by just a tiny bit.

That's probably a good thing -- showing that the rising warm, moist air is going out rather than being blocked and causing condensation to rain down on the birds.

 

[saysfaa]

That's probably a good thing -- showing that the rising warm, moist air is going out rather than being blocked and causing condensation to rain down on the birds.

I don't know. It is blocked by snow much of the time, so not much gets out most of the time. I'm much more worried about too much airflow when it isn't covered by snow than not enough at any time during the winter.

I think the warm moist air still goes out - through the top of the open side. That is how the Woods' design works even when the monitor windows are closed and the "open side" is just the front side of the lower section. As it cools, it sinks, but as it sinks it flows to and out the top of the open front because the incoming air is warmed as it flows slowly to the back of the coop so it rises under/behind the warm moist air pushing it forward and down.

Most people I've seen talking about their Woods' coops in winter, close the monitor windows as temperatures fall to about 40-45F, and open them as the temperatures rise back up to 40-45F. I'm not sure why but I suspect it is to slow the air turnover enough to keep the snow out of the front

 

[saysfaa]

I guess I could go out with some light-weight ribbon the next time we get a strong wind and try to confirm what the air movement is.

 

[3KillerBs]

I'm much more worried about too much airflow when it isn't covered by snow than not enough at any time during the winter.

There's really no such thing as too much airflow as long as it's draft-free.

I guess I could go out with some light-weight ribbon the next time we get a strong wind and try to confirm what the air movement it.

Just what I was going to suggest.

 

[saysfaa]

I thought measuring without wind might be relevant too. My ribbon stash is not easily accessible so I cut strips of a plastic grocery bag.

Results are an the inconclusive side of helpful. There was so little air movement that the ribbon didn't move enough to tell if it was air movement or the stiffness of the ribbon. I tried turning it around and still couldn't really tell.

anyway that I took my glove off and used my fingers. It is cold enough that I don't need to wet them to feel movement (and dangerous to wet them).

I can feel the movement in along the bottom half, more so on the east side. I couldn't feel it either way along the top half.

I did notice that it is warmer inside the coop than outside - my face stings outside but stopped stinging after a little while inside - I think I couldn't feel air going out, if it does, because it was warmer on the movement side. Or the air is getting out through the ridge vent (under many inches of snow) and the very small cracks around the eaves and slightly bigger cracks around the window (that last would explain why there is more air movement on the east side - the windows are on the east side.

I'll try again with a better "ribbon" and/or where is at least some wind.

Spice and Nutmeg both helped.

 

[saysfaa]

I'm not worried about how little velocity the incoming air has, regardless of how it gets out. If the air is flowing through at a given rate is enough to keep one chicken dry then it is enough - it doesn't matter if that air comes in a one square foot opening at a x velocity or if it comes in a ten square foot opening at one tenth x velocity or a hundred square foot opening at a hundredth the velocity... conceptwise.

There is more than enough cubic feet of air inside the shed to

 

[saysfaa]

There's really no such thing as too much airflow as long as it's draft-free.

I've been considering this.
It occurred to me that I might just find it easier to tell other people this (because I think I have, several times) than to apply it.

I don't think so for my climate and set up, though. Either that or the definition of "draft" is variable.

Once there is enough what is the benefit of more? One benefit would be the have more margin for unusual weather or adding more chickens. Ok, both are also circumstances in which there is enough, albeit a greater amount. If you have more than that amount, then what benefit is more?

 

[aart]

I'm not worried about how little velocity the incoming air has, regardless of how it gets out. If the air is flowing through at a given rate is enough to keep one chicken dry then it is enough - it doesn't matter if that air comes in a one square foot opening at a x velocity or if it comes in a ten square foot opening at one tenth x velocity or a hundred square foot opening at a hundredth the velocity... conceptwise.

There is more than enough cubic feet of air inside the shed to

Velocity could be an issue.
What you don't want is 'drafts' strong enough to ruffle feathers on the roost.
More velocity = stronger 'drafts'.

I've been considering this.
It occurred to me that I might just find it easier to tell other people this (because I think I have, several times) than to apply it.

I don't think so for my climate and set up, though. Either that or the definition of "draft" is variable.

Once there is enough what is the benefit of more? One benefit would be the have more margin for unusual weather or adding more chickens. Ok, both are also circumstances in which there is enough, albeit a greater amount. If you have more than that amount, then what benefit is more?

Maybe none, but as long as it's not a detriment(too strong of a draft)<shrugs>

 

[U_Stormcrow]

While I don't use a Wood's style coop myself, and will do an open air for my third coop, this may be useful for those who haven't read Dr. Woods complete book. As with so much else, this is a case where a little knowledge is (potentially) dangerous, as the ratios matter with this coop design. (really, they matter with any passive airflow system, but some systems are more tolerant of design alterations than others)

 

[3KillerBs]

I don't think so for my climate and set up, though. Either that or the definition of "draft" is variable.

"Draft" is usually considered a breeze strong enough to ruffle the chickens' feathers so as to rob them of their heat-retention capability. It doesn't mean to stop all air movement because air movement is necessary to carry away the moist, ammonia-laden air.

As for "enough" and "too much", I'm a great believer in the health benefits of fresh air for all living creatures. We in the modern west, especially in the USA, tend to live in stuffy, stale, artificially conditioned air -- to the point that a relatively new manufactured home does not have enough venting to support the safe use of a woodstove or fireplace unless the installer punches a hole in the wall to bring fresh air directly to the fire.

It's usual practice to keep the heat no lower than 68F and the AC no higher than 75F with the ideal generally being held to be a steady 72F year round. Additionally, Americans in the current day usually react to a house feeling stuffy or odorous by putting air fresheners in to cover unpleasant scents with (putatively), more pleasant ones instead of opening windows to exchange fresh air for stale air.

This gives us a skewed perspective since we're used to a very narrow range of temperature and humidity variation.

As an asthmatic, I have a sensitive respiratory system for a human and I react to stale air in buildings. Chickens, like all birds, have EXCEEDINGLY delicate respiratory systems.

I'm sure that there is data available in re: commercial chicken keeping to dictate exactly how much ammonia is acceptable/unacceptable and what volume the fans must be able to move to keep birds healthy. I know that there are instruments capable of monitoring the air quality in commercial chicken buildings.

On a backyard scale I believe that, as long as the birds aren't having their feathers ruffled on the roosts and have the ability to get out of the wind when they want to, the more air moving over their heads to carry away moisture and ammonia the better because that gives me a margin if something in the system fails.

The usual rule of thumb is for the temperature and humidity inside and outside to match. We used a Christmas gift Amazon card to order a thermometer/hygrometer with multiple sensors, one of which will go into the coop.