The emergence of digital electronics has had a tremendous impact on industrial societies throughout the world. In the heating, ventilating, and air-conditioning (HVAC) industry, the development of digital electronics has brought an end to the use of many mechanical devices; typical of this is the diminished use of mechanical controls for HVAC air and water systems. Today’s digital control systems, with built-in intelligence, more accurately evaluate water and system conditions and adjust pump operation to meet the desired water flow and pressure conditions.

Drafting boards and drafting machines have all but disappeared from the design rooms of heating, ventilating, and air-conditioning engineers and have been replaced by computer-aided drafting (CAD) systems. Tedious manual calculations are being done more quickly and accurately by computer programs developed for specific design applications. All this has left more time for creative engineering on the part of designers to the benefit of the client.