WO2007010575A1

WO2007010575A1 - Shutter or casing and relative system capable of producing energy by solar radiation

Info

Publication number: WO2007010575A1
Application number: PCT/IT2005/000567
Authority: WO
Inventors: Enzo Nicchi
Original assignee: Enzo Nicchi
Priority date: 2005-07-22
Filing date: 2005-09-30
Publication date: 2007-01-25
Also published as: ITPI20050081A1

Abstract

A system that employs solar energy for producing thermal or electric energy, using the elements constituting a shutter or other casing as absorbing and/or converting elements. In particular, thermal or photovoltaic panels can constitute or be applied to the single bars (1) of a shutter. This shutter, connected to a suitable circuit (2, 3), is capable of producing energy.

Description

"SHUTTER OR CASING AND RELATIVE SYSTEM CAPABLE OF PRODUCING ENERGY BY SOLAR RADIATION"

Description Technical Field The present invention concerns the technical sector relating to the production of plants for the employment of solar energy and its conversion into electric or thermal or cooling energy, by production of sanitary water and/or thermoregulated air and/or electricity. Background Art

Nowadays, several types of plants for this purpose exist, but they essentially consist of systems substantially constituted by the following components: 1. the panel gathering solar energy; 2. the tank for the exchange of heat;

3. two separate circuits, one for the fluid of the main circuit of the panel (diathermy oil or the like) and the other one, held in the tank, heated by the thermal exchange with the first one, which will supply the various services inside the house.

This brief description of the plant makes it clear that a lot of buildings must be excluded from this specific purpose. As a matter of fact, in order to have the possibility to employ solar energy, buildings must have a sufficient external surface exposed to the sunrays, but in current building types this surface is limited to the roof or alternatively to a sufficient specific outer space.

In practice, certainly from an economic point of view, the usefulness of the employment of solar energy is sole prerogative of detached houses, which are able to install external absorbing panels.

Consequently, many users are prevented from making use of this technology, like people living in town flats or terraced houses, i.e. in all those building types not directly connected to the roof and without available external surfaces. This evident restriction, great in percentage compared with the possibility of employment of other technologies at present more tested, is an obstacle to the enormous energetic saving a widespread use of alternative energies, such as this solar power, would entail to the society in general (to the single user in particular) , not only with economical advantages but also with environmental benefits.

Furthermore, despite the ecological and economical advantages resulting from the use of the solar panels, such as technologically conceived at present, we cannot fail to disclose that these applications involve a strong environmental impact.

It's often possible to see rustic villas in the country equipped with said "all-roof" technologies, implying such an invasive effect that the more polluting and expensive gas tanks would be preferable. Therefore, solar panels currently existing involve many drawbacks, concerning not only their shape but also their colour, which prevent in fact their installation either on existing or new buildings. Another drawback in the existing technology of the solar panels is that they are installed over the roof of the building, so as to be in high position with no parts in shadow.

The subsequent drawback is that the panels are so exposed to the action of the wind. As a matter of fact, these panels are often installed on suitable supports separating them by the roof, so the wind can easily fit between the panel and the roof with the inevitable risk of lifting the panel or even damaging it in the case of strong wind. A further drawback is that the installation of the panels over the roof, therefore over the tiles, prevents the maintenance of the same roof; whenever it's necessary to repair the roof or replace one or more tiles, we need to previously remove the panels in order to facilitate the access to the roof, which would have been otherwise very uncomfortable or impossible. Even when it's possible to install traditional systems, they have such a strong environmental impact from the aesthetic point of view, that the owners of the building or the civil service in historical centres or other places cannot install them, in order to preserve the honour and beauty of that place. The current law relating to the environmental impact requires that new buildings should be well uniform with the location they are built in.

This invention aims at avoiding the above-mentioned and other drawbacks, supplying a system for the generation of electric energy, warm water or cooling air, employing the solar radiation, using casings or other pieces of furniture as collectors, with a non-mvasive aesthetic result, applicable to any type of building, implying the only limits of having necessarily windows directed from south-east to south-west. Disclosure of invention

We reached the above-mentioned result thanks to a casing or other piece of furniture comprising at least one, preferably more than one element absorbing and/or converting solar energy into thermal and/or electric energy, applied or integrated to it.

According to a first convenient solution corresponding to the conversion of solar energy into thermal energy, the casing, made like a shutter, is constituted by an external bell in low-lead toughened glass, which includes an element absorbing heat formed by a sheet like a radiator, isolated by vacuum from the external glass and containing the pipes where the fluid circulates . This fluid technically includes both liquids and gasses. Therefore in this system both a liquid and a gas, in particular air, can circulate. Said casing also comprises an inner inlet and outlet for the fluid, particularly realized so as to connect two or more elements each other, by means of the circuit that connects the outlet of a casing with the inlet of the successive element and so as to form a whole of single elements connected each other.

This element is conceived like a traditional solar panel. The external surface in glass has an internal dark cover that absorbs the energy transmitted by solar radiation, more precisely convert (s) this energy in thermal energy, through the heating of the internal fluid by conduction and/or convention and/or radiation.

The single casings can be united each other, so as to form all or part of the shutter of any building, and can be connected each other, so as to form a sort of hydraulic circuit. According to the known physical rules concerning temperature and density of fluids, the fluid circulating inside the hydraulic circuit rises as its temperature increases. Nevertheless, a pump or a fan can force the circulation of the fluid inside the circuit.

The fluid releases the heat gathered into an exchanger, so producing thermal energy from solar energy. The exchanger may be directly in contact with one or more rooms for example of a house, so in this way, it will release the heat of the fluid to these rooms; in alternative or combination, the exchanger may exchange heat for example with the sanitary water, in this case the fluid will release the gathered heat to the same sanitary water.

The fact the shape of the element is substantially similar to the shape of a casing or the like, permits to avoid the drawbacks relating to the prior art. As a matter of fact the shutters of a building can be entirely or partially realized with said elements, and it results non-invasive on the environmental impact. In a second preferable solution, the elements are realized like casings and comprise on their external surface at least one, but preferably more than one means to convert solar energy into electric energy, such as e.g. the known photovoltaic panels. The presence of said means permits the direct conversion of solar energy into electric energy, while the shape of the same element allows it to be installed without substantially modifying the aesthetic of a shutter according to the prior art, thus avoiding the drawbacks relating to it. Therefore, according to this second solution, it's possible to realize a shutter according to its traditional shape, together with the advantages entailed by the use of solar panels .

The advantages resulting from the present invention essentially consist of the fact that it's possible to make use of the energy for any type of building, as it's no more necessary to have a roof or another large external surface; that there is no environmental impact, as this system is completely invisible from the outside; that it can be varied as desired, as it's possible to use one or more collectors according to the type and quantity of energy we want to obtain; that the plant of this system can be realized by few operations without difficult installations.

This invention can be used in any type of building, with the only limit that windows directed to south-south/east- south/west are necessary. It permits to absorb solar energy with no need of modifying the external structure of the house with anti-aesthetic solar or photovoltaic panels. Everyone can benefit from this energy, avoiding all the aesthetic and technical restrictions of the existing plants, as well as the necessity to have roofs or large external surfaces. This invention can be prefixed in the construction of new buildings, as well as it can be successively used for replacing the traditional shutters. It can be used for different purposes, such as the production of warm water, the cooling of air and the production of electric energy. Furthermore, the possibility to realize a shutter of a building by means of the elements object of the present invention, permits to avoid the installation of solar panels over the same building. In this way it's possible to eliminate the drawbacks relating to the existing solar panels that are installed over the roof. The invention is now described referring to the figures of the enclosed drawings, given as practical examples of the invention but not to be considered restrictive.

Fig. 1 of the enclosed drawings shows a front view of a standard application system, both for new buildings and for replacing existing shutters, so keeping their original functions. This system comprises a series of elements (1), made like the usual cells absorbing solar energy; these elements, made of glass, includes a preferably dark cover, for a better attraction of the sunrays, which is isolated from the external casing by vacuum. These casings (1) are dark coloured, like traditional casings, which permits to get a system with no visual impact that can be placed on any shutter . The cover (section A) includes a copper pipe (3) carrying diathermy oil or other fluid. The circuit is supplied by a primary inlet pipe (2), inside the frame of the shutter, which, pushed by a pump, circulates back (3) into every cell, getting heat, later released to a water tank (4) placed inside the. house, by means of connecting pipes (8 and 9) crossing the wall. This is a clean and economical method to provide the house with hot water, by means of solar radiation. Every element (1) is separately connected to the circuit of the fluid. In this situation, every element is connected to the lower and upper element. In the lower part of the casing, the cool fluid arrives pushed by a pump and follows the entire length of the element (1) heating up. The fluid comes out from the outlet (3), directly connected with the inlet of the upper element. This is possible because a heated fluid becomes less stiff and so naturally rises. To this purpose, the elements are hydraulically connected each other, preferably in horizontal direction, so as to create a hydraulic circuit containing a fluid or diathermy liquid. Consequently, the fluid coming out from the element on the top of the shutter will be the one that has absorbed the greatest heat. It's possible to use directly the hot liquid for domestic or non-domestic employs, simply taking it by the element on the top of the shutter.

In alternative or combination with the natural circulation of the liquid, due to the continuous heating of the same liquid, the hydraulic circuit formed by the elements hydraulically connected can be pushed by a pump, e.g. a hydraulic pump or a fan, placed in the room, in the case the fluid circulating in the circuit is gaseous. Fig. 2 of the enclosed drawings schematically shows this exchange, thanks to a section of the various elements (1) forming the shutter, having an elliptical shape in order to avoid implosions. It shows in detail the external layer in glass (5), the vacuum (6), the black inner container (7) holding the pipe (3) where the fluid or preferably the diathermy oil circulates in a closed circuit inside the water exchanger (4), heating it and then circulating back inside every cell. This exchanger can be placed for example inside the building in the ordinary box holding rolling shutters or in a specific place.

It's however possible, in combination or alternative, that the horizontal lines of the elements are hydraulically connected each other at least for part of the entire horizontal extension, and are connected to the upper elements by means of at least one hydraulic connection, preferably more than one. In this way, it's possible to have different preferred "paths" of heating, realized connecting hydraulically the elements each other in different and preferred ways.

Fig. 3 of the enclosed drawings shows a further solution of this invention consisting of the possibility of assembling a kind of shutter with vertical elements (16), suitable both for absorbing solar energy and for darkening the room. Even these absorbing elements can be differently directed in order to compensate e.g. an imperfect direction of the window to the sunrays . Fig. 4 of the enclosed drawings shows that it's possible to replace rolling shutters with this energy shutter, using the upper box (10) for the insertion of the water boiler (9). Anyway, also in this case the principle of functioning is the same: the elements differently directed (1) absorb the energy and heat the suitable fluid inside the closed circuit (2=mlet; 3=outlet) from the shutter to the accumulator (9), where they release the heat and then get heat again in the I I

successive circulation inside the various elements. A pump can be provided for facilitating the circulation of the liquid inside the hydraulic circuit; in alternative or combination the hydraulic circuit can comprise no pump, or keep the pump off, e.g. when the boiler is placed so that the circulation is natural .

In particular, this system may be provided with at least one temperature sensor for registering the temperature of the fluid. As a matter of fact, the temperature of the fluid of the hydraulic circuit is strictly related, as above explained, to the circulation of the fluid inside the hydraulic circuit. Higher is the temperature of the fluid, better is the circulation inside the hydraulic circuit constituted by the whole of the elements hydraulically connected. Said temperature sensor can be operatively associated to the pump, so as to activate/deactivate the same pump when the temperature of the fluid is not sufficient to guarantee a perfect circulation or to meet the prefixed criteria. For example, when the circulating fluid is a liquid, during summer the circulation can be easily "natural", with no need of the pump, whereas in winter the pump should be activated. We would like to point out that the terms "upper" and "lower" indicate the assembling position of the element. According to a preferred practical solution, not herein depicted, a thermoconductor fluid, like e.g. air or similar, rather than a thermoconductor liquid, can circulate inside the cxrcuit constituted by the elements. The functioning of the hydraulic circuit containing a fluid is equivalent to the functioning of the hydraulic circuit containing a liquid. Fig. 5 of the enclosed drawings shows a different version of this energy shutter making use of a sliding system by means of flexible circuit pipes (11) and suitable rollers (13) to keep them on line during movement.

This case schematically depicts a kind of energy shutter aimed at cooling the internal room, thanks to the known principle used by three-functions refrigerators: obviously, gas or other fluid circulates into the cells m place of oil. This gas or fluid, heated up, is spread in the suitable cell (14) and then sent back to the absorbing elements (1): the cooling obtained by the spreading of the fluid is captured by the split (15) and then introduced into the room.

Said absorbing elements can be different in number and shape, according to the external structure of the shutter and to the quantity of desired electric or thermal energy. The technical solution object of the present invention makes use of a series of elements absorbing and/or converting solar energy, placed either horizontally or vertically and directed separately or together with the supporting frame. They replace the shutters in original position and functions, making them a series of absorbing elements designed to gather solar (thermal) energy, later converted by means of suitable instruments into electric energy or, by different constructing procedures, to produce sanitary water and/or thermoregulated air.

In the case the single elements are mounted on the frame for producing sanitary water or warm air, they essentially take the constructive conception of a solar panel, with the shape and size of a single element forming a shutter or other casing.

The exposure of any element is fundamental for a perfect radiation, thus the single elements can be directed separately or, thanks to an opposite frame, together, so as to always get the best result.

Each element is hydraulically connected to a collector pipe, placed in axis with the hinges fixing the casing, so as to permit to open the window without difficulties. The collector supplies all the vertical elements, creating an internal circulation of the diathermy oil or other fluid, by means of a pump or thanks to the natural flow of the same fluid.

The oil or other liquid or gaseous fluid, crossing the elements, increases its temperature and later releases it into a tank gathering water, placed inside the house. Inside the tank, through the thermal exchange, the fluid, preferably a liquid, permits to heat water and supply it to the house.

When we wish to heat the rooms, the external air represents the fluid circulating in the collector. This air is pushed into the first element through a suitable circulation system and, heating up, proceeds into the next elements thanks to natural circulation. Once heated, the air is directly spread in the rooms without the aid of an exchanger.

As above stated, the elements can be placed either horizontally, like in traditional shutters, or vertically, which, in this solution, are more effective and/or pleasant to look at.

In place of these elements, the shutters can be provided with two dark panes, consisting of a traditional solar panel connected to the water circuit.

In addition, the shutter can be constructed for a sliding opening, by means of particular rollers for the connecting pipes . In the specific case of replacing rolling shutters with energy shutters, the box previously filled by the rolling shutter can be conveniently filled by the boiler, so getting a considerable saving of space a's well as a closeness convenient for the good functioning of the hydraulic circuit. In all the above-described cases, the thermal energy absorbed by the elements can be used not only for heating water, but even for cooling rooms, thanks to the known principle used by three-functions refrigerators: the fluid heated by the absorbing elements is spread in a panel and successively reinserted in the same exchangers. The cooling obtained by the spreading of the fluid is captured by the split and then introduced into the room. In all these cases, however, the single elements are generally made of an external bell in low-lead toughened glass, capable of gathering the sunrays . This bell has an elliptical shape in order to avoid implosions due to the change in pressure caused by -the vacuum and by the variations of temperature. It includes an element absorbing heat formed by a sheet like a radiator, isolated by vacuum from the external glass and containing the pipes where the diathermy oil or other fluid circulates. The ends, compatible with the possibility of direction to the frame, will have valid hinged axis that, outside, coincides with the in and out coaxial passage of the fluid reaching the boiler.

The fluid crosses every single element, from the lower part to the. upper part, so getting the heat later transmitted to the internal water tank, heating it.

Once cooled, the circuit takes the fluid back into the shutter (s), starting from the base.

The shutter object of the present invention can convert thermal energy into electric energy. As a matter of fact, in the case that photovoltaic elements are associated to the shutter, placed in series and connected to a collector, according to the known art and with the same general possibilities of employ, it's possible to set the system with the purpose of gathering electric energy, so getting a versatility of use however deriving from the same concept concerning the present invention. Reduced to its essential structure and with reference to the figures of the enclosed drawings, a system for producing energy by solar radiation, according to the present invention, comprises at least one, preferably more than one element capable of absorbing and/or converting solar energy into thermal or electric energy, integrated or applied to at least one, preferably more than one element constituting a shutter or casing or piece of furniture designed to be exposed to the sun. This invention also comprises a shutter, casing or other piece of furniture equipped with at least one, preferably more than one element capable of absorbing and/or converting solar energy into thermal or electric energy, integrated or applied to it. Conveniently, for producing thermal energy, solar panels are applied or integrated to the casing. In the case this thermal energy is used to heat water, it's necessary that these panels are connected to a system for converting radiation into energy, consisting e.g. of a heat exchanger, a boiler or other similar means.

In the case thermal energy is used to heat the air crossing the element, there is no need of an exchanger, as this air is directly spread in the room. In this case, the circulating air is taken either from the room or from the outside. Conveniently, for producing electric energy, photovoltaic panels or cells are applied or integrated to the casing. In this case, said photovoltaic panels act also as exchangers, since they immediately convert the absorbed energy into electric energy.

The elements constituting the casing can be one or more windows of the same casing, one or more dark panes and so take the shape of a solar panel or cell. Said elements can be also constituted by horizontal or verticals bars forming a shutter or any other element forming any casing. In the case this invention is used to produce warm water, for sanitary purposes or for preheating the water of the boiler of a heating plant, said elements (1) are constituted by solar panels absorbing solar energy, made of glass, which include a cover inside, preferably dark for a better attraction of the sun rays, isolated by vacuum from the external glass. In this solution, the elements forming a shutter or casing are constructed like real solar panels according to the known constructing technology.

The cover of every element includes a pipe (3) holding a product necessary for the exchanger, e.g. diathermy oil, glycol, cooling gas or other fluid. The^' circuit is supplied by a primary inlet pipe (2), preferably inside the frame of the window, holding a fluid, either liquid or gas, which, pushed by a pump or due to natural circulation, circulates back (3) inside every panel. The fluid, in particular the water, during circulation gets heat and later releases it to a tank (4) placed inside the house, by means of connecting pipes (8 and 9) crossing the wall.

Conveniently, the single element constituting a casing or other piece of furniture designed to be exposed to the sun is made of a solar panel or cell that takes the shape of the same element .

Conveniently, any casing or other piece of furniture can be constructed so that its entire body is made of a solar panel or cell. In the case of a shutter, said element takes the shape of its typical bar, in the case of a grating, it takes the shape of the vertical or horizontal axes, in the case of a door, it takes the shape of a real panel. Conveniently, the shutter, in place of the two panes with the typical horizontal bars as above depicted, can be formed by two dark homogeneous panes, made of the traditional solar panels and connected to the plant like in the previous case. This invention particularly relates to a shutter or other casing formed by a frame, comprising a circuit supplying the various absorbing elements, replacing the traditional bars or dark panes, which are crossed by a fluid heating it; this hot fluid is carried by the same circuit into a water tank that, crossed by said (closed) circuit, gets the heat necessary to raise the temperature of the water it contains. This invention also relates to a system that employs solar energy for conditioning a room. In particular, it consists of a shutter, or other casing, similarly equipped with internal circuit and absorbing elements, but in this case crossed by suitable fluid or gas that, once heated, is spread into a specific cell and then sent back in circulation. The spreading of the gas causes a cooling that is captured by a split and then released into the room.

In particular, it consists of a shutter, or other casing, equipped wxth a series of photovoltaic cells or panels replacing the dark panes. Said cells, differently directed, are electrically connected in series and, by means of various existing devices, they permit to supply the house by alternated 220V current, like a traditional method. Conveniently, the shutter or other casing can be of any constructing type (sliding, hinged, with vertical dark panes, fixed or variable) , without losing any of its positive characteristics .

In practice, the constructing details may however equally vary as regards shape, size, position of elements and type of materials used, but still remain within the range of the idea proposed as a solution and, consequently, within the limits of the protection granted by this patent for invention. Brief description of drawings Advantages and characteristics of the present invention can be better understood by every expert in this field, referring to the enclosed drawings, given as practical examples of the invention, but not to be considered restrictive.

- Fig. 1 shows a first practical solution of the present invention, where said casings are placed horizontally and constitute a hydraulic circuit.

- Fig. 2 shows a section view of a hydraulic circuit according to the present invention and in particular an element of this invention.

- Fig. 3 shows a second practical solution of the present invention, where said casings are placed vertically and constitute an electric circuit.

- Fig. 4 shows the first practical solution of the present invention, where said casings are placed horizontally and constitute a hydraulic circuit, with the exchanger placed over the window.

- Fig. 5 shows another practical solution of the present invention, where said casings are placed horizontally with a sliding system and constitute an electric circuit.

Different versions of energy shutters can be conceived for obtaining different types of energy, such as electric energy.

As a matter of fact, in place of the above-mentioned suitable panels, it's possible to use photovoltaic cells placed in series like the dark panes of a shutter, so that they can convert, by known art, thermal energy into electric energy and thus supply the various services of the house. According to a preferred practical solution, not herein depicted, a thermoconductor fluid, like e.g. air or similar, rather than a thermoconductor liquid, can circulate inside the circuit constituted by the shutter. The functioning of the hydraulic circuit containing a fluid is equivalent to the functioning of the hydraulic circuit containing a liquid, when the final aim is the heating of the sanitary water. The heated air can also be used in order to raise the temperature of the room and, in this case, the air coming out from the top of the roof can be directly pushed into the desired rooms, with no exchange or waste of heat.

Claims

1) System for producing energy by solar radiation, characterized in that it comprises one, ^' preferably more than one element absorbing and/or converting solar energy into thermal and/or electric energy, constituted and/or integrated or applied to one or more elements constituting a shutter or other casing or piece of furniture designed to be exposed to the sun.

2) Shutter, casing or other piece of furniture, characterized in that it comprises one, preferably more than one element capable of absorbing and/or converting solar energy into thermal or electric energy.

3) Invention as claimed in claim 1 or 2, characterized in that said absorbing and/or converting elements are thermal panels.

4) Invention as claimed in claim 1 or 2, characterized in that said absorbing and/or converting elements are photovoltaic panels .

5) Invention as claimed in claim 1 or 2, characterized in that said elements are constituted by the bars (1) forming a shutter or other casing.

6) Invention as claimed in claim 1 or 2, characterized in that said bars (1) consist of cells absorbing solar energy, made of glass, which include a cover inside, preferably dark for a better attraction of the sun rays, isolated by vacuum from the external glass. 7) Invention as claimed in claim 1 or 2, characterized in that Said cover includes a pipe (3) carrying a fluid for the exchanger, such as diathermy oil, glycol or cooling gas.

8) Invention as claimed in claim 1 or 2, characterized in that the single element or bar (1) constituting a casing or other piece of furniture designed to be exposed to the sun is made of a solar panel or cell that takes the shape of the same element.

9) Invention as claimed in claim 1 or 2, characterized in that the element constituting the casing or other piece of furniture consists of the entire body of the same casing, made like a solar panel or cell.

10) Invention as claimed in claim 1 or 2, characterized in that the element constituting the casing or other piece of furniture consists of one or more dark closed panes made by solar panel or cell.

11) Invention as claimed in claim 1 or 2, characterized in that it comprises a circuit supplied by a primary inlet pipe (2), preferably inside the frame of the casing, holding a fluid that, pushed by a pump or due to natural circulation, circulates back (3) inside every element.

12) Invention as claimed in claim 11, characterized in that said fluid, in particular a liquid, during circulation gets heat and later releases it to a water tank (4) placed inside the house, by means of connecting pipes (8 and 9) crossing the wall. 13) Invention as claimed in claim 11, characterized in that said hydraulic circuit is provided with at least one temperature sensor for registering the temperature of the circulating fluid. 14) Invention as claimed in claim 11, characterized in that said fluid, particularly a gas, once heated, is spread into a specific cell and then sent back in circulation, thus causing a cooling.

15) Shutter, casing or other piece of furniture made of a frame, characterized in that it comprises a circuit supplying the various absorbing and/or converting elements, replacing the traditional bars or dark panes, which are crossed by a fluid, preferably a liquid, heating it; this hot fluid is carried by the same circuit into a water tank that, crossed by said circuit, gets the heat necessary to raise the temperature of the water it contains.

16) Shutter, casing or other piece of furniture, characterized in that it comprises an internal circuit and absorbing and/or converting elements, crossed by a fluid, particularly a gas that, once heated, is spread into a specific cell and then sent back in circulation. The spreading of the gas causes a cooling that is captured by a split and then released into the room.

17) Shutter, casing or other piece of furniture, characterized in that it comprises one or more photovoltaic panels, replacing or applied to the dark panes or other element forming the casing, which are electrically placed in series and permit to supply the house with electric energy. 18) Shutter, casing or other piece of furniture, characterized in that the fluid circulating in the element (s) consists of the external air. This air is pushed into the first element through a suitable circulation system and, heating up, proceeds into the next elements thanks to natural circulation. Once heated, the air is directly spread in the rooms without the aid of an exchanger.