普渡大学的中央冷冻水系统为占地约647英亩的校园提供服务。冷却装置的装机冷却能力为13200吨，通过大约35500英尺（6.7英里）的地下管道与44座不同的建筑相连。在44栋建筑中，中央冷却系统为260个主要空调系统和2775个风机盘管感应装置提供服务。安装在44栋建筑中的冷却设备的总装机负荷为12900吨。作者们认为，如果他们能够设想一种控制系统，使终端设备能够在整个负荷范围内利用冷冻水的全部温升，并提供相等的空间冷却，他们将大大提高系统的容量。 此外，控制系统必须适用于现有系统。其中一个途径是回水温度控制，本文对此进行了讨论。引文:德克萨斯州达拉斯ASHRAE交易会第82卷第1部分研讨会

The Purdue University central chilled water system serves a campus of some 647 acres. The,chiller plant has an installed cooling capacity of 13,200 tons and is connected to 44 differentbuildings by approximately 35,500 ft. (6.7 miles) of underground piping. Within the 44 buildings,the central cooling system serves 260 major air conditioning systems and 2,775 fan coilor induction units. The cooling equipment installed in the 44 buildings represents totalinstalled load of 12,900 tons.The authors believed that if they could conceive a control system that would allow terminal units to utilizethe full temperature rise of the chilled water over the entire load range, and provideadequate space cooling, they would greatly increase the capacity of the system. Also, the controlsystem had to be applicable to the existing systems. One of the avenues pursued was return watertemperature control which is discussed this paper.