Part load performance

Part load performance of the heat pump must be properly taken into account, and be based on relevant testing standards.  
Night set back is a choice in some calculation models; this is not relevant for heat pumps and should not be a part in a new calculation model.  
 Back up heaters is sometimes necessary to complete the energy demand of the house. Back up heaters should be included in the calculation model. Supplementary heating should be possible to choose between different sources of supplementary heat, e.g. electricity, solar or biomass heating