×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Compressor Output vs. Elevation Change

## Compressor Output vs. Elevation Change

(OP)
Can someone provide the equations to determine the effect elevation change has on compressor flow rate?

I have a compressor that provides 100 CFM at 1000 RPM at standard ambient conditions and need to calculate what the flow rate will be at an altitude of 10,000 feet where the air is less dense.

I cannot find this information anywhere else on the web.

### RE: Compressor Output vs. Elevation Change

What type of compressor?  I'm assuming at 1000 rpm it's some type of recip compressor.

In that case, the change in capacity will be relative to the air pressure at 10,000 feet (and inversely proportional to temperature if that's a factor) versus the pressure at sea level.  Roughly, the compressor will deliver 2/3s of what it will at sea level.

The compression ratio for the compressor will also increase (if you keep the discharge pressure constant) due to the lower suction pressure and you will want to ensure you don't exceed the allowable discharge temperature.

### RE: Compressor Output vs. Elevation Change

To put it another way, to a first approximation the machine will deliver the same suction volume of 100cfm, but the mass flow will drop in proportion to the inlet density.

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
The Great Project Profitability Debate
A/E firms have a great opportunity to lead the world into the future, but the industryâ€™s greatest assetâ€”real-time dataâ€”is sitting wasted in clunky, archaic ERP platforms. Learn how real-time, fully interactive dashboards in a modern ERP allow you to unlock data that will shape the future of the world. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!