# Calculation of HVAC Energy Consumption from EnergyPlus loads

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:

### Simple HVAC

Boiler energy = *EnergyPlus heating
loads / *Heating system CoP

Chiller energy = *EnergyPlus cooling
loads / *Cooling system CoP

### Compact HVAC

Boiler energy = (*EnergyPlus heating
loads* x Heating distribution loss factor) / Boiler
CoP

Chiller energy = (*EnergyPlus cooling
loads* x Cooling distribution loss factor) / Chiller
CoP

Where:

Heating distribution loss factor = 1 + (Heating
Distribution Loss) / 100

Cooling distribution loss factor = 1 + (Cooling
Distribution Loss) / 100

### DHW (Simple and Compact HVAC)

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)

Where:

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 .