I created two copies of a midrise multifamily residential building in OpenStudio 1.13 and applied split AC with gas furnace to one and LG VRF measures from BCL to the other. Looking at the HVAC Load Profile tables in the OpenStudio output report shows that the VRF building has significantly higher monthly cooling and heating loads compared to the split AC building.
I checked the weather files between the two models (same), I compared the sensible heat gain components (same values, other than VRF shows air cooling and heating occurring with the zone equipment and the split systems show air cooling and heating in the terminal unit columns). From reading these boards, I understand that there is no way to dis-aggregate the load components in Open Studio, but I tried running the zone component loads report in EnergyPlus and did not see any differences there either. As far as I can tell, neither system is doing mechanical ventilation and the infiltration rates are the same. In July, the VRF building has a cooling load of 23.11 MBtu compared to 12.96 MBtu for the split AC building.
Any suggestions for diagnosing this issue would be greatly appreciated.
