ZEMCH 2015 - International Conference Proceedings | Page 758

of 5 cm and 10 cm to investigate the effect of the positioning and the thickness on the indoor air
temperatures. Figure 6 illustrates the result of the simulation analysis using various insulation
materials in Feb 2011. It can be seen that the application of all types of thermal insulation with
5 cm and 10 cm thicknesses resulted in higher indoor air temperatures in both classrooms. The
application of thermal insulation materials reduced the heat transfer from the external walls and
as a result provided higher indoor air temperature because of the lower U-value compared to
the original external walls without any thermal insulation materials. Moreover, adding 10 cm of
insulation material resulted in a higher increase in temperature than the 5 cm thermal insulation.

Figure 6: Indoor temperature profile with different wall insulation in classrooms S and N in Feb 2011
Applying the insulation material on the outer side of the walls had almost the same effect on indoor air temperatures as when it was put on the inner side. For example, based on the result from
the simulation analysis, applying 10cm of XPS insulation material on the outer side of the wall
increased the indoor air temperature to 25.3°C and applying the same material to the inner side
of the wall increased the indoor air temperature to 25.1°C at 12pm. However, it is suggested to use
the thermal insulation material on the outer surfaces of walls with mass construction to give the
advantage of greater thermal mass in the winter period. In addition, thicker insulation material
results in lower U-values and as a result has more effect on increasing the indoor air temperature.
The U-value of the classrooms using 10 cm of the 3-type insulation materials decreased from 1.61
W/ K to 0.32, 0.28 and 0.32 W/ K when using glass wool, extruded polystyrene (XPS) and expanded polystyrene (EPS) (Table.2). In addition, XPS thermal insulation results in lower U-values
compared to other types of thermal insulation but the difference was very minimal.
Table 2: Effect of thickness of insulation materials on overall U-value of external wall

756

Thermal Insulation

Thickness (cm)

Base Case

-

1.614

Glass wool

5

0.535

Glass wool

10

0.321

U-value (w/

XPS

5

0.478

XPS

10

0.281

EPS

5

0.535

EPS

10

0.321

k)

ZEMCH 2015 | International Conference | Bari - Lecce, Italy