当用于空调制冷系统时，冷冻水被用作中间传热流体，用于将热量从空间（通过冷却盘管）输送到制冷循环，通常从制冷循环“泵送”到室外空气或可用水源的高温水槽。随着冷冻水系统技术的发展，越来越明显的是，除了作为一个热输送机，能够在负载和水源之间实现物理分离（这样每个负载和水源的位置都可以方便地满足其他设计参数），出现了两个额外的主要优势:水的固有储存特性提供的热滞后或时间常数，在需要多个冷却点或调节空气时，改善和简化了空气侧设备和制冷机的控制，这些负载之间的差异可应用于制冷机械的尺寸和运行模式。 这一特点降低了制冷和散热设备的投资，降低了制冷原动机的能耗。近年来，冷冻水制冷系统的集中化已经超出了单个建筑的范围，这使得为购物中心服务的中央冷冻水设备、为教育机构、医疗保健设施和办公大楼提供的校园式开发项目，以及为大量商业客户提供服务的市政式设备得以广泛使用。在许多情况下，无论是通过最初的规划还是缺乏规划，一组建筑（如大学校园或单个大型建筑）已经开发出一套独立的冷冻水系统，为单个建筑或单个建筑的单个部分提供服务。 本文讨论的概念是将这些孤立的冷冻水系统集成到单个系统或“回路”中，以恢复集中系统的优势的方法。引文:德克萨斯州达拉斯ASHRAE交易会第82卷第1部分研讨会

Chilled water when applied to air conditioning refrigeration systems is employed as an intermediate heat transfer fluid for the purpose of conveying heat from the space (via a cooling coil) to the refrigeration cycle from which it is normally "pumped" to the higher temperature sink of the outdoor air or an available water source. As technology in chilled water systems developed, it became increasingly evident that in addition to being a thermal conveyor, enabling a physical separation between the load and the source (such that each could be located for the convenient satisfaction of other design parameters), two additional primary advantages emerged:The thermal lag or time constant provided by the inherent storage characteristic of the water provides improvements and simplifications in the control of both the air side apparatus and the refrigeration machineryWhen multiple points of cooling or conditioning the air are required, the diversity between these loads can be applied to the refrigeration machinery size and operating modes. This feature results in lower investment in refrigeration and dissipation apparatus and a reduced energy consumption by the refrigeration prime mover.In recent years the centralization of chilled water refrigeration systems has been seen to grow beyond the lines of a single building, lending to the extended use of central chilled water plants serving shopping centers, campus type developments for educational institutions, health care facilities, and office complexes, and municipal-type plants serving multitudes of commercial customer loads.In many cases, whether by original planning or for lack thereof, a grouping of buildings such as a college campus, or a single large building, has developed a system of separate chilled water systems serving individual buildings or individual portions of a single building.The concept discussed herein is a method for integrating these isolated chilled water systems into a single system or "loop" to regain the advantages of the centralized system.