×
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

Ventilation issues on cooling load calculations

Ventilation issues on cooling load calculations

Ventilation issues on cooling load calculations

(OP)
I am working on the design of a Constant volume, DX a/c system (cooling only)for a Government Office.  For the   cooling load calculation  I am  including a ventilation  load of 15 CFM/person in occupied office areas.  Now in this same  building I also have a cafeteria room,  to be used only by the office  staff (around 20 people). If  I now again include a ventilation load of 15 CFM/person for these same people when in the cafeteria,  I will be doubling the required ventilation air and  introducing double  the air  I actually need (and oversizing my equipment). If I don’t,  I will run short  on the supply air for the cafeteria.  What is the  criteria to follow? Perhaps the best  would be  to have an independent system for the cafeteria,  but what if this is not possible?

Another  issue on  ventilation:  Considering  the local construction standards I know  I will be having some  infiltration,   this however  is hardly  quantifiable.  Should I reduce my  system  ventilation requirements (i.e. 15CFM/person to 10 CFM person)  to compensate for the infiltration  ventilation?

Thank you,


RE: Ventilation issues on cooling load calculations

You need follow the ASHREA 62 guidelines.  It is no longer as simple as 15 cfm/person.  You will need to take into account the airflow percentage that is delivered to each space, and what portion of that is OA.  Since it is a constant volume system this is an easy calculation.  Also, ASHREA 62 now requires OA for space contaminates, this is a OA/sf number, and OA occupants.

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