Air-Conditioning Apparatus for Indoor Environments

This application claims priority to Italian Patent Application No. 102024000006139 filed Mar. 19, 2024, the entire contents of which is hereby incorporated in its entirety by reference.

The present invention relates to an air-conditioning apparatus for indoor environments, comprising a pellet stove combined with an internal monoblock heat pump.

An indoor environment to be air-conditioned, i.e., to be heated and/or cooled, is understood to be a room or space delimited by walls, possibly provided with doors and/or windows.

An outdoor environment means the exterior of the dwelling and/or building to be air-conditioned.

Heating apparatuses, such as particularly stoves or boilers, to be fuelled by solid fuel, e.g., wood or pellets, are known and widely used for heating air and/or water in dwellings.

Such known apparatuses usually comprise a containment structure in which there are housed, respectively, a combustion chamber, an electric igniter, a solid fuel storage tank, movement means for the fuel in the combustion chamber, a first pumping means, or fan, for the movement of the combustion air under pushing or suction and for the related evacuation of combustion fumes, an air-to-air heat exchanger, and a second pumping means, or fan, for forced heat exchange and conveying of hot air into the home environment.

The combustion chamber usually houses a brazier in which the fuel is deposited through appropriate devices, usually of the auger type.

The combustion air is drawn from outside the containment structure by suction due to the action of a first blade fan operable by an electrically powered motor, and conveyed through an inlet duct at the brazier; here, through appropriate ignition means, the combustion is ignited, which generates high-temperature combustion gases.

The combustion air can be drawn from outside the dwelling to be heated, through a connection duct between the stove structure and the building wall. This is known as an airtight installation.

An airtight installation requires a hole in the wall of the house to let in the combustion air.

The combustion gases then pass through a heat exchanger, usually arranged downstream of the combustion chamber, to exchange heat with the containment structure of the apparatus, which in turn dissipates it, by radiation and/or natural convection, into the home installation environment.

Possibly, second pumping means, such as a second fan operable by an electric motor, may be provided to distribute heat into the outdoor environment in a forced convective manner, improving the thermal efficiency of the apparatus and allowing also heating environments other than that in which the apparatus itself is installed.

The combustion fumes are then expelled from the apparatus through an appropriate exhaust duct due to the action of the first pumping means.

Command and control means, such as a conveniently programmed electronic board, are generally provided to manage and coordinate the various electrical utilities provided in the apparatus to allow the correct operation thereof.

In the case of pellet stoves for household use, a visible flame is generated through a glass, and heat is released into the environment by virtue of the combination of radiation and convection, forced and natural, implemented in the stove structure.

Pellet stoves are used exclusively for home heating in the winter period, generally from October to March.

Pellet stoves have seasonal operation and thus remain unused in the summer period, generally from April to September.

Therefore, during the summer period, portable devices can be used in homes for summer air-conditioning.

The portable devices are usually heat pumps, which can be used for cooling and/or heating an environment.

A portable device can be considered as a monoblock heat pump unit, in which all the components of the cooling cycle, such as compressor, condenser, expansion device, evaporator, and control system, are enclosed in a single package.

For the operation of the monoblock heat pump, a refrigerant medium is used in a closed circuit to move heat from a hot source to a cold source, preferably a natural refrigerant gas, such as R290 gas.

R290 gas is preferred because it is a refrigerant medium with a low global warming potential.

In a standard heat pump, the closed refrigerant fluid circuit is composed as follows: the compressor sucks in the refrigerant gas by compressing it in the high-pressure zone of the circuit. The compressed gas is pushed into a first heat exchanger (condenser), where it yields heat to the environment and cools down, until it condenses into liquid form. The low-pressure liquid reaches a second heat exchanger (vaporizer), where it absorbs heat from the environment by switching to the gaseous form to be sucked in again by the compressor, beginning the cycle again.

A monoblock heat pump thus has two inlets for the air drawn from the indoor environment.

A monoblock heat pump, in the cooling mode, has an inlet, where the indoor air passes through the heat exchanger of the condenser to absorb heat from the refrigerant fluid before exiting towards the outdoor environment by means of an outlet pipe.

A monoblock heat pump, in the cooling mode, has a second inlet, where the indoor air passes through the exchanger of the evaporator to yield heat to the refrigerant fluid, and then be cooled and/or dehumidified before exiting towards the indoor environment.

The monoblock heat pump usually has a system for disposing of the condensate water recovered from cooling the condenser, which is disposed of through the air heated by the condenser exiting towards the outdoor environment.

Indicatively, the use of two separate devices is required to air-condition an indoor environment in both winter and summer.

This known solution has some disadvantages and drawbacks.

Indeed, as mentioned above, the use of two air-conditioning devices requires placing the two apparatuses at different locations in the same indoor environment.

An additional disadvantage of such a solution is the need to provide two holes in the walls of the internal structure to match the two separate apparatuses. Indeed, a first hole is used to channel the input combustion air needed by the pellet stove, and a second hole is used to channel the output of hot air produced by the heat pump in the indoor room cooling operation mode. Examples of the above-described prior art are disclosed by EP 3367006 A1, WO 2006/008762 A1, KR 2023 0012743 A and CN 116336569 A.

Therefore, the need is felt to overcome the drawbacks and limitations mentioned with reference to the prior art.

Such a need is met by an apparatus as described and claimed herein.

In the following embodiments, individual features, given in relation to specific examples, may be interchanged in practice with other different features existing in other embodiments.

With reference to the figures, in particular, a winter and summer air-conditioning apparatus indicated by reference numeralis shown, which is a containment structurehaving a casing delimiting a first compartmentand a second compartment. In particular, a pellet stoveis housed in the first compartment, and a portable monoblock heat pumpconfigured to operate in heating and/or cooling mode is housed inside the second compartment.

Preferably, the first compartmentand the second compartmentare airtight.

Preferably, the first compartmentand the second compartmentare mutually separate compartments.

According to a possible embodiment, in the first compartment, which houses the pellet stove, there are housed, respectively, a storage tankfor solid biomass fuel, e.g., pellets, an augerfor movement of the solid biomass fuel, a combustion chamber, a brazier, an electric igniter, a first fan or fume extractor, for movement of combustion airunder suction and subsequent evacuation of combustion fumes, and a second fanfor movement of indoor airdrawn from the indoor environment and which is heated before being reintroduced into the indoor environment.

According to an embodiment, in the second compartment, which houses the monoblock portable heat pump, there are housed, respectively, a condenser, a third fan, for the movement of the airdrawn from the indoor environment which absorbs the heat released by the condenserbefore exiting towards the outdoor environment by means of a pipe, an evaporator, and a fourth fan, for the movement of the airdrawn from the indoor environment that is cooled and dehumidified, yielding heat to the evaporatorbefore being reintroduced into the indoor environment.

A first duct, for the movement of the combustion airinput into the pellet stove, and a second duct, for the movement of the heated airoutput from the heat pump, are present in the air-conditioning apparatus.

According to a possible embodiment, the first ductand the second ductare connected to a junction box, which is connected to an outlet holeof the air-conditioning apparatus.

The outlet holeis fluid-dynamically connected to a corresponding hole arranged on the wall of the indoor environment by means of an outlet duct.

According to a possible embodiment, in the junction boxthere is a valvefor alternately opening and closing the first ductand the second duct.

Specifically, in a heating operating mode with a pellet stove, the valvecloses the second duct, while in a cooling operating mode with a heat pump, the valvecloses the first duct.

The valveallows airtight operation and installation. In both operating modes, the first ductand the second ductare not connected to each other and are in communication only and exclusively with the outdoor environment.

When using the apparatus in the heating operating mode with the pellet stove, the valvecloses the outlet ducttowards the outside of the heat pump. This avoids the suction of combustion air from the heat pumpin the case of a refrigerant fluid leak.

According to another embodiment, the first ductand the second ductare connected together with a “Y” fittingor a “T” fitting. In this variant, a duct opening and closing valve is not necessary to ensure an installation and operation of the air-conditioning apparatus.

In a further embodiment of the present invention, the first ductand the second ductare connected by a concentric fitting, where a coaxial pipeis connected, to put the air-conditioning apparatusinto communication with the outdoor environment. A duct opening and closing valve is not necessary in this variant to ensure an airtight installation and operation of the air-conditioning apparatus.

An electronic board, conveniently programmed, is connected with appropriate wiring to the various electrical utilities. Alternatively, the pellet stoveand the heat pumpcan have two independent electronic boards communicating with each other.

For example, an electronic panel, which allows managing and coordinating the various electrical utilities in the air-conditioning apparatus, is provided. Alternatively, the pellet stoveand the heat pumpcan have two separate and independent control panels.