CIBSE reference
CIBSE reference
(OP)
thread403-320544: three way control valve balancing
A question to Waramanga: "According to my CIBSE reference, a three way valve on a coil needs a balancing valve on the bypass line along with one in the return line back to the chiller/boiler. That bypass valve gets set to provide the same dP as the coil when in full bypass mode."
Can you tell me what the CIBSE reference is that you were referring to in the previous thread (copied above)? I would like to know the title of the reference so that I can buy a copy from CIBSE to study - I looked up a few HVAC books that I have but none tells about bypass balancing valve. Thank you for your help.
A question to Waramanga: "According to my CIBSE reference, a three way valve on a coil needs a balancing valve on the bypass line along with one in the return line back to the chiller/boiler. That bypass valve gets set to provide the same dP as the coil when in full bypass mode."
Can you tell me what the CIBSE reference is that you were referring to in the previous thread (copied above)? I would like to know the title of the reference so that I can buy a copy from CIBSE to study - I looked up a few HVAC books that I have but none tells about bypass balancing valve. Thank you for your help.





RE: CIBSE reference
Balancing valves in a 3-way bypass line or in a coil return line are limiters. They won’t normally play any part unless there is a problem, such as all coil valves fail open, CHW temperature gets too warm, etc.
At that point, they hold the flow to a certain limit if/when the respective control valves serving that coil are wide open.
To me, the three way BYPASS circuit setter should be throttled to about ¼ of the coil design flow. This would assure pump minimum flow while reducing pump energy in non-demand situations.
RE: CIBSE reference
RE: CIBSE reference
This could have been done with a screen capture saved to png format.
Markups can be done in any number of image editing programs.
Then viewing your image would have been one click away within the browser.
Instead, I fired up a behemoth cripple-ware Microsoft viewer to see a single image!
Wow!