Question of System Curve
Question of System Curve
(OP)
Dear all,
I've designed a ventilation system, which comprise 6 branch from the main ductwork, and each branch is end cap with motorized on/off damper & diffuser.
Since the required flowrate and total pressure for critical path of the captioned ductwork is identified. System curve can be plotted with relation P=kQ^2 by the such value.
However, if three branch outlet is kept no airflow status by the motorized damper (off position) and all these three branch outlet is not included in the critical path,
I would like to know, would the new operation point still on the original "System Curve" or a new system curve would generate in such occurance.
Thanks for help!
I've designed a ventilation system, which comprise 6 branch from the main ductwork, and each branch is end cap with motorized on/off damper & diffuser.
Since the required flowrate and total pressure for critical path of the captioned ductwork is identified. System curve can be plotted with relation P=kQ^2 by the such value.
However, if three branch outlet is kept no airflow status by the motorized damper (off position) and all these three branch outlet is not included in the critical path,
I would like to know, would the new operation point still on the original "System Curve" or a new system curve would generate in such occurance.
Thanks for help!





RE: Question of System Curve
RE: Question of System Curve
You can do this system by both air & water flows.
RE: Question of System Curve
Thanks for your kind opinion, since I've identified the critical path and calculate with the corresponding total pressure drop ventilation system.
Then, is it accurate to generate the "System Curve" by using the value "total pressure drop" and the design flowrate of the captioned system.
Thanks a lot
RE: Question of System Curve
The balancer must adjust dampers in branches to kill off excess pressure available in the low loss runs so eventually the loss through them is each equal to the loss through the worst run. Then when you do part load analysis of particular branches you must take note of this adjusted damper PD1. Note that PD2 through it with new flow will equal PD1 x CFM2^2/CFM1^2.
RE: Question of System Curve
And I would like to know, does the "total pressure drop" of branch ductwork (Tee-off from Main ductwork) has influence when predicting the system curve?
Since when calculating the pressure drop of "Critical Path", pressure drop of such branch ductwork is ignored.
Thanks
RE: Question of System Curve