The unit consists of a vertical brass pipe heated by a cartridge heater inside it. The pipe looses heat to atmosphere by natural convection. It is fitted in an enclosure to provide undisturbed natural convection currents. Thermocouples are attached on the pipe to measure local temperatures. Heater input is measured on voltmeter and ammeter. Thus students can determine overall heat transfer coefficient and local transfer coefficients in natural convection at various heat transfer rates.