WO2004106810A1

WO2004106810A1 - Heating system with heat transmission fluid distributed in finished floor boards

Info

Publication number: WO2004106810A1
Application number: PCT/EP2004/005820
Authority: WO
Inventors: Adelio Da Rold
Original assignee: Adelio Da Rold
Priority date: 2003-05-30
Filing date: 2004-05-28
Publication date: 2004-12-09
Also published as: ITBL20030007A1; EP1629235A1; US20070017656A1

Abstract

Object of this invention is to provide a new heating system, particularly of a floor heating for flats, offices, shops and any kind of civil dwelling place, said system being able to combine the best thermal conductivity and the least bulk of irradiation surface of the floor, besides assuring the best uniformity or distribution of the areas to be heated with consequent decrease of the energy consumption. It is disclosed that one feature of this invention is to provide a board (1) preferably made of metal which can be cut into portions having the sam length as that of the room (V), can be put side by side and joined together to reach the whole width of the room (V), and have the same height (H) and width (L) as a floor board. It is further provided with a series of ducts (12, 13, 14 and 15) that can be linked to delivery connections (4a, 4b, 4c) etc. and to backflow connections (4z, 4y, 4x) etc., each of them having a inlet wing (45) and an outlet wing (46) that form with respective pipe portions (6a, 6b, 6c) etc. and (6z, 6y, 6x) the delivery collector or duct (A) and the backflow collector (B) of the circuit for the transmission of the heat transmission fluid. The fluid passes through the ducts (12, 13, 14 and 15) of each board (la, lb, lc) etc. thereby transmitting the temperature to the room (V).

Description

HEATING SYSTEM WITH HEAT TRANSMISSION FLUID DISTRIBUTED IN

FINISHED FLOOR BOARDS

The present invention relates to a heating system, particularly a floor heating, for flats, offices, shops and any kind of civil dwelling places or housings, said system being able to combine the best thermal conductivity and the least bulk of irradiation surface of the floor, besides assuring the best uniformity or distribution of heat to areas to be heated with consequent decrease of the energy consumption due to reduced temperature required by a heat transmission fluid.

One feature of the invention is to provide a floor heating system using an element preferably made of metal which can be manufactured, for instance, by extrusion, and can be cut individually, for example, as long as the length of a room to be heated, the element being put side by side with other elements or modules of the same kind to reach or cover the whole width of the room. Therefore, the element is shaped as a floor board having a connectable side surface and a cross section that provides several ducts for the heat transmission fluid which are arranged adjacent to free rooms for structural reduction. An end of each duct is furthermore connectable, for example, by means of joining tight rings or sealing rings to linear connections for the linking with an adjacent duct, or is connectable to "Y"-shaped or three-line connections, which are able to feed only one duct of each extruded element and to feed other following identical connections of other contiguous ducts, so as to distribute the heat transmission fluid to several batteries of heating modules .

In comparison to traditional heating systems having radiators to be fixed to a wall, the floor heating of the present invention for flats, offices, shops or any other civil housing has the advantage of eliminating the body of the radiator on the walls of the room, and further allows decoration of the room without presence of the radiant elements which are unwanted for aesthetical reasons.

The floor heating equipment has also the advantage of a more uniform distribution of heat, can be further used to cool the room, and after all provides a heating or heat of a quality which is surely higher than the one of traditional heating systems having wall radiators .

Some techniques for providing floor heating installations are, anyway, based on the principle of placing one or more coils directly on a bottom of each room to be heated or on an insulating layer which lays on the bottom, such coils being connected to a delivery duct and back-flow collector or duct which are respectively linked to a boiler.

The different known floor heating systems then require the application of a sand layer or other insulating and filling materials having the thickness of the coil, the application of a layer of cement, mortar or other materials stiff enough to allow support of floor tiles, parquet, moquette or other final coverings of the floor.

As a matter of fact, the presence of a stiff and solid layer of material for supporting and fixing the finished floor, in junction with the thickness of the tile itself or of other coverings determines the formation of a layer that can be between 8 - 10 cm of material that opposes heat transmission of the below coil of any topical floor installation.

This disadvantage constitutes the main reason for limited (heat) diffusion of the floor heating system, since before having the room heated, a certain time for the heating of the thick layer placed over the coil is required, since it forms a barrier against heat propagation.

An improvement of this known floor heating technique has been suggested in patent WO 88/07158, Fig. 5 of which provides an embodiment of a flat modular plate with seats for the housing of ducts for the thermal heat transmission fluid, the upper surface of which can be covered by a finished floor, thereby spreading immediately the absorbed heat without excessive thicknesses that delay the thermal efficiency.

The same patent WO 88/07158 suggests a valid solution of another great inconvenience of the prevailing technique for floor heating which is represented by the long rest times required by concrete of the floor before laying the traditional heating installation. Since said patent suggests an independent laying of the radiant plate directly on the rough state floor, time can be saved during the stage of delivery and use of the dwelling place.

Unfortunately, with the embodiment of the radiant plate proposed in the above-mentioned patent it is difficult to carry out the covering of ordinary floors with respect to both the difficulty in providing bulky radiant surfaces and the difficulty in placing effectively and/or efficiently the ducts for the heat transmission fluid, and finally since said patent suggests several generic uses, without presenting any real solution that can be used for the application in floor heating systems .

Another drawback of all the topical floor heating systems is given by the large quantity of water which is to be heated and required to feed each coil, not to mention the fact that in order to affect the room temperature the same large quantity of water has to be heated to at least 35 - 40° with a great energy consumption to achieve a thermal range also after switching off the system.

A further disadvantage of conventional floor heating systems is given by the problem of their maintenance, particularly with respect to the fact that whole floors have to be re-r-made in case of breakdown or occlusion of the coil.

It is an object of the present invention to allow transmission of heat from the floor immediately and instantaneously like the heat provided by conventional radiators, wherein the advantage of a distribution from the floor and the advantage of enabling the use of large amounts of water in the installation with a minimal increase of temperature is maintained with respect to the temperature that is wished to be achieved in the room, its transmission to the room being immediate.

It is another object of the present invention to provide a floor heating system, which is directly in contact with the room to be heated, and can determine an immediate transmission of its heat to the room, also after an improvement of its circuit for the delivery of the thermal heat transmission fluid.

Still another object of the present invention is to achieve a prompt and sufficient heating of the room even at minimal difference between the temperature of the heat transmission fluid and the desired room temperature, thus achieving great reduction of energy consumption for a reduced heating of big amounts of water circulating in the installation.

It is still another object of the present invention to achieve the temperature of the heat transmission fluid also using alternative energy sources, like solar panels.

Further object of the present invention is to assure a best possible uniformity of the temperature in all the rooms or single areas to be heated, presenting the most versatility in installation and use.

Another object of the present invention is to assure best condition for installation and maintenance of the system, the system being formed of few, simple, fast, and interchangeable constructive elements . Last but not least object of the present invention is to provide a floor heating system that does not negatively affect the height of the room, and being substantially as thick as a conventional floor board.

These and other objects of the present invention are perfectly achieved by the present invention, as it can be understood from the following description of embodiments given by way of example only and being not intended limiting, illustrated also with reference to 10 schematic figures, in which:

Fig. 1 represents a perspective partial view of a portion of a modular metallic floor heating element according to the present invention, which is manufactured, for example by extrusion and already finished for application as floor covering, and is further provided with four ducts for the passage of a heat transmission fluid;

Fig. 2 represents a perspective view of a pair of modular elements of Fig. 1 that can be connected to each other to form part of a surface of a radiant floor;

Fig. 3 represents a front view of a three-point connection intended for heat transmission fluid delivery connections from a net to, at least, some of the ducts of the modular elements of Figs. 1 and 2, as well as to other ducts of these modular elements for backflow to the net; Fig. 4 represents a top view of the connection of Fig. 3 according to one of its ideal axial sections;

Fig. 5 represents a side view of the connection_, of Fig. 3;

Fig. 6 represents an axial sectional view of a male portion of a linear connection for linking a pair of ducts of the modular elements of Fig. 1 being adjacent to each other in order to achieve an inversion (of flow) of the heat transmission fluid between these adjacent ducts;

Fig. 7 represents an axial sectional view of a female portion that can be linked to the male portion of the connection of Fig. 6;

Fig. 8 represents a top view of several modular elements of Fig. 1 coupled to each other side-by-side and linked to form a portion of a finished floor of a corresponding room to be heated, they being represented with an adjacent series of joints for the delivery of the heat transmission fluid coming or entering into each element, and joints for the collection of the fluid coming out from the modular elements, after having circulated in the other ducts of each module under passage in the provided linear connections of Figs. 6 and 7 placed at an opening of each duct which is not already engaged with one of the three-point connections of Figs. 3 to 5; Fig. 9 represents a vertical sectional view of a longitudinal intersection between walls and a floor of a room into which the delivery and backflow system for the heat transmission fluid of Fig. 8 is applied;

Fig. 10 represents a first constructive variation of the system illustrated in Fig. 8.

In all figures same elements are represented or are to be understood as being represented by the same reference numbers.

According to the embodiments illustrated in the attached drawings, a modular metallic element 1, preferably made of aluminum alloy or of any other material that combines lightness, steadiness and good thermal conductivity, is accomplished, for example by extrusion in order to have two flat opposite surfaces 10 and 11 linked by a series of four cylindrical ducts 12, 13, 14, and 15 having the same distance one to the other and with the outer ducts 12 and 15 being spaced apart from edges 16 and 17 by half of the distance between the ducts 12, 13, 14, and 15.

According to the proposed embodiment, the two flat surfaces 10 and 11 are linked to each other by the thickness of the ducts 12, 13, 14, and 15 as well as by a series of middle ribs 18, 19, and 20 for forming together with the lateral edges or sides 16 and 17 and said ducts 12, 13, 14, and 15, respectively, the empty and clear openings 21, 22, 23, 24, 25, 26, 27, and 28.

The modular stiff element 1, as already mentioned, can advantageously be accomplished by extrusion, and then can be cut into portions of fixed or particular sizes in order to be able to be laid down as a floor covering any room having an standard length.

To the upper surfaces 10 of the modular element 1 a tape 2 or a final floor covering is glued or fixed in an arbitrary manner in order to provide the element 1 also with the aspect or appearance and function of a finished floor board.

The modular element 1 further comprises a male side rib 30 and female rib 31, respectively, provided in order to be able to connect the different elements 1 placed side-by-side to cover the whole width of the room and to avoid their uncoupling or any possible movement.

According to one exemplary but not limiting embodiment, the modular element 1 can have a length L of about 180 - 200 mm, while its overall height can be of about 15 - 16 mm, that can reach together with the final covering 2 a thickness H of about 20 mm, that means said modular element 1 can have the same section as that of a wooden floor board as well as an identical appearance and function once it has been laid down.

In Figs. 3 to 5 an embodiment of a three-point connection 4 is illustrated, said connection 4 comprising a joint 41 with a hole 42 communicating with holes 43 and 44 of two wings 45 and 46.

Said wings 45 and 46 diverge with respect to an axis of the joint 41 by an angle α of about 100° - 150° and their respective holes 43 and 44 have a bigger diameter in comparison to the hole 42 of the orthogonal duct 41. In Figs. 6 and 7 a possible shape of a linear connection 5, alternative and complementary to the connection 4, is illustrated with respect to the connections of the ducts 12 to 15 of each element 1 or of more elements 1 arranged side by side.

A male angular element 51 is linked to a female angular element 56 such that their respective free ends 52 and 57 can be inserted into two adjacent ducts 12 to 15 of one or more elements 1 arranged side by side.

An opposite end 53 of the male angular element 51 is housed and inserted into a hollow or boring 59 of an opposite end 58 of the female angular element 56 after having placed between them proper tight rings or sealings or other kinds of sealings that can be also incorporated.

Also the stability and sealing of the connection 41 with the ducts 12 to 15 of the element 1 as well as the stability and sealing of the ends 52 and 57 of the linear connection 5 with the remaining holes 12 to 15 of the elements 1 is achieved by putting in between a proper number of elastic sealing rings or other kind of sealings .

A better stability can be ensured by fixing every connection 4 or 5 to the respective joining point on the ducts of the modular element 1 by means of clamps or other known mechanical fixing systems.

The present system can be completed by provision of a traditional pipe 6' (cf. Fig. 8) for the delivery A of a heat transmission fluid, and provision of a corresponding traditional pipe 6" for the backflow B as well as a series of flexible pipe portions 6a, 6b, 6c, ..., 6z, 6y, 6x etc. that respectively form a duct or collector for the delivery and recovery of the heat transmission fluid, being able to be linked by putting in between proper sealing rings or seals as well as being closed with elastic bands or other known and corresponding fixing systems .

After having so described some of the parts included by the present system, their clear assembling and their logic function is illustrated below also with reference to the achievement of the objects specified above, in particular with reference to attached Fig. 8, in which the elements la, lb, and lc are arranged side by side belonging to a line of elements mentioned to form the entire length and the entire width of a floor of the room to be heated.

In Fig. 8 is shown a first three-point connection 4a being inserted into the duct 12 of the first element or board la, in order to link the wing 45 of the duct 12 to a net for the delivery or backflow of the heat transmission fluid.

The free end 46 of the connection 4a is linked, preferably with a pipe portion or an elastic connection 6a, to the end 45 of the subsequent three-point connection 4b which is inserted into the hole 12 of the adjacent element lb.

An outlet of the duct 12 of the element la is linked to an inlet of the contiguous duct 13 by means of a linear connection 5a, while an outlet of the duct 13 is linked to the adjacent duct 14 by means of an opposite linear connection 5b. An outlet of the duct 15 is so linked to another three-point connection 4z that, in turn, includes an arm 45 linked to a backflow collector and the other arm 46 coupled to the adjacent connection 4y by means of a pipe portion 6z.

This connection system is clearly repeated in each element or board lb, lc and so on that are linked to the starting element la, while a final portion 6d can be applied to a wing 46 of a last delivery connection 4d to be reversed and inserted into a wing 46 of a final backflow connection 4x indicated at 6x, so as a male elbow or angular element 51 can be housed in the final duct 12 to 15 of the last board 1 of the floor to collect the coming out fluid and pass it into the backflow duct 6x, while the wing 46 of the last delivery connection is closed.

As an effect of these connections, the heat transmission fluid coming from a boiler by means of the collector gets in contact with the first connection 4a to feed both the first duct 12 and the pipe portion 6a and the following pipe portions 6b, 6c, etc., so as to feed every initial ducts 12 of each element la, lb, lc, etc. at the same time and with the same input temperature.

Going through the ducts 12, 13, 14 and 15 of each contiguous element la, lb, lc, etc., the heat transmission fluid transfers heat partially to the ducts of boards la, lb, lc, etc. and needs so to go back to the boiler to absorb new heat, i.e. to be reheated.

As a matter of fact, for example, in the case of the element la, the "cooled" fluid coming out the duct 15 is collected by the connection 4z and is conveyed with the "cooled" fluid already collected by the other connections 4y, 4x, etc, of the other elements lb, lc, etc., to be forced to leave the arm 45 of such a connection 4z and join the remaining fluid that, due to the collector, is pushed towards the heating boiler.

With particular reference to Fig. 9, a practical laying down of the installation of Fig. 8 is highlighted, supposing its application on a floor that separates two different flats or rooms placed one over the other.

The modular element 1, finished with its final floor covering 2 is placed on an insulating layer I, preferentially after having placed therebetween a sound-dampening covering G, the length of the element 1 being lightly shorter than the length of the room V to be heated.

A three-point connection 4a is applied on the head of the duct 12 at an end of the element 1, while an opposite flat reversal connection 5a is applied to the opposite side of this duct 12 of this board 1 and a further outlet connection 4z is applied to the following duct 15 of this board 1.

The presence of the delivery connections 4a, 4b, 4c, etc. and of the similar backflow connections 4z, 4y, 4x, etc. besides a minimal room for connecting to the respective flexible delivery pipes 6a etc. and 6z etc. requires the presence of a pass or space Cl provided on a base of walls that form the length of the room V, said longitudinal space being accomplished, for example, by applying a gypsum cardboard that remains raised from the floor by some centimeters and has a proper thickness. Also the presence of the opposite series of flat connections 5a and 5c require the provision of an opposite pass or space C2 even if it needs a lower depth, its overall dimensions being lower and being similarly made of gypsum cardboard with a thinner lower thickness than that of the space Cl.

In both the inlet and outlet sides of the installation, the room V is anyway regularly closed by the respective skirting boards S that cover the edges of the panels 1 and link them to the walls of the room V.

From Fig. 9 the easiness and immediacy of laying down the present heating system as well as its easy and cheap maintenance and can be inferred, since a skirting board S can be temporarily lifted to reach the connection 4 or 5 to check or replace it without having to ruin the floor as it happens in all the topical floor heating systems .

From the above explanation it is clear that the heat absorbed by each element or board 1 is immediately transmitted to the room, since the board 1 is insulated only by a thin layer of covering or flooring surface 2 that absorbs all the heat received and spreads it to the room.

The immediacy of the transmission, from the heating element 1 to the room, linked to the great volume of heat transmission fluid that characterizes this one as any other kind of floor heating system, allows to limit the temperature of the fluid by a temperature lightly higher than that wished in the room, thereby ensuring a reduction in the energy consumption, besides the possibility of resorting to solar panels or any other alternative kind of energy.

The presence of only one delivery duct and backflow collector for each board 1, preventing the heat transmission fluid from running through the whole coil net of a floor, assures the minimal decrease of temperature and so the uniformity of heating in every single area of the floor.

The easy embodiment and assembling of a few elements forming the described system ensures then the most easy provision, maintenance and revision of each installation accomplished with this system, and further allows easy replacement of possible ruined parts .

With reference to Fig. 10, one possible version among the many versions possible with the present system is described.

According to this embodiment, a floor element la is provided with ducts 12, 13, 14, and 15, but, for example, in case of a longer course to be run by the heat transmission fluid, the same fluid is forced to go back to its backflow duct B after only three ducts 12, 13, and 14 have been passed, while a second delivery connection 4b is applied to an inlet of the duct 15 of the panel la, in order to feed then the duct 12 of the following panel lb and so on, to feed connections 4a, 4b, 4c etc. a series of three ducts for each backflow B with the respective ducts 4z, 4y, 4x, etc, as well as middle flat connections 5a and 5b and final reversal connections 51. This arrangement with an odd number of ducts gives also the advantage of placing the delivery duct A on a head wall and the backflow B on the opposite back wall that form the length of the room V to be heated adjusting the depth of the respective passes Cl and C2.

Of course it is possible in both illustrated solutions that the heat transmission fluid runs through a longer course than that relative to the ducts of each element or board 1, joining, for example at the outlet of the duct 15 of Fig. 8 a further linear connection 5 that links it to the following duct 12 of the following panel lb to postpone the application of the backflow connection 4z onto a following duct of the second or other floor element 1.

Then, it is also possible to skip the heat feeding of one or more ducts or one or more boards 1, joining the outlets and the inlets of the last delivery connections 4c and backflow connections 4x directly with the fist connections 4a and 4z of the following area to be heated, or linking them to a pair of male elbows 5 linked to each other by means of a proper flexible pipe.

It is also possible to provide the panels or boards 1 with a different number of ducts, thus it is possible that the delivery and backflow connections 4 at the back of the feeding position of the installation are replaced with simple male elements 51 that can be linked to each other for the backflow through a last duct of the last panel 1 to be placed or also through a flexible duct linking them. The floor heating system till now described, like any other topical floor heating system, is also intended to be used as a perfect cooling system for the room, simply by replacing the hot water with a proper cooling fluid, so as in the heating system any other possible use of hot water or any other fluid transmitting the temperature to be spread into the room is possible.

Finally, the floor heating system according to the present invention till now described can be subjected to several changes and adjustments for every requirement and solution without departing from the scope of the invention as defined by the appended claims.

It is disclosed that one feature of this invention is to provide a board 1 preferably made of metal which can be cut into portions having the same length as that of the room V, can be put side by side and joined together to reach the whole width of the room V, and have the same height H and width L as a floor board. It is further provided with a series of ducts 12, 13, 14 and 15 that can be linked to delivery connections 4a, 4b, 4c etc. and to backflow connections 4z, 4y, 4x etc., each of them having a inlet wing 45 and an outlet wing 46 that form with respective pipe portions 6a, 6b, 6c etc. and 6z, 6y, 6x the delivery collector or duct A and the backflow collector B of the circuit for the transmission of the heat transmission fluid. The fluid passes through the ducts 12, 13, 14 and 15 of each board la, lb, lc etc. thereby transmitting the temperature to the room V.

Claims

1. A modular element (1) for usage in a floor heating system comprising: a top surface (10) and an opposing bottom surface (11); the top surface (10) and the bottom surface (11) being linked by a series of longitudinal ducts (12 - 15) through which a heat transmission fluid, particularly water, is to be passed; wherein the longitudinal ducts (12 - 15) are adapted for connection with three-point connections (4) and/or two-point connections (5) for coupling each of the ducts (12 - 15) to a delivery duct (A) for feeding the heat transmission fluid to the ducts (12 - 15), and to a backflow duct (B), respectively, for collecting and feeding back the transmission fluid, wherein the two-point connections (5) connect adjacent ducts (12 - 15) and the three-point connections (4) connect the ducts (12 - 15) to the delivery duct (A) or the backflow duct (B).

2. The modular element (1) of claim 1, wherein the element (1) further comprises lateral longitudinal edges (16, 17) being adapted to be joined with another modular element (1) side by side.

3. The modular element (1) of claim 1 or 2 , wherein the modular element (1) is made of a material, particularly of a metal such as an aluminum alloy, having a good thermal conductivity.

4. The modular element (1) of one of the preceding claims , wherein the modular element is manufactured by extrusion.

5. The modular element ( 1 ) of one of the preceding claims, wherein the ducts (12 - 15) respectively are spaced to each other with an identical distance.

6. The modular element (1) of claim 5, wherein outermost ducts (12 - 15) of the ducts (12 - 15) are spaced to lateral edges (16, 17) of the element (1) half the distance.

7. The modular element (1) of one of the preceding claims , wherein the modular element ( 1 ) is adapted to be cut into portions having an individual length.

8. The modular element (1) of one of the preceding claims, wherein the upper surface (10) is coupled to a tape (2) or a final floor covering, particularly by glueing, for providing a finished floor board.

9. The modular element (1) of one of the preceding claims, wherein the modular element (1) has a length (L) and a height (H) corresponding to the width and height of an ordinary floor board.

10. The modular element (1) of claim 2, wherein one of the lateral edges (16, 17) is provided with a projection (30), wherein the opposite lateral edge (17, 16) is provided with a corresponding recess (31) such that the projection (30) and the recess (31) are connectable.

11. The modular element (1) of claim 2, wherein the modular element (1) is provided with shoulders (30, 31) for steady and movable linking adjacent modular elements (1).

12. The modular element (1) of any of the preceding claims, wherein the modular element (1) is adapted to be laid down on a rough floor, and further comprises an insulating layer (I) .

13. The modular element (1) of claim 11, wherein the insulating layer (I) is arranged on the bottom surface (11), wherein a further covering (G) is provided between the bottom surface (11) and the insulting layer (I), and has sound- dampening characteristics .

14. The modular element (1) of any of the preceding claims further comprising middle ribs arranged between the ducts (12 - 15) .

15. A heating system comprising at least one modular element (1) according to one of claims 1 to 14, and further comprising a delivery duct (A) for feeding the heat transmission fluid, a backflow duct (B) for collecting and feeding back the transmission fluid, two-point connections (5) for connecting adjacent ducts (12 - 15) of the modular element (1), and three-point connections (4) for connecting ducts (12 - 15) of the modular element (1) with the delivery duct (A) or the back- flow duct (B) .

16. The heating system of claim 15, wherein each of the three-point connections (4) comprises a joint (41) having a hole (42) for communicating with holes (43, 44) of a pair of wings (45, 46) of a three-point connection (4), the joint (41) being adapted to be steadily linked to an opening of one of the ducts (12 - 15) of the modular element (1).

17. The heating system of claim 15 or 16, wherein the heating system further comprises sealing rings .

18. The heating system of claim 16, wherein the hole (42) of the joints (41) has a lower diameter than the holes (43, 44) of the pair of wings (45, 46).

19. The heating system of any of claims 15 to 18, wherein the heating system further comprises flexible pipe portions (6a, 6b) for connecting three-point connections (4).

20. The heating system of any of claims 15 to 19, wherein the two-point connection (5) is formed by a male element (51) and a female element (56) which can be linked together by inserting an end (53) into a corresponding seat (59), wherein a distance of joints (52, 57) is identical to a distance between adjacent ducts of the ducts (12 - 15).

21. The heating system of one of claims 15 to 20, wherein an alternated application of three-point connections (4) with at least one two-point connection (5) allows the reversal of the direction of the heat transmission fluid between two neighboring ducts of the same board or of two adjacent boards (1), while a subsequent arrangement of three-point connections (4) and two-point connections (5) gives the possibility of fixing the length of the way the heat transmission fluid has to pass from the delivery duct (A) to the backflow duct (B).

22. The heating system of any of claims 15 to 21, wherein the three-point connections (4) are linked to each other by means of flexible pipe portions (6a, 6b, 6c) for forming the delivery duct (A) .

23. The heating system of any of claims 15 to 22, wherein the three-point connections (4) are linked to each other by means of flexible pipe portions (6z, 6y, 6x) to form the back- flow duct (B) .