Embodied energy of building Embodied energy of building envelopes and its influence on envelopes and its influence on

cooling load in typical Indonesian cooling load in typical Indonesian middle-class housesmiddle-class houses

Agya Utama and Shabbir H. Agya Utama and Shabbir H. Gheewala Gheewala

The JJoint GGraduate SSchool of EEnergy and EEnvironment (JGSEE) King Mongkut’s University of Technology Thonburi, Bangkok,

Thailand

IntroductionIntroduction

50% from the total 24,000 50% from the total 24,000 MW capacityMW capacity

80% in Java and Bali island80% in Java and Bali island

Electricity in residential Electricity in residential sector in Indonesia sector in Indonesia consumed more than any consumed more than any other sectorsother sectors

USA energy demand

others65%

residential

35%

Indonesia energy demand

residential50%

others50%

IntroductionIntroduction

Why should we focus on Why should we focus on building envelopes?building envelopes?

Building envelopes Building envelopes

contribute more than 60% contribute more than 60% compare to other part in compare to other part in the buildingthe building

Building envelopes are Building envelopes are more adjustable compared more adjustable compared to the structureto the structure

Building envelopes can be Building envelopes can be dismantled or changed dismantled or changed easilyeasily

Building envelopes is the Building envelopes is the biggest contributors for the biggest contributors for the cooling loadcooling load

Building properties in landed single house (price)

walls46%

roof16%

others38%

IntroductionIntroduction

Void 50% 130 MJ/m2

latent40%

internal34%

perimeter26%

Building with 50% void Building with 50% void can be:can be:

Reduced the latent Reduced the latent and internal loadand internal load

But increasing the But increasing the perimeter loadperimeter load

Variable to reduce the Variable to reduce the perimeter loadperimeter load

Building orientationBuilding orientation Material chosenMaterial chosen DesignDesign

Void 0% 190 MJ/m2

latent47%

internal34%

perimeter19%

Hirano et al, 2004

MethodologyMethodology

Electricity used - household energy audit

Energy use data collection – process analysis (cradle to gate)

quarry transport transportmanufacture construction

MethodologyMethodology Life cycle energy from cradle to gateLife cycle energy from cradle to gate

– Raw material extractionRaw material extraction– ProductionProduction– ConstructionConstruction– Occupation phaseOccupation phase

Investigation and open interview for acquiring Investigation and open interview for acquiring data from factories and construction sitedata from factories and construction site

Direct and indirect questionnaire to obtain data Direct and indirect questionnaire to obtain data from householdfrom household

Focused on two similar house with different Focused on two similar house with different enclosure materials enclosure materials

MethodologyMethodology

Life Cycle Energy (LCE)Life Cycle Energy (LCE)

where:where:– LCELCE = Life-cycle energy= Life-cycle energy– EEiEEi = Initial embodied energy of enclosure = Initial embodied energy of enclosure

material material– EErecEErec = the recurrent embodied energy = the recurrent embodied energy

(maintenance) (maintenance)– OEOE = the total annual operational energy (cooling = the total annual operational energy (cooling

load) load)– YearYear = Building lifetime= Building lifetime

year)*(OEEEEELCE reci

Case StudyCase Study

SimilaritySimilarity Landed house in SemarangLanded house in Semarang Gable roofGable roof 55 m55 m2 2 total floor areatotal floor area Air conditioned at 2 bed rooms and non A/C Air conditioned at 2 bed rooms and non A/C

at living room at living room Similar occupation behaviorsSimilar occupation behaviors 1-1.5 m’ fenestration1-1.5 m’ fenestration Facing northFacing north Both has the same building structure and Both has the same building structure and

other finishing material (ceramics and wall other finishing material (ceramics and wall paints)paints)

Case StudyCase Study

HOUSE 1HOUSE 1 Concrete roofConcrete roof Concrete block wallsConcrete block walls

Steel roof frameSteel roof frame Gypsum ceiling (3mm)Gypsum ceiling (3mm) Clear glass (2mm)Clear glass (2mm) Aluminum frame Aluminum frame

windows and doorswindows and doors

HOUSE 2HOUSE 2 Clay roofClay roof Bricks wallsBricks walls

Steel roof frameSteel roof frame Gypsum ceiling (3mm)Gypsum ceiling (3mm) Clear glass (2mm)Clear glass (2mm) Aluminum frame Aluminum frame

windows and doorswindows and doors

ResultResult

Material Embodied EnergyMaterial Embodied Energy

* reference sources

Material Embodied energy Common Steel Gypsum (3 mm) Single glass (clear 2 mm) Aluminum frame (1 mm) Mold (m2)

Cement Sand

32.54 MJ/kg * 2.69 MJ/kg 13 MJ/kg * 232 MJ/kg 3.361 MJ/kg 0.6 MJ/kg

House 1 Concrete roof (2 mm) (18 pcs/m2) Concrete block (100 mm) (24 pcs/m2) Mold (1 PC : 5 sand)

0.817 MJ/kg 0.762 MJ/kg 16.41 MJ/m2

House 2 Clay roof (2 mm) (18 pcs/m2) Bricks wall (100 mm) (60 pcs/m2) Mold (1 PC : 5 sand)

0.26 MJ/kg 1.3 MJ/kg 29.61 MJ/m2

ResultResult

Embodied EnergyEmbodied EnergyEmergy Construction

Material Volume/mass/area Emergy per

unit [MJ] [MJ]

Common Steel 482.78 kg 32.54 MJ/kg 15,709.66 Gypsum (3 mm) 55 m2 21.60 MJ/m2 1,188.00 Single glass (clear 2 mm) 4.8 m2 671 MJ/m2 3,220.80 Aluminum frame (1 x 5) 0.00432 m3 353,104 MJ/m3 1,525.41 House 1 Concrete roof (2 mm) (18 pcs/m2) 55 m2 14.54 MJ/pcs 14,394.60 concrete block (100 mm) (24 pcs/m2) 90 m2 6.49 MJ/pcs 14,018.40 Walls mold 90 m2 0.13 MJ/m2 11.70 House 2 Clay roof (2 mm) (18 pcs/m2) 55 m2 5.19 MJ/pcs 5,135.13 Bricks wall (100 mm) (60 pcs/m2) 90 m2 3.13 MJ/pcs 16,902.00 Walls mold 90 m2 0.23 MJ/m2 20.70

ResultResult

Energy usedEnergy used

17,728.80

322.34

23,638.80

429.8

0 5,000 10,000 15,000 20,000 25,000

[MJ/year]

[MJ/m2/year]

[MJ/year]

[MJ/m2/year]

HO

USE

2H

OU

SE 1

Energy used

ResultResult

LCE for HOUSE 1LCE for HOUSE 1

50,068.57

50,068.57

50,068.57

0

0

0

23,638.80

23,638.80

23,638.80

522,844.57

759,232.57

1,232,008.57

0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000

Emergy

Replacement

Operational

Total

LCE HOUSE 1 [MJ]

20 years 30 years 50 years

ResultResult

LCE for HOUSE 2LCE for HOUSE 2

43,701.70

43,701.70

43,701.70

0

0

5,135.13

17,728.80

17,728.80

17,728.80

398,277.70

575,565.70

935,276.83

0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000

Emergy

Replacement

Operational

Total

LCE HOUSE 2 [MJ]

20 years 30 years 50 years

ResultResult

The emergy percentage at total LCEThe emergy percentage at total LCE

11

8

5

10

7

4

0 2 4 6 8 10 12 14

20 y

30 y

50 y

20 y

30 y

50 y

HO

USE

2H

OU

SE 1

Emergy [%]

ConclusionConclusion

Cement based material consumes more energy Cement based material consumes more energy during production compared to the clay based during production compared to the clay based material material

By using clay based material instead of cement By using clay based material instead of cement base for enclosure will safe 6,400 MJ during base for enclosure will safe 6,400 MJ during production and 124,600 MJ during its occupation production and 124,600 MJ during its occupation phase for 20 years scenario in single landed phase for 20 years scenario in single landed househouse

Using clay based material for enclosure at Using clay based material for enclosure at residential sectors in this regions (Semarang, residential sectors in this regions (Semarang, approx 1,4 mil inhabitant) will safe more than approx 1,4 mil inhabitant) will safe more than 86,400 GJ 86,400 GJ

ConclusionConclusion High thermal resistance material is more High thermal resistance material is more

preferable for tropical weatherpreferable for tropical weather Clay based material have higher R-value than Clay based material have higher R-value than

concrete based material and therefore more concrete based material and therefore more thermal resistancethermal resistance

Reduction in perimeter load in tropical country Reduction in perimeter load in tropical country has significant effect on the overall energy has significant effect on the overall energy requirement as compared to internal and latent requirement as compared to internal and latent loadload