A study on optimum insulation thickness in walls and energy savings in Tunisian buildings based on analytical calculation of cooling and heating transmission loads

Naouel Daouas

Applied Energy, 2011, vol. 88, issue 1, 156-164

Abstract: In Tunisian climate, both heating in winter and cooling in summer are required to reach comfort levels. Due to the significant increase in building energy consumption, insulation of external walls is recently applied with a thickness typically ranging between 4Â cm and 5Â cm regardless of structure and orientation of walls and of economic parameters. In the present study, optimum insulation thickness, energy saving and payback period are calculated for a typical wall structure based on both cooling and heating loads. Yearly transmission loads are rigorously estimated using an analytical method based on Complex Finite Fourier Transform (CFFT). Considering different wall orientations, the west and east facing walls are the least favourite in the cooling season, whereas the north-facing wall is the least favourite in the heating season. A life-cycle cost analysis over a building lifetime of 30Â years shows that the south orientation is the most economical with an optimum insulation thickness of 10.1Â cm, 71.33% of energy savings and a payback period of 3.29Â years. It is noted that wall orientation has a small effect on optimum insulation thickness, but a more significant effect on energy savings which reach a maximum value of 23.78Â TND/m2 in the case of east facing wall. A sensitivity analysis shows that economic parameters, such as insulation cost, energy cost, inflation and discount rates and building lifetime, have a noticeable effect on optimum insulation and energy savings. Comparison of the present study with the degree-days model is also performed.

Keywords: Optimum; insulation; thickness; Energy; savings; Cooling; loads; Heating; loads; Complex; Finite; Fourier; Transform; Life-cycle; cost (search for similar items in EconPapers)
Date: 2011
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (37)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306-2619(10)00299-0
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:88:y:2011:i:1:p:156-164

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().