When researching necessary features of a chicken coop, many people will focus on square footage, the number of roosting bars and nesting boxes, and whether it will keep chickens warm enough. These are all good features to consider, but there is one aspect that is much more important and could make the difference between life and death for your chickens.
Ventilation is a crucial aspect of a chicken coop. Chickens have a sensitive respiratory system and require constant air flow to ensure good health. A respiratory illness in a chicken can be caused by dust, ammonia (from excessive manure), and too much moisture in the air.
Keep reading to learn more about a chicken’s respiratory system (it’s very different from humans) and what can be done to ensure your coop has plenty of ventilation to ensure good health for your flock.
Why is Ventilation So Important?
Chickens have a high respiration rate compared to humans and other animals, meaning they use more air in proportion to their body size. Because of this, they exhale a comparatively large amount of air, which is full of moisture.
|Respiration Rate |
A chicken’s respiratory system is much different from a human’s.
They have a primary respiratory system where air enters the nostril and then travels through the pharynx and trachea, eventually entering the lungs.
When a chicken exhales, the air passes over a series of bones and membranes which remove water from the air. This process helps prevent dehydration in hot weather.
Chickens also have a secondary respiratory system which contains nine air sacs.
These air sacs circulate air into the body as they occupy the space in a chicken’s body that is not occupied by organs. This air is drawn from the lungs into pneumatic bones.
When a chicken flaps its wings, it is able to draw more air into its air sacs and pneumatic bones.
A chicken’s respiratory system helps them to regulate their temperature. When a chicken inhales, the cool air goes through a one-way direction in the lungs and does not mix with the hot air that is exhaled, as it is all moving in the same one-way direction.
This complex respiratory system is very sensitive, which makes chickens susceptible to many different respiratory disease (which are the most common cause of death, after predation).
With adequate ventilation, chickens are less likely develop respiratory illness and will have good health.
How Much Ventilation is Needed in a Coop
There are a few tests you can perform to identify if your coop is getting enough ventilation:
- Sniff test
- Flash light test
- Sneeze test
1. The Sniff Test
When you stick your head in the coop, does it smell like ammonia?
If there is even a faint smell of ammonia, you probably need to add more ventilation.
High levels of ammonia in a chicken coop can cause “ammonia burn”, or conjunctivitis in chickens that can lead to blindness.
Ammonia odor is caused by unsanitary conditions, such as excess manure in a coop.
2. The Flash Light Test
Move the bedding in the coop with a stick or your foot if you coop is tall enough for you to walk in.
After a few minutes, shine a flashlight into the coop and see if there is dust lingering in the air. If there is, then the coop needs additional ventilation.
3. The Sneeze Test
When your chickens are in the coop, either at night when they’re roosting or during the day when they go to lay eggs, listen for sneezing.
If your chickens are sneezing either when they’re in the coop or shortly after they’ve left, then you might have a ventilation issue.
In general, if you don’t smell ammonia, you don’t see dust lingering in the air, or you don’t hear chickens sneezing, then you probably have adequate ventilation.
A chicken coop requires proper ventilation at all times. This includes ventilating the coop at night and also in inclement weather.
In general, to maximize ventilation in a chicken coop, or any other structure, there are some basic principles to follow.
The amount of air that is moved through a structure will be directly proportional to the size of your air inlets and outlets.
Make sure you open at least two windows at opposite ends of the structure to get a benefit from the cross breeze. Opening several windows on the same side of the structure won’t have the same impact as opening windows 180 degrees or even 90 degrees from each other.
Tips to Increase Ventilation in Your Existing Coop
In case your coop doesn’t have enough ventilation, there are a few things you can do to increase ventilation.
1. Open Windows
I know, this sounds obvious, but it’s a good place to start.
Make sure the windows are open 99% of the time. This includes during the winter!
But won’t the chickens get cold if you have the windows open during the winter? Probably not.
Chickens handle cold much better than heat. You need to protect your chickens from drafts, which can lead to frostbite on their combs, wattles, and toes, but they absolutely still require ventilation.
When chickens are fully grown, their feathers provide them with warmth when they are fluffed up. Chickens will snuggle with each other to maintain warmth when they are cold.
Chickens will conserve body heat when standing by standing on one leg, reducing the area of their body that is exposed to the cold.
We experienced one of the coldest winters in recent history in Texas when our chickens were about 6 months old.
The temperatures were between 5 to 15 degrees F for 3 days straight and it snowed several inches.
We thought there was too much snow for our chickens to be in their run so we kept them in their coop, along with their water and feed.
Being totally ignorant we also had a heat lamp in their coop with the windows closed. There was condensation on their windows, which was a giant clue that they needed more ventilation!
Learn from our mistake and have a window cracked for your chickens during the winter.
If there is condensation on the windows, that means there’s too much moisture in the air and your chickens are at risk of getting sick.
2. Replace Coop Door with a Screen Door
Our chicken coop came with a solid door where we enter the coop (aka the “human door”).
During the summer, it can get up to 100 degrees F inside the coop.
The chickens were still going inside the coop to lay eggs, but I was concerned about the heat and the stillness in the air inside the coop.
Steven and I decided to replace the human door with a screen door this summer.
We used the current door as a pattern and used half inch hardware cloth to make the door predator proof.
The coop has much more ventilation now and the chickens seem to enjoy the additional breeze!
The highest temperature I have seen in the coop since this modification has been 95 degrees F, which is still hot, but not quite in the triple digits like before.
Depending on your coop construction, you might consider replacing the regular door with a screen door.
Just make sure to not use the lightweight mesh screen that typically comes on screen doors or windows. This material is not secure enough and won’t keep out an animal intent on entering the coop.
Half inch hardware cloth makes a great screen for the door (and windows): it’s secure, cheap, and can be bought at Lowe’s, Ace Hardware, Tractor Supply, or Walmart.
3. Add Fans
Adding a fan to a coop is great way to get air moving.
The goal is not to create a draft in the coop, but rather to move air.
A good fan for a chicken coop will move roughly 5 cubic feet per minute per chicken.
While you can use a residential fan for the coop, a fan specifically designed for agricultural use will last longer when exposed to dust and humidity that is often found in chicken coops.
After we added the screen door to the coop, we added a small fan to blow air through the screen door and straight out the chicken door on the opposite side of the coop.
This has really helped not only with ventilation, but also keeps the flies at bay during the summer and helps cool any hens that are in their nesting boxes laying eggs during the day.
I also have a box fan that I sit on the ground outside of the chicken’s expanded run.
This fan blows air into the bushes that the chickens like to hang out in during the day.
One day I forgot to set-up this fan and I heard a tremendous squawking. I went to check on the chickens and they were letting me know they were hot!
After I set-up the fan, they went and sat as close to the fan as possible, just to make sure that I knew I had messed up by forgetting their fan. That mistake has not been made again.
4. Add Ventilation Holes Near Ceiling
Our chicken coop came with ventilation holes near the ceiling. They have a cover that prevents adequate air flow, however, so we will be replacing these with a hardware cloth soon.
If your coop does not already have ventilation holes, they are easy to add.
You can use a drill bit used for making door knob holes to drill two holes near the ceiling of your coop, exactly opposite of each other.
If you are able to make the holes along the north and south walls, that’s even better.
From the inside of the coop, attach half inch hardware cloth using screws and washers. This will allow air flow in the coop, while also preventing a predator from trying to enter the coop through these holes.
Ventilation is the most important aspect of a chicken coop because lack of it can lead to serious illness or death.
Check your chicken coop to make sure it passes the sniff test, the flash light test, and the sneeze test.
If it doesn’t pass, then consider the options above to add more ventilation to the coop.
When in doubt, err on the side of too much ventilation rather than not enough.
Your chickens are hearty birds that can handle the weather, but their respiratory systems need extra care.