We propose a novel algorithm for rapid adsorption enthalpy characterization, based on the reduction of the sampling space from 3D to 2D. This method is more accurate than the previous Voronoi sampling strategy. Moreover, the dimension reduction coupled with symmetric properties makes it faster than the standard Widom insertion method. This algorithm has been tested on xenon and is directly applicable for any spherical adsorbate model; and it can then be adapted to polyatomic adsorbate molecules as well. This algorithm can be used in the future to speed up the calculation of adsorption properties in regular or ML-assisted high-throughput computational screenings of nanoporous materials.