Optimization of residential roof insulation layer thickness based on economic analysis by grey relation method

This study is focussed on the optimization of residential building roof insulation layers that includes weathering tile,wood wool and phase change material through grey relation analysis and numerical simulation techniques. the optimum thickness of insulation layers is determined for the quality objective of minimization of insulation material cost and energy consumption cost by air conditioning system over a life time of 10 years. for optimization of roof insulation layer,the insulation layers are varied to five levels with reference to the height of concrete (hc) layer and various combination of roof layers are obtained from taguchi’s l25 orthogonal array. the 25 combination of roof structures are analysed by numerical simulation technique to determine yearly heating transmission load and in turn used to calculate the cost of energy consumption for cooling a period of 10 years. as a result,the optimum thickness value of roof insulation layer - weathering tile,wood wool and phase change material are predicted as 0.33*hc,0.33*hc and 0.066*hc respectively and this optimum value will have the cost of insulation and yearly electricity cost of cooling for 10 years as 92 $/m2 and 12.45$/m2 respectively. © school of engineering,taylor’s university.