空调的变风量方法肯定不是什么新鲜事。事实上，据我们所知，美国有一些设施可以追溯到1964年。真正的VAV，顾名思义，通过改变空气量而不是温度来实现控制。这个概念可以在第一成本和能源成本方面带来显著的节约，相信我，先生们，这在今天的市场上很重要，你们都知道。可变风量系统设计的早期尝试发现了几个问题领域，这些问题在解决之前或多或少地影响或限制了工程师在大型建筑设计中广泛使用VAV。在过去的几天里，三个最重要且未得到满足的需求是:一个扩散器，能够在没有通风或倾倒的情况下提供各种各样的辉光。 随着冷负荷的变化而改变风扇容量的可靠方法。在不同程度的系统超压下限制终端最大空气流量的一种方法。今天，我将尝试在分配的时间内快速介绍与高速可变风量系统相关的四个关键考虑领域:1）风扇运行特性；2） 风扇调制方法；3） 风扇选择；4）风扇控制和传感器的位置。引文:研讨会，ASHRAE交易，第83卷，第一部分，伊利诺伊州芝加哥

The variable air volume approach to air conditioning is certainly not new. In fact, there areinstallations which we know of that date back to 1964 in the United States. True VAV as the name implies achieves control by means of varying the volume of air rather than the temperature.The concept can result in significant money savings both in first cost and in energy cost and believe me, gentlemen, that's important in today's marketplace as you well know. Early attempts at variable air volume system design uncovered several problem areas which until resolved more or less retricted or limited the broad use of VAV by engineers at large building designs.Three most important and unfulfilled needs in past days were:A diffuser capable of supplying wide variations in glow withoug draft or dumping.A reliable means of changing fan capacity as the cooling load changes.A means of limiting the maximum air flow of a terminal under varying degrees of systemoverpressure.Today, I'm going to try to quickly cover in the time allotted four key areasof consideration as they relate to high velocity variable air volume systems:1) Fan operating characteristics; 2) Fan modulation methods; 3) Fan selection;and 4) Fan Control and location of the sensors.