formed on the various directions . The eight main directions ( N , NW , W , SW , S , SE , E and NE ) have been considered for the prototype school building , from 0 ° to 315 °. The building was rotated anti-clockwise for eight primary directions , starting with 0 ° in the North . Figure 4 shows the hourly variations in indoor air temperatures in classrooms S and N , based on the eight main geographic directions . It can be seen that the indoor air temperature was in the highest range when the south facade faced west and south-west respectively in Classroom S but when the facade faced north and north-east , the indoor air temperature dropped , compared to the other side . However , the indoor air temperature in Classroom N was increased in all directions . This is because the main facade of the classroom faced north in the base case and it received the minimum solar radiation , compared to the other directions .
Temperature ° C
26 25 24 23 22 21 20 19
S
02 / 02 / 11 12:02:13 AM 02 / 02 / 11 09:02:13 AM 02 / 02 / 11 06:02:13 PM 02 / 03 / 11 03:02:13 AM 02 / 03 / 11 12:02:13 PM 02 / 03 / 11 09:02:13 PM 02 / 04 / 11 06:02:13 AM 02 / 04 / 11 03:02:13 PM 02 / 05 / 11 12:02:13 AM 02 / 05 / 11 09:02:13 AM 02 / 05 / 11 06:02:13 PM 02 / 06 / 11 03:02:13 AM 02 / 06 / 11 12:02:13 PM 02 / 06 / 11 09:02:13 PM 02 / 07 / 11 06:02:13 AM 02 / 07 / 11 03:02:13 PM 02 / 08 / 11 12:02:13 AM 02 / 08 / 11 09:02:13 AM 02 / 08 / 11 06:02:13 PM 02 / 09 / 11 03:02:13 AM 02 / 09 / 11 12:02:13 PM 02 / 09 / 11 09:02:13 PM
Temperature ° C
27 26.5 26 25.5 25 24.5 24 23.5 23
N
02 / 02 / 11 12:02:13 AM 02 / 02 / 11 10:02:13 AM 02 / 02 / 11 08:02:13 PM 02 / 03 / 11 06:02:13 AM 02 / 03 / 11 04:02:13 PM 02 / 04 / 11 02:02:13 AM 02 / 04 / 11 12:02:13 PM 02 / 04 / 11 10:02:13 PM 02 / 05 / 11 08:02:13 AM 02 / 05 / 11 06:02:13 PM 02 / 06 / 11 04:02:13 AM 02 / 06 / 11 02:02:13 PM 02 / 07 / 11 12:02:13 AM 02 / 07 / 11 10:02:13 AM 02 / 07 / 11 08:02:13 PM 02 / 08 / 11 06:17:13 AM 02 / 08 / 11 04:02:13 PM 02 / 09 / 11 02:02:13 AM 02 / 09 / 11 12:02:13 PM 02 / 09 / 11 10:02:13 PM 02 / 10 / 11 08:02:13 AM
|
Time
S ( base case ) E N W
|
SE NE NW SW |
Time
N ( base case ) W S E
|
NW SW SE NE |
Figure 4 : Indoor temperature profile for eight primary directions in classrooms S and N in February 2011
Based on Kasmai ( 2008 ), the southern walls gain direct solar radiation for 10 hours a day in winter in the city of Tehran at 35 ° N latitude . However , the northern walls receive no solar radiation in the winter season . The east and west walls gain at least 4 hours a day of sunshine in the winter season . The comparison of indoor air temperature variations in all directions shows that the south and south west directions caused the maximum indoor air temperature in winter . However , when it faced north and north east , it had the minimum internal air temperature , compared to the other directions .
Glazing Improving the insulation of windows has a significant impact on heating in buildings . To reduce the heating demands of a building , it is suggested to decrease the U-value of the glazing area ( Ford et al . 2007 ). The thermal characteristics of the glazing area are an important part of the window design , which has a considerable effect on thermal performance of indoor spaces . Thermal characteristics include U-values and insulation of the windows , the framing type and the overall area of the windows ( Mikler et al . 2009 ). To improve the thermal insulation performance of the glazing area , it is suggested that the number of panes should be increased , up to triple glazing , which results in reducing the U-value of the windows ( Ford et al . 2007 ). The effect of the windows on the indoor air temperature was investigated by applying various glazing types to the windows , such as double glazed and triple glazed windows . Figure 5 shows the impact of various glazing type on indoor air temperature . The actual glazing type for the given building was a 6 mm sin-
754 ZEMCH 2015 | International Conference | Bari - Lecce , Italy