While modeling a variable speed blower fan and variable compressor rooftop unit heat pump the Simulation Report lists the EM1 Electricity MBTU for space heating as ?nan?. Does anyone know why I don?t receive a quantity for heating?

In the Air-Side HVAC System Parameters dialog box I?ve selected system type: ?Pkgd Var Vol Var Temp?, Heat Source: ?Heat Pump?, Heating Electric Input Ratio Curves: ?PVVT-Heat-EIR-fEDB&OAT?. My system does not have supplemental electric heat.

Michael Schaefer - P.E., LEED? AP