ADEME highlights efficiency factors in heat pump energy costs

The French Agency for Ecological Transition (ADEME) has highlighted how identical heat pump models can result in significant differences in annual energy costs. Simulations based on ADEME studies show that two homes with identical heating needs and the same equipment can experience a cost discrepancy of up to 733 euros per year.

The primary driver of this variation is the water temperature required by the heating system. Installations using large radiators or underfloor heating that operate with water temperatures between 35 and 45 °C are significantly more efficient than those using smaller radiators requiring temperatures near 55 °C. Unlike traditional boilers, air-to-water heat pumps experience decreased performance as the required water temperature increases.

ADEME reports that the Coefficient of Performance (COP) varies widely; while the average for 100 studied homes was 2.9, some installations reached above 4.0 while others struggled at 1.8. The agency notes that lowering the water temperature by 10 °C can increase the COP by one point.