为了准确评估其对冷负荷的影响，有必要测量建筑物内设备的空间热增益和辐射/对流分离。建筑设计的最新进展以及隔热材料和建筑围护结构系统热特性的改善，显著降低了外部来源的冷负荷；然而，在建筑中增加各种办公室、实验室和医院设备已成为内部冷负荷的主要来源。不幸的是，目前的手册中缺乏关于这些设备的总热增量的准确信息。影响冷负荷计算的另一个因素是设备的辐射热增益和对流热增益之间的分配。从设备传递到周围环境的热量的对流部分是瞬时负荷，因为它通过自然或强制对流无延迟地添加到室内空气中，而辐射部分被房间表面吸收，然后随时间消散。

Measurement of heat gain to space and radiant/convective split from equipment in buildings is necessary in order to make accurate assessment of its impact on cooling loads. Recent advances in design of buildings and improvement on the thermal characteristics of insulation materials and building envelope systems have significantly reduced the cooling load from the external source; however, the addition of various office, laboratory and hospital equipment to the building has become a major source of internal cooling load. Unfortunately accurate information on the total heat gain from those equipment items is lacking in current handbooks.Another factor affecting the cooling load calculation is the split between the radiant and convective heat gain from the equipment. The convection portion of the heat transferred from the equipment to the surroundings is an instantaneous load since it is added to room air by natural or forced convection without time delay, whereas the radiation portion is absorbed by the surfaces of the room and then dissipated over time.