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Hello,

I'm trying to compare the energy use between a VRF system and a PTHP system in EnergyPlus. Both systems have a DOAS to supply outdoor air (efficiencies of the DOAS are the same, OA rates are the same), and all other parameters are the same. The VRF and PTHP system have the same rated efficiencies: cooling COP 3.3, heating COP 3.5. Capacities and supply air flow are being autosized. Both systems' fan mode is cycling. Other parameters are using the default values in OpenStudio.

I'm getting higher energy use in the VRF model, and I'm not sure what the reason is to that... any insight would be greatly appreciated.

Thanks Tina

Hello,

I'm trying to compare the energy use between a VRF system and a PTHP system in EnergyPlus. Both systems have a DOAS to supply outdoor air (efficiencies of the DOAS are the same, OA rates are the same), and all other parameters are the same. The VRF and PTHP system have the same rated efficiencies: cooling COP 3.3, heating COP 3.5. Capacities and supply air flow are being autosized. Both systems' fan mode is cycling. Other parameters are using the default values in OpenStudio.

I'm getting higher energy use in the VRF model, and I'm not sure what the reason is to that... any insight would be greatly appreciated.

Thanks Tina

Hello,

I'm trying to compare the energy use between a VRF system and a PTHP system in EnergyPlus. Both systems have a DOAS to supply outdoor air (efficiencies of the DOAS are the same, OA rates are the same), and all other parameters are the same. The VRF and PTHP system have the same rated efficiencies: cooling COP 3.3, heating COP 3.5. Capacities and supply air flow are being autosized. Both systems' fan mode is cycling. Other parameters are using the default values in OpenStudio.

I'm getting higher energy use in the VRF model, and I'm not sure what the reason is to that... any insight would be greatly appreciated.

Thanks Tina