Hello all,
When I try to perform a simulation of my building I get an error message
that says "cooling coil temperature must be at least 6F higher than
entering water temp." I am using a single zone air handler with
electric heating that is on a chilled water loop, and in the building
creation wizard under this unit it doesn't ask anything specific about
entering and leaving water temperatures. I trying to find the window
that I need to make this change in so I can run the simulation. Thanks
for any kind of help that you can provide.
Christopher Sturdivant
Christopher,
I've been working through issues with this same message, and here is
what I have found so far:
The entering water temperature comes from the chilled water loop "Design
CHW Temp" value.
The cooling coil temperature comes from the HVAC system's "Cooling" tab,
the "Coil Cap/Control" subtab, the "Cold Deck Min Leaving Temp" value.
A related issue that I have found is that if you specify the "Zone
Entering Min Supply Temp" on the same tab and subtab, and if you specify
a Supply Delta T on the "Fans" tab "Fan Power and Control" subtab, then
the program will give you the same error message if the "Zone Entering
Min Supply Temp" minus the "Supply Fan Delta T" is less than 6 degrees
greater than the "Design CHW Temp" value.
It would be nice if there were two separate message for these
conditions. It would also be nice if this error could be made into a
warning instead, since we occasionally have a 5 degree difference on
coils with large numbers of coil rows.
I hope this helps.
Jason Schaeffer