Composition of cooling load formed by non-transparent envelopes of a common office building under air-conditioning intermittent operation

Under air-conditioning intermittent operation, interior envelopes become the quasi-exterior ones of a partial room and thereby may cause the specified heat loss. However, it is unknown for the heat transfer capacity rate of interior envelopes in the room heat loss, which is of vital significance on the optimization direction of envelopes. To analyze the cooling load composition formed by non-transparent envelopes, an office building was chosen and inner surface heat flows in the studied room were measured under the different intermittent groups of air-conditioning in the adjacent rooms, and combined with the envelop area and heat flow values, the heat transfer capacity through the different envelops could be gained. The results showed that the air-conditioning operation in the adjacent rooms had a large effect on the heat transfer capacities, and the higher the room area, the more remarkable the air-conditioning operation in the adjacent rooms. The average heat transfer capacity rate of the exterior envelope was 21%–35% for room with two exterior walls and only 7%–10% for room with one exterior wall, which were much lower than those of the interior envelopes. It showed that thermal performance of the interior envelopes should be paid more attention to under air-conditioning intermittent operation.