A heating device, preferably for the combustion of biomass, in particular of pellets of biomass, in one aspect, includes a burner part and a heating part. The burner part includes a combustion chamber; a double-walled, internally hollow combustion-chamber wall, which has an upper opening leading above the combustion zone into the combustion chamber; a flue-gas duct which leads the flue gas downwards along the combustion chamber, wherein the flue-gas duct is followed by a heat-exchanger area including initially, a flat-tube flue-gas heat exchanger, then, a tertiary-air heat exchanger; a flue-gas ventilation stack, a radiant-heat exchanger located above the combustion chamber, a flue-gas flap at the upper end of the flue-gas duct, which, when open, connects the flue-gas duct to the stack. A flat-tube flue-gas heat exchanger of the heating part forms a heat-exchanger circuit with an exhaust-air heat exchanger with the same heat-transfer medium as the flat-tube flue-gas heat exchanger.

A heater having a combustion chamber. The heater includes a hopper and a chute extending from an outlet of the hopper to the combustion chamber. The heater includes a chute extending from the hopper to the combustion chamber, a screw extending through the chute into the hopper, and a drive connected to the screw for turning the screw in a direction in which the flight would, but for downward forces, lift the fuel. The heater has a vane rotatably attached to the screw that rotates downward along the screw in absence of upward forces counteracting gravity. The vane is cambered to produce upward forces when turning with the screw beneath an upper surface of the fuel. The vane is biased toward the upper surface of the fuel to level the upper surface of the fuel and prevent the fuel from rat holing and arching.

A heating device, preferably for the combustion of biomass, in particular of pellets of biomass, in one aspect, includes a burner part and a heating part. The burner part includes a combustion chamber; a double-walled, internally hollow combustion-chamber wall, which has an upper opening leading above the combustion zone into the combustion chamber; a flue-gas duct which leads the flue gas downwards along the combustion chamber, wherein the flue-gas duct is followed by a heat-exchanger area including initially, a flat-tube flue-gas heat exchanger, then, a tertiary-air heat exchanger; a flue-gas ventilation stack, a radiant-heat exchanger located above the combustion chamber, a flue-gas flap at the upper end of the flue-gas duct, which, when open, connects the flue-gas duct to the stack. A flat-tube flue-gas heat exchanger of the heating part forms a heat-exchanger circuit with an exhaust-air heat exchanger with the same heat-transfer medium as the flat-tube flue-gas heat exchanger.

An air-conditioning apparatus for air conditioning indoor environments has a containment structure having a casing delimiting a first compartment and a second compartment. A pellet stove configured to operate in heating mode and provided with a first duct for movement of combustion air in input to the pellet stove is housed inside the first compartment. A monoblock portable heat pump configured to operate in heating and/or cooling mode and provided with a second duct for movement of heated air in output from the monoblock portable heat pump is housed inside the second compartment.