iLTC: Achieving Individual Comfort in Shared Spaces

Automatic control of HVAC and artificial lights has been one of the popular methods for achieving energy-efficient buildings. The current systems operate using fixed setpoint controls, which are usually based on a conservative approach. Moreover, the lighting systems require additional sensor deployment to cope up with continuous fluctuation of natural light intensity. In this work, we describe a smart system called indoor Lighting and Temperature Controller (iLTC), which eliminates the fixed set-points and requirement of additional light sensors. iLTC decides operating set-points more aggressively, which is energy optimal and tries to provide maximal user comfort to all the co-occupants in a shared space. The flexibility in choosing energy optimal set-points stems from the knowledge of comprehensive temperature and lighting comfort functions of individuals. To track the fluctuations in natural light intensity, we employ a smart estimation technique that requires light measurements only during the training phase. Using the proposed distributed system, we show the energy consumption of HVAC can be reduced up to 39%. Similarly, compared to traditional on/off based and multilevel lighting systems with iLTC, energy consumption can be reduced up to 33% and 60%, respectively. We also provide qualitative user experience evaluation.