In the present work, an experimental investigation was carried out to study the influence of design parameters of impinging air jets on heat transfer, temperature and Nusselt number in a multi-jet air impingement system. Studies have been conducted to see the effect of parameters such as type of nozzle, area of nozzle, Reynolds number and H/D ratio on the heat transfer characteristics. Square, triangle and circular type nozzles with area 8, 10 and 12 mm2 were used for the analysis considering Reynolds number 18000, 20000 and 22000. The H/D ratio used was 2D, 4D and 6D. Taguchi based design of experiment approach with L27 orthogonal array was used to design the experiments. Grey relational analysis is used to optimize the multiple responses and the uncertainty in the experimental data is handled using fuzzy logic technique. The complexity, vagueness and softness in the experimental data are eradicated using fuzzy rules and hence the deductive inference based on rules is used for effective decision making. The investigation reveals that the type of nozzle contributes the most towards overall performance with contribution of 86% followed by area of nozzle, H/D ratio and Reynolds number respectively. A significant improvement in experimental data is observed with the application of fuzzy logic technique. © 2018 Editura Academiei Romane. All rights reserved.