Development and experimental evaluation of a thermography measurement system for real-time monitoring of comfort and heat rate exchange in the built environment

A measurement system based on infrared (IR) thermovision technique (ITT) is developed for real-time estimation of room thermal variations and comfort conditions in office-type environment as a part of a feasibility study in the EU FP7 project 'INTUBE'. An IR camera installed on the ceiling allows thermal image acquisition and post-processing is performed to derive mean surface temperatures, number of occupants and presence of other heat sources (e. g. computer) through detecting algorithms. A lumped parameter model of the room, developed in the Matlab/Simulink environment, receives as input the information extracted from image processing to compute room exchanged heat rate, air temperature and thermal comfort (PMV). The aim is to provide in real time the room thermal balance and comfort information for energy-saving purposes in an improved way with respect to traditional thermostats. Instantaneous information can be displayed for the users or eventually used for automatic HVAC control. The system is based on custom adaptation of a surveillance low-cost IR system with dedicated radiometric calibration. Experimental results show average absolute discrepancies in the order of 0.4 degrees C between calculated and measured air temperature during a time period of a day. A sensitivity analysis is performed in order to identify main uncertainty sources.