The ambient air temperature was monitored continuously sing a thermocouple identical to the other ones. The results of temperature measurements for the closed steady state are shown in Fig. 2. The figure presents the readings of thermocouples placed in air. (filled circles) and inside the walls (unfilled circles). The thermocouples are shown at their positions, as in Fig. 1b. ear each thermos couple, its reading is listed. In order to eliminate the effect of a changing temperature in the room, the differences between .the local temperatures and the ambient one are shown in the figures instead of the absolute temperature values.