[Equest-users] an inadequate cooling capability warning

[Kevin Kyte]

I have been struggling with this scenario.  A pump room does not need to exceed 104F.  Lake water is used for cooling.  The room is expected to contain internal loads requiring cooling at almost all times.  Below 55F the OA and RA modulate to provide 55F supply air.  Above 55F, 100% OA and the cooling coil turns on.  I have the cooling Tstat set to 90F and cooling coil available at 55F.  I am unsure how to even model Below 55F except for economizing which is not really exact but when I set the economizing low limit to 55F I get 200F in the space.  I have set economizing to 90F integrated with the coil and no low limit.  The cooling coil is rarely used and not needed in its full capacity yet I am getting inadequate cooling warnings.

The Min-Supply-T is set to 55F because supply should not be less than this and hourly reports show acceptable supply temperatures into the mid 70s (I don't know if this is acceptable to the program?)  I am not using a lake water chiller because I am not trying to use the same coil temperature.  I am using a simple packaged single zone with the cool-control range set to max and EIR zero'd because there is enough force off the main header to not need any pumping through the loop.

This is only for energy code compliance and I need an explanation on the warnings.  Other than stating several obvious limitations I don't really understand why this warning is occurring.  Does anyone have suggestions on how I may model this system?

I understand that electronic files would help and I will work on that.

Thank you.





Kevin Kyte, LEED (r) AP
Watts Architecture & Engineering, P.C.
95 Perry Street, Suite 300
Buffalo, NY  14203
p:  716.206.5174
f.:  716.206.5199
e:   kkyte at watts-ae.com<mailto:kkyte at watts-ae.com>
http://www.watts-ae.com<http://www.watts-ae.com/>



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