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<DIV><SPAN class=187524523-21112009><FONT face=Arial color=#0000ff
size=2>Karen,</FONT></SPAN></DIV>
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<DIV><SPAN class=187524523-21112009><FONT face=Arial color=#0000ff size=2>I've
faced the same problem and as a quick fix, I found best to undersize the
condenser water loop till the differential was aggreeable, like you said 10F or
so, this as you mentioned reduced the pump energy by a quarter. I'm sure
there is a more correct way to do this, please share once you figure it
out.</FONT></SPAN></DIV>
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<DIV><SPAN class=187524523-21112009><FONT face=Arial color=#0000ff
size=2>Regards,</FONT></SPAN></DIV>
<DIV><SPAN class=187524523-21112009><FONT face=Arial color=#0000ff
size=2>Amarpreet</FONT></SPAN></DIV>
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<FONT face=Tahoma size=2><B>From:</B> Karen Walkerman
[mailto:kwalkerman@gmail.com] <BR><B>Sent:</B> Friday, November 20, 2009 12:12
PM<BR><B>To:</B> equest-users@lists.onebuilding.org<BR><B>Subject:</B>
[Equest-users] Loop Operation<BR></FONT><BR></DIV>
<DIV></DIV>Hi All,<BR><BR>I'm having some issues with loop and pump operation in
eQuest.<BR><BR>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!<BR><BR>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.<BR><BR>Any suggestions are greatly
appreciated!<BR><BR>Thanks,<BR><BR>--<BR>Karen<BR><INPUT type=hidden><INPUT
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