Summer operative temperatures in free running existing buildings with high glazed ratio of the facades

•Operative temperatures were calculated in offices with large transparent areas.•Indoor thermal comfort parameters were measured using TESTO 480 calibrated instrument.•Calculated and measured operative temperatures were compared.•The operative temperature was determined in three different points of a room.•The effect of curtains on the operative temperature was analysed.

Nowadays, low energy and low exergy solutions are widely used for new buildings, but existing buildings have high energy demand because of poor thermal properties of their envelope. The situation is worse in summer period in case of buildings built before 1970 with large transparent areas on the facades. The high summer outdoor temperatures and the increased number of heat waves can lead to extremely hot indoor environments or extremely high cooling energy use in these buildings. In this paper indoor operative temperatures and PMV were calculated in east and west oriented offices using measured meteorological parameters and the methodology given by EN ISO 13790. Furthermore, indoor comfort parameters were measured using TESTO 480 instrument. The operative temperature was calculated based on the measured air and globe temperatures in different locations of a room. The effect of lace curtains and drapes on the operative temperatures was analysed.