**3.2.2 Cement products**

The west-facing reinforced concrete surface, recorded a surface temperature of 47 oC, and was, at 19:30 warmer than the air by 10 oC.

The building facades of typical construction (brick wall with external rendering of limecement mortar painted in different colours), were of the following colours: white, beige, grey and dark red. As was expected, the white-painted surfaces remained relatively cool, with maximum temperatures that did not exceed 40 oC and mean temperature that was similar to the mean air temperature. The beige surfaces with western orientation had relatively low mean temperatures, maximum temperatures around 45 oC and were warmer than the air by 4 oC, around sunset. The highest temperatures on western facades were measured by the dark red and grey surfaces. Their maximum temperatures were 56 oC for the dark red facade and 60 oC for the grey one, while their respective T19:30 temperatures were higher than the air temperature by 6 oC and 12 oC. Finally, these surfaces had observed mean temperatures, which were higher than the respective air temperature by 3 oC and 7.5 oC.

#### **3.2.3 Ceramic products**

The in-situ study was a building, whose four facades were covered with dark brown ceramic blocks. Based on the IR readings, the eastern facade reached a maximum temperature of 38 oC, and the western one, a temperature of 44 oC. Around sunset, the ceramic blocks of the western facades were warmer than the air by 6 oC.


#### The Summer Thermal Behaviour of "Skin" Materials in Greek Cities as a Decisive Parameter for Their Selection 433

432 Solar Radiation

8:00 to 20:00 at 1-hour intervals. One day of the measurements included night-time readings (from 20:00 to 08:00) in order to examine the cooling rate of the materials. Furthermore, for a one-day period, a contact thermometer (Technoterm 9500) was used simultaneously with the IR one, in order to confirm the accuracy of the IR readings and account for possible discrepancies. Air temperatures, relative humidity and air velocity measurements were also

Light-coloured stone panels, such as white marble and beige sandstone did not record high surface temperatures in any of the four basic orientations (north, south, west and east). Furthermore, for all the examined orientations, their temperature at T19:30 was higher than the corresponding air temperature by only 1 to 2 oC. However, the panels of dark-coloured stone, namely grey and black granite, tended to overheat, with surface temperatures that may well exceed 50 oC for facades which face towards the east and the west. It is also important to note that for west-facing facades, clad with grey or black granite, the surface temperatures around sunset (T19:30) were a lot higher than the air temperature (15 oC and

The west-facing reinforced concrete surface, recorded a surface temperature of 47 oC, and

The building facades of typical construction (brick wall with external rendering of limecement mortar painted in different colours), were of the following colours: white, beige, grey and dark red. As was expected, the white-painted surfaces remained relatively cool, with maximum temperatures that did not exceed 40 oC and mean temperature that was similar to the mean air temperature. The beige surfaces with western orientation had relatively low mean temperatures, maximum temperatures around 45 oC and were warmer than the air by 4 oC, around sunset. The highest temperatures on western facades were measured by the dark red and grey surfaces. Their maximum temperatures were 56 oC for the dark red facade and 60 oC for the grey one, while their respective T19:30 temperatures were higher than the air temperature by 6 oC and 12 oC. Finally, these surfaces had observed mean temperatures, which were higher than the respective air temperature by 3 oC and

The in-situ study was a building, whose four facades were covered with dark brown ceramic blocks. Based on the IR readings, the eastern facade reached a maximum temperature of 38 oC, and the western one, a temperature of 44 oC. Around sunset, the

ceramic blocks of the western facades were warmer than the air by 6 oC.

**3.2 Results of the in-situ measurements of facade materials** 

done at the site.

The results are presented in Table 3.

**3.2.1 Natural stone products** 

17 oC, respectively).

7.5 oC.

**3.2.2 Cement products** 

**3.2.3 Ceramic products** 

was, at 19:30 warmer than the air by 10 oC.

Table 3. Overview of the in-situ measurements on building facades.
