Abstract: Apparatus for recovering heat or cooling from a room space and ventilating it, consisting of heat accumulators in which the outgoing air releases its heat and from which the incoming air picks up heat or vice versa and which are alternatively connected by one end with the exhaust duct and intake duct of the room space, the direction of flow in these ducts being the same all the time under control by two flaps, and the opposite ends of the heat accumulators being connected to the fresh air intake duct and the outgoing exhaust duct, the direction of flow being the same in these latter ducts all the time under control by the two flaps. The heat accumulators consist of elements which may be added or taken off two and two, in accordance with the required capacity of the apparatus, and that the intake and exhaust ducts carried to the room spaces can correspondingly in a manner known in itself be lengthened or shortened by means of branch pieces.

Abstract: A vaporizer-burner using liquid fuel such as oil, in which the oil conducted to the combustion chamber is vaporized before being ignited and in which the air required for combustion has been conducted to the combustion chamber along a separate duct. The problem in this type of vaporizer-burners of prior art is the continuous vacuum prevailing in the combustion chamber during operation, which renders the flame unstable and sensitive to changes in ambient conditions, such as wind squalls. With the vaporizer-burner of the invention, the problem has been solved in that the air supply duct has been divided into two parts, one directing air to the oil vaporizing process and the other to the combustion process, and that the supply proportion of said so-called primary and secondary airs can be adjusted with the aid of a turnable flap placed in the duct.

Abstract: A heating appliance operable with a single heat source to heat both circulating water and water for domestic use includes an upright cylindrical reservoir containing water for household use and having an inlet at its lower end and an outlet at its upper end. A closed cylindrical tank of smaller diameter extends vertically concentrically through the reservoir and contains an electric immersion heating element for heating circulating water flowing through the tank from a lower inlet to an upper outlet. An elongated cylindrical tube in the reservoir extends concentrically about the tank in closely spaced relationship thereto and has a closed bottom end secured about a lower portion of the tank and an open upper end spaced from the upper end of the reservoir.

Abstract: A means for recovering the heat of a room space and for ventilation, consisting of at least two heat accumulators, to which the outgoing air delivers its heat and from which the incoming air takes up heat, and each of which has one end connected to the room space outflow duct and inflow duct, in which ducts the direction of flow is always the same under control by a flap. The opposite ends of the heat accumulators have been connected to the fresh air intake duct and to the outgoing exit duct, in which ducts the direction of flow is always the same under control by another flap.