Study of human response in conditions of surface heating, asymmetric radiation and variable air jet direction

Low temperature radiant heating systems are widely used in buildings being advantageous both from energy use and thermal comfort point of views. However, attention should be paid to asymmetric radiation especially in the case of wall heating. The aim of our research was to analyse the perception of thermal asymmetry in combination with different air velocities. A series of measurements were carried out in controlled environment involving 20 subjects (10 female, 10 male). It was shown that the thermal asymmetry is perceived at low air velocities, but increasing the air velocity to 0.1 m/s, 0.15 m/s or 0.2 m/s the perception of air movement overwrite the perception of thermal asymmetry. The heat removed by convection by the same air flow and air jet velocity was different for women and men group. The higher decrease of the skin temperature in case of women (around 2 K) leads to thermal sensation votes under −0.5 (even though the air and mean radiant temperature were 24 °C). The responses of women and men group regarding draught perception were different as well.