If the declared

Where Tj is the outdoor (bin) temperature and Tdesign is the lower temperature limit of the selected climate.
If the declared capacities of a unit matching with the required heating/ cooling demand the corresponding COP/EER value is to be used. This may occur with staged capacity or variable speed capacity units. If the declared capacity is higher than the heating/cooling loads, the unit has to cycle on/off. Then a degradation factor (Cd (air/air or Water/air) or Cc (others)) has to be used to calculate the corresponding COP/EER values. Cd and Cc can be determined by testing; else a default value of 0.25 and 0.9 respectively is used.  
The bivalent temperature, which is the lowest temperature when the heat pump can deliver 100% of the heat demand of the building, is necessary to use the excel sheet. The design heat demand of the building is a consequence of the stated bivalent temperature. The reference annual heating demand, kWh/a, is given by the product of the full load in heating Pdesign and the equivalent number of heating hours.  
The operation limit of the heat pump is set to the lower temperature limit for which the heat pump can operat