Thermal Insulation in Roof The base case building had 5 cm of glass wool installed in the roof layer as a thermal insulation material . Three typical types of insulation materials were employed in the roof layer , in a similar way to the external wall experiment . The applied insulation materials included glass wool , XPS and EPS . They were applied to the outer and inner sides of roof separately , with 10 cm of thickness to investigate the effect of the positioning and thickness of the insulation materials on the indoor air temperature . Figure 7 presents the effects of various thermal insulation materials on outer side and inner side of the roof , on indoor air temperatures in the north-facing classroom only as the south-facing classrooms located on the first floor . It can be seen that the application of all types of thermal insulation with 10cm of thickness caused slightly higher indoor air temperatures in Feb 2010 on the top floor . The indoor air temperatures increased by around 0.3K only in this classroom which shows that 5 cm thickness of the thermal insulation is enough to keep the indoor air temperature in an acceptable range .
Temperature ° C
25 24.8 24.6 24.4 24.2
24 23.8 23.6 23.4 23.2
23
N
02 / 02 / 11 12:02:13 AM 02 / 02 / 11 07:02:13 AM 02 / 02 / 11 02:02:13 PM 02 / 02 / 11 09:02:13 PM 02 / 03 / 11 04:02:13 AM 02 / 03 / 11 11:02:13 AM 02 / 03 / 11 06:02:13 PM 02 / 04 / 11 01:02:13 AM 02 / 04 / 11 08:02:13 AM 02 / 04 / 11 03:02:13 PM 02 / 04 / 11 10:02:13 PM 02 / 05 / 11 05:02:13 AM 02 / 05 / 11 12:02:13 PM 02 / 05 / 11 07:02:13 PM 02 / 06 / 11 02:02:13 AM 02 / 06 / 11 09:02:13 AM 02 / 06 / 11 04:02:13 PM 02 / 06 / 11 11:02:13 PM 02 / 07 / 11 06:02:13 AM 02 / 07 / 11 01:02:13 PM 02 / 07 / 11 08:02:13 PM 02 / 08 / 11 03:02:13 AM 02 / 08 / 11 10:02:13 AM 02 / 08 / 11 05:02:13 PM 02 / 09 / 11 12:02:13 AM 02 / 09 / 11 07:02:13 AM 02 / 09 / 11 02:02:13 PM 02 / 09 / 11 09:02:13 PM
Time
Glass wool 5cm outside ( base Case ) Glass woll 10cm inside EPS 10cm inside XPS 10cm inside
Glass wool 10cm Outside EPS 10cm outside XPS 10cm outside
Figure 7 : Indoor temperature profile with different roof insulation materials in classrooms N in May 2010
Table 3 presents the impact of various insulation types with various thicknesses on the U-value of the roof . The tested variations of thermal insulation materials including glass wool , XPS and EPS , reduced the U-value of the base case building from 0.53 W / K to 0.32 , 0.28 and 0.32 W / K respectively . As can be seen , using 10 cm of XPS reduced the overall U-value of the roof more than the other types of thermal insulations , with similar thickness .
Table 3 : Effect of thermal insulation materials and their thicknesses on U-value of the roof |
Insulation |
Thickness |
U-value |
( cm ) |
( W / |
K ) |
Base Case |
5 |
0.527 |
Glass Wool |
10 |
0.318 |
XPS |
10 |
0.279 |
EPS |
10 |
0.318 |
Passive design strategies on indoor comfort of school buildings in hot-dry climates 757