Mean Radiant Temperature Measurements through Small Black Globes under Forced Convection Conditions

One of the most critical variables in field thermal comfort measurements is mean radiant temperature which typically measured with a standard 150 mm black globe thermometer. This also reference instrument required for assessment heat stress conditions by means well-known Wet Bulb Globe Temperature index (WBGT). However, one limitations this method represented relatively long response time. why recent years there has been more and pressing need smart sensors controlling Heating Ventilation Air Conditioning (HVAC) systems, pocket meters (e.g., WBGT provided table tennis balls). Although it widely agreed that clear advantage small probes terms times, their accuracy still debated matter no systematic studies aimed at metrologically characterizing performances are actually available, due to difficulty reproducing measuring such as enclosure uniform temperature. In paper results metrological analysis two globes (38 50 diameter) carried out an experimental apparatus specifically designed reproduce presented discussed. Experimental revealed underestimation predicted than 10 °C forced convection high radiative loads.