The P.E.T. comfort index: Questioning the model

This work is a first thorough presentation of the widely used PET (Physiological Equivalent Temperature) comfort index. It underlines the simplifications made in solving the equation system for the PET and proposes a correction of the errors in the widespread version of the PET calculation routine. A comparison of the corrected model with a stringent solving of the equation system is made: as a result, the PET calculated after the original method introduces a bias of −0.5 to +2.3 [K] in the studied conditions (operative temperature, high mean radiant temperature and windy environments).