April 2-4, 2012 Effect of Built-Form Configuration on Energ and Structural Performance of Skscraper Buildings Mohamed Krem Dr. Simi Hoque Dr. Sanja R. Arwade Universit of Massachusetts Amherst (UMASS) 1
Global Population and Tall Building Council on Tall Buildings and Urban Habitat (CTBUH),2011 ; An Analsis of Global Population and Tall Building 2
Council on Tall Buildings and Urban Habitat (CTBUH),2011 ; An Analsis of Global Population and Tall Building 3
In the US Buildings account for almost 40% of all energ use 68 % of the electricit energ 33 %of the total energ are used to heat, cool, and operate buildings Results Current global energ crisis Non-renewable sources of energ Decreasing the sustainabilit http://www.nap.edu/reports/energ/suppl.html 4
Solution Tall and Green Buildings Green Buildings ma be defined as buildings must meet the needs of the present generations without compromising the abilit of future generations to meet their needs as well (brundtland commission) Future Generations compatibilit between the The building Green building components and the environment. Once building construction ends, it becomes a part of its environment, like a tree or stone, and is eposed to the effects of the sun, wind, and rain. If the building is designed with these different environmental conditions in mind, it ma take advantage of http://ecocit.wordpress.com/press-onl/ available solar or 5
Problem statement Building morphologies Energ performance How these three parameters are related to each other. Structural performance 6
An Approach It is been suggested that Using the structural sstem of a building to improve energ efficienc in addition to resisting gravit and lateral loads Yeang [The Green Skscraper]. Central Edge Half Sides Sides core wall N Climate Cool Temperate Arid Tropical Aspect ratio Y:X 1:1 1:1.6 1:2 1:3 7
e Schematic deformation mode Central Edge Half Sides Sides core Wind pressure P R e P T T R T T Central e= 0 Edge e= 20.3 m Half sides e= 9.18 m Sides e= 0 : Centroid : Center of rigidit e: Eccentricit R: Rotation T: Translation 8
Agenda Energ performance Energ demand Operational energ cost Structural performance Structural analsis Material quantities Total Cost Envelope stud Equivalent percentages of opaque surfaces(epo) Update total cost Conclusions http://www.earthfuture.com/econews/images /07-01c.jpg 9
Energ analsis 10
36.75 m 13.5 m 18.4 m 8 m 22 m 21 m 12.6 m 50 @ 4 m 30 m 41 m 20.5 m 15 m 10.5 m 17 m 1 1 Central Ecotect models Edge 20 m 14 m 20 m 18 m 8 m 19 m 21 m 65.75 m 15.53 m Plan view -central configuration [ 100% glazing] Plan view -edge configuration [31% opaque ; 69% glazing] Half Sides Sides 23 m 20 m 28 m 18 m 34 m 28 m 15.6 m 23 m 90 m 73.50 m Plan view -half sidrs configuration [17% opaque ; 83% glazing] Elevation Plan view -sides configuration [25% opaque ; 75% glazing]
Ecotect Analsis : is a comprehensive conceptto-detail sustainable building design tool, with a wide range of simulation and building energ analsis functionalit. Input Building geometr in 3D Building location and orientation Building material use Thermal resistance (Rvalue) for the building s envelope (According to IECC 2009) Thermal analsis conditions Thermal Analsis 12 Output Annual heating/ cooling loads Others
Thermal analsis results Tpe Climate Central Edge Half sides Sides % Difference [between Energ Use Intensit (kwh/m 2 ) Energ Use Intensit (kwh/m 2 ) Energ Use Intensit (kwh/m 2 ) Energ Use Intensit (kwh/m 2 ) lowest EUI and highest EUI] Cool 62.31 51.4 54.6 46.9 32 % Temperate 36.70 32.5 33.9 30.6 20 % Arid 63.9 56.3 59.3 54.4 17 % Tropical 57.9 56.4 57.4 54.6 6.0 % 13
Operational energ cost of 50 ears life span 14
Trade-off Now, we need to know whether the trade-off of placing the structural walls to maimize operating energ efficienc will not cause the total cost to be too great http://www.faqs.org/photodict/phrase/2775/balance.html 15
Variables Structural wall placements Building shape Supplementar lateral load resistance sstem(sllr) Structural Analsis Output Lateral displacements Amount of Materials used Embodied energ Material used cost 16
Structural Analsis 17
Structural Analsis 18
Structural Analsis 19
Configurations Sides Half Sides Edge Central Structural Analsis Results Maimum displacement service wind load P w and 0.75 P w With SLLR - strength checked With SLLRserviceabilit checked Maimum displacement service wind load P w and 0.75 P w With SLLR - strength checked With SLLRserviceabilit checked Serviceabilit threshold (m) (ASCE 7-10) U (m) U (m) 0.87 0.45 0.88 0.46 0.98 0.44 1.16 0.43 0.5 1.24 0.43 1.36 0.41 1.0 0.44 1.1 0.45 SLLR: supplementar lateral load resistance sstem 20
configuration Embodied energ of the material used (for BSS & SLLR) Material quantit Steel (t) From SLLR concrete (t) From BSS Embodied energ GJ/t SLLR Steel BSS Concrete Normalized Embodied energ SLLR Steel BSS Concrete Total Central 10189 20719 2.57 0.96 3.53 Edge 11653 23697 2.94 1.10 4.04 Half Sides 11.51 2.12 15142 13213 3.82 0.61 4.43 Sides 8095 21542 2.04 1.0 3.04 The embodied energ is normalized with respect to material embodied energ (BSS) in the Sides configuration. SLLR: supplementar lateral load resistance sstem BSS: base structural sstem 21
Total material used cost inde Material quantities Normalized cost configuration Steel (t) From SLLR concrete (m 3 ) From BSS Total material (BSS+SLLR) Central 10189 8633 1.22 Edge 11653 9874 1.39 Half Sides 15142 5505 1.69 Sides 8095 8976 1.0 The cost is normalized with respect to material cost in the Sides configuration. SLLR: supplementar lateral load resistance sstem BSS: base structural sstem 22
Total cost of 50 ears life span 23
Edge configuration Envelope stud Half Sidrs configuration 20 m 18 m 17 m 15.83 m 18.4 m 20 m 12.5 m 41 m 20.5 m 19 m 21 m 36.75 m 28 m 15.6 m 23 m 65.75 m 73.50 m 31% Structural walls (Mass material) 10% framing of 69% glazing walls ---------------------------------------------- 37.9 opaque surfaces 17% Structural walls (Mass material) 10% framing of 65.5% glazing walls 14.35 % curtain walls ---------------------------------------------- 37.9 opaque surfaces Central configuration 15.53 m Sides configuration 14.29 m 20 m 21 m 14 m 15 m 23 m 1.5 m 15.53 m 30 m 28 m 18 m 34 m 15.36 m 21 m 90 m 10% framing of 69% glazing walls 31% curtain walls ---------------------------------------------- 37.9 opaque surfaces 25% Structural walls (Mass material) 10% framing of 69.5% glazing walls 5.95% curtain walls ---------------------------------------------- 37.9 opaque surfaces Structural walls : Glazing walls curtain walls 24
Results of EPO Climate Envelope Central Edge Half sides Sides EUI ( kwh/m2) Cool Temperate Arid Tropical Initial 62.32 50.89 54.58 46.87 EPO 45.27 50.89 52.32 45.75 Initial 36.71 32.51 33.91 30.6 EPO 30.05 32.51 33.5 29.95 Initial 63.98 56.29 59.32 54.44 EPO 51.75 56.29 56.53 53.3 Initial 57.95 56.38 57.37 54.6 EPO 54.17 56.38 56.83 54.32 EUI: Energ Use Intensit EPO: Equivalent Percentages of Opaque surfaces 25
Total cost of 50 ears life span 26
Conclusions 27
Conclusions 1- Building morphologies (footprint shape and the placement of structural vertical core/walls) significantl influences overall energ performance. N Climate Cool Temperate Arid Tropical Aspect ratio Y:X 1:1 1:1.6 1:2 1:3 28
2- The structural Conclusions vertical walls in the east and west sides and with an aspect ratio of 1:3, ma lead to a reduction in energ consumption of 5% to 32%, depending on the climatic zone. wall 29
Conclusions 3- Significant improvement in energ performance can be gained b adding opaque surfaces in the Central configuration envelope (reduction in energ consumption of 7% to 37%) depending on the climatic zone N 30
Conclusions 4- The trade-off of placing the structural walls to maimize operating energ efficienc is too great. The potential irregularit in the rigidit, caused a substantial growth cost (about 40% more than normal cases) in materials that reflected negativel on the total cost. 31
Man Thanks mkrem@engin.umass.edu 32