Primary Energy Use vs Heat Demand in the Home.

Original Article
February 10th, 2018


Question: Why does the current primary energy use multiplied by the total floor area not match the energy used in the home’s heat demand?

Answer: the home’s heat demand, i.e. the space heating demand of the dwelling, is independent of the system used to heat it. 

The primary energy is the energy requirement of house for heating, hot water and lighting and a primary energy factor is applied (see SAP Table 12). 

For example, to ‘deliver’ 1 kWh of electricity to a property takes 2.8kWh (losses, production etc), therefore, the primary energy factor is 2.8.