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RSS-Amman, 18 ةيلخادلا ةبوطرلا -

January 2006 ةقاطلا ظفحل يخانملا ميمصتلا يرارحلا لزعلل ةيئيبلا ةمهاسملا 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: [email protected]

• •

Mobile no.: 00 962 79 5772533

• • 1

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

0.06

0.05

0.04

0.03

0.02

Expanded Polystyrene Polyurethane Rock Wool 0.01

Economical Design

Criteria:

Cost Availability Requirements (Architectural, Codes, etc) Durability Vapor Barrier Gloss Health hazards Fire hazards 0 10 20 30 40 50 60 70 80 90 100

Density of Thermal Insulating Materials Kg/m3

Material Concrete Lime Stone Normal Glass Concrete Hollow Blocks Plastering Polystyrene (expanded) Glass Wool Polystyrene (expanded) Polystyrene (extruded) Rock Wool Polystyrene (expanded) Polyurethane (on site) Density K valve W/m2.k

Cost US $/ m3 2005 2300 2200 2500 1200 1570 15 64 20 28-35 50-100 25 30 1.75

1.53

1.05

0.77

0.53

0.040

0.038

0.036

0.035

0.034

0.026

2 2 90 150 100 125 90 110 300 1 1 1 4

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 cm

plain 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 1 U = 2.6 W/m2.k

Wall 2 U = 2.19 W/m2.k

Wall 3

U = 0.76 W/m2.k

•

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

•

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%

• • • • • • • • • • • • • •

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

consumption is: needs 1300 Heating Hour Day and 700 cooling hour day, then the total 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.

• It must be noted here that

air gaps

do not have the ability to resist heat more than

0.18 W /m. k

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).

, no matter how thick the gap is (provided the gap • 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

resistance to heat flow the air gap sustains.

. (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 9

BS 6993:PART1-1989 1.2

Heat Flow Direction in Summer

Cavity Heat Flow Direction in Winter Aluminum Foil 0.8

0.6

Cavity with one aluminum surface Cavity uncoated 0.4

0.2

0 0 10 50 20 30

Cavity thickness (mm)

40 Figure 4 60 10

Very Hot Zone

20 10

Very Cold Zone Comfort Zone

0 5 15 20 25 Average surface temperature of internal walls Figure 5 a 11

13 degrees Wall 1 12

0 C o o 31. C 0 C o out side o 20 C o 20 C o 16.5 C inside o 50 C o 26 C inside Wall 1 (Vertical section-Winter) 6 ( a ) Wall 1 - plan- Winter 6 ( b ) Wall 1 - plan - Summer 6 ( c )

5 6 3 4 7 8 9 1 2

Table 2

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

Breathing and Sweating Using petrol based fuel in heaters of no exhausts 4 – 7 kg 10 – 15 Kg Cooking Bathing (Twice weekly) Washing activities Laundry Drying clothes Washing and drying dishes Other activities, plants, .. etc Total 2 – 6 kg 1 – 3 kg 1 – 2 kg 2 – 4 kg 4 – 8 kg 0.5 – 1 kg 0.5 – 1 kg

25 – 47kg

Picture 1 - 3 15

Outside 0 k

Plate 1

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

outside Area of extremely sharp temperature gradient p T Plate 2

Plate 2

m p e r a t u r e 18

Cold Joints

See picture 1-2

0 C o o 31. C 0 C o out side o 20 C o 20 C o 16.5 C inside o 50 C o 26 C inside Wall 1 (Vertical section-Winter) 6 ( a ) Wall 1 - plan- Winter 6 ( b ) Wall 1 - plan - Summer 6 ( c )

13 degrees Wall 1 22

Infra Red Scanning

Reference: S, Baradey, Iproplan , Germany 23

o 0 C 19 Co o 18.2 C o 19.2 C o 50 C o 0 C o 20 C Wall 3 (Vertical cross-section) 8 ( a ) Wall 3 - plan , Winter 8 ( b ) 27.2o

o 28.2 C Ambient temp. = 26 C o Wall 3 - plan , Summer 8 ( c ) 24

Iso-thermal Lines No 18 18.2K

19.2K

Wall 3 25

•

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 .

Shading

Solar, Shading and ventilation

Thermal Mass-Trombe wall

Passive design in Traditional houses لع جت يتلا لماوعلا صيخلت عيطتسن ةميدقلا تويبلا نيب ًايلج ًاحضاو قرافلا : تآ وه امب ةثيدحلاو .

ةلمعتسملا ءانبلا داوم عون .

فوقسلاو ناردجلا ةكامس .

فوقسلاو ناردجلا نول ،ةيوه .) ،ةحاسملا ( ءانبلا ميمصت ةعيبط تلا بيلاسأ ،قباوطلا ددع ،عافترلاا اهلكشو ةيجراخلا تاحتفلا ةحاسم ءانبلا لوح ةعقاولا تلاظملا ،اههاجتاو كلذ وحنو ،ةيجراخلا هتاحتف لوحو ن اكسلا ددع ( ةيطمنلا ةلئاعلا ةعيبط ،ةعاس ةر 24 للاخ لاغشلإا ةرتف ،نينطاقلا تفو ةلمعتسملا ةئفدتلا لئاسو عون .) اهتيوهت ةقيرطو اهليغشت • • • • • • 30

ن وللا ىلإ لئاملا يعيبطلا رجحلا نول كلذكو ،شقلاو نيطلا نول نإ ءاتشلاو فيصلل ًادج بسانم عصان نولل نم % 90 ىل نايدولا ىصح ام اذهو .

رثكأ نكامأ اه ثعتبت اميف لخادب غبني لاو .

، طقف ةيرارحلا ةقاطلا نم عملالا ينبلا نوللا ىلإ وأ حئافلا رفصلأا ا ضيبأ حبصيل ريشانملاب هصق متي يذلا ،مويلا رجحلاف % 50 ةعتمو ةحار رثكأ .

ًاعم اوح يرارحلا ثاعتبلاا لعفب ،ءاتشلا لصف يف دقفي ،ضايبلا ،لزنملا ةئفدت نم اهبستكي يتلا ةيرارحلا ةقاطلا ةبسن ،ًلاثم ،ةيعيبطلا ةراجحلاو شيعلا يف اندادجأ عتمت يتلا ةيديلقتلا تويبلا نم لعج نأ نظُي نأ ي وأ ماخرلا ةرد قف ،فيصلا لصف يف ةَءافك لضفأ نوكتس ءاضيبلا ةراجحلا طلزلا نإف لباقملاب ، نأ ينعي اذهو .

% .

53 – سمشلا ةعشأ نم طقف راح لا فيصلا لصف يف 44 غلبت سمشلا ةعشأ صاصتما ىلع % يلاتلابو ،ءاتشلا لصف يف ًائفد 29 اهيف نكسلل ةعتمو ةحار رثكأ رجحلا صتمت ةيديلقتلا ةراجحلاو تناك يلاتلابو ،ًاضيأ •

Beehives

ةدامل نوللا

ةيوهتلا تاحتفلا للاظلا قصلاتلا هاجتلالا ةنوشخلا

Thermal mass

Materials, Color and Emissivity

مو هفم وه لولأا ،نييساسأ نيرصنع ىلع ةداملاو نوللا ريثأت ةدعاق موقت ناك اذإف .

اذهو .

وذ مسجلا ًاضيأ ًابير 1 يف ةريبك ةق Absorption ةيصاصتملاا موهفم يناثلاو ةعشلأا ةفاك نأ كلذ ينعي ، 1 اط دقفت طقف دوسلأا تلفسلإاب Emissivity ةيثاعتبلاا وه عملالا ريغ دوسلأا نولل ةيصاملا لماعم نإف لباقملابو ،اهصاصتما متي دوسلأا مسجلا ىلع ةطقاسلا ةيئوضلا قت لماكلاب هيلع ةطقاسلا تاعاعشلإا سكعي رفصلا نم ةبيرق ةيصام يواس ت ةيلاع ةيثاعتباب زيمتي عملالا ريغ دوسلأا مسجلا نأ ًاضيأ ينعي ا يئام ةلوزعملا حوطسلا نأ ينعي اذهو ءاتشلا لصف % 65 صتمتو % 91 ةبسنب ) ةرارح دقفت ( ثعتبت ةناسرخلا نإ % % 53 – 44 صتميو % 93 ةبسنب ثعتبيف رجحلاو ماخرلا امأ 45 % 12 صتمتو صتميو % % 90 ةبسنب ثعتبت ضيبلأا نوللا تاَءلاطو 90 ةبسنب ثعتبيف حتافلا رفصلأا نوللا ءلاط امأ % 18 صتميو % 30 ةبسنب ثعتبي موينموللأا ءلاطو % 29 صتمتو % 50 ةبسنب ثعتبت ) طلزلا ( نايدولا ىصحو ًافي ص ديفم موينموللأا ءلاطب تلفسلإا ناهد نأ هلاعأ ماقرلأا نم جتنتسن .

34 نايدولا ىصح مادختسا كلذكو ،َءاتش • • • • • • • •

•

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

comfort

able 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.