That air-conditioning system is non-eiger gray system is proposed. By a real example, gray interval predicting of loads of building hygrothermal system is studied. Compared with real measurement, it is feasible to apply ULLLM to build gray plane.

• 本文简述了负荷预测的意义及一般与特殊预测方法；分析了建立灰色平面的三种方法；从而提出了上下限线划分法；论述了空调系统是一非本征灰色系统；结合实例进行了系统负荷的灰色区间预测；经与实测比较；证实上下限线划分法所建立的灰色平面是可行的.