Hello,
I?m currently modeling a VRF system in eQUEST 7175. The equipment cut
sheets include both cooling EER and heating COP values. However, I
noticed that the VRF condensing unit input in eQUEST only allows for
cooling efficiency?there?s no direct field for heating COP.
I looked into this and wasn?t able to find any documentation or
settings that allow for a direct input of heating COP.
Here?s the approach I?ve taken to work around this:
For compressor energy consumption in cooling, heating, or combined
modes, I?m using the following formula:
P = Prated ? EIR_FPLR ? EIR_FT ? CAP_FT
The default performance curves applied are:
VRF044-Cap-fSST&SDT
VRF044-EIR-fSST&SDT
VRF044-EIR-fPLR
Energy consumption is calculated as follows:
At cooling SST & SDT ? based on cooling EER
At heating SST & SDT ? based on heating COP
So, instead of directly inputting both cooling and heating EIR values,
I rely on:
Cooling EIR
Cooling SST & SDT (used to calibrate the default curve)
Heating SST & SDT (used to reflect heating performance through the
same default curve)
A detailed breakdown of the calculations is provided in the attached Excel file.