completely confused about ventilation

[Dhkoenig]

Hi All. I just read the winterizing article that came on today and it says the same thing that I know to be true from so many other sources, that you need 1 square foot of ventilation per chicken. I have a coop that is designed to hold up to 12 chickens ( built from plans) and I have seven. The dimensions of the coop are 5 feet wide, 6 feet deep and 6 foot 11 tall. I will attach a photo. It has two windows and those are just lower than the high perch and right in line with the other three perches. So opening those would cause them to have a breeze/draft since they are not higher than the chickens. Here is my question. I do not think I have an unusually small coop but if I had 7 square feet of ventilation, that would barely leave any coop! Plus if I had to put all of those above where they perch I literally would pretty much have to either build my coop 12 feet high (impossible where I live) or basically just cut the roof off! LOL. Can someone explain to me how I am supposed to put 7 square feet of ventilation into my 5x6 coop? Even if I only had four chickens I still wouldn't have enough coop to have 4 square feet of ventilation. Am I the only person who has 7 chickens sleeping in a coop this size? Why do all the coops this size say that they fit up to 12 chickens comfortable? Do all of you that have 7 chickens have a coop big enough for 7 square feet of ventilation over their heads? Help!

 

[Shadrach]

Hi All. I just read the winterizing article that came on today and it says the same thing that I know to be true from so many other sources, that you need 1 square foot of ventilation per chicken. I have a coop that is designed to hold up to 12 chickens ( built from plans) and I have seven. The dimensions of the coop are 5 feet wide, 6 feet deep and 6 foot 11 tall. I will attach a photo. It has two windows and those are just lower than the high perch and right in line with the other three perches. So opening those would cause them to have a breeze/draft since they are not higher than the chickens. Here is my question. I do not think I have an unusually small coop but if I had 7 square feet of ventilation, that would barely leave any coop! Plus if I had to put all of those above where they perch I literally would pretty much have to either build my coop 12 feet high (impossible where I live) or basically just cut the roof off! LOL. Can someone explain to me how I am supposed to put 7 square feet of ventilation into my 5x6 coop? Even if I only had four chickens I still wouldn't have enough coop to have 4 square feet of ventilation. Am I the only person who has 7 chickens sleeping in a coop this size? Why do all the coops this size say that they fit up to 12 chickens comfortable? Do all of you that have 7 chickens have a coop big enough for 7 square feet of ventilation over their heads? Help!

You don't need a square foot of ventilation per hen. It's complete nonsense as it seems you've discovered.
Pre pack coops are notoriously optomistic in their fit for so many hens specifications.
The four square feet per hen is also unrealistic and often not required.

What you need is adequate ventilation. It's all about air flow rather than square footage. What you should aim for is having air intake at the bottom of the coop close to the floor and below the roost bars and venting under the eaves of the roof. Your climate should have a major influence on how much ventilation is needed. It changes from season to season for many.

How you keep your chickens should be what determines how much space in the coop they need. If for example your chickens free range from dawn till dusk every day then they will just require a coop to roost in and lay eggs in hopefully. Roost bar space is a better measure imo. One foot of space per chicken isn't a bad starting point. You often find that no matter how much space you provide in the coop and on the roost bars, your chickens will choose to huddle together.
If you expect your chickens to live in the coop because you have extreme climate conditions; usually cold, but very hot is also relevant, then four square feet per chicken is not enough space.

 

[CoconutCoffee]

Some photos will help people give ideas on how to modify things to add more ventilation. The "square foot per bird" thing is just a general rule of thumb. Too many variables at play for it to be a hard rule.

 

[igorsMistress]

If you put vents up high just under the roof, 6” high and 5’ long you’ll have ten square feet of ventilation. Easy.

 

[Dhkoenig]

You don't need a square foot of ventilation per hen. It's complete nonsense as it seems you've discovered.
Pre pack coops are notoriously optomistic in their fit for so many hens specifications.
The four square feet per hen is also unrealistic and often not required.

What you need is adequate ventilation. It's all about air flow rather than square footage. What you should aim for is having air intake at the bottom of the coop close to the floor and below the roost bars and venting under the eaves of the roof. Your climate should have a major influence on how much ventilation is needed. It changes from season to season for many.

How you keep your chickens should be what determines how much space in the coop they need. If for example your chickens free range from dawn till dusk every day then they will just require a coop to roost in and lay eggs in hopefully. Roost bar space is a better measure imo. One foot of space per chicken isn't a bad starting point. You often find that no matter how much space you provide in the coop and on the roost bars, your chickens will choose to huddle together.
If you expect your chickens to live in the coop because you have extreme climate conditions; usually cold, but very hot is also relevant, then four square feet per chicken is not enough space.

wow that is really helpful! I put in two big 12x12 louver vents at the bottom of the coop this summer but since then all I have read is that the ventilation should be at the top. We have 1" holes all along the long walls at the very top and 10 in a triangle on each end in the eve. Our climate gets cold - we are in NJ and temps last year went down to the minuses a couple of times. I don't free range them except under supervision but we have two runs. Let me show you a few pix and see what you think if you would:?

 

[Dhkoenig]

wow that is really helpful! I put in two big 12x12 louver vents at the bottom of the coop this summer but since then all I have read is that the ventilation should be at the top. We have 1" holes all along the long walls at the very top and 10 in a triangle on each end in the eve. Our climate gets cold - we are in NJ and temps last year went down to the minuses a couple of times. I don't free range them except under supervision but we have two runs. Let me show you a few pix and see what you think if you would:?

 

[U_Stormcrow]

So...

(not my photo - but its so damned good I saved it) This is how under-eave ventilation is supposed to work. Its passive, it turns over air very effectively, it creates no breeze on the bars, and its weather sheltered.

Windows in coops exist primariliy because they satisfy HUMAN aesthetics. NOT because they are the optimum design for your chickens.

A 5' x 6' coop is cramped for a dozen chickens, and will promote (note, not guarantee) misbehavior. It also offers limited roost opportunity and at that height, limited options in ensureing the nesting boxes are below the level of the roosting bars (to discourage roosting in the nests). Otoh, it has 22 linear feet of perimeter - meaning a mere 7" slot around the coop provides at least 12' sq ft of 24/7/365 free ventilation without a single window. Not that that's optimum design - its not - but it is a possibility.

From my goat house / second chicken shelter

 

[Shadrach]

IgorsMistress has it covered in a post above.
I would increase the ventilation at the top of the coop under the eaves. My preference would be to use louver vents for that.
What I would also do is lower the top roost bar to ensure chickens are not roosting directly in line with any vents.
Other than that looks like a good job from the pictures.

 

[ChickenLeg]

If I was concerned about ventiliation I would remove your top roost, then cut out a triangle on both ends. If your windows open from the top Id crack them a few inches for airflow, and possibly cut out a 6in wide vent across the opposite side of windows. Cheers

 

[3KillerBs]

Those "Amish" style coops are much better than the majority of coops you see, but they are usually short on ventilation, have the ventilation in the wrong place, and the plans misrepresent how many chickens actually fit appropriately as badly as the prefabs do.

I have a coop that is designed to hold up to 12 chickens ( built from plans) and I have seven. The dimensions of the coop are 5 feet wide, 6 feet deep and 6 foot 11 tall.

Do those dimensions include the nests? If yes, you don't have a 5x6, 30 square foot, 7-hen, coop, you have a 4x6, 6-hen coop. That little difference may or may not make a difference, but it's important to know -- especially if the food and water is taking up space in the coop instead of being out in the run.

You don't need a square foot of ventilation per hen. It's complete nonsense as it seems you've discovered.

Having a general guideline is NOT nonsense. It's an important data point from which the chicken-keeper can use local knowledge and observed conditions to adapt the coop to his specific needs -- the goal (for those not in the most severe of sub-arctic conditions), being to equalize the temperature and humidity inside and outside the coop.

For example, in my climate a single square foot per bird is only adequate summer ventilation in the coop with the Monitor Roof and then only if the coop is located in the shade. I discovered this spring that I need at least double or triple that recommended minimum to keep an unshaded coop with a flat roof under 100F on days over 90F.

There's no substitute for actually measuring conditions, but the guidelines are a useful starting point.

The four square feet per hen is also unrealistic and often not required.

What's "unrealistic" about providing a flock with adequate housing? I submit that if a person can't afford to give their chickens adequate space -- either on account of building costs or lack of available space on the property -- they need to rethink their plan for keeping chickens.

Your point about 100% free range is valid, but expecting the average backyard chicken keeper to be able to 100% free-range their chickens over a generous area and to never have to leave them in the coop after dawn or shut them up before dusk and to never experience weather conditions that make the chickens unwilling to leave their coop is considerably less realistic than advising them to build spacious housing.

Of course the Usual Guidelines are *guidelines*, not hard-and-fast rules. @Ridgerunner's excellent article on the subject should be mandatory reading for all new chicken keepers: https://www.backyardchickens.com/articles/how-much-room-do-chickens-need.66180/

However, though I admit that the plural of "anecdote" is not "data", in years of reading these forums (even when I was not actively keeping chickens), I am convinced that the vast majority of health, behavioral, and sanitation problems that people seek help for here are due to over-crowding and/or inadequate ventilation.

There is nothing that is made worse by ensuring plenty of fresh air and elbow room.