High-temperature radiant heaters - those with a surface temperature greater than 300°F - typically are applied in large, open, and occupied spaces such as warehouses and aircraft hangers.  These heaters provide an efficient means of delivering thermal comfort to specific work stations without having to condition the entire occupied space.  Highly efficient thermal comfort can be delivered because radiant heaters focus thermal energy, and therefore thermal comfort, directly on the occupants, rather than controlling room temperature as do other heating systems.  

The goal of this research project was to develop a simplified thermal comfort methodology that reliably calculates the thermal comfort effect, as expressed as the operative temperature, of high-temperature radiant heaters.  The developed methodology would be an add-on module to the already-existing Discrete-Ordinates Radiation Solver used in the Building Comfort Analysis Program (BCAP), which was developed under ASHRAE project RP-657 (Chapman, 1994).

This research report contains: 1) a study of the types of high-temperature radiant heaters and mathematical heat transfer characteristics of each; 2) an examination of radiation models; 3) a review of thermal comfort and radiant heat transfer measures; 4) an explanation of the developed model; and 5) several case studies where the model is applied.  The developed method can be used as a design tool for sizing and placing high-temperature radiant systems, possibly in combination with other heating systems as it encompasses a wide range of building materials and operating conditions.