×
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

Heat Exchange Question

Heat Exchange Question

Heat Exchange Question

(OP)
I'm electrical not to good in thermo, so heres my question.  I am needing to calculate the size of an enclosure for a VSD, I know how many BTU's are being put of by the drive, but I need to how many BTU's are being put off by the change in temperature between the desired inside temp and actual outside temp.  I then need to know how surface area of steel is required to dissipate this heat.  Any help would be appreciated.

RE: Heat Exchange Question

Control Concepts:

This actually should be easy for you:  think of it as a big resistance.  The formula is q(in BTU/hr)= hA(To-Ti).  h is the average unit thermal conductance and is defined as the thermal conductivity, K, divided by the area, A, so that hA=K.  K for steel depends on type and temperature (for stainless it runs between 8 an 13 for a temperature range from 32F to 1000F), so you will need to look in a handbook for your application.  You have your q and your outside temperature, that will tell you what your inside temperature will be.  If it's higher than your "desired" temperature, then no matter what your area, you're not going to get the cooling you probably want.  Hope this helps!

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Forums"

RE: Heat Exchange Question

(OP)
Thanks VPL, thats what I been using.  I was just having a hard time explaining to my boss that the enclosure itself absorbs heat which also needs to be dissipated.  

Thanks
Micky

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