Abstract: A device for adjusting to a predetermined value the rate of flow of air introduced into an enclosed space having at least one inlet for introducing warm or cold air by means of a fan into the enclosed space includes structure for controlling the velocity of the air thus introduced into the enclosed space, structure for varying the velocity of rotation of the fan, at least one extractor for discharging the air from the enclosed space, and structure responsive to the pressure prevailing in the enclosed space for setting the extractor speed so that the removal of air from the enclosed space is adjusted automatically as a function of the predetermined volume of air introduced into the enclosed space.

Abstract: This system for burning low-grade fuels, notably used mineral oils, comprises a first so-called decantation tank receiving the fuel and connected, through an overflow device, to a second so-called storage tank, and a burner connected to this storage tank. The first decantation tank comprises means for heating the fuel under the control of a thermostat. A level detector is incorporated in the storage tank and connected to a pump inserted in the circuit supplying fuel to the first tank. The burner comprises a pump set to supply fuel to the burner jet through a reservoir provided with reheating means, so that the fuel delivered to the burner has a minimum temperature of 100.degree. C.