Adding Ventilation question

[Howard E]

So this is a sketch of what I had in mind for a scaled down A-frame style like Tolman's original, except to get the head room I needed, it turned into a simple gable end building, about 6' high. Goal was to use single sheets of plywood for the roof. The top image is the side elevation. The bigger part below is an end view shown with 2'6" x 5' door. Overall size of coop being about 5' x 8' with attached 5' x 8' run. Or screen in the end and forget the run, making it 5' x 8' overall. Cross ties at the sills are the roosts and would be 4' off the floor. Nest boxes would be external and mounted on the back wall under the gable end or on either side.

If a person wanted the visual of the true A-frame, they could lower the sidewalls to only 2', go to 8' rafters vs. 4' and steepen the pitch of the roof. Same foot print, but a different visual.




This would have about the same overall footprint, with half being open run, as a 5' x 16' livestock panel laid flat on the ground. Where the enclosed coop meets enclosed run, there would be no wall at all. Just a continuation of the roof line with solid walls being replaced by wire. With some side windows for light, it might work. On the other hand, I think the same thing could be accomplished using a mono-slope shed roof, with high side facing south. More like a Wichita style that can be found on BYC. It would allow more room for the door and more room for windows. If you wanted to shrink the footprint, retain the wide open end into a run, but shrink the run and elevate the floor to leave about 2' or so head space for the birds beneath the floor.

The key to making this open end building work is to retain the ratio of at least 1.6 width to depth (i.e., 5' x 8', 6' x 10', etc.). A rectangle with one short side being wide open. That is what creates the dead air zone on the end opposite the open wall. That is how you get well ventilated and draft free, which at first glance would seem to be self contradictory but isn't. It works.

 

[Howard E]

I fear we may have hijacked the OP's thread. Back to his dilemma.......to increase the ventilation, what if he were to replace one or both of his solid entry doors with study screen doors, or at least the top half of them. They would face west, but that is better than north.

 

[RobertPlamondon]

Quote:
Yeah, a lot of people are still stuck in the bad old days of 1875. They'd do a lot better if they advanced even as far as 1910. Katie Thear's 1990 "Free-Range Poultry" had a cover photo showed a newly built chicken coop that was almost identical to the one Prof. Dryden pointed out as "the worst ever built" in his 1916 Poultry Breeding and Management. (I wish I still had my copy of Katie's book so I could do a side-by-side comparison.) Here's Dryden's illustration -- you still see plenty of houses like this:

 

[RobertPlamondon]

So this is a sketch of what I had in mind for a scaled down A-frame style like Tolman's original, except to get the head room I needed, it turned into a simple gable end building, about 6' high. Goal was to use single sheets of plywood for the roof. The top image is the side elevation. The bigger part below is an end view shown with 2'6" x 5' door. Overall size of coop being about 5' x 8' with attached 5' x 8' run. Or screen in the end and forget the run, making it 5' x 8' overall. Cross ties at the sills are the roosts and would be 4' off the floor. Nest boxes would be external and mounted on the back wall under the gable end or on either side.

If a person wanted the visual of the true A-frame, they could lower the sidewalls to only 2', go to 8' rafters vs. 4' and steepen the pitch of the roof. Same foot print, but a different visual.




This would have about the same overall footprint, with half being open run, as a 5' x 16' livestock panel laid flat on the ground. Where the enclosed coop meets enclosed run, there would be no wall at all. Just a continuation of the roof line with solid walls being replaced by wire. With some side windows for light, it might work. On the other hand, I think the same thing could be accomplished using a mono-slope shed roof, with high side facing south. More like a Wichita style that can be found on BYC. It would allow more room for the door and more room for windows. If you wanted to shrink the footprint, retain the wide open end into a run, but shrink the run and elevate the floor to leave about 2' or so head space for the birds beneath the floor.

The key to making this open end building work is to retain the ratio of at least 1.6 width to depth (i.e., 5' x 8', 6' x 10', etc.). A rectangle with one short side being wide open. That is what creates the dead air zone on the end opposite the open wall. That is how you get well ventilated and draft free, which at first glance would seem to be self contradictory but isn't. It works.

We built a few gable houses resembling this one, and I'd offer two additional notes:

1. My eaves, like yours, were fairly minimal, and the rainwater running off the eaves splashed against the walls near ground level enough to rot the walls before their time. I'll use wider eaves next time.
2. Like you, I'm a big fan of using full, uncut sheets of plywood for the walls, but for the roof I (a) don't use plywood anyway, just metal roofing, and (b) I can't make the dimensions come out the way I want with 4x8 plywood on the roof, but I can use either standard (8, 10, 12, 16-foot) lengths of corrugated steel or have the lumber store cut longer pieces for me.

Robert

 

[dtabor]

EH Jr, you know my dilemma living up here. We cant hope to have winters like last year!

I could put a quite a few good sized holes in the soffit area along the front of the coop which I realize arent going to be great but every bit helps. In such a small coop, any side that large venting is open, window sized or larger, the winter winds will blow around inside the coop, meaning drafts on the roosting birds. In addition to the wind, any larger openings will have snow inside the coop. The two main doors on the front open wide, and I have made a screened frame insert for that entire opening so that they can be opened wide but still keep the birds inside safe. That could potentially be opened up in the winter but then the inside would be getting snow which would in turn melt and cause dampness which I believe is also taboo.

 

[JackE]

EH Jr, you know my dilemma living up here. We cant hope to have winters like last year!

I could put a quite a few good sized holes in the soffit area along the front of the coop which I realize arent going to be great but every bit helps. In such a small coop, any side that large venting is open, window sized or larger, the winter winds will blow around inside the coop, meaning drafts on the roosting birds. In addition to the wind, any larger openings will have snow inside the coop. The two main doors on the front open wide, and I have made a screened frame insert for that entire opening so that they can be opened wide but still keep the birds inside safe. That could potentially be opened up in the winter but then the inside would be getting snow which would in turn melt and cause dampness which I believe is also taboo.

You do as I suggested, and you will not have drafts, or snow blowing in. With just the south facing end of the coop, with the lower half cut away, and the other windows shut, you would have NO problems at all. With the other windows shut, there is no pathway through the coop for the wind to follow. So that means, NO drafts. What you will get, is mass fresh air exchange, and that is not a problem. Take a look at the pic below, the whole wall is wide open, when it snows, there may be a light dusting of snow on the floor behind that open wall, that's it, it's nothing. You have a 12' deep coop. That's plenty deep enough. I'm not talking about any new concept here, the idea is over 100yrs old, and proven.