Energy Conservation Through Thermally Insulated Structures Ayoub Abu-Dayyeh*

1. RSS-Amman, 18th January 2006التصميم المناخي لحفظ الطاقة - الرطوبة الداخلية - المساهمة البيئية للعزل الحراري Energy Conservation Through Thermally Insulated Structures • Ayoub Abu-Dayyeh* • *Engineer and Doctor of Philosophy • President of the society of Energy Conservation and Environmental sustainability • P.O.Box: 830305 Amman 11183 Jordan • E-mail: E_casesociety@yahoo.com • Mobile no.: 00 962 79 5772533

2. The purpose of this paper is to explicate its title through investigating the following: 1) How is energy saving possible through thermal insulation and passive design? 2) The feasibility of investing in thermal Insulation? 3) Is Thermal Comfort and a healthy atmosphere possible inside the dwellings during all seasons! (Insulation and passive design) 4) What Environmental Impacts can exist due to thermally insulating buildings?

3. Economical Design 0.06 Criteria: Cost Availability Requirements (Architectural, Codes, etc) Durability Vapor Barrier Gloss Health hazards Fire hazards 0.05 Rock Wool 0.04 o Expanded Polystyrene 0.03 K- value (W/m. C ) Polyurethane 0.02 0.01 100 10 90 20 80 0 40 60 50 70 30 Density of Thermal Insulating Materials Kg/m3

4. 1 1 2 1 2

5. Design: The Jordanian thermal insulation code published in 2002, specifies a minimum of thermal transmittance value (U -value) of 1.8 W /m2.k for exterior walls (Including exterior openings) and a value of 1 W/m2.k for roofs Wall 1.30 cmplain concrete and stone cladding (3-5 cm thick) with 2cm cement-sand plastering from the inside, traditional wall. Wall 2 Recently, the construction industry has been using a similar sort of construction by introducing hollow blocks made of concrete, 10 cm thick, 40 cm in length and 20 cm in height. They are used as a replacement to formwork from the inside, keeping the total thickness of the wall in the range of 30 cm. The section consists of an extra 2 cm of cement-sand plastering from the inside as. Wall 3 Our recommended economical section 33cm Wall 2 Wall 1 Wall 3 U = 2.6 W/m2.k U = 2.19 W/m2.k U = 0.76 W/m2.k

6. Definitions of symbols: • K (Thermal Conductivity); R (Thermal Resistance) = d / k ; U (Thermal Transmittance); e ( Emissivity ) ; d ( Thickness ) • U – value calculations: • U = 1 ÷ R ; R = d ( Thickness ) ÷ K ( Thermal Conductivity ) • Ri = 0.13 ; Ro = 0.04m2.k/W • For Wall 1 • U1 = 1 ÷ (Ri + Ro + (0.05 ÷ 1.53) + (0.25 ÷ 1.72) + (0.02 ÷ 0.53) • = 1 ÷ 0.383 • = 2.6 W/m2.k • For Wall 2 • U2 = 1 ÷ (Ri + Ro + (0.05 ÷ 1.53) + (0.15 ÷ 1.75) + (0.10 ÷ 0.77) + (0.02 ÷ 0.53) • = 1 ÷ 0.46 • = 2.19 W/m2.k • For Wall 3 • U3 = 1 ÷ (Ri + Ro + (0.05 ÷ 1.53) + (0.15 ÷ 1.75) + (0.03 ÷ 0.035) + (0.10 ÷ 0.77) +(0.02 ÷ 0.53) • = 1 ÷ 1.32 • = 0.76 W/m2.k

7. Energy Saving: If we add exterior opening effects on the over whole U-value of the walls (Doors and Windows), which we assume they constitute 20 % of the total exterior peripheral area, we can then calculate the saving attained in energy and fuel consumption due to thermally insulating the exterior walls only. The calculations follow: • Assume that the average U-Value for exterior openings U-value (Windows & Doors) = 4 W/m2.k • The average U-value becomes:- • 0.76 × 0.8 + 4 (0.2) • = 1. 4 < 1.8 • This is okay for the existing Jordanian thermal Insulation code, but we are striving to reduce this value by 50% which will still be dramatically higher than the values recommended by many European standards. • The average U-value for the traditional wall: • 2.6 x 0.8 + 4 x 0.2 • = 2.88 W/m2.k Percentage saving ( W3-W1) = 2.88-1.4 / 2.88 = 51.3%

8. Fuel Saving: Assuming that the air exchange stays the same before and after applying the new insulated section, and also assuming that the flat is loosing heat from four directions only. • Where the roof is occupied by neighbors and heated. The area of the flat is 15 × 10 =150m2. Where U1 & U3 represent Walls 1 & 3 • Q saved = (U1-U3) x A x T (Ti-To) • Where U1=2.88, U3 = 0.76, A= 125m2, T = 20 K (Average temperature change) • The flat in question has a wall surface area of 125 m2. • Q = (2.88 – 1.4) × (125 m2) (20) • = 3700W = 3.7 Kj/second • = 3.7x3600 Kj/ hour • One liter of diesel = 7000 K.calory = 7000x4.2 Kj ( 1calory=4.2 joules) • Saving in diesel/hour = 3.7x3600/7000x4.2 • = 0.45 lt./ hour • If we Assume that Amman needs 1300 Heating Hour Day and 700 cooling hour day, then the total consumption is: • 0.45x2000 = 900 lt. yearly • This means nearly 200 US$ Saving on fuel only by thermally insulating walls only, if we add reduction in maintenance and spare parts and increasing the time life of the electro-mechanical system, this number is easily doubled. Therefore saving is up to 400$ yearly. Remember that if improvement on the thermal properties of the roof is also administered, the savings are far greater. This is a substantial amount of money to most people in Jordan.

9. It must be noted here that air gaps do not have the ability to resist heat more than 0.18 W /m. k, no matter how thick the gap is (provided the gap is bounded by traditional construction materials, such as concrete). Actually the wider the gap is the worse would be its resistance to heat transfer as convection currents become more effective in wasting energy in winter (see figure 3 for details). • If we calculate U3, for wall 3 once again using an air gap 2cm wide, then the U-value becomes as follows: • U3 = 1 ÷ (Ri + Ro + (0.05 ÷ 1.53) + (0.15 ÷ 1.75) + (0.03 ÷ 0.035) + (0.10 ÷ 0.77)+ 0.18 ( see figure 3, the value 0.18 is illustrated by arrows) + (0.02/0.53) • U3 = 1/1.46 • = 0.67 W/m2.k • It is clear now that not much change has been achieved through adding the effect of the air gap, that is from 0.76 to 0.67W/m2.k. (i.e. 13% improvement )Whatever width the air gap is, no more resistance to heat flow is attained. Actually the opposite happens as the wider the gap becomes the lesser the resistance to heat flow the air gap sustains.

10. Cavity Cavity with one aluminum surface BS 6993:PART1-1989 1.2 Aluminum Foil Heat Flow Direction in Summer K / W) 1 2. Heat Flow Direction in Winter 0.8 Cavity with one aluminum surface 0.6 Cavity uncoated Thermal resistance -R-value (m 0.4 0.2 0 0 10 20 30 40 50 60 Cavity thickness (mm) Figure 4

11. Very Hot Zone 20 Average Temperature of Ambient Air Comfort Zone 10 Very Cold Zone 5 10 15 20 25 0 5 10 15 20 25 Average surface temperature of internal walls Figure 5 a

12. 13 degrees Wall 1

13. o 0 C o o o o o o o 33 C 16 32 14 o 15 31. C o 16.5 C 33 C o o 14 33.5 C 13 o o o 32 15 o o o o o 16.5 C o 20 C 26 C 50 C 0 C o 16 31. C out side o inside inside 20 C o 16.5 C Wall 1 (Vertical section-Winter) Wall 1 - plan - Summer Wall 1 - plan- Winter 6 ( a ) 6 ( c ) 6 ( b )

14. Table 2 Averages of weight of water vapor produced by a family in Jordan consisting of an average of 5 persons

15. Picture 1 - 3

17. Plate 1 Outside 0 k Window Frame Plate 1 Winter Condition Area of a Sharp Temperature Gradient Inside 20 k

18. Area of a Sharp Temperature Gradient Plate 2 Plate 2 outside Area of extremely sharp temperature gradient

19. Cold Joints

20. See picture 1-2

21. o 0 C o o o o o o o 33 C 16 32 14 o 15 31. C o 16.5 C 33 C o o 14 33.5 C 13 o o o 32 15 o o o o o 16.5 C o 20 C 26 C 50 C 0 C o 16 31. C out side o inside inside 20 C o 16.5 C Wall 1 (Vertical section-Winter) Wall 1 - plan - Summer Wall 1 - plan- Winter 6 ( a ) 6 ( c ) 6 ( b )

22. 13 degrees Wall 1

23. Infra Red Scanning Reference: S, Baradey, Iproplan , Germany

24. o o 0 C o 27.2 o 19.2 C 19 C o o o 28.2 C 18.2 C 19 C o o o 19.2 C 50 C 27.2 C o o 20 C 0 C o o o 20 C Ambient temp. = 26 C 19.2 C Wall 3 - plan , Winter Wall 3 - plan , Summer Wall 3 (Vertical cross-section) 8 ( b ) 8 ( c ) 8 ( a )

25. Iso-thermal Lines No 18 19.2K Wall 3 18.2K

26. Passive Design • Passive design is that which does not require mechanical heating or cooling. Homes that are passively designed take advantage of natural energy flows to maintain thermal comfort. At almost no extra cost: • Significantly improves comfort. • Reduces or eliminates heating and cooling bills. • Reduces greenhouse gas emissions from heating, cooling, mechanical ventilation and lighting.

27. Shading

28. Solar, Shading and ventilation

29. Thermal Mass-Trombe wall

30. Passive design in Traditional houses • نستطيع تلخيص العوامل التي تجعل الفارق واضحاً جلياً بين البيوت القديمة والحديثة بما هو آت:- • - نوع مواد البناء المستعملة. • - سماكة الجدران والسقوف. • - لون الجدران والسقوف. • - طبيعة تصميم البناء ( المساحة، الارتفاع، عدد الطوابق، أساليب التهوية، مساحة الفتحات الخارجية وشكلها واتجاهها، المظلات الواقعة حول البناء وحول فتحاته الخارجية، ونحو ذلك). • - طبيعة العائلة النمطية (عدد السكان القاطنين، فترة الإشغال خلال 24 ساعة، نوع وسائل التدفئة المستعملة وفترة تشغيلها وطريقة تهويتها).

31. إن لون الطين والقش، وكذلك لون الحجر الطبيعي المائل إلى اللون الأصفر الفائح أو إلى اللون البني اللامع، مناسب جداً للصيف والشتاء معاً. فالحجر اليوم، الذي يتم قصه بالمناشير ليصبح أبيض اللون ناصع البياض، يفقد في فصل الشتاء، بفعل الابتعاث الحراري حوالى 90 % من الطاقة الحرارية التي يكتسبها من تدفئة المنزل،فيما تبتعث حصى الوديان والحجارة الطبيعية، مثلاً، نسبة 50 % من الطاقة الحرارية فقط. وهذا ما جعل من البيوت التقليدية التي تمتع أجدادنا في العيش بداخلها أماكن أكثر دفئاً في فصل الشتاء، وبالتالي أكثر راحة ومتعة.ولا ينبغي أن يُظن أن الحجارة البيضاء ستكون أفضل كفاءَة في فصل الصيف، فقدرة الرخام أو الحجرعلى امتصاص أشعة الشمس تبلغ 44– 53 %، بالمقابل فإن الزلط والحجارة التقليدية تمتص 29 % فقط من أشعة الشمس. وهذا يعني أن الأبنية التي أشادها أجدادنا كانت ألطف جواًفي فصل الصيف الحار أيضاً، وبالتالي كانتأكثر راحة ومتعة للسكن فيها.

32. Beehives المادة اللون التهوية الفتحات الظلال التلاصق اللاتجاه الخشونة

33. Thermal mass

34. Materials, Color and Emissivity • تقوم قاعدة تأثير اللون والمادة على عنصرين أساسيين، الأول هو مفهوم الابتعاثية Emissivity والثاني مفهوم الامتصاصية Absorption. فإذا كان معامل الماصية للون الأسود غير اللامع هو 1، يعني ذلك أن كافة الأشعة الضوئية الساقطة على الجسم الأسود يتم امتصاصها، وبالمقابل فإن الجسم ذو ماصية قريبة من الصفر يعكس الإشعاعات الساقطة عليه بالكامل تقريباً. وهذا يعني أيضاً أن الجسم الأسود غير اللامع يتميز بابتعاثية عالية تساوي 1 أيضاً. وهذا يعني أن السطوح المعزولة مائيا بالإسفلت الأسود فقط تفقد طاقة كبيرة في فصل الشتاء • إن الخرسانة تبتعث (تفقد حرارة) بنسبة 91 % وتمتص 65 % • أما الرخام والحجر فيبتعث بنسبة 93 % ويمتص 44 – 53 % • وطلاءَات اللون الأبيض تبتعث بنسبة 90 % وتمتص 12 % • أما طلاء اللون الأصفر الفاتح فيبتعث بنسبة 90 % ويمتص 45 % • وطلاء الألومنيوم يبتعث بنسبة 30 % ويمتص 18% • وحصى الوديان (الزلط) تبتعث بنسبة 50 % وتمتص 29 % • نستنتج من الأرقام أعلاه أن دهان الإسفلت بطلاء الألومنيوم مفيد صيفاً شتاءَ، وكذلك استخدام حصى الوديان.

35. Conclusion: • In Jordan, we have proved that using wall 3 solution at an extra cost of 1000 US $ per 150 m2 flat is immediately refunded from the reduction in boiler capacity, quantity of radiators, diameter of pipes and capacity of pumps. • The profitable investment in thermal insulation persists and multiplies by time ever since the moment of occupying the building, as less fuel and electricity is spent on heating and cooling, and very little maintenance thereafter is needed. We have proved that a saving of 400 $ per flat per year is achieved, only via heat losses through walls. • Less fuel consumption, i.e. Sustainable natural resources • A more comfortable environment is also prevailing inside the house, whence thermal insulation is used. Less cracks and less thermal movement within the insulated zone. • No condensation is possible and no fungus growth. • And above all less fumes are emitted to the atmosphere. That means less pollution for the environment.