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The presented study reveals a multi-point experimental measurement of the airflow speed, generated in the exhalation phase from the human respiratory cycle, based on data from 10 real human subjects. The results obtained demonstrate the exceptional irregularity and the transient character of the human respiratory cycle, in terms of measured speed at different points of man-generated exhalation air flow. The presented exponential trend lines show as expected, that there is a reduction in the exhalation speed, with the increase of the distance from the nose. The summary analysis shows that at 10 cm distance from the nose the maximum as well as the average measured speeds are higher than the one, measured at 5 cm distance. This suggests that due to the physiology of the human nose, 5 cm distance is not enough to characterize the fully developed exhalation jet flow. It is suggested that at this distance the exhalation jets are still two, issuing from each nostril, with different flowrate ratio. The obtained flow characteristics can be used to compare, validate and verify data from conducted numerical studies of the breathing process, via virtual models or real breathing thermal mannikins.

The “thermal bridges” are defined as an isolated building’s areas, where the construction elements have higher thermal conductivity, compared with the rest of the building envelope. Thus, at cold winter conditions, a significant temperature difference may occur between neighbouring solid and air volumes within the construction. Moreover, it has been documented, that the heating energy demand of a building may be increased with more than 30%, due to the existence of thermal bridges and the increased heat losses from the indoors. Consequently, in the recent years, norms and standards have been developed, for avoiding thermal bridges during the building design process. But still, thermal bridges exist in the indoor environment, especially in older buildings, where no energy efficient measures have been applied. That is why, the presented study focuses on instantaneous field measurements of thermal bridge parameters in real existing ground floor residential room. The thermal bridge propagation is analysed relative to the indoor and outdoor air temperature and relative humidity, as well as with infrared thermal images of the affected external walls. The achieved results give valuable information about the generic conditions for thermal bridge existence, without considering the building envelope properties.

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