Automatic controls in building services

Until recently, the term ¿controls¿ was confined, in building services, to the thermostatic devices associated with the heating, ventilating and air conditioning (HVAC) systems. Nowadays, the definition is generally considered as encompassing the motor starter and control panels, energy management and building automation systems, lighting controls and, at least, the interfacing with fire, security and lift systems. Based on this premise, the review covers the range and applications of the automatic control systems now available, with a review of the state of the art, and some predictions as to the likely direction in future. The aim of the review is to provide an insight into current and future control systems. The intention is to enable electrical engineers to better co-ordinate their activities with their mechanical and HVAC colleagues who commonly specify the control systems which have to be integrated into the total services design. The topics reviewed include the effect of correct selection on the operation of the HVAC system, the electrical requirements of controls, guidelines on the application of controls to particular systems, coordination of effort between all the parties involved, the variations and scope of EMS/BAS and direct digital control, lighting control, and testing and commissioning.