[Equest-users] Package Terminal Heat Pump Simultaneous Heating and Cooling

[Paul Diglio]

I have a project that is giving me some odd results.

It is a mid rise apartment building modeled with PTHP units in each apartment.  
A DOAS system feeds ventilation air to each PTHP.

In the shoulder months (Jan-May & Sep-Dec) I am getting a significant amount of 
simultaneous heating and cooling during the same hour as reported in the Hourly 
Reports.  I checked the kW to Heat and kW to Cool for the PTHP units in the 
Hourly Report.

I am not controlling humidity, so the heat energy is not for reheat.

Does anyone know what energy is included in the kW to Heat and kW to Cool?  Is 
this simultaneous energy because the units are defrosting?  I chose reverse 
cycle defrost.  It is possible that the unit goes into defrost, which counts as 
kW to Cool, then after the defrost is complete the unit switches to heating mode 
because the space temperature dropped during the defrost cycle?

I left the throttling range at the default of .3 degrees.

Thank you for any help,


 Paul Diglio, CEM, CBCP


87 Fairmont Avenue
New Haven, CT  06513
203-415-0082


www.pdigliollc.com
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