Guidelines For Moisture Detection, Mold Detection & Detection Of Water Damages; Guidelines For Detection Of Air Infiltration & Insulation Deficiencies - FLIR ThermaCAM B2 User Manual

7 – Introduction to building thermography
7.2.1.2
Building defects related to moisture and water damages may only show up when
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heat has been applied to the surface, e.g. from the sun.
The presence of water changes the thermal conductivity and the thermal mass of
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the building material. It may also change the surface temperature of building mate-
rial due to evaporative cooling. Thermal conductivity is a material's ability to conduct
heat, while thermal mass is its ability to store heat.
Infrared inspection does not directly detect the presence of mold, rather it may be
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used to find moisture where mold may develop or has already developed. Mold
requires temperatures between +4°C to +38°C (+40°F to +100°F), nutrients and
moisture to grow. Humidity levels above 50% can provide sufficient moisture to
enable mold to grow.
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7
Figure 7.2 Microscopic view of mold spore
7.2.1.3
For very accurate camera measurements, take measurements of the temperature
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and enter this value in the camera.
It is recommended that there is a difference in pressure between the outside and
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the inside of the building structure. This facilitates the analysis of the infrared images
and reveals deficiencies that would not be visible otherwise. Although a negative
pressure of between 10 and 50 Pa is recommended, carrying out the inspection
at a lower negative pressure may be acceptable. To do this, close all windows,
doors and ventilation ducts and then run the kitchen exhaust fan for some time to
reach a negative pressure of 5–10 Pa (applies to residential houses only).
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Guidelines for moisture detection, mold detection & detection of
water damages
Guidelines for detection of air infiltration & insulation deficiencies
Publ. No. 1557882 Rev. a156 – ENGLISH (EN) – February 28, 2006