Journal of Computational Applied Mechanics

Comparative study between dynamic transient and degree-hours methods to estimate heating and cooling loads of building’s wall

Document Type : Research Paper

Authors

Center of Excellence in Design and Optimization of Energy Systems, School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran

Abstract

In this paper, dynamic transient method and conventional degree-hours method (static) have been compared to estimate heating and cooling loads of building’s wall. All main wall surfaces of various orientations, i.e.South, West, East, North, and horizontal are considered in the climate of Tehran, Iran. In this study, a conventional wall structure, which is comprisedconcrete as main wall material, and EPS (expanded polystyrene), as insulation material, areused. The actual outdoor air temperature (used in dynamic method) was obtained by mean hourly measurementsrecorded in meteorological data over the period of 2006–12. Annual heating and cooling degree-hoursare calculated based on this recent weather data, and results are compared with the values reported in the national building regulations (topic 14). One dimensional transient heat transfer problem for multilayer walls has been solved to obtain temperature distribution within the wall. Annual heating and cooling load resulting from dynamic method have been compared with degree-hoursmethod; the results showed that there is a significant difference between these two estimations.

Keywords

Main Subjects

[1].J. Yu, L. Tian, C. Yang, X. Xu and J. Wang, "Optimum insulation thickness of residential roof with respect to solar-air degree-hours in hot summer and cold winter zone of china," ENERG BUILDINGS , vol. 43, pp. 2304-2313, 2011.
[2].O. Kaynakli, "A study on residential heating energy requirement and optimum insulation thickness," RENEW ENERG, vol. 33, p. 1164–1172, 2008.
[3]."Ministry of Energy," 2013. [Online]. Available: http://www.moe.gov.ir/.
[4].A. Bolatturk, "Optimum insulation thicknesses for building walls with respect to cooling and heating degree-hours in the warmest zone of Turkey," Building and environment, vol. 43, pp. 1055-1064, 2008.
[5].O. Kaynakli, "A review of the economical and optimum thermal insulation thickness for building applications," Renewable and Sustainable Energy Reviews, vol. 16, pp. 415-425, 2012.
[6].M. Ruth and A. Lin, "Regional energy demand and adaptations toclimate change: methodology and application to the state of Maryland," USA. Energy Policy, vol. 34, no. 17, pp. 2820-2833, 2006.
[7].R. Cox, M. Drews, C. Rode and S. Nielsen, "Simple future weather files for estimating heating and cooling demand," Building and Environment, vol. 83, pp. 104-114, 2015.
[8].Minisrty of Roads & urban development, national building regulations part 14, tehran, 2010.
[9].American Society of Heating, Refrigerating and Air-conditioning Engineers, Inc., 2009 ASHRAE handbook, fundamental, AHSRAE, 2009.
[10]. M. Ozel, "Determination of optimum insulation thickness based on cooling transmission load for building walls in a hot climate," Energy Convers Manage, vol. 66, pp. 106-114, 2013.
[11]. S. A. Al-Sanea, M. Zedan and S. A. Al-Ajlan, "Effect of electricity tariff on the optimum insulation-thickness in building walls as determined by a dynamic heat-transfer model," APPL ENERG, vol. 82, pp. 313-330, 2005.
[12]. H. Asan, "Investigation of wall’s optimum insulation position from maximum time lag and minimum decrement factor point of view," ENERG BUILDINGS, vol. 32, pp. 197-203, 2000.
[13]. J. Duffie and . W. A. Beckman, Solar Engineering of Thermal Processes, 2nd ed ed., New York: John Wiley & Sons, Inc., 1991.
[14]. H. Hottel, "A simple model for estimating the transmittance of direct solar radiation through clear atmospheres," Sol Energy, vol. 18, no. 2, pp. 129-134, 1976.
[15]. M. Ozel and K. Pihtili, "Optimum location and distribution of insulation layers on building walls with various orientations," BUILD ENVIRON, vol. 42, no. 8, p. 3051–3059, 2007.
[16]. R. L. Burden and J. D. Faires, Numerical Analysis, Boston: Brooks/Cole, Cengage Learning, 2011.
[17]. "I. R. Iran's Meterological Organization," 2013. [Online]. Available: www.weather.ir.
 
Journal of Computational Applied Mechanics
Volume 46, Issue 2 - Serial Number 2
July 2015
Pages 153-165
  • Receive Date: 29 December 2014
  • Revise Date: 21 March 2015
  • Accept Date: 21 March 2015