Design heat loss

Design heat loss is the calculated heat loss of a room or whole property at the indoor and outdoor design temperatures used for heating design. In heat pump work, it is usually part of a room-by-room heat load calculation carried out to BS EN 12831-1:2017 for MCS design. The figure, normally expressed in watts for rooms or kilowatts for a whole dwelling, helps set heat pump capacity, emitter output and design flow temperature. It is not a measured energy bill, an EPC rating, a running-cost forecast, a comfort guarantee or proof that the survey assumptions were correct.