PERSPECTIVES

The majority of fossil energy loss is attributed to the typical and non-standard building patterns which take place during heating or cooling operations due to their inconformity with their climate conditions. Some measures have been also prepared for this purpose; for instance, the building materials are checked for their heat capacity.

Investigating the relationship between building materials and energy consumption, the present study examines the effectiveness of revealed theories. Table 2 shows the information about the consumption rate of water, electricity and gas energy in residential flats of approximately same area, number of residents and climate conditions. Each row indicates the mean consumption rate of a flat located in the middle stories of a 6-8 unite apartment.

Table 2: Energy consumption of different types of buildings Gas use

m3

Power Use

kwh Water Use Litre

Infrastructure M2

Area M2

Year of construction

10 183.4 13000 100 120 1386 1

27 237.1 10022 022 001 1386 2

02 0.380 00222 162 180 1387 3

1. 256,5 8010 150 171 1374 0

30 294,3 03122 021 0.3 1382 5

Table 3 shows the materials used in each building. According to the above mentioned issues, the heating and cooling process of a building plays a significant role in its rate of energy consumption. So the data collected from the selected buildings (see table 3) is based on the type of material used in their external walls. Walls are selected

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because of the fact that the main part of heat transfer occurs through them for they are in contact with the outdoor air. Other building conditions effective on the results of this study have been selected uniformly as much as possible. For example, in order to eliminate the effect heat transfer through floor and roof, the energy consumption rate of the flats located in the middle stories of each building was examined. In addition to this, all flats have the same kind of floor and ceiling covering materials and use the same heating and cooling methods and systems.

Table 3: Energy usage and the materials used in each building

Gas use m3

Power Use

kwh Water Use Litre

Façade

materials Exterior wall

materials Type of Glass

10 183.4 13000 Brick Brick Double 0

27 237.1 10022 Brick Brick Normal 0

02 0.380 00222 Cement Brick Double 3

1. 256,5 8010 Stone Common

Brick(solid) Normal 0

34 294,3 03122 Cement Brick Normal 1

The flats were compared in terms of the consumption rate of electricity and gas as the main heating and cooling sources in under study cases. Table 3 shows the impact of external wall materials on energy consumption rate, regarding the fact that the flats are the same in other conditions. Building No. 1 with double pane glass windows and external brick walls has the minimum rate of energy consumption (heat transfer is lower in Brick due to its higher heat capacity). Building No. 3 has double pane glass windows as well and with respect to its area, which is more than other cases, it had lower rate of energy consumption. Among all studied cases, building No. 4 had the maximum energy consumption. Therefore, the general condition of external walls of all selected buildings was rechecked. The main reason creating such a difference is the percentage of openings (windows) on the external walls of the building No. 4 which was 80% of the wall.

171 Figure 1: ( Authors , 2011)

Water was the third type of energy studied in the selected cases. Water is mostly used for washing and drinking purposes in buildings and usually plays a negligible role in heating and cooling. Meanwhile, the amount of water used for drinking is very low and negligible which means that the majority of water is used for washing purposes. Thus, the washable surfaces have been studied in terms of their porosity.

Table 4 shows the area (m²) of outdoor spaces which are more likely subject to pollution including the yards, terraces, parking and so on. The kitchen and bathroom areas are not taken into account because of having the same condition.

Table 4: Area (m2) of outdoor spaces which are more likely subject to pollution

Type of Depth joint

Depth of joint Less than 1mm

Joint (type no.1)

Depth of joint Between 1-3 mm

Joint (type no.2)

Depth of joint Between 3-5 mm

Joint (type no.3)

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In the cases where the flooring materials have no considerable difference in their surface porosity, they could be ignored. Flooring methods are divided into three groups regarding the depth of joints (see table 5).

Table 5: Flooring methods and energy consumption Joint

(type no.3)

Joint (type no.2)

Joint (type no.1)

Water Use Litre

Patio M2

13000 02 0

10022 01 0

00222 02 3

8010 01 0

03122 0. 1

The results of investigations on the relationship between the water consumption rate and the type of joints in the surfaces subjected to pollution which needs to be washed frequently are shown in Graph 2.

Figure no.2 (Authors , 2011)

The building No. 4 is the only case in which a low depth grout joint have been used in

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flooring. This building has significantly lower water consumption rate (for washing purposes) compared with other buildings.

12.4 CONCLUSION

The findings of carried out study are as follows:

 Double pane glass windows are more effective than typical windows in decreasing the rate of energy consumption in the same condition.

 Using brick in dry climates as well as the other climate compatible materials reduces energy consumption.

 Simultaneous use of climate compatible materials and double pane glass windows is more effective in reducing the energy consumption.

 The window-to-wall ratio of building has an effect in energy consumption. The more the ratio is, the higher the energy loss is.

 The type of joints and flooring in outdoor open spaces is effective on energy consumption. The joint depth is directly proportional to the energy consumption.

If the above mentioned measures about external walls and the other optimising factors are observed in buildings, investigating these optimum groups in different climates, we can obtain a range of energy consumption as an international standard for future buildings which requires another study In line with the present study.

REFERENCES

Ghobadian, V. (2001). Climatic Analysis of the Iranian Traditional Buildings, Tehran University Publications.

Azizi, gh. (2005). Climet change, Tehran. Ghomes Publications.

Kasmaie, M. (2006). Climate and Architecture, Tehran, Published by the Iranian Construction-co, pp. 54-8.

Farshchi, R. (2010). Architecture in the age of climate change. Tehran. Published by Soffeh. No.48. p 65-78.

Ashrafian, T. Mahdavi tabatabaei, J. Moazzen ferdos, N. (2011). Sustainable Energies in Desert Climate Buildings. Technical and Physical Problems of Engineering, vol.3, no.1.

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