Energy crisis is one of the most important problems the world is facing now-a-days. With the increase of cost of electrical energy operating cost of cold storage storing is increasing which forces the increased cost price of the commodities that are kept. In this situation if the maximum heat energy (Q) is absorbed by the evaporator inside the cold room through convective heat transfer process in `terms of –heat transfer due to convection and heat transfer due to condensation and also heat enter in the cold store due to infiltration through cold room doors, more energy has to be wasted to maintain the evaporator space at the desired temperature range of 2-6 degree centigrade. In this paper we have proposed a modified theoretical heat transfer model of convective heat transfer in the evaporator space and heat enter in the cold store due to infiltration through cold room doors using Taguchi L9 orthogonal array. Velocity of air (V), Temperature difference (dT), Height of cold store door (H) are the basic variable and three ranges are taken each of them in the model development. Graphical interpretations from the model developed by polynomial multiple regression analysis.