[Equest-users] eQUEST 3.65 build 7175 VRF heating COP input

[Danny Xu]

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.
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