Looking for experienced input on a cold-climate open-air coop

[Beekissed]

Thanks, Beekissed, for your photos, and for taking the time to explain your setup so well.

Much of what you describe seems counter to dominant doctrine for open-air coops -- and even for coops in general. For instance, you have air actively traveling past the roosts, which I've heard described as "drafts," rather than ventilation. But I trust your judgment that this is the best you've had, and am inclined to take that as more endorsement of the open-air dynamic!

Since the roosts are in the back of the coop, the air from the front of the coop doesn't seem to reach there in an active manner, much like in a Wood's style coop. Instead it seems to meet the air being taken in from the pop door in the rear and lifts the warm air from the floor upwards, past the flock and out the roof vents. My thermometer in the roosting area regularly reads over 10 degree warmer than the outside air, even though my coop is largely exposed to the outside air with these large openings and thin walls of just tarp. I think it's working like it's supposed to in some hard to explain way.

A draft is air that would blow out a candle and there is no air that active in my roosting region of the coop..or even at the floor level, for that matter... it's more of a passive flow of air.

Here's some diagrams of typical air flow in a coop that has a good, working ventilation....it shows the air entering from the top, moving downward because it is cooler than the internal air, then moving along with the warmer air from the coop and moving it upward towards the roof vents. That's how mine works as well...that warmer, passive airflow keeps chickens warmer. As long as that cool air picks up the warm air and moves it past the chooks, they are golden. My coop faces south and my winter winds are usually west to east, so no active drafts going on inside the coop unless we have a day with variant winds and those are the days I hang my flap over the front door window. Remember, cold sinks and heat rises, so the cold air doesn't move directly into the coop and straight back the coop to the roosts...it dips downward to the floor and then has a gentle, upward movement just as the first pic describes. It's a type of convection.



Quote:

 

[Kutschka]

Since the roosts are in the back of the coop, the air from the front of the coop doesn't seem to reach there in an active manner, much like in a Wood's style coop. Instead it seems to meet the air being taken in from the pop door in the rear and lifts the warm air from the floor upwards, past the flock and out the roof vents. My thermometer in the roosting area regularly reads over 10 degree warmer than the outside air, even though my coop is largely exposed to the outside air with these large openings and thin walls of just tarp. I think it's working like it's supposed to in some hard to explain way.

A draft is air that would blow out a candle and there is no air that active in my roosting region of the coop..or even at the floor level, for that matter... it's more of a passive flow of air.

Here's some diagrams of typical air flow in a coop that has a good, working ventilation....it shows the air entering from the top, moving downward because it is cooler than the internal air, then moving along with the warmer air from the coop and moving it upward towards the roof vents. That's how mine works as well...that warmer, passive airflow keeps chickens warmer. As long as that cool air picks up the warm air and moves it past the chooks, they are golden. My coop faces south and my winter winds are usually west to east, so no active drafts going on inside the coop unless we have a day with variant winds and those are the days I hang my flap over the front door window. Remember, cold sinks and heat rises, so the cold air doesn't move directly into the coop and straight back the coop to the roosts...it dips downward to the floor and then has a gentle, upward movement just as the first pic describes. It's a type of convection.

Brilliant! Thanks for this, Beekissed.

I'd been thinking of "draft" almost dogmatically, as any air movement at all that's directly on the birds, which wasn't making sense with the fact that air must in fact be exchanged. Your definition makes coherence possible in my head, which is always a nice gift to be given.

What's the source of those diagrams and the quote? It sounds like something I should acquire.

Thanks!

 

[aart]

The 'Woods Open Air' coop name often gets confused with the open air coops used in hot climates, but they are much different concepts.

The Woods has a couple vital criteria to effectively execute the concept, which actually is pretty simple:
-the width to depth to split roof heights proportions of the building.
-only one open side, no other openings at all in winter.
These 2 things is what doesn't allow winds to come into the coop very far, if at all, even if blowing directly towards the open side but allows enough air exchange for a healthy environment.

Anything else makes it something other than a Woods Open Air coop, no matter what you call it.

I've read the book, and it is confusing....there's a lot of irrelevant info to wade thru, kind of like reading BYC<smirk>
JackE's coop is the only one I've seen that executes the concept fully and properly.

 

[Beekissed]

Brilliant! Thanks for this, Beekissed.

I'd been thinking of "draft" almost dogmatically, as any air movement at all that's directly on the birds, which wasn't making sense with the fact that air must in fact be exchanged. Your definition makes coherence possible in my head, which is always a nice gift to be given.

What's the source of those diagrams and the quote? It sounds like something I should acquire.

Thanks!

YW!

https://www.extension.purdue.edu/extmedia/AE/AE-97.html

 

[Kris64]

I'm going with the one side open only for a 6' x 6' shelter. Initially we were going to have vents along the roof line all round, but the wind is fierce at times. Now we're hoping to be deep enough to act like a garage and not get wind in the back. I still think there'll be enough ventilation with one whole side (7' x 6') open. In a worst case scenario we'll have to cut out openings later. During super windy nights, we'll have hooks set up to support plywood over some of the opening if the wind reaches the roosts.

 

[WthrLady]

Another 8 hour work day on mine. Winds howling outside to 30 mph...and no movement AT ALL inside !!!

outside the windchill was below 20. Inside with no wind and sun streaming through the upper windows it matched the outside temp of 48'!


Proportion and window operation, and open end direction are very important with a Woods.

 

[Beekissed]

Another 8 hour work day on mine. Winds howling outside to 30 mph...and no movement AT ALL inside !!! outside the windchill was below 20. Inside with no wind and sun streaming through the upper windows it matched the outside temp of 48'!


Proportion and window operation, and open end direction are very important with a Woods.

Love this coop! Lot's of air and light....love the perky color too!

 

[centrarchid]

I'm going with the one side open only for a 6' x 6' shelter. Initially we were going to have vents along the roof line all round, but the wind is fierce at times. Now we're hoping to be deep enough to act like a garage and not get wind in the back. I still think there'll be enough ventilation with one whole side (7' x 6') open. In a worst case scenario we'll have to cut out openings later. During super windy nights, we'll have hooks set up to support plywood over some of the opening if the wind reaches the roosts.

I block wind with the a tarp or even feed sacks. When not in use during warm part of year they store very compactly in a barrel.

 

[Kris64]

Do you have any issues with the flapping of a tarp freaking the chickens out or has the tarp ever ripped and flew into the coop? Those were two potential issues I wondered about when considering a tarp. Maybe it's just a matter of securing it well enough.

Or do you have a screen or fencing on the open side? I won't--our open side will be wide open to a secure run/yard.

 

[centrarchid]

Flapping controlled with bungy strap. Birds otherwise not bothered by flapping.

Generally one or even three sides are left open with respect to tarp but otherwise fenced to confine birds so my setup is a bit more open than average. In the past i have used a lean but also had hogs seeking shelter there as well. Chickens then roosted above hogs.