Heat Transmission in Closed Space with a Heat Source

Abstract

Heating a room by a room-heater or Japanese “Kotatsu” is one of the examples of warming closed space by means of a heat source placed in the space.
In order to study the convection produced by this way of heating, three simpler models were used.
In the present report, two methods were employed to investigate convection ; (1) --temperature was measured at different points in the model placed in air and in a vacuum respectively ; (2) --air streams were observed by making smoke.
It has been found by smoke method studies on “Kotatsu” that there is convection in “Kotatsu” until thermal equilibrium is established after electricity is turned on ; this convection had been rather unthinkable because the heat-source is on the ceiling of the “Kotatsu”; but the existence of convection was confirmed.
Further research was done, on the basis of the smoke method studies with models, to elucidate why there is convection in “Kotatsu”.