Thermal management of LED lighting integrated with HVAC systems in office buildings

The light-emitting diode (LED) market is expected to account for half of lamps worldwide in 2020. Despite the numerous benefits of LED lighting, the heat from LED lights affects indoor thermal conditions in buildings and increases the indoor cooling load in summer. A new method for integrating LED lighting with heating, ventilation, and air conditioning (HVAC) systems are proposed to prevent this heating effect in buildings by exchanging the lighting heat to outdoor and indoor spaces according to a seasonal operating strategy. Field measurements of a mock-up model were used to determine the lighting heat removal and reuse rates of the seasonal strategy. The ratio of lighting heat removal and reuse to LED input power was 70.3% in the summer test and 49.5% in the winter test. An indoor thermal effect analysis was performed using a simulation program with lighting heat input fractions obtained from the measured data. The sensible thermal loads in the mock-up chamber were reduced by 7.5% for cooling and 1.4% for heating using the proposed method, and the annual site energy reductions of reference office buildings were 8.5% for Houston, 8.1% for Atlanta, and 5.9% for Boulder, compared to the base case.