Ventilation

TheRealDelia

Chirping
Dec 19, 2020
18
67
89
Massachusetts
I'm planning my coop and have a question about ventilation.

I know I need high and low ventilation.

For high ventilation I'm thinking ridge vent along the whole roof. For low ventilation I was thinking soffit vents.

So, would soffit vents still be too high? Should I do gables or transom window-like vents instead?

Any and all input is appreciated! Thanks in advance everyone!
 
I'm so glad to see a person addressing this in the planning stage instead of trying to correct bad ventilation afterward!

The combination of ridge and soffit vents provides excellent high ventilation for the draft-free removal of moisture and ammonia -- though since you're in Massachusetts you'll need to consider the fact that snow will obstruct your ridge vent for much of the winter. Vents at the top of the gables, well-shielded by the roof overhang or by louvers, may be needed to keep the air flow moving when you've got a foot or more of snow sitting on the roof. :)

I don't know if a Monitor roof design is appropriate for cold climates but I remember seeing the functioning cupolas on the famous barns at the Shelburne farm museum in Vermont. The thing in your area would be to keep piled up snow from blocking the ventilation.

For low ventilation to use in hot weather windows are appropriate. Ideally with top-hinged covers to keep rain out. :)

Some people in cold climates have a system of interior baffles to prevent direct drafts on the roof while maintaining excellent airflow. I can't speak to the details since I didn't keep chickens when I lived up there in Monson.

P.S. I love your avatar!
 
I'm so glad to see a person addressing this in the planning stage instead of trying to correct bad ventilation afterward!

The combination of ridge and soffit vents provides excellent high ventilation for the draft-free removal of moisture and ammonia -- though since you're in Massachusetts you'll need to consider the fact that snow will obstruct your ridge vent for much of the winter. Vents at the top of the gables, well-shielded by the roof overhang or by louvers, may be needed to keep the air flow moving when you've got a foot or more of snow sitting on the roof. :)

I don't know if a Monitor roof design is appropriate for cold climates but I remember seeing the functioning cupolas on the famous barns at the Shelburne farm museum in Vermont. The thing in your area would be to keep piled up snow from blocking the ventilation.

For low ventilation to use in hot weather windows are appropriate. Ideally with top-hinged covers to keep rain out. :)

Some people in cold climates have a system of interior baffles to prevent direct drafts on the roof while maintaining excellent airflow. I can't speak to the details since I didn't keep chickens when I lived up there in Monson.

P.S. I love your avatar!

Good point about the snow obstructing the ridge!

Would it be overkill to have the ridge, soffit vents, and gables?

I do plan to have windows protected with ¼in hardwire cloth on the South, North, and East sides of the coop.
 
Good point about the snow obstructing the ridge!

Would it be overkill to have the ridge, soffit vents, and gables?

I do plan to have windows protected with ¼in hardwire cloth on the South, North, and East sides of the coop.

I do not think it would be overkill at all.
I always say it is easier to put way more ventilation than the minimum and build in a way to close them in case of extreme wind.
It is much much easier to address a way to baffle or cover when it ISN'T whipping snow or rain in extreme cold than trying to rig emergency covers during a storm.
 
I always say it is easier to put way more ventilation than the minimum and build in a way to close them in case of extreme wind.

A great way to think about it.

In my area I can get storms from any direction and I get hurricanes so when I build my new coop I'm going to have to do just that.
 
You can think of ventilation as powered by nature in two different ways and you need both. And your needs are different in summer and winter.

One comes from a blowing wind. In summer it doesn't matter if a breeze hits them or not. In your winters you do not want a breeze hitting them when on the roost. There are different ways o achieve that in winter, baffles or the roost sin a cul de sac so wind can't hit them. To me the simplest is to have any openings over their heads so any breezes miss them. A breeze going over their heads still causes some turbulence in the coop, which I consider good as long as it is not very strong. You do not want to ruffle their feathers and let trapped heat out but that small turbulence helps exchange good air for bad. In summer, openings down low that allow a breeze to hit them on the roosts are OK.

The other is that warm air rises. Cooler air is heavier than warm air so cool air pushes warm air up out of the way. This becomes important when the wind is not blowing. In winter you have several heat and moisture sources in the coop: the chicken's breath, their poop, and thawed water can be sources of both warmth and moisture. If your coop is on the ground the soil will be warmer than the air in a cold snap. Warm air holds more moisture. So even with no wind blowing the warmer moister air will rise and exit through a higher opening.

In summer it is good to have a source for cooler air. Probably the coolest place for you in Massachusetts is on the north side of the coop in the shade. If the vent is on the sunny side the air may not be that much cooler than the air inside the coop.

A ridge vent is great as long as snow doesn't block it. You'll appreciate that in summer too. Soffit vents might be enough in winter but adding a gable vent will also be good.
 
You can think of ventilation as powered by nature in two different ways and you need both. And your needs are different in summer and winter.

One comes from a blowing wind. In summer it doesn't matter if a breeze hits them or not. In your winters you do not want a breeze hitting them when on the roost. There are different ways o achieve that in winter, baffles or the roost sin a cul de sac so wind can't hit them. To me the simplest is to have any openings over their heads so any breezes miss them. A breeze going over their heads still causes some turbulence in the coop, which I consider good as long as it is not very strong. You do not want to ruffle their feathers and let trapped heat out but that small turbulence helps exchange good air for bad. In summer, openings down low that allow a breeze to hit them on the roosts are OK.

The other is that warm air rises. Cooler air is heavier than warm air so cool air pushes warm air up out of the way. This becomes important when the wind is not blowing. In winter you have several heat and moisture sources in the coop: the chicken's breath, their poop, and thawed water can be sources of both warmth and moisture. If your coop is on the ground the soil will be warmer than the air in a cold snap. Warm air holds more moisture. So even with no wind blowing the warmer moister air will rise and exit through a higher opening.

In summer it is good to have a source for cooler air. Probably the coolest place for you in Massachusetts is on the north side of the coop in the shade. If the vent is on the sunny side the air may not be that much cooler than the air inside the coop.

A ridge vent is great as long as snow doesn't block it. You'll appreciate that in summer too. Soffit vents might be enough in winter but adding a gable vent will also be good.

Awesome feedback. Thank you!
 
I too agree with the more ventilation the better. We have a ridge vent and it does require a snow rake to remove the snow. We also have gable vents. Leave the windows open all the time, plus the pop door. And something we started doing most days in the last couple years, we prop the egg roof open a couple inches every day. Our in coop sensor says it is 32F & 81% humidity. Exactly the same as the conditions in our yard.
 

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I know I need high and low ventilation.

For high ventilation I'm thinking ridge vent along the whole roof. For low ventilation I was thinking soffit vents.

So, would soffit vents still be too high? Should I do gables or transom window-like vents instead?

not sure where did you get your information from.
Ventilation should be as high as possible - hot humid air that needs to be evacuated rises.
Away from the roosts as much as possible - cold does not kill well feathered chickens, frosty wind does.
All on the same level if possible - having it both high and low would create constant draft.

So the highest (ridge) vent would be ideal if you can put enough opening there which is probably not the case. Unless you have high pitched roof and concern of shingles overheating in the summer and condensation in the winter it is really not necessary.

That leaves us with soffit vents through open rafters. Make sure the roosts are well below them. One neat way to ensure the cold air from rafters will be not falling on the heads of the sleeping chickens is to build a loft directly above the roosts and below the open rafters.

hope this helps
 

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