We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is an Air Cycle Machine?

Patrick Wensink
By
Updated May 23, 2024
Our promise to you
WikiMotors is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WikiMotors, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

An air cycle machine is the system that provides fresh, temperature-controlled oxygen to an airplane cabin. This complex machine avoids using freon-like air conditioning units and eliminates the moisture associated with those systems. It comes in different types, with each providing a different level of circulation. This machine is the industry standard for providing air to a cabin and has many other benefits, such as its reliability and environmental impact.

This machine begins its complex process at the engines. Bleed air is the excess air from these enormous turbines, and it is fed into a heat exchanger. The bleed air is too hot for comfort at this point, so the natural air temperature in the sky, usually hovering around the freezing mark, is used as a natural form of coolant. This air is sent to a centrifugal compressor in order to compress the air for efficiency purposes, but this also heats the air up again. The air once again passes through a cooling process using the outside temperature as it gets closer to being expelled inside the plane.

The compressed air is expanded and fed into an inlet fan of the air cycle machine. The fan draws the cooled air through the cabin to the individual air vents and then to the general air vents. The temperature of this system can be raised by a control panel that allows uncooled bleed air into the system to raise the temperature to a desired level.

Depending on the size of the cabin, the air cycle machine can be any of four sizes. The smallest and simplest is one consisting of a turbine and a fan. From this point, more compressors and turbines can be added. The most complex machine consists of two turbines, a fan, and a compressor.

This device has been preferred by airlines for many reasons in addition to its ease of use. One of the main reasons is the fact that it is environmentally friendly because it does not use harmful chemicals such as freon. The system does not create moisture and vapor, so it tends to last much longer than traditional air conditioning systems. By utilizing the bleed air properly, it also erases the need for a separate heating system because the engine air creates as much heat as necessary.

WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Patrick Wensink
By Patrick Wensink
Patrick Wensink, a bestselling novelist and nonfiction writer, captivates readers with his engaging style across various genres and platforms. His work has been featured in major publications, including attention from The New Yorker. With a background in communication management, Wensink brings a unique perspective to his writing, crafting compelling narratives that resonate with audiences.
Discussion Comments
By Mor — On Jun 28, 2012

@umbra21 - Well, there are a few things you can do to make it easier. For one thing, you should drink a lot of water. I know people don't like doing that on long haul flights because they think they'll have to get up and go to the toilet all the time, but it's really important to stay hydrated, particularly in that dry air.

The other thing you can do is seal your lips with chapstick and try not to lick at them at all, because that can dry them out further. Also, the hot towels that many airlines offer periodically throughout the flight can really help.

Finally, try getting a small bottle of water and spraying your face with it whenever you start feeling a bit blah.

I find that some airlines are better than others about making sure the air isn't too dry coming off the air cycle machine, although I'm not sure what they do. The more expensive the airline, the better the air quality, I think.

By umbra21 — On Jun 28, 2012

@browncoat - The only problem is that it's so well controlled that I find it very artificial. It doesn't bother me so much when it's a short flight, but I had to fly half way across the world a few months ago and after sitting in airports and airplanes for over 30 hours my lips were completely chapped and sore. They took a few days to come right.

I guess if the aim is to remove as much moisture from the air as possible, in order to keep the machinery sound, they are going to end up making it too dry for the average person, especially over long term exposure.

Which is not to say that I think they should do differently, mind you. I'm all for keeping the machinery sound. I just wish that it didn't have to be at the cost of my eyes and lips!

By browncoat — On Jun 27, 2012

I never tend to notice the air in an airplane, so I guess that's a sign that the air cycle machine does its job well. I've actually always thought they made the right choice in making the air fairly cool, so that you will want to use a blanket, just because the opposite would be very oppressive.

If I feel too warm, and I'm in an airplane, there's just not going to be a way to cool down and I can imagine feeling a bit panicky. If you have a bunch of people who feel that way, then you've got trouble. After all, once you get down to the last shirt, there's nothing more you can do to cool down, while you can always put on another bit of clothing if you're cold.

I guess it's all carefully calibrated to be just the right temperature.

Patrick Wensink
Patrick Wensink
Patrick Wensink, a bestselling novelist and nonfiction writer, captivates readers with his engaging style across various...
Learn more
WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.