ASHRAE RP-1383, "Develop a Radiant System Module for the Simulation and Analysis of Spaces and Systems," produced analysis procedures that allow calculation and display of comfort conditions at any point within a room. These procedures are implemented in a PC-based application called Radiant Performance Explorer (RPE), an enhanced version of the ASHRAE Thermal Comfort Tool. The project developed a method for calculating view factors from an arbitrarily positioned occupant to all surfaces of an arbitrarily shaped space.

With this general ability and knowledge of room surface temperatures, mean radiant temperature (MRT) can be calculated for any occupant position This in turn allows derivation of common comfort measures such as predicted mean vote (PMV) and predicted percentage dissatisfied (PPD). Other radiant values, such as radiant temperature asymmetry, are also calculated. RPE displays these results in a computer-graphics-based visualization screen.

RPE can import and display data generated by the threedimensional (3D) drawing tool, SketchUp; the building energy simulation application, EnergyPlus; or other sources. Export of comfort results is available. The project also enhanced EnergyPlus to more flexibly model controlled-temperature panels.