Other inputs

Other inputs to the calculations is type of heat pump, type of operation of the heat pump, type of control of the heat pump, type of heating (floor heating or radiator heating), minimum source operating temperature, the effect of auxiliary equipment and backup electricity heater.  
Other possible energy sources can also be chosen, but this chapter only treats the heat pumps.  
Output from the calculations The model calculates the energy use and losses based upon constant fractions. The fraction of the energy use and the different losses is displayed by the model. A diagram shows the energy supply per temperature bin and how it is covered from different energy sources.  The seasonal energy efficiency, etas, is calculated.  
Etas = Lh/Qtot+cctrl where Qtot=Lh + Lsys + Qgen + Qel
etas is the net space heating demand of the house over the sum of the generated heat of the system. Qtot is the sum of the space heating demand (Lh), the losses from the heating system (Lsys), the primary energy losses of the energy input to the system (Qgen) and the energy needed by the auxiliary equipment such as control and heat sink pumps (Qel).