An Innovative Low Cost IR System for Real-Time Measurement of Human Thermal Comfort PDF

An innovative, low-cost, infrared (IR) measurement system has been developed for real-time monitoring of thermal comfort conditions in indoorenvironment. The device is composed by a linear 8x1 array of thermopiles, together with two fixed-step motors, to be assembled and installed onthe ceiling of the occupied room. The embedded microcontroller together with the software implemented allows the automatic scanning of each indoorsurface to evaluate the temperature distribution. According to the algorithms provided by ISO 7726 and ISO 7730, Mean Radiant Temperature(MRT) and Predictive Mean Vote (PMV) are calculated for several positions in the environment and provided as output of the device throughwireless or wired connection. The capability of predicting thermal comfort conditions for multiple positions of the room has been tested and validatedin a real case study: it resulted in an accuracy of +/-0.5°C (+/-0.9°F) in the MRT measurement and +/-0.1 for PMV with respect to a referencemeasurement system (microclimate station). The system can easily communicate with commercial BMS (Building Management System) andprovide PMV room distribution, as shown in the paper. This can prove the advance of using the proposed solution instead of the typicalmeasurement provided by the thermostat, which allows a control based only on the air temperature in one position.