Efficient HVAC controls: A symbolic approach

Heating, ventilation, and air conditioning (HVAC) systems contribute significantly to energy consumption in buildings, and are the target of an ongoing push towards energy efficiency, which reflects on new requirements for the configuration and operation of HVAC units. On-off actuators are being replaced by staged or modulated ones, and additional components are being added to the HVAC units, which have to be properly managed by new, advanced control architectures. As such, it is increasingly more difficult for traditional control approaches to cope with new devices and meet new objectives. This leads to an opportunity for alternative, novel approaches to be adopted by the industry: promising are recently developed formal methods for controller synthesis. In this article, we employ formal, symbolic techniques to synthesize controllers for a model of a roof-top unit conditioning a low-rise commercial building. The synthesized controller is validated on a simulation with practically relevant operating conditions.