Automatic Indoor Environmental Conditions Monitoring by IR Thermography

This paper presents a new approach to monitor an indoor environment on thermodynamic basis. It uses temperature as the driving parameter and is especially suited for comfort analysis or evaluation of moisture. The method is based on infrared (IR) thermography, which proved to be very effective in this application. The system measures all fundamental environment parameters (e.g., air temperature, relative humidity and air speed) by imaging with a thermal camera a set of special targets arranged in a grid, which can be placed close to a wall or in any other place of the room . At the same time, the system images the wall surface behind the grid and so can measures the wall’s temperature, as well. The thermal camera was mounted on a pan-til unit to realize the monitoring process in an automatic way. The core of the device is a software that can process the thermal images online and control the pan-tilt unit. A fast automatic learning procedure enables to recognize the special target on the grid also in challenging environments and in very different environment conditions. This coupled with the advanced features of modern off the shelve IR cameras allows effective and robust results. This paper illustrates the developed device (both the hardware and the software) and shows the current application of evaluating the decay risk of a heritage building covered by Italian renaissance frescoes. However, the presented approach can be applied in different applications, for instance: indoor environmental monitoring, energy saving, NDT of buildings, and information technology with geomatics.