The influence of feedback and convection on imposed heating conditions when using gas-fired radiant panels in fire testing

Gas-fired radiant panel arrays (RPAs) are a common experimental tool used in fire science and material testing. Unlike devices such as Cone Calorimeter or the Fire Propagation Apparatus (FPA), RPAs typically consume gaseous fuel within a porous medium through which fuel is burnt. When RPAs are used, thermal feedback from the surface of heated samples, as well as the effects of hot gases within the zone of convective influence of the RPA will cause an increase in the surface temperature of the RPA. To investigate this, experiments were conducted using a gas-fired RPA. Target samples made from vermiculite board, concrete, and a water-cooled aluminium plate were exposed to various severities of pre-calibrated incident radiant heat fluxes (HF). It was confirmed that the presence of a target sample led to an increased surface temperature for the RPA of nearly 80 °C (for a calibrated incident HF of 144 kW/m2). This increased surface temperature results in an incident HF nearly 78% higher than the pre-calibrated value at the sample’s surface Based on the results in this paper, a correction method has been proposed which can be used by gas-fired RPA users to account for the increase in incident heat fluxes.