Heat pumps are generally sized based on the __________.

Heat pumps are typically sized based on the heating load, which refers to the amount of heat energy required to maintain a comfortable indoor environment during the coldest times of the year. This calculation takes into account factors such as the thermal characteristics of the building, including insulation levels and air leakage, as well as the external climate conditions.

Sizing a heat pump according to the heating load ensures that it can effectively meet the demands placed on it during peak heating periods, providing adequate comfort without excessive energy use. While cooling load is an important consideration for air conditioning systems, heat pumps serve dual purposes; however, their primary sizing consideration is often the heating load to ensure optimal performance in heating mode. The number of occupants and building materials, while relevant to overall energy efficiency and comfort, are secondary factors in determining the appropriate size for a heat pump system.