Determination of the thermal conductivity coefficient and of the current state

Heat flow measurements and determination of heat transfer coefficient (U) of characteristic walls, roofs and window components is performed in order to determine the real state in conditions of exploitation.  In this way it is possible to confirm the calculated or determine the real value of heat transfer coefficient, without having to know the structure composition or perform invasive drilling techniques.

Measurements are performed in accordance with recommendations given in standard SRPS ISO 9869:2012 “Thermal insulation -- Building elements -- In-situ measurement of thermal resistance and thermal transmittance Heat flow meter method”.

Measurements are performed in specific characteristic spots of the thermal envelope (exact position is most often determined by thermal imaging) for a longer period of time (min 72h) in order to minimize the influence of variations in temperatures and other outdoor climatic and indoor behavioural factors. Measurement of a single component includes maximum of 3 measurement spots.

The necessary temperature difference of min. 10°C between indoor and outdoor space also shouldn’t vary significantly during the measurement process.

Besides the heat flux measurements, both indoor and outdoor air and wall temperatures are measured, as well as humidity.

Results of the measurements are presented in the form of an appropriate report.

Measurements are performed using the calibrated devices of the German manufacturer Almemo, as well as dedicated software packages.