[Equest-users] Loop Operation

[Karen Walkerman]

Hi All,

I'm having some issues with loop and pump operation in eQuest.

I have tested this issue with water loop heat pump loops.  Basically, I set
my loop design DT, but for many hours, the loop operates at very low
temperature differentials.  With the given load on the loop, this requires a
high flow, and results in high pump energy!

Specifically, for a heat pump loop, I'm expecting a 7-10 F difference in
supply and return temperatures at all times.  I just ran a test model with a
loop design DT specified at 10 F.  For hours when there is a heating only
load on the loop, I have an average difference in supply and return
temperatures of about 3 degrees.  This requires the pump to move about 3
times more water than necessary.  My system is modeled with variable speed
pumps, and isolation valves at each heat pump.

Any suggestions are greatly appreciated!

Thanks,

--
Karen
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