The convective heat transfer coefficient of the shell-side of helically coiled tube heat exchangers is numerically investigated in the present study. The present study’s purpose is to evaluate the influence of geometrical parameters on local convective heat transfer coefficients. The heat exchangers’ coil and shell-sides flow are fully laminar and steady. Grid independence for the numerical simulation is implemented, and the results are validated against corresponding experimental measurements. The highlights of the present simulation are the fluid-to-fluid model of the heat exchangers and the calculation of exact local heat transfer coefficients and its variation concerning pitch changes that are primarily prohibitive to conduct through experimental measurements on the same type of compact heat exchangers in terms of the complexity of the thermal energy exchange mechanisms. It is concluded from the results that the optimum pitch for the helically coiled tube that provides maximum heat transfer coefficients is achievable at some intermediate pitch values.