Robust Sliding Mode Control of Air Handling Unit for Energy Efficiency Enhancement

In order to achieve feasible and copacetic low energy consuming building, a robust and efficient air conditioning system is necessary. Since heating ventilation and air conditioning systems are nonlinear and temperature and humidity are coupled, application of conventional control is inappropriate. A multi-input multi-output nonlinear model is presented. The temperature and humidity of thermal zone are ascendance by the manipulation of the water and air flow rates. A sliding mode controller (SMC) is designed to ensure robust performance of air handling unit in the presence of uncertainties. A simple proportional-integral-derivative (PID) controller is used as a comparison template to highlight the efficiency of the proposed controller. To accomplish tracking targets, a variety of desired temperature and relative humidity commands (including ramp and combination with sequence of steps) are investigated. According to simulation results, SMC transcends the PID controller in terms of settling time, steady state and rise time, which makes SMC more energy efficient.