Use of Airborne Thermal Surveys for the Detection and Quantitative Evaluation of Heat Losses from Buildings.

The paper is concerned with the problem of quantifying heat losses of buildings using an airborne thermal infrared scanner. The thermal anomalies sensed by the infrared survey, properly corrected for atmospheric influence, can be used for determining the heat dissipation as a result of convection and radiation. For this kind of measurements some preliminary data are necessary, which can be easily obtained: the radiation temperature of the surfaces under investigation and that of the ground, the average emissivity of the surfaces under investigation and that of the ground, the average emissivity of the temperature and moisture content of the air, as well as the wind speed and a ″shape coefficient″ of the buildings. As a final result, the minimum instantaneous amount of heat loss can be evaluated. Checking the thermal behavior of roofs and walls is often essential for the proper insulation of buildings and consequently is an effective and economical way leading to the practical possibility of greatly reducing the heat demand of dwellings and industrial sites.