- Email: [email protected]
The Significance of the Orientation on the Overall buildings Thermal Performance-Case Study in Australia
Available online at www.sciencedirect.com Available online at www.sciencedirect.com
ScienceDirect ScienceDirect
Available onlineat00 atwww.sciencedirect.com www.sciencedirect.com Available Energyonline Procedia (2018) 000–000 Energy Procedia 00 (2018) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
Energy (2018) 000–000 372–377 EnergyProcedia Procedia152 00 (2017) www.elsevier.com/locate/procedia
Applied Energy Symposium and Forum 2018: Low carbon cities and urban energy systems, CUE2018-Applied Energy and Forum 2018: Low and Applied Energy Symposium andSymposium Forum 2018: Low carbon cities andcarbon urbancities energy systems, CUE2018, 5–7 June 2018, Shanghai, China urban CUE2018, energy systems, 5–7 June 2018, Shanghai, China 5–7 June 2018, Shanghai, China
The Significance of the Symposium Orientation on the Overall buildings The 15th International on District Heating and Cooling The Significance of the Orientation on the Overall buildings Thermal Performance-Case Study in Australia Thermal Performance-Case in demand-outdoor Australia Assessing the feasibility of using Study the heat
Aiman Albataynehaa*, Dariusz Altermanbb, Adrian Pagebb and Behdad Moghtaderibb temperature function for Alterman a long-term district heat demand forecast Aiman Albatayneh *, Dariusz , Adrian Page and Behdad Moghtaderi a Energy Engineering Department, German Jordanian University, Amman, Jordan P.O. Box 35247 German University, Jordan P.O. Box PriorityaEnergy Research Centre for Department, Frontier Energy Technologies Utilisation, The University of Newcastle,Australia a,b,cEngineering a aJordanianand b Amman, c 35247 b Priority Research Centre for Frontier Energy Technologies and Utilisation, The University of Newcastle,Australia b
I. Andrić
*, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Correc
a
IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France Abstract c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France
Abstract Containing and then reducing greenhouse gases (GHG) emissions required designing energy efficient buildings which save Containing and then reducing greenhouse (GHG) required energy efficient buildings heating which save energy and emit less GHG. Orientation hasgases an impact on emissions the building overalldesigning thermal performance and designing and energy and emit occupants less GHG.thermal Orientation has an impact on the building overall thermal performance and designing heating and cooling to reach comfort. Abstract cooling reach occupants thermal comfort. Correct to orientation is a low cost option to improve occupant's thermal comfort and decrease cooling and heating energy. An Correct orientation is a low cost option to addressed improve occupant's thermal comfort decrease cooling and heating energy. An appropriate building orientation will allow the desirable winter sun toasenter building and allowsolutions ventilation summer by District heating networks are commonly in the literature one the of and the most effective forindecreasing the appropriate building orientation will allow desirable winter to enterhigh the investments building allow ventilation in the summer facing the summer wind stream. this paperthe asector. building module insun Newcastle area, Australiaand will be assessed to find effect of greenhouse gas emissions fromIn the building These systems require which are returned through the by heat facing the summer stream. Inspeed thisconditions paper a building module in Newcastle area, Australia will be in assessed to find the effect of the building orientation and wind and direction the overall thermal performance. sales. Due to thewind changed climate andonbuilding renovation policies, heat demand the future could decrease, the building and wind speed and direction on the overall thermal performance. It prolonging was foundorientation that the northern wall (windows side) of the Insulated cavity Brick (InsCB) module consistently provided the most the investment return period. It wastomain found that through the northern wall side) ofthe thesun Brickthe (InsCB) module consistently thedemand most heat the room the window which in winter to enter and heat it upfunction andprovided avoid main wind The scope of this paper is to (windows assess theallows feasibility ofInsulated using thecavity heat demand –building outdoor temperature for heat heat to the The roomdistrict throughofthe windowlocated which allows the sun in winterwas to enter and heat up andisavoid main of wind stream. forecast. Alvalade, in Lisbon (Portugal), used the as abuilding case study. The itdistrict consisted 665 stream. buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district Copyright © 2018 Elsevier All rights(shallow, reserved.intermediate, deep). To estimate the error, obtained heat demand values were renovation scenarios wereLtd. developed Copyright © 2018 2018 Elsevier Elsevier Ltd. All rights rights reserved. reserved. Copyright © Ltd. All Selection and peer-review under responsibility of the scientific committee of Applied Energy Symposium and Forum 2018: Low comparedand withpeer-review results fromunder a dynamic heat demand model, previously developed validated by the authors. Selection responsibility of the scientific committee of theand CUE2018-Applied Energy Symposium and Selection and peer-review under responsibility of the scientific committee of Applied Energy Symposium and Low carbon cities and urban energy systems, CUE2018. The results that when onlyurban weather change is considered, the margin of error could be acceptable forForum some 2018: applications Forum 2018: showed Low carbon cities and energy systems. carbon citiesinand urbandemand energy was systems, (the error annual lowerCUE2018. than 20% for all weather scenarios considered). However, after introducing renovation Keywords: Buildings orientation; thermal performance; buildings; design. scenarios, the error value increased up to 59.5%sustainable (depending on thepassive weather and renovation scenarios combination considered). Keywords: Buildings orientation; thermal performance; sustainable buildings; passive design.
The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
© 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: 962-06- 4294444. Cooling.
*E-mail Corresponding author. Tel.: 962-06- 4294444. address: [email protected] E-mail address: Keywords: Heat [email protected] demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. 1876-6102and Copyright © 2018 Elsevier Ltd. All of rights reserved. committee of the Applied Energy Symposium and Forum 2018: Low carbon cities Selection peer-review under responsibility the scientific Selection peer-review responsibility of the scientific committee of the Applied Energy Symposium and Forum 2018: Low carbon cities and urbanand energy systems, under CUE2018. and urban energy systems, CUE2018. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the CUE2018-Applied Energy Symposium and Forum 2018: Low carbon cities and urban energy systems. 10.1016/j.egypro.2018.09.159
2
Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Aiman Albatayneh/ Energy Procedia 00 (2018) 000–000
373
1. Introduction Large contribution to climate change comes from building sector. Energy consumption of buildings covers about 40% of the total energy [1], mainly used for operating and constructing buildings which emitted on third of global greenhouse gases (GHG) emissions. To save buildings operating energy and reduce GHG emissions sustainable building design should be used; to correctly predict the amount of energy will be consumed. Accurate orientation, correct location on a site, and landscaping changes may decrease the energy consumption of a typical building by 20% [2] and provide the building designers with the economical tools to reduce energy consumptions. There are two ways to ensure optimal orientation: Analyze various parameters and certify optimal design and orientation for each building but this approach consume more designing time and cost. The second way is develop „adaptable‟ designs which perform well across a range of orientations, which is used in the volume build industry [3], but this approach does not give the optimum building orientation. 2. Methodology Current research program has been proceeding in the Priority Research Centre for Energy at the University of Newcastle, Australia on the thermal performance of Australian housing which include the construction of four full scale housing modules and monitoring the thermal performance under different seasons conditions, the modules are; Cavity Brick (CB), Insulated Cavity Brick (InsCB), Insulated Brick Veneer (InsBV) and Insulated Reverse Brick Veneer (InsRBV)) [4]. 2.1. InsCB module All the modules were built at the University of Newcastle, Callaghan Campus (Longitude 151.7 E and latitude 32.9 S). The modules were selected to represent typical forms of construction in Australia. The modules 7m away from each other to reduce wind obstruction and avoid shading, all modules had an exact design with square floor plan of 6m x 6m [5] as shown in Fig.1. a)
374
Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Author name / Energy Procedia 00 (2018) 000–000
3
b)
c)
d)
Fig.1 ((a) Real module photo, (b) North plan, (c) South plan, (d) Top view plan) [6].
The module shares these building materials; Window; 6.38 mm laminated clear glass in a light color aluminum frame in the northern wall of each module. Door; to access the module, the highly insulated door were constructed in the southern wall to eliminate any heat losses. Roof; Concrete and clay tiled with sarking insulation. 10mm plasterboard ceiling with R3.5 glass wool batts insulation between rafters. Slab; 100mm thickness concrete slab cover the whole building floor [7]. All modules have same design and share same construction materials except for their walling system, for this reason all the modules will be named after their walling system. InsCB module consists of two 110 mm brickwork skins with 50mm cavity insulated by R1 polystyrene insulation and the internal walls covered by 10mm internal render [8]. More than 100 sensors were installed in each module to record; the external weather conditions and internal environment, the data recorded every 5 minutes interval over the testing period using Datataker DT600. External environment conditions will exclusively determine internal air temperature for all of the modules “free-floating” without mechanical heating or cooling. No ventilation for all of the modules and the internal air temperature documented at a 1200mm elevation inside the buildings.
4
Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Aiman Albatayneh/ Energy Procedia 00 (2018) 000–000
375
2.2. AccuRate AccuRate Sustainability (V2.3.3.13 SP1) is a rating tool that assigns a star rating to residential buildings in Australia, based on its calculated annual heating and cooling energy requirements. The assessment of the building is stated as a star rating of between 0 and 10, the more stars (bands), the better the performance (AccuRate Sustainability V2.3.3.13 SP1). Star ratings (bands) are set for each specific climate zone to allow fair comparison of the buildings across climates. Using one year of typical weather data appropriate for the location, the heating and cooling energy requirements are calculated hourly over a period of one year, where the lower energy requirements, the higher the stars[9] [10]. 3. Results and Discussion The overall thermal performance of the InsCB module was largely influenced by the weather conditions (i.e. solar radiation, wind and external air temperature). Fluctuations in the solar radiation during the day had a direct impact on the thermal behavior of the module. Under summer environments a high solar radiation produced high external surface temperatures on the roof, eastern and western walls and was limited on the north facing wall. The southern wall just received diffused solar radiation (southern hemisphere) as shown in Fig. 2 for one week in summer.
Fig.2. Incident solar radiation on the modules external surfaces for one week in summer.
In winter season the incident solar radiation on the exterior surfaces of the modules western and eastern walls was decreased compared with summer week. However, the major difference was the significant increase in the solar radiation on the north side of the InsCB module due to the lower sun altitude in the sky as shown in Fig.3. The diffused solar radiation on the southern wall remained low as it was in summer.
Fig.3. Incident solar radiation on the modules external surfaces for one week in winter.
Author name / Energy Procedia 00 (2018) 000–000 Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377
376
5
The high solar radiation fallen on the northern wall throughout the whole day act as a crucial heat source for the module. Shading has a great influence on the buildings overall thermal performance, the requirements for shading vary according to the house‟s orientation and the climate (to eliminate the summer sun and allow the full winter sun to enter the building). Shading in summer in a hot climate improves comfort and decreases energy bills, and on top of that appropriate shading reduces the chance of exposure to harmful UV rays in Australia. The main two types of shading are; internal shading, such as blinds, rollers and curtains and external shading caused by overhangs or nearby trees or buildings. For the current building thermal assessment model used in Australia, such as AccuRate, the internal shading is considered but not the external shading because it keeps changing with time (growing trees and new buildings constructed). The energy consumption inside the building depends on the heat transfer between buildings and the surroundings which occurs through convection, conduction, and radiation through roof, floor, walls and windows. The main factor affecting convection heat transfer is the wind speed and direction. For example in the winter season, the wind speed and direction recorded at the site every 5 minutes from 13/08/2009 to 4/12/2009 are shown in Fig. 4.
Wind speed (m/s)
a)
b) 45 40 35 30 25 20 15 10 5 0
Aug
Sep
Oct
Nov
Dec
Fig4. a) Wind speed b) wind direction recorded at the top of InsCB module in 2009.
Higher wind speeds increase the heat lost/gain for the module which results in an increase in the energy bill particularly with the wind effect on the windward wall. Since most wind came from the east and west directions, the effect on the eastern and western wall was much higher compared to the northern and southern walls. Better insulation for walls and double glazed for windows also minimize air leakage, this will improve the module thermal performance, since the window towards the north side which does not face the direct wind this will improve the module thermal performance in winter but replacing the glass to double glazed will minimize the heat losses even more. Fast moving air causes a physiological cooling effect by convicting heat away from the body, and evaporating perspiration, which cools the skin. Ventilation can be increased by building higher than the ground for increased exposure to cooling breezes; windows need to be at opposite ends of the room for better inlet and outlet where bigger inlets and outlets are better. A typical Australian home with wall vents in each room and ceiling increases the overall heating energy costs but allows acceptable ventilation. Occupant can save energy by adjusting ventilation to allow summer breeze into the building. Ventilation is an important in a building because an air speed of 0.5 m/s equates to a 3 degree drop in temperature at a relative humidity of 50% [11]. Ventilation highly depends on the building openings and the wind speed, which is nearly impossible to calculate because the openings depend on the occupant‟s behavior, which is hard to predict, and the wind speed which is highly variable and unpredictable (with changing speed and direction).
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Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Aiman Albatayneh/ Energy Procedia 00 (2018) 000–000
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The orientation for the InsCB module was changed to determine the effect of orientation on the AccuRate star rating (there are a set of default data for wind speed and direction in AccuRate). Changing the module orientation from north to any another direction showed a significant decrease in the AccuRate ratings and substantial surge in the annual energy requirements for cooling and heating as is shown in Table 1. Table1. Effect of orientation on the AccuRate star ratings and annual energy requirements (MJ/m2. annum). Orientation
AccuRate star ratings
Annual energy requirements
Main window facing North
8.7
24
Main window facing East
6.4
57
Main window facing West
6.2
54
Main window facing South
5.4
78
4. Conclusions To tackle the climate change and global warming, measured need to be taken to reduce greenhouse gases emissions such as designing low energy buildings. In this paper the influence of the orientation of the Insulated cavity brick module on the overall thermal performance was analyzed. Appropriate orientation is a low cost option to improve comfort and decrease energy bills. Changing the building‟s orientation to either the east or west will heat the building during unwanted time (summer) because the east and west windows lose more heat than they gain in winter and gain more heat in summer and faces the cold wind stream in winter the hot stream in summer which accelerate the heat losses/gain . A southern orientation results in a little solar gain and heat losses through the window in winter. The final results confirmed that the best orientation is when the windows face the north in southern hemisphere to allow the winter sun's radiation to enter the module and to avoid main wind stream. Appropriate orientation helped to minimize heat losses in winter months by at least three times compared to the module when window facing south which impressively improve the overall thermal performance. References [1]
Lucon O, Ürge-Vorsatz D, Ahmed AZ, Akbari H, Bertoldi P, Cabeza LF, Eyre N, Gadgil A, Harvey LD, Jiang Y, Liphoto E. Buildings. [2] Mirkovic M, Alawadi K. The effect of urban density on energy consumption and solar gains: the study of Abu Dhabi‟s neighborhood. Energy Procedia. 2017 Dec 31;143:277-82. [3] Morrissey J, Horne RE. Life cycle cost implications of energy efficiency measures in new residential buildings. Energy and buildings. 2011 Apr 1;43(4):915-24. [4] Albatayneh, A., Alterman, D., Page, A. W., & Moghtaderi, B. (2016). warming issues associated with the long term simulation of housing using CFD analysis. Journal of Green Building, 11(2), 57-74. [5] Albatayneh, A., Alterman, D., Page, A., & Moghtaderi, B. (2015). The significance of time step size in simulating the thermal performance of buildings. Advances in Research, 5(6), 1-12. [6] Albatayneh, A., Alterman, D., Page, A., & Moghtaderi, B. (2016). Assessment of the Thermal Performance of Complete Buildings Using Adaptive Thermal Comfort. Procedia-Social and Behavioral Sciences, 216, 655-661. [7] Albatayneh, A., Alterman, D., Page, A., & Moghtaderi, B. (2017). The Significance of Temperature Based Approach Over the Energy Based Approaches in the Buildings Thermal Assessment. Environmental and Climate Technologies, 19(1), 39-50. [8] Albatayneh, A., Alterman, D., Page, A., & Moghtaderi, B. (2017). Thermal Assessment of Buildings Based on Occupants Behavior and the Adaptive Thermal Comfort Approach. Energy Procedia, 115, 265-271. [9] Albatayneh, A., Alterman, D., Page, A., & Moghtaderi, B. (2017). Discrepancies in Peak Temperature Times using Prolonged CFD Simulations of Housing Thermal Performance. Energy Procedia, 115, 253-264. [10] Albatayneh, A., Alterman, D., Page, A., & Moghtaderi, B. (2017). Temperature versus energy based approaches in the thermal assessment of buildings. Energy Procedia, 128, 46-50. [11] Santamouris, M. and Allard, F. eds., 1998. Natural ventilation in buildings: a design handbook. Earthscan.
ScienceDirect ScienceDirect
Available onlineat00 atwww.sciencedirect.com www.sciencedirect.com Available Energyonline Procedia (2018) 000–000 Energy Procedia 00 (2018) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
Energy (2018) 000–000 372–377 EnergyProcedia Procedia152 00 (2017) www.elsevier.com/locate/procedia
Applied Energy Symposium and Forum 2018: Low carbon cities and urban energy systems, CUE2018-Applied Energy and Forum 2018: Low and Applied Energy Symposium andSymposium Forum 2018: Low carbon cities andcarbon urbancities energy systems, CUE2018, 5–7 June 2018, Shanghai, China urban CUE2018, energy systems, 5–7 June 2018, Shanghai, China 5–7 June 2018, Shanghai, China
The Significance of the Symposium Orientation on the Overall buildings The 15th International on District Heating and Cooling The Significance of the Orientation on the Overall buildings Thermal Performance-Case Study in Australia Thermal Performance-Case in demand-outdoor Australia Assessing the feasibility of using Study the heat
Aiman Albataynehaa*, Dariusz Altermanbb, Adrian Pagebb and Behdad Moghtaderibb temperature function for Alterman a long-term district heat demand forecast Aiman Albatayneh *, Dariusz , Adrian Page and Behdad Moghtaderi a Energy Engineering Department, German Jordanian University, Amman, Jordan P.O. Box 35247 German University, Jordan P.O. Box PriorityaEnergy Research Centre for Department, Frontier Energy Technologies Utilisation, The University of Newcastle,Australia a,b,cEngineering a aJordanianand b Amman, c 35247 b Priority Research Centre for Frontier Energy Technologies and Utilisation, The University of Newcastle,Australia b
I. Andrić
*, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Correc
a
IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France Abstract c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France
Abstract Containing and then reducing greenhouse gases (GHG) emissions required designing energy efficient buildings which save Containing and then reducing greenhouse (GHG) required energy efficient buildings heating which save energy and emit less GHG. Orientation hasgases an impact on emissions the building overalldesigning thermal performance and designing and energy and emit occupants less GHG.thermal Orientation has an impact on the building overall thermal performance and designing heating and cooling to reach comfort. Abstract cooling reach occupants thermal comfort. Correct to orientation is a low cost option to improve occupant's thermal comfort and decrease cooling and heating energy. An Correct orientation is a low cost option to addressed improve occupant's thermal comfort decrease cooling and heating energy. An appropriate building orientation will allow the desirable winter sun toasenter building and allowsolutions ventilation summer by District heating networks are commonly in the literature one the of and the most effective forindecreasing the appropriate building orientation will allow desirable winter to enterhigh the investments building allow ventilation in the summer facing the summer wind stream. this paperthe asector. building module insun Newcastle area, Australiaand will be assessed to find effect of greenhouse gas emissions fromIn the building These systems require which are returned through the by heat facing the summer stream. Inspeed thisconditions paper a building module in Newcastle area, Australia will be in assessed to find the effect of the building orientation and wind and direction the overall thermal performance. sales. Due to thewind changed climate andonbuilding renovation policies, heat demand the future could decrease, the building and wind speed and direction on the overall thermal performance. It prolonging was foundorientation that the northern wall (windows side) of the Insulated cavity Brick (InsCB) module consistently provided the most the investment return period. It wastomain found that through the northern wall side) ofthe thesun Brickthe (InsCB) module consistently thedemand most heat the room the window which in winter to enter and heat it upfunction andprovided avoid main wind The scope of this paper is to (windows assess theallows feasibility ofInsulated using thecavity heat demand –building outdoor temperature for heat heat to the The roomdistrict throughofthe windowlocated which allows the sun in winterwas to enter and heat up andisavoid main of wind stream. forecast. Alvalade, in Lisbon (Portugal), used the as abuilding case study. The itdistrict consisted 665 stream. buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district Copyright © 2018 Elsevier All rights(shallow, reserved.intermediate, deep). To estimate the error, obtained heat demand values were renovation scenarios wereLtd. developed Copyright © 2018 2018 Elsevier Elsevier Ltd. All rights rights reserved. reserved. Copyright © Ltd. All Selection and peer-review under responsibility of the scientific committee of Applied Energy Symposium and Forum 2018: Low comparedand withpeer-review results fromunder a dynamic heat demand model, previously developed validated by the authors. Selection responsibility of the scientific committee of theand CUE2018-Applied Energy Symposium and Selection and peer-review under responsibility of the scientific committee of Applied Energy Symposium and Low carbon cities and urban energy systems, CUE2018. The results that when onlyurban weather change is considered, the margin of error could be acceptable forForum some 2018: applications Forum 2018: showed Low carbon cities and energy systems. carbon citiesinand urbandemand energy was systems, (the error annual lowerCUE2018. than 20% for all weather scenarios considered). However, after introducing renovation Keywords: Buildings orientation; thermal performance; buildings; design. scenarios, the error value increased up to 59.5%sustainable (depending on thepassive weather and renovation scenarios combination considered). Keywords: Buildings orientation; thermal performance; sustainable buildings; passive design.
The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
© 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: 962-06- 4294444. Cooling.
*E-mail Corresponding author. Tel.: 962-06- 4294444. address: [email protected] E-mail address: Keywords: Heat [email protected] demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. 1876-6102and Copyright © 2018 Elsevier Ltd. All of rights reserved. committee of the Applied Energy Symposium and Forum 2018: Low carbon cities Selection peer-review under responsibility the scientific Selection peer-review responsibility of the scientific committee of the Applied Energy Symposium and Forum 2018: Low carbon cities and urbanand energy systems, under CUE2018. and urban energy systems, CUE2018. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the CUE2018-Applied Energy Symposium and Forum 2018: Low carbon cities and urban energy systems. 10.1016/j.egypro.2018.09.159
2
Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Aiman Albatayneh/ Energy Procedia 00 (2018) 000–000
373
1. Introduction Large contribution to climate change comes from building sector. Energy consumption of buildings covers about 40% of the total energy [1], mainly used for operating and constructing buildings which emitted on third of global greenhouse gases (GHG) emissions. To save buildings operating energy and reduce GHG emissions sustainable building design should be used; to correctly predict the amount of energy will be consumed. Accurate orientation, correct location on a site, and landscaping changes may decrease the energy consumption of a typical building by 20% [2] and provide the building designers with the economical tools to reduce energy consumptions. There are two ways to ensure optimal orientation: Analyze various parameters and certify optimal design and orientation for each building but this approach consume more designing time and cost. The second way is develop „adaptable‟ designs which perform well across a range of orientations, which is used in the volume build industry [3], but this approach does not give the optimum building orientation. 2. Methodology Current research program has been proceeding in the Priority Research Centre for Energy at the University of Newcastle, Australia on the thermal performance of Australian housing which include the construction of four full scale housing modules and monitoring the thermal performance under different seasons conditions, the modules are; Cavity Brick (CB), Insulated Cavity Brick (InsCB), Insulated Brick Veneer (InsBV) and Insulated Reverse Brick Veneer (InsRBV)) [4]. 2.1. InsCB module All the modules were built at the University of Newcastle, Callaghan Campus (Longitude 151.7 E and latitude 32.9 S). The modules were selected to represent typical forms of construction in Australia. The modules 7m away from each other to reduce wind obstruction and avoid shading, all modules had an exact design with square floor plan of 6m x 6m [5] as shown in Fig.1. a)
374
Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Author name / Energy Procedia 00 (2018) 000–000
3
b)
c)
d)
Fig.1 ((a) Real module photo, (b) North plan, (c) South plan, (d) Top view plan) [6].
The module shares these building materials; Window; 6.38 mm laminated clear glass in a light color aluminum frame in the northern wall of each module. Door; to access the module, the highly insulated door were constructed in the southern wall to eliminate any heat losses. Roof; Concrete and clay tiled with sarking insulation. 10mm plasterboard ceiling with R3.5 glass wool batts insulation between rafters. Slab; 100mm thickness concrete slab cover the whole building floor [7]. All modules have same design and share same construction materials except for their walling system, for this reason all the modules will be named after their walling system. InsCB module consists of two 110 mm brickwork skins with 50mm cavity insulated by R1 polystyrene insulation and the internal walls covered by 10mm internal render [8]. More than 100 sensors were installed in each module to record; the external weather conditions and internal environment, the data recorded every 5 minutes interval over the testing period using Datataker DT600. External environment conditions will exclusively determine internal air temperature for all of the modules “free-floating” without mechanical heating or cooling. No ventilation for all of the modules and the internal air temperature documented at a 1200mm elevation inside the buildings.
4
Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377 Aiman Albatayneh/ Energy Procedia 00 (2018) 000–000
375
2.2. AccuRate AccuRate Sustainability (V2.3.3.13 SP1) is a rating tool that assigns a star rating to residential buildings in Australia, based on its calculated annual heating and cooling energy requirements. The assessment of the building is stated as a star rating of between 0 and 10, the more stars (bands), the better the performance (AccuRate Sustainability V2.3.3.13 SP1). Star ratings (bands) are set for each specific climate zone to allow fair comparison of the buildings across climates. Using one year of typical weather data appropriate for the location, the heating and cooling energy requirements are calculated hourly over a period of one year, where the lower energy requirements, the higher the stars[9] [10]. 3. Results and Discussion The overall thermal performance of the InsCB module was largely influenced by the weather conditions (i.e. solar radiation, wind and external air temperature). Fluctuations in the solar radiation during the day had a direct impact on the thermal behavior of the module. Under summer environments a high solar radiation produced high external surface temperatures on the roof, eastern and western walls and was limited on the north facing wall. The southern wall just received diffused solar radiation (southern hemisphere) as shown in Fig. 2 for one week in summer.
Fig.2. Incident solar radiation on the modules external surfaces for one week in summer.
In winter season the incident solar radiation on the exterior surfaces of the modules western and eastern walls was decreased compared with summer week. However, the major difference was the significant increase in the solar radiation on the north side of the InsCB module due to the lower sun altitude in the sky as shown in Fig.3. The diffused solar radiation on the southern wall remained low as it was in summer.
Fig.3. Incident solar radiation on the modules external surfaces for one week in winter.
Author name / Energy Procedia 00 (2018) 000–000 Aiman Albatayneh et al. / Energy Procedia 152 (2018) 372–377
376
5
The high solar radiation fallen on the northern wall throughout the whole day act as a crucial heat source for the module. Shading has a great influence on the buildings overall thermal performance, the requirements for shading vary according to the house‟s orientation and the climate (to eliminate the summer sun and allow the full winter sun to enter the building). Shading in summer in a hot climate improves comfort and decreases energy bills, and on top of that appropriate shading reduces the chance of exposure to harmful UV rays in Australia. The main two types of shading are; internal shading, such as blinds, rollers and curtains and external shading caused by overhangs or nearby trees or buildings. For the current building thermal assessment model used in Australia, such as AccuRate, the internal shading is considered but not the external shading because it keeps changing with time (growing trees and new buildings constructed). The energy consumption inside the building depends on the heat transfer between buildings and the surroundings which occurs through convection, conduction, and radiation through roof, floor, walls and windows. The main factor affecting convection heat transfer is the wind speed and direction. For example in the winter season, the wind speed and direction recorded at the site every 5 minutes from 13/08/2009 to 4/12/2009 are shown in Fig. 4.
Wind speed (m/s)
a)
b) 45 40 35 30 25 20 15 10 5 0
Aug
Sep
Oct
Nov
Dec
Fig4. a) Wind speed b) wind direction recorded at the top of InsCB module in 2009.
Higher wind speeds increase the heat lost/gain for the module which results in an increase in the energy bill particularly with the wind effect on the windward wall. Since most wind came from the east and west directions, the effect on the eastern and western wall was much higher compared to the northern and southern walls. Better insulation for walls and double glazed for windows also minimize air leakage, this will improve the module thermal performance, since the window towards the north side which does not face the direct wind this will improve the module thermal performance in winter but replacing the glass to double glazed will minimize the heat losses even more. Fast moving air causes a physiological cooling effect by convicting heat away from the body, and evaporating perspiration, which cools the skin. Ventilation can be increased by building higher than the ground for increased exposure to cooling breezes; windows need to be at opposite ends of the room for better inlet and outlet where bigger inlets and outlets are better. A typical Australian home with wall vents in each room and ceiling increases the overall heating energy costs but allows acceptable ventilation. Occupant can save energy by adjusting ventilation to allow summer breeze into the building. Ventilation is an important in a building because an air speed of 0.5 m/s equates to a 3 degree drop in temperature at a relative humidity of 50% [11]. Ventilation highly depends on the building openings and the wind speed, which is nearly impossible to calculate because the openings depend on the occupant‟s behavior, which is hard to predict, and the wind speed which is highly variable and unpredictable (with changing speed and direction).
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The orientation for the InsCB module was changed to determine the effect of orientation on the AccuRate star rating (there are a set of default data for wind speed and direction in AccuRate). Changing the module orientation from north to any another direction showed a significant decrease in the AccuRate ratings and substantial surge in the annual energy requirements for cooling and heating as is shown in Table 1. Table1. Effect of orientation on the AccuRate star ratings and annual energy requirements (MJ/m2. annum). Orientation
AccuRate star ratings
Annual energy requirements
Main window facing North
8.7
24
Main window facing East
6.4
57
Main window facing West
6.2
54
Main window facing South
5.4
78
4. Conclusions To tackle the climate change and global warming, measured need to be taken to reduce greenhouse gases emissions such as designing low energy buildings. In this paper the influence of the orientation of the Insulated cavity brick module on the overall thermal performance was analyzed. Appropriate orientation is a low cost option to improve comfort and decrease energy bills. Changing the building‟s orientation to either the east or west will heat the building during unwanted time (summer) because the east and west windows lose more heat than they gain in winter and gain more heat in summer and faces the cold wind stream in winter the hot stream in summer which accelerate the heat losses/gain . A southern orientation results in a little solar gain and heat losses through the window in winter. The final results confirmed that the best orientation is when the windows face the north in southern hemisphere to allow the winter sun's radiation to enter the module and to avoid main wind stream. Appropriate orientation helped to minimize heat losses in winter months by at least three times compared to the module when window facing south which impressively improve the overall thermal performance. References [1]
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