Effect of insulation location on dynamic heat-transfer characteristics of building external walls and optimization of insulation thickness

Özel, Meral

doi:10.1016/j.enbuild.2013.11.015

Cited by 136 publications

(58 citation statements)

References 37 publications

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“…However, when insulation is placed on the outside of the wall, the time lag will be higher and decrement factor will be lower. The same trend has also been reported in a recent study by Ozel (2014).…”

Section: Resultssupporting

confidence: 85%

“…Also, several authors used sol-air temperature instead of ambient air temperature in this method (Al-Khawaja, 2004;Yu, Yang, Tian, & Liao, 2009). The dynamic time-dependent model is an accurate model to determine heat loss or gain from the composite walls, which has been used in models proposed by several authors (Al-Sanea, Zedan, & Al-Ajlan, 2005;Daouas, 2011;Daouas, Hassen, & Ben Aissia, 2010;Ozel, 2012Ozel, , 2013aOzel, , 2014Mavromatidis, EL Mankibi, Michel, & Santamouris, 2012). The dynamic transient model has been solved numerically and analytically for multi-layer walls in the literature.…”

Section: Introductionmentioning

confidence: 99%

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Determination of optimum insulation thickness in different wall orientations and locations in Iran

Ramin

Hanafizadeh

Akhavan-Behabadi

2015

Advances in Building Energy Research

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The present study numerically investigated the optimum insulation thickness determination for conventional walls in Tehran, the capital of Iran. In this study, aerated brick and concrete were considered as the main wall materials, and XPS and EPS as the insulation materials. The onedimensional transient heat transfer problem for multi-layer walls has been solved to obtain temperature distribution within the wall. Different combinations of wall materials and insulations were examined. Furthermore, the effect of the position of the insulation (inside and outside of the wall) was studied as well. Finally, in order to determine the optimum thickness, which minimizes the total cost of insulation and energy dissipation, economic analysis was carried out for a lifetime of 25 years. It is worth mentioning that in the present study, both cooling and heating seasons were taken into account in the optimization process. The findings revealed that after using insulation, among different wall configurations, yearly transmission load can be decreased in the range of 70-82% compared with an uninsulated wall made from concrete and 31-58% for the aerated brick wall. Moreover, the findings indicated that two different locations of insulations resulted in an approximately equal transmission load and optimum insulation thickness, while their time lag and decrement factor were not the same. NomenclatureAlphabetic symbols R b geometric factor A o amplitude of the temperature wave at the outer surface of a wall S e net energy saving per unit area ($/m 2 ) A i amplitude of the temperature wave at the inner surface of a wall T b base temperature A s annual energy saving per unit area ($/m 2 ) T i indoor air temperature B dummy variable (n − 1) 360/365 T o outdoor air temperature b payback period (year) T e sol-air temperature C enr cost of energy ($/m 2 ) T surr surrounding temperature C e cost of electricity ($/kWh) t max Tx=0 time when outdoor temperature is at its maximum (h) C g cost of natural gas ($/m 3 ) t max Tx=L time when indoor temperature is at its minimum (h) C t total cost (energy + insulation) T max X =L maximum temperature at the inner surface of a wall (K) T min X =L minimum temperature at the inner surface of a wall (K) c heat capacity (J/kg · K) T max X =0 maximum temperature at the outer surface of a wall d inflation rate (%) T min X =0 minimum temperature at the outer surface of a wall E equation of time x distance (m) f decrement factor H u lower heating value of the fuel (J/m 3 ) Greek symbols h i indoor surface combined convection heat transfer coefficient (J/m 2 · K) a thermal diffusivity (m 2 /s) h o outdoor surface combined convection heat transfer coefficient (J/m 2 · K) a s solar absorptivity ( W ) i interest rate (%) b slope of the surface ( W ) I total solar radiation on a horizontal surface (W/m 2 ) g surface azimuth angle ( W ) I b beam solar radiation on a horizontal surface (W/m 2 ) d declination angle ( W ) I d diffuse solar radiation on a horizontal surface (W/m 2 ) DT temperature difference I T total ...

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Section: Resultssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Determination of optimum insulation thickness in different wall orientations and locations in Iran

Ramin

Hanafizadeh

Akhavan-Behabadi

2015

Advances in Building Energy Research

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“…Tremendous publications have investigated the impact of different improvements of the TQBE on the heating and cooling load of the buildings [8][9][10][11][12][13][14][15][16][17][18][19]. 45% Reduction in heating load of could be fulfilled in Ankara by adding insulation to external envelope along with the reorienting the building (relative to the Sun) [11].…”

Section: Introductionmentioning

confidence: 99%

Comparison between different measures to reduce cooling requirements of residential building in cooling-dominated environment

Kharseh

Al‐Khawaja

Hassani

2015

Energy and Buildings

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“…Studies on verifying the excellence of external insulation method in terms of energy efficiency, LCC (Life-Cycle Cost) and construction period through comparative analysis of internal and external insulation methods have been consistently proposed [16][17][18][19][20]. In recent years, studies have been conducted to evaluate the heat transfer rate and airtightness of the external insulation method applied to the Passivhaus-a voluntary standard for energy efficiency in a building that recommends annual heating and cooling demands to be less than 15 kWh/m 2 and the total specific heat load as less than 10 W/m 2 [21][22][23][24][25][26][27]. In addition, various researches have been carried out to improve the external insulation method in terms of determining the optimal insulation material thickness in order to secure the insulation performance considering the characteristics of the construction industry of various countries, their regional conditions and climatic conditions [28][29][30][31][32][33][34].…”

Section: Research Background and Purposementioning

confidence: 99%

Simulation Model for Productivity Analysis of External Insulated Precast Concrete Wall System

Baik

Kim

Lee³

et al. 2018

Sustainability

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External Insulation Finishing System (EIFS) is recognized as a suitable method for attaining energy efficiency of buildings. However, conventional EIFS is not actively applied to building construction due to additional time and cost compared with interior insulation method. Therefore, as an alternative that can contribute to active utilization of the external insulation system, this study proposes an External Insulated Precast Concrete (PC) Wall System and its simulation for performing productivity analysis. Results of this study are as follows: (1) an external insulated PC-Wall system is developed of which its insulation performance is above 40% higher than that of the conventional EIFS; (2) performance of the developed system satisfied American Standards for Testing of Materials (ASTM) and American Architectural Manufacturers Association (AAMA) standards; (3) applicability of the developed system is verified via test-bed with construction time lapsing about 40 min for each PC-Wall; and (4) CYCLONE modeling methodology is employed to perform productivity analysis of the developed system compared with conventional EIFS.

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Effect of insulation location on dynamic heat-transfer characteristics of building external walls and optimization of insulation thickness

Cited by 136 publications

References 37 publications

Determination of optimum insulation thickness in different wall orientations and locations in Iran

Determination of optimum insulation thickness in different wall orientations and locations in Iran

Comparison between different measures to reduce cooling requirements of residential building in cooling-dominated environment

Simulation Model for Productivity Analysis of External Insulated Precast Concrete Wall System

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