The importance of mini shell and tube heat exchangers (STHEs) in industrial and other engineering applications cannot be underestimated. Hence, based on the problems associated with the design of STHEs, a mini STHE was developed for transfer of heat between two fluids without mixing on the laboratory scale using locally available materials and technology based on an optimized LMTD technique. The performance of the heat exchanger was assessed and evaluated to determine the optimum combination of design parameters. Copper was utilized for the tube side fluid due to its higher thermal conductivity and anti-microbial property, while galvanized steel was used for the shell side fluid due to its cost and corrosion resistance. Parametric studies were carried out on STHE design parameters to obtain an optimal design for efficiency and effectiveness after relevant design considerations. Experimental results were validated with quantitative models, and it was discovered that both Dell-Belaware and Engineering Science Data Unit (ESDU) approaches produced the optimal results required for the selection of shell side and tube fluid film coefficients, respectively over other correlations. In conclusion, the values of parameters of interest were also presented after rigorous mathematical calculations at optimal level and probable recommendations were later made.