Climate change and the growing demand for energy, when at the same time fossil energy sources are getting ever scarcer, represent one of the greatest global challenges. Because a relevant proportion of emissions involve the building sector, special efforts are needed in this area to achieve the internationally agreed climate objectives.
A large part of heating energy is lost through poorly insulated walls, roofs and windows. Effective insulation therefore not only saves costs, but also protects the environment through lower CO2 emissions. Thermography has developed as a method for checking the actual condition of buildings and the potential for energy savings. Both hidden weak spots and implementation defects can be detected non-destructively and their causes determined.
For a thermographic inspection of the outer building shell, the following prerequisites have to be met:
In order to carry out outdoor thermography correctly, the weather must be dry with low temperatures.
The building shell may not be moistened by precipitation – outdoor thermography cannot be conducted in rain, snow or heavy fog.
Wind speed must be below 5 m/s (18 km/h).
The pre-condition is a temperature difference of at least 10 to 15 °C between indoors and outdoors over a period of at least 12 hours.
The inspection generally takes place in cold seasons in the morning before sunrise – sunshine influences on outer surface, even in the previous hours, falsify the results.
An example of an exception is thermography on refrigerated stores, where the necessary temperature difference applies, however the other way round, and is therefore carried out in the warmer seasons.
Another exception is thermography on half-timbered buildings, which is usually conducted in the summer half of the year, utilizing the differing heating and cooling behaviour of the materials. In this area, thermography is ideally carried out two hours after sunset.
Thermal imagers testo 871s, testo 872s, testo 883