تاثير الجدران المزدوجة ذات الفجوة الهوائية الحرارية على البيئة الداخلية للمبنى في مدينة بغداد == Effect of The Double Walls With Thermal Air Gap On Internal Environment of Buildings In Baghdad
Author name:
فاطمة جمعة عيدان
Supervisor name:
مقداد حيدر الجوادي
General topic:
Architecture
Specific topic:
architecture techniques
Degree:
Master
University:
University of Technology
Language:
Arabic
University location:
Baghdad
Key words:
- الجدران الخارجية المزدوجة - البيئة الحرارية الداخلية - الفجوة الهوائية - الخصائص الحرارية لمواد الانشاء والاكساء
First pages:
42T297 - p.pdf
Abstract:
Since the building envelope represents the main axis for all thermal controlling processes being the insulation of internal environment from the external one, and as a responsive and adaptable with the external changes through its thermal conduct by preventing external effects.In addition, it includes all the external means that ensure comfort for occupants represented by walls, roofs, grounds, and all vents (doors and windows) whereas the external walls represent one of the most important structural elements that have a direct effect on the thermal performance of the building.In order to achieve the aim of the research the experimental approach and style of analytical study were adopted. The current study included two main aspects : first, the theoretical side : Which included the time delay factor calculation and cooling load depending on the Radiant Time Series (RTS) theory that achieve accurate and detailed results and ease of application The theoretical results for each hour were calculated using a new version of Mat lab program. While the second aspect included the practical test and measurement where three test chambers have been constructed as samples for the purpose of study located in the department of the mechanism and productivity of Al - Fao Engineering in Altajiat in Baghdad. The three chambers were constructed with dimensions (3000mm x 2250mm) and (2250mm) height without windows and the ceilings and walls were made the only effective resource in changing the level of thermal comfort inside it. The longest side of the three test chambers was directed towards the east - west. The walls of the first chambers have been made of perforated brick , the second chamber of thermo - stone, the third of double glazing units. The ceilings of rooms were treated by materials of humidity contraindications with thermal insulators are quite similar in order that the comparison would be only confined to the walls, and to identify the effect of the air cavity (100mm,25mm) when using it with the different materials of cladding such as ( white marble, black marble, stone of Ba Athra, composite - panel).Two iron structures were made in order to exchange the termination materials and the thickness of the cavity as well as each chamber has been equipped with (one ton) air conditioning with a same cooling degree for each chamber, the devices were connected by a scale to measure the amount of energy spent in each chamber with a fixed temperature inside, in addition to thermal sensors fixed on the inner and outer surface of the wall and in the inner space, consequently the energy exchange was considered as an evidence and indicator to the differentiation among the materials used and types of cavities in double walls. The theoretical and practical results made a good rapprochement, whereas the first test chamber (in which Brick is the material construction of the walls) has made a contrast ratio between the theoretical calculations and practical application for the electric power about 23.6%, while the second test chamber (in which thermo - stone is the material construction of the walls) has made a contrast ratio for the electric power about 22.3%. Consequently, Results of the study showed that the Exterior cladding material by using perforated brick of 120 mm thickness recorded the highest proportion of the economy in the amount of electric energy which considered to be the best thermally. However, Exterior cladding material (such as black Marble) and cladding materials with fewer block (such as composite - panel) represent the worst thermal performance because they made the lowest economic proportion of the amount of electric power. Besides, the thermo - stone material as a material of walls constructing has made an economic ratio of electric energy higher than the one made by the 240mm thickness perforated brick. The research, As well as, concluded that increasing the thickness of cavities from 25mm to 100mm may reduce the consumed amount of electric power about 6.6% when the construction material for the walls is 240 mm thickness perforated brick and 4.3% when the construction material for walls is thermo - stone.
