×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Jobs

any correlation btwn cfm and gal/day - evap. humidifiers?

any correlation btwn cfm and gal/day - evap. humidifiers?

any correlation btwn cfm and gal/day - evap. humidifiers?

(OP)
Hello,

Thanks for you interest in my question.  Restated in more detail, the question is:

With respect to evaporative humidifiers, I would guess that there is some correlation between CFM and rate of output, or gallons of water per day.  Of course, this would only be true for a given system with all other things being equal, i.e. wick efficiency, R.H., ambient temp...etc.  Is this true to any extent, and are there any rules of thumb defining this relationship?  What are the system variables that drive such a relationship?

Thank you for any input or ideas.

Nathan Rollins
BearsFeat Consulting Services
bearsfeat.com

RE: any correlation btwn cfm and gal/day - evap. humidifiers?

There is no simple solution for this. That mainly depends upon the wet bulb temperature and evaporation efficiency. For estimation, a ball park figure of 75% is good enough. As the process is isenthalpic, you can do energy balance to derive a relationship if you know some parameters.

1.08 x cfm x (T1-T2) = 1000 x m

Where T1 is initial temp. of air in deg.F
T2 is final temp. of air in deg.F
m is mass flow rate of evaporating water in lb/h.
1000 is latent heat of water in btu/lb

I ignored mass addition to air flow in terms of water vapor as this quantity will be marginal when compared to mass flow rate of air.

Regards,
 

Eng-Tips.com : Solving your problems before you get them.

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!


Resources