Influence of external shading on optimum insulation thickness of building walls in a tropical region

Abstract

Please cite this article as: E. Wati, P. Meukam, M.K. Nematchoua, Influence of external shading on optimum insulation thickness of building walls in a subtropical region, Applied Thermal Engineering (2015), Abstract 7 This study aims to optimize the thicknesses of insulation layers in external walls of 8 continuously used building in a subtropical region according to shade level. The investigation 9 is carried out under steady periodic conditions for various wall orientations using a Simulink 10 model constructed from H-Tools (the library of Simulink models). Walls are assumed to be 11 insulated using expanded polystyrene material. The shade level of the building site is assumed 12 to be varying from 0 to 97% with an increment of 25% or 22%. Yearly cooling load is 13 calculated and used as input to an economic model for the determination of the optimum 14 insulation thickness. It is seen that as shade level increases, optimum insulation thickness 15 decreases at an average rate of 0.035 cm, 0.029 cm and 0.036 cm per percentage of solar 16 radiation blocked for south, north and east/west oriented wall, respectively. Results also show 17 that energy savings vary between 46.89 $. m ିଶ and 101.29 $. m ିଶ and payback periods vary 18 between 3.56 years and 4.97 years depending on shade level and wall orientation.19

Investigation of efficient parameters on optimum insulation thickness based on theoretical‐Taguchi combined method

“…Comakli et al examined OIT for cold provinces (Erzurum, Kars, Erzincan) in Turkey. Kaynakli [16]. Yu et al calculated OIT for four typical cities of Shanghai, Changsha, Shaoguan and Chengdu in China.…”

Calculation of optimum insulation thickness of external walls in residential buildings by using exergetic life cycle cost assessment method: Case study for Turkey

“…The study stated that the economic model, which includes cost of energy consumption and cost of insulation material and the cost over a lifetime of 22 years of the building, were used to find optimum insulation thickness, energy saving and payback period, for buildings in Cameroon . Wati et al intended to optimize the thicknesses of insulation layers in external walls of continuously used building in a tropical region according to shade level . Axaopoulos et al determined that the optimum insulation thickness for external walls of different orientation of a piggery building was determined accounting for both the heating and the cooling period .…”

A Multi-Parametric Mathematical Approach on the Selection of Optimum Insulation Thicknesses in Buildings

“…Although very simple and fast in estimating OIT, the degree-days concept and the subsequent simplified relations, Equations (2) and (3), have been criticized for inconvenience, by ignoring the effect of solar radiation and thermal mass [15,16]. Actually, there are a few other parameters that have also been confirmed as affecting OIT significantly, but are not included yet in the above relations.…”

“…Other researchers examined alternatively the effect of external surface absorptance [17] and color [18] on OIT. In [16] it was examined the effect of shading on OIT, and demonstrated that full shading may decrease OIT by 3-3.5 cm (for a solar absorptance of 0.6). The significant effect of indoor temperature on OIT was also demonstrated [15], with the latter increasing remarkably with the winter Figure 1.…”