Optimum control policies to minimize energy use in HVAC systems

The purpose of this work is to compare conventional control and proposed new control methods to determine the energy savings in a HVAC space. The conventional method consists of a temperature control (thermostat) and a humidity control (humidistat) operating independently to keep the room at a comfort point. The new method consists of controlling temperature, humidity, and velocity simultaneously to keep the room at the comfort region recommended by ASHRAE and to minimize the corresponding energy expenditure. The method implements static and dynamic optimization schemes and includes the interdependence of those three parameters. The theory of optimal control was utilized to develop the new control policies. The results include percent savings realized by the proposed control system as compared with that of conventional control systems. A fair comparison of two methods under a common basis is demonstrated by experiments.