用作空调、制冷等的空气加热系统盘管和空气系统冷却盘管的液-空气盘管很少使用其设计容量。因此，必须相应地降低容量，传统上采用通断操作或控制阀。传统控制的缺点是由于高流量以及需要平衡阀和具有权威的控制阀，导致压降过大，泵的驱动功率过大。然而，也有可能大幅降低空气盘管泵和风机的驱动能量，例如，通过直接控制分散式泵和风机取代阀门和风门控制。这可以以更低的成本实现更好的控制，同时使用更少的驱动能量。本文包括传热和控制方法的基本分析，以研究盘管设计如何影响空气盘管在容量转弯时的传递函数- 向下分析表明，使用变速泵的直接流量控制可能只需要传统阀门控制所需驱动功率的一小部分。此外，低流速和压降的系统设计也为新型层流盘管设计提供了机会。结果表明，空气盘管容量和出口温度的替代控制方法的传递函数可以写成控制变量（供给温度、入口温度或盘管液体流量）的简单函数。通过改变设计参数，例如空气和液体流速的设计值，以及相应空气和液体侧的传热特性和传热面积，可以根据具体需要调整传递函数。此外，本文还提供了一个替代系统设计和控制策略的例子。 引文:内华达州拉斯维加斯ASHRAE会议论文

Liquid-to-air coils used as air heating system coils and air system cooling coils for air-conditioning, refrigeration etc. rarely use their design capacity. The capacity must therefore be reduced accordingly, traditionally by means of onoff operation or by means of control valves. Draw-backs of traditional control are excessive pressure drop and drive power to pumps due to high flows as well as the need for balancing valves and control valves with authority. There are, however, possibilities to substantially reduce the drive energy of pumps and fans for air coils, e.g. by replacing valve and damper control by direct control of decentralized pumps and fans. This may achieve better control at a lower cost while using substantially less drive energy.This paper includes basic analysis of heat transfer and control methods to study how coil design affects the transfer function of an air coil on capacity turn-down. The analysis indicates that direct flow control, using variable-speed pumps, may require only a fraction of the drive power needed by traditional valve control. Furthermore, system designs for low flow rate and pressure drop also provide opportunities for new types of laminar-flow coil designs.Results show that the transfer functions of alternative control methods for the capacity and outlet temperatures of air coils can be written as simple functions of the controlling variable (supply temperature, inlet temperature or coil liquid flow rate). The transfer functions may be tailored to specific needs by changing design parameters such as the design values of air and liquid flow rate and the heat transfer characteristics and heat transfer areas of the respective air and liquid sides. Also, the paper provides an example of alternative system design and control strategy.