This standard specifies procedures@ apparatus@ and instrumentation for rating thermal performance of ceiling panels in a specific indoor configuration and thermal conditions. Thermal performance of a ceiling panel is measured in terms of heat delivered or heat removed by the ceiling panel as a function of the average fluid temperature of the heat transfer medium in the ceiling panel and the temperatures characterizing the surrounding indoor space. This standard covers testing of ceiling panels in the following effective panel surface high and low temperature range limits: Sensible Heating Ceiling Panels: from 24??to 65??(75??to 149?? for nonmetal heat transfer elements in the ceiling panel or from 24??to 150??(75??to 302?? for metal heat transfer elements in the ceiling panel. Sensible Cooling Ceiling Panels: from 14??to 24??(57??to 75??. This standard does not cover the following ceiling panels: a. Hybrid (combined thermal radiation and forced-convection: load-sharing) ceiling panels. b. Ceiling panels that are embedded into the ceiling@ wall@ or floor structure. c. Test methods for design@ production@ or field-testing of ceiling panels. PURPOSE This standard establishes uniform methods of laboratory testing for rating steady-state thermal performance of ceiling panels used in indoor spaces for sensible heating@ sensible cooling@ or both. The objective is to rate ceiling panels under repeatable conditions.