×
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

Fan Coil Unit

Fan Coil Unit

Fan Coil Unit

(OP)
I have a problem that I don't understand !!!

I am useing a FCU (vertical cabinet) to cool the air in the summer and to make it hot in the winter !

The FCU I am useing is in the 2 pipe chage over system, so the coil is used by the cold water (7-12 grdC) and by the hot water (80-70 grdC) !

Here is the problem : my room need the same quantity of heat in the winter as it need in the summer : 1000Watt ; but the FCU provides me in the summer 1000Watt and in the winter 2500 Watt minimum !

How do I solve the problem? I dont need that much heating capacity in the winter !

Can I use this FCU ? Can I make it work in the winter at 1000Watt ? What are the implications ?

I must also say that I cant use the 4 pipe system, with separate coils for winter and summer !

Please help me , cos I'm in a big dilema !
Thank you very much !

RE: Fan Coil Unit

The one thing that you can easily control is flowrate. Add a control valve to the inlet and reduce the flow through the coil in the winter.

As far as implications I'd speak with the manufacturer of the fan coil unit and see if they have any recommendations.

RE: Fan Coil Unit

Pipedesign:

Could use two coils in parallel and shut off the flow to one in the winter?

Could you bypass some the the air around the coil in the winter?

or

Could you, as Chris Conley said, add a control valve two or three way depending on the system.

RE: Fan Coil Unit

The problem of a FCU having more heating than cooling is a natural consequence of the greater temperature differential between air and water when in heating mode.

The normal method of controlling the room temperature with a FCU, is to have a 3-port water control valve.  This is controlled by a thermostatic fan speed switch (with automatic change-over).  Assuming you don't need really tight temperature control, a 3-port water control valve with an on/off rather than a modulating head will do the job just fine.

Hope this helps

Cooky
Carrier Air Conditioning

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