DesignBuilder calculates boiler, chiller, DHW fuel consumption from the loads calculated by EnergyPlus using the CoP data at the building level on the HVAC tab as follows:
Boiler energy = EnergyPlus heating loads / Heating system CoP
Chiller energy = EnergyPlus cooling loads / Cooling system CoP
Boiler energy = (EnergyPlus heating loads x Heating distribution loss factor) / Boiler CoP
Chiller energy = (EnergyPlus cooling loads x Cooling distribution loss factor) / Chiller CoP
Heating distribution loss factor = 1 + (Heating Distribution Loss) / 100
Cooling distribution loss factor = 1 + (Cooling Distribution Loss) / 100
DHW energy (kWh) = DHW CoP x 1000 (kg/m3) x 4.187 (KJ/kg-K) x (EnergyPlus DHW m3 loads) x (Delivery water temperature - Mains water temperature)
DHW CoP is Heating system CoP when using '1-Central heating boiler' DHW type
Data shown in blue is HVAC model data.
Data shown in italics is read from the EnergyPlus results eso file .