Ping-pong globe thermometers for mean radiant temperatures

Thermal comfort models and indoor climate standards require their users to input micro-environmental parameters which usually include an expression for the radiant field surrounding the building occupant. The traditional instrument for this last measurement has been a 15 cm diameter hollow copper sphere, painted matt black and with a mercury-in-glass thermometer at its core. The current paper describes the performance of a cheaper and readily assembled alternative to the 15 cm globe thermometer. Also discussed is the heat transfer equation necessary to derive mean radiant temperature estimates from its readings which can then be input to thermal comfort models and standards.