Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*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.

Students Click Here


CO² concentration over time

CO² concentration over time

CO² concentration over time

Hi all,

I don't know how to calculate following problem:

I have a room with a certain concentration of CO2. There is a leak which causes the concentration to fall over time.

CO2 concentration start = 43.0%
CO2 concentration after 10 minutes = 22.2%
CO2 concentration air outdoors = 0.04%

What should the initial CO² concentration be to have the minimal CO2 concentration after 10 minutes = 38% ?

Any help?


RE: CO² concentration over time

You need two readings at two different times inside the room to establish the leak rate.

RE: CO² concentration over time

Now you have all the information.

RE: CO² concentration over time

This is comically ill defined for me, if the answer is to matter in some way. Why does the concentration change? Does the leak selectively permit C02 to leave? Is the CO2 diluted by infill? Is it a leak at the bottom of a chamber where C02 sinks to the bottom? These possibilities give different meanings and solutions to the problem.

A common engineering assumption would be that dC/dT is constant and that C(t) is linear and determine dC/dT from 2 points where the change in C and the change in time is known, and you're doing 7th or 8th grade math in the US, or 5th grade math in many other countries. That's as simple as it gets. Beyond that responsibility for passing on this, getting this right or wrong is yours.

RE: CO² concentration over time

when you figure out the answer, let us know, please.

another day in paradise, or is paradise one day closer ?

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.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close