I have created a model for a one story building with four thermal zones in OpenStudio 1.7.0. VRF is the only HVAC system of this building. The heat recovery mode is turn on and all other setting are as default. I tried to understand how the heat recovery affect the total heating/cooling energy so I look into the comparison between total terminal heating/cooling rate and VRF heat pump total heating/cooling rate in detailed output variable mode.

Based on the InputOutputReference, VRF Heat Pump Total Heating/Cooling Rate shall match the sum of the individual zone terminal unit output variable for Zone VRF Air Terminal Total Heating/Cooling Rate.

However, I found that wasn't true for my model. The VRF Heat Pump Total Heating/Cooling Rate isn't equal to the sum of the individual zone terminal unit output variable for Zone VRF Air Terminal Total Heating/Cooling Rate at each timestep. Have anyone seen this situation before? Please help me understand what is wrong with my model.

Thank you Chuangye