SCOP (seasonal coefficient of performance)

SCOP (seasonal coefficient of performance) is a heat-pump efficiency measure for a designated heating season rather than one test point. It compares the reference annual heating demand with the annual electricity consumption for heating in the standard calculation, so a higher figure means more heat is delivered for each unit of electricity in that seasonal rating. Product datasheets and energy-label information use SCOP because it reflects a seasonal pattern of part-load operation and changing outdoor temperatures rather than one fixed COP rating. It should still be read as a standardised rating, not a guarantee of household running cost. Measured seasonal performance can sit above or below the quoted SCOP depending on heat loss, emitter sizing, flow temperature, controls, weather and any separate hot-water duty. MCS customer paperwork may also use SPF, or seasonal performance factor, for estimated annual system performance in a specific design, which is related but not the same as a manufacturer SCOP rating.