General instructions for thermal imaging

Buildings are mainly designed to be underpressured compared to the outside air, so that the inside air humidity cannot create microbes and other damages to its foundations. When examining the air leakage of a building, it is important to understand the pressures of its foundations and their meaning. Some heat leakage is thus normal, resulting from this design principle. So, the difference between a "planned" heat leak versus an abnormal leak has to be recognized. 

The following circumstances have to be acknowledged before and during thermal imaging:

• At least 12 hours before thermal imaging: 
  • The outside temperature cannot differ with more than ±10 °C from the initial temperature of the thermal imaging 
  • The difference between inside and outside temperatures cannot fall below 15 °C 
  • The part imaged cannot be exposed to sunlight. If so, the effects of sunlight has to be included in examining the results.
• During thermal imaging, the outside temperature cannot differ for more than  ±5 °C and the inside temperature cannot differ for more than  ±2 °C from the start of the imaging.
• The inside of the building imaged has to be underpressured compared to the outside air.
• DO NOT ventilate on the day of the imaging!
• Always image the target perpendicularly.

For specific instructions and details contact directly energy advisors:

Tanja Nyholm tanja.nyholm@lappeenranta.fi +358 40 703 3366
Matti Pylkkö matti.pylkko@lappeenranta.fi +358 40 759 6692