[BLDG-SIM] eQUEST - odd DHW behavior

[Maxwell, Sean]

Hi All,

 

I can't figure out what eQUEST is doing with some DHW loads that I've
assigned to several DHW loops.  I've got 8 water heaters that are also
serving as space heat, providing hot water to coils in PTAC systems.
I've divided a PROCESS-FLOW for DHW proportionally to all of these via a
global parameter.  

At higher flows (like 66 gpm building-wide), all of the PROCESS-FLOW
shows up as hot water gas consumption.  Fine.  But at somewhat lower
flows (45 gpm), the consumption gets split up about half and half
between hot water and "misc. equip."  At even lower flows (20 gpm), the
hot water consumption disappears and only the miscellaneous equip.
consumption remains.  Any idea why?  

 

I've tried assigning this same flow to a separate water heater that is
not serving any space heat loads, and the effect is absent.  Overall,
the combined gas use for the misc. equip. and hot water are the same for
the two schemes.  In addition, space heat gas consumption is the same in
all cases, telling me that the process flow has nothing to do with the
space heat.  

 

What is it about the PROCESS-FLOW on a combined space-heat / hot-water
heater that makes this happen? 

 

Thanks.

 

***********

Sean Maxwell

Energy Performance Analyst

Conservation Services Group

40 Washington St. Westborough, MA 01581

C:  508-328-2603  ph:  508-836-9500 x13230   fx: 508-836-3181



===========================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20071026/212cd29f/attachment.htm>