EP3924574A1

EP3924574A1 - Device for heating the water of an above-ground pool, such as an above-ground spa pool or a swimming pool

Info

Publication number: EP3924574A1
Application number: EP20702475.3A
Authority: EP
Inventors: Jean-Christophe FILLOT; Maxime DESVIGNES
Original assignee: Polytropic
Current assignee: Polytropic
Priority date: 2019-02-15
Filing date: 2020-01-31
Publication date: 2021-12-22
Anticipated expiration: 2040-01-31
Also published as: EP3924574B1; AU2020220610A1; PL3924574T3; ES2959992T3; US20220195744A1; WO2020164931A1; EP3924574C0; CA3129686C; US11639608B2; FR3092854B1; CA3129686A1; EP4234847A3; EP4234847A2; HUE062705T2; FR3092854A1; CN113423902A

Abstract

Said heating device (2) is well-functioning, easy to install, aesthetically pleasing and convenient to use at the same time. According to the invention, it comprises a frame (10) having an upper face (14), which connects the rear and front faces (13) and which generally has a step-shaped shape having at least two levels, which, in use, are at different respective heights and the highest level (N3) of which opens onto the rear face while the other level(s) (N1, N2) are distributed substantially uniformly between a base of the frame and the highest level, such that, in use, a user may access the pool (1) by successively walking on the levels of the step-shaped shape by climbing said levels from the ground to enter the pool and by descending said levels to the ground to leave the pool. The device also comprises an air-water heat pump, arranged in an internal volume of the frame, which is defined between the base and the rear, front and upper faces, and through which air from the outside of the frame flows. The device also comprises means to be connected to the pool, adapted both to bring water from the pool from the outside of the frame to the heat pump and to return the water heated by the heat pump to the outside of the frame to supply the pool.

Description

TITLE: Device for heating the water of an above-ground swimming pool, such as a spa or an above-ground swimming pool

The present invention relates to a device for heating the water of an above-ground swimming pool. It also relates to a bathing installation comprising such a heating device.

The invention is concerned with above-ground swimming pools, which covers, among others, whirlpool tubs, non-in-ground spas, free-standing above-ground pools and above-ground support pools. Regardless of their embodiment, these above-ground swimming pools have an envelope, which is intended to contain water and which is large enough for one or a few adults to bathe in them by at least diving. partially their body in the water. This envelope is above ground, that is to say that it rises from the ground, without being buried or otherwise marginally at its base, which moreover obliges the user or users to pass over the edge of the side wall of the casing to enter or exit the pelvis, either by stepping over the side wall of the casing, or by using a staircase, small ladder, step, stepladder or similar equipment , juxtaposed to the outer face of the side wall of the envelope.

In addition, these above-ground swimming pools are equipped with a hydraulic circuit that circulates the water contained in the casing outside it in order to treat it before returning it to the casing. envelope, the treatment (s) implemented may be of a diverse nature depending on the embodiment of the pool: for example, in the case of a spa or a balneo bathtub, these treatments may be water filtration then mixing water with pressurized air to force a jet of water with bubbles into the envelope; in the case of a swimming pool, these treatments can be filtration and then chemical treatment of the water. In all cases, the circulation of water in the hydraulic circuit is driven by a pump in this circuit, generally electric.

In order to heat the water in the above-ground pool, it is known practice to use an air-water heat pump, which is connected to the hydraulic circuit of the pool and which allows heat to be transferred from the air to the circulating water. in the hydraulic circuit. Such a heat pump is efficient, in particular by being more efficient than electrical systems with heating resistance. However, it is bulky and is difficult to integrate in the immediate vicinity of above-ground pools without harming their aesthetics, which is prohibitive for luxurious or well-being facilities. like spas or spa baths. The heat pump can of course be moved away from the above-ground pool, in particular to hide it away from the pool, but such a distance is detrimental to the efficiency and to the operating costs of the heat pump.

In a field other than that of above-ground swimming pools, namely the field of in-ground swimming pools, EP 0 599 666 discloses a technical unit for an in-ground swimming pool. This technical unit is intended to be arranged adjacent to an in-ground swimming pool, resting on the bottom of this swimming pool and including a watertight partition which forms part of the side wall of the swimming pool. This watertight partition is provided with one or more portholes or bay windows, which allow a person, standing inside a cavity of the technical block, to observe the interior of the swimming pool underwater. . Inside the cavity of the technical unit, are arranged one or more stairs, the steps of which are immersed in the water of the swimming pool and which allow a user to enter the interior of the swimming pool by descending gradually when the user advances from the side of the technical unit, opposite the watertight partition, to this watertight partition. Therefore, even in the artificial hypothesis where this technical block would be associated with an above-ground swimming pool, this technical boc would not allow a user standing on the ground outside the swimming pool to easily access the pool. inside the swimming pool since the aforementioned staircase (s) are turned in the "wrong direction".

The aim of the present invention is to provide a heating device for an above-ground swimming pool which, while being efficient and easy to install, is both aesthetic and practical in use.

To this end, the invention relates to a device for heating the water of an above-ground swimming pool, such as a spa or an above-ground swimming pool, this heating device being as defined in claim 1.

Thus, the idea at the base of the invention is to seek to use an air-water heat pump to efficiently heat the water of the above-ground pool, by placing this heat pump in a stepped frame allowing the user to access the pool by climbing on it as on a stepladder or stairs. For this purpose, the frame has an upper face shaped in steps with several levels, typically two or three levels, which succeed each other at regularly increasing respective heights between a front face of the frame, facing away from the basin, and a face rear of the frame, juxtaposed against the outer wall of the pool. In addition, the frame delimits, under its upper face in step, an internal volume inside which the heat pump is arranged and through which circulates air from outside the chassis: the heat pump is thus concealed in an aesthetic way, while being operational nearby of the basin, which limits pressure drops and facilitates the connection between the heat pump and the basin by ad hoc connection means of the heating device according to the invention. Of course, the heating device according to the invention is advantageously removable from the basin, the connection means then being provided to be reversible.

In practice, the stepped shape of the upper face of the frame can have very varied geometric and dimensional specificities as long as this upper face allows the user to walk successively on the levels of the stepped form, in the way in which one go up and down a staircase, in order to easily access the water in the pool to enter the interior of the envelope of the latter from the ground outside the pool, then to exit the envelope and join the ground outside the basin. Thus, the stepped shape may resemble stair treads, a stepladder, rungs of an inclined ladder, etc.

Likewise, the heating device according to the invention can be used with all types of above-ground swimming pools, such as those mentioned above. The invention finds a particular application to spas for which the use of a staircase of a few steps is very frequent: the invention makes it possible to easily associate an air-water heat pump with an existing spa, without substantially modifying the latter. nor encumber its periphery further, since it suffices to replace the traditional staircase there with the heating device according to the invention and to connect this heating device to the spa, in particular to the hydraulic circuit of the spa.

Additional advantageous features of the heating device according to the invention are specified in claims 2 to 8.

The subject of the invention is also a bathing installation, as defined in claim 9. The above-ground swimming pool of this installation is advantageously a spa.

The invention will be better understood on reading the description which follows, given only by way of example and made with reference to the drawings in which:

[Fig 1] Figure 1 is a schematic perspective view of a bathing installation comprising a heating device according to the invention; and [Fig 2] Figure 2 is a schematic section along the plane II of Figure 1.

In Figures 1 and 2 is shown a bathing installation comprising a spa 1 not buried and a device 2 for heating the water in the spa 1.

Spa 1 includes a casing 3 which, when spa 1 is in use, contains water for bathing. Depending on the size of envelope 3, an adult or a few adults can thus immerse their body in the water contained by envelope 3.

The embodiment of the envelope 3 is not limiting. The envelope 3 can thus be self-supporting, for example by being at least partially inflatable, or integrate a supporting structure supporting a tank or a shell containing the spa water. In all cases, the envelope 3 is above ground, that is to say that, when the spa 1 is used, the envelope 3 rises upwards from the ground, resting directly on the latter, without being buried there or then marginally buried at the base of the casing 3. Thus, the side wall of the casing 3 protrudes from the ground, to a height of several tens of centimeters.

The spa 1 also comprises a hydraulic circuit 4 shown schematically in FIG. 2. In this FIG. 2, the hydraulic circuit 4 is integrated into the thickness of the wall of the casing 3, but this schematic arrangement is not limiting and other arrangements, known in the field, can be envisaged. In all cases, the hydraulic circuit 4 is designed to form a circulation loop for the water contained in the casing 3, this loop being closed on the inside of this casing: the hydraulic circuit 4 thus makes it possible to suck up the water contained in the envelope 3, to treat the water thus sucked in, then to return the water thus treated in the envelope 3, as indicated by the water circulation arrows C1. To this end, in the exemplary embodiment considered here, the hydraulic circuit 4 comprises:

- a pump 5, in particular electrically powered, which is designed to drive the water in the hydraulic circuit 4 from the upstream end of the latter to the downstream end of the hydraulic circuit, these two ends opening inside of envelope 3,

- a filter 6 which retains the impurities from the water passing through it,

- delivery nozzles 7, which are arranged at the downstream end of the hydraulic circuit 4 and which reintroduce into the casing 3 the water circulating in the hydraulic circuit 4, for example in the form of bubble jets with the mixing, for example the delivery nozzles, water circulating in the hydraulic circuit 4 with air injected from outside the casing 3, and - pipes 8 connecting to each other the upstream end of the hydraulic circuit 4, the filter 6, the pump 5 and the delivery nozzles 7.

The specific features of the hydraulic circuit 4 are not limiting as long as this hydraulic circuit ensures the circulation of water in a closed loop on the casing 3, between the upstream and downstream ends of the hydraulic circuit. In particular, in addition to and / or replacement of the filtration carried out by the filter 6, one or more other treatments of the water circulating in the hydraulic circuit 4 can be implemented by ad hoc equipment integrated into the hydraulic circuit. Likewise, the delivery nozzles 7 envisaged above can be replaced by other delivery elements depending on the effects that one wishes to give to the reintroduction of the water flow into the casing 3, as is well known in the art. spa area.

The heating device 2 comprises a frame 10 which, as clearly visible in FIGS. 1 and 2, gives the heating device 2 an external appearance resembling that of a staircase of a few steps, in this case three steps for the example considered here.

More specifically, the frame 10 comprises a bottom 11 which, as clearly visible in FIG. 2, rests directly on the ground, outside the spa 1, when the heating device and, more generally, the bathing installation, are in service. The frame 10 has a rear face 12 and a front face 13, which each rise from the bottom 1 1 and which are opposite to each other, being located at opposite ends of the bottom 1 1. In use , the rear face 12 of the frame 10 is designed to be contiguous against the outer face of the side wall of the casing 3, being pressed against this side wall or slightly distant from this side wall.

Overhanging its bottom 1 1, the frame 10 has an upper face 14, which connects the rear 12 and front 13 to one another and which generally has a stepped shape, typically here in a staircase. This stepped shape has several levels which, when the heating device 2 is in service, are located at different respective heights with respect to the ground and which are distributed in a substantially regular manner vertically, that is to say according to a direction perpendicular to the ground: in the embodiment considered here, the stepped shape of the upper face 14 thus has three levels, namely a lowest level N1, an intermediate level N2 and a highest level N3. The highest level N3 opens onto the rear face 12 of the chassis 10 and the other levels N1 and N2 are distributed substantially evenly between the level on higher N3 and the bottom 1 1, with the lowest level N1 which opens onto the front face 13. In practice, the vertical spacing between the levels N1, N2 and N3 is expected to be constant, with clearances, or, more generally, substantially constant, for example to within 10%: in all cases, this spacing must allow a user to be able to walk successively on levels N1, N2 and N3 the way one goes up and down a staircase.

Of course, frame 10 is designed to support the weight of a user standing on any of the levels N1, N2 and N3. According to a practical embodiment, which is implemented in the exemplary embodiment considered in the figures, the frame 10 comprises stair treads 15.1, 15.2 and 15.3, which respectively constitute the levels N1, N2 and N3 and which are supported by structural parts of the frame 10, not detailed in the figures. The material (s) constituting the steps 15.1, 15.2 and 15.3, as well as constituting the aforementioned structural parts are not restrictive, since sufficient mechanical strength is guaranteed for a user to be able to climb and descend on these steps. Likewise, the depth of the steps 15.1, 15.2 and 15.3, that is to say their dimension in a horizontal direction connecting the rear 12 and front 13 faces, is not limiting, as long as the user can put a sufficient part of his foot on each of these steps when he walks successively on levels N1, N2 and N3, as illustrated in FIG. 1. This being the case, according to an advantageous arrangement which is implemented in the exemplary embodiment considered in the figures, the depth of the step 15.3 can be provided greater than that of the other steps 15.1 and 15.2: more generally, the part, located at the highest level N3, of the upper face 14 of the frame 10 advantageously has a greater depth to that of the parts of this upper face 14, located at the other levels, which is more reassuring for the user by giving him a greater extent in which to put his feet when he is standing on the highest level N3.

In all cases, the frame 10 defines an internal volume V10 which, as clearly visible in Figure 2, is delimited between the bottom 1 1 and the rear faces 12, front 13 and top 14, and which as clearly visible in the figure 12, is also delimited by two side faces 17 of the frame 10, which each extend from the bottom 1 1 to the upper face 14 and which are opposite to each other. This internal volume V10 thus corresponds to a cavity delimited inside the frame 10, inside which air can circulate from outside the frame 10. In order to control the conditions of air circulation through the frame 10, the latter advantageously comprises perforated walls 18A and 18B which allow air to pass between the outside of the frame 10 and the internal volume V10. As clearly visible in Figures 1 and 2, the perforated walls 18A are arranged on the front face 13 of the frame and on the parts of the upper face 14 of the frame, located between the consecutive levels N1 and N2 and between the consecutive levels N2 and N3. In the exemplary embodiment considered here, these perforated walls 18A are integrated into risers 16.1, 16.2 and 16.3 which are respectively associated with the steps 15.1, 15.2 and 15.3. The perforated walls 18B are for their part arranged on the side faces 17 of the frame 10, as shown in FIG. 1. The advantage of the respective arrangements of the perforated walls 18A and the perforated walls 18B will appear a little later. In all cases, the construction of the perforated walls 18A and 18B is not limiting and is for example chosen from grids, bars, mesh walls, perforated plates, etc.

The heating device 2 also comprises a heat pump 20. This heat pump 20 is an air-water heat pump, making it possible to transfer the heat from the air, passing through the heat pump, to water also passing through. this heat pump. Within the heater 2 when the latter is in use, the heat pump 20 is suitable for transferring heat from the ambient air to the water in the spa 1.

As clearly visible in FIG. 2, the heat pump 20 is arranged inside the frame 10, in other words in the internal volume V10 of this frame. According to an advantageous practical arrangement, which is implemented in the example considered in FIG. 2, the heat pump 20 is, entirely or at least essentially, arranged in only part of the internal volume V10, namely plumb vertical step 15.1, that is to say, more generally, vertically in line with the part of the upper face 14 of the frame 10, located at the highest level N3 of the stepped shape: this arrangement of the heat pump 20 in the internal volume V10 makes it possible to position the heat pump 20 in the immediate vicinity of the rear face 12 of the frame 10 and thus as close as possible to the spa 1 when the heating device 2 is in service within the bathing installation, while taking advantage of the fact that the distance between the bottom 1 1 and the highest level N3 is maximum compared to the other levels N1 and N2, as well as taking advantage, where appropriate, of the fact than the depth of the part, located at the most top N3, the upper face 14 can be provided larger than that of the parts of this upper face 14, located at the other levels N1 and N2.

The embodiment of the heat pump 20 is not limiting, as long as this heat pump 20 transfers to the water of the spa 1 the heat of the air coming from outside the frame and circulating through the internal volume V10. For this purpose, in a manner known per se, the heat pump 20 includes components allowing thermodynamic transfer of heat from the air, circulating through the internal volume V10, to the water which comes from the spa 1 and which is returned to the spa 1 once heated by the heat pump 20. As shown schematically in Figure 2, the aforementioned components of the heat pump 20 can thus include:

- a condenser 21 in which a refrigerant from the heat pump 20 releases its heat to the water from the spa 1, circulating in this condenser,

- an expansion valve 22 which reduces the pressure of the refrigerant which has passed from the gaseous state to the liquid state at the level of the condenser 21,

- an evaporator 23 which takes heat from the air circulating in the internal volume V10 to vaporize the refrigerant circulating in this evaporator, and

a compressor 24 which, by being actuated by a motor, typically electric, increases the pressure and temperature of the gaseous refrigerant by compressing it.

In addition, the heat pump 20 advantageously includes a fan 25 which, by means of its actuation by a motor, typically electric, rotates on itself and thus entrains the air in the internal volume V10, forcing the circulation of this air to through the evaporator 23. This fan 25 is configured, in particular by virtue of its arrangement and its structure, to direct the circulation of air through the frame 10, on the one hand by allowing air to enter from the outside from the chassis 10 to the interior of the internal volume V10 via the perforated walls 18A, as indicated by the arrows F1 in Figures 1 and 2, and on the other hand by discharging air from the internal volume V10 to outside the frame 10 via the perforated walls 18B, as indicated by the arrows F2 in FIG. 1. In this way, the cooled air having circulated in the heat pump 20 is evacuated from the heating device 10 through the side faces 17 of the frame 10, without being sent directly nt on the user standing on the levels N1, N2 and N3 of the stepped shape of the upper face 14 of the frame.

The heater 2 further comprises connection tubes 31 and 32, shown schematically in FIG. 2, which allow the heater 2 to be connected to the spa 1. The connection tube 31 is suitable for bring water from the spa 1 from the outside of the frame 10 to the heat pump 20, being connected to the hydraulic circuit 4, typically to one of the pipes 8 of this hydraulic circuit. The connection tube 32 is adapted to return the water heated by the heat pump 20 to the outside of the frame 10 to supply the spa 1, by being connected to the hydraulic circuit 4, typically to one of the pipes 8 Of course, the connection tubes 31 and 32 are only one non-limiting example for connection means 30 of the heating device 2 making it possible to connect the latter to the spa 1, advantageously in a removable manner to allow installation and operation. remove at will the heating device 2 vis-à-vis the spa 1. In all cases, the connection of these connection means 30 to the spa 1 is advantageously made on the hydraulic circuit 4 of the latter so that, under the 'effect of the entrainment of water in this hydraulic circuit 4, typically by the pump 5, the water circulates in the connection means 30 and in the heat pump 20, as indicated by arrows C2 in FIG. 2 Of course, the connection means 30 include fittings and valves allowing their connection to the hydraulic circuit 4.

It is understood that, because of their function, the connection means 30 necessarily extend between the interior and the exterior of the frame 10, crossing the bottom 1 1 and / or one of the rear faces 12, front 13 , upper 14 and lateral 17. In particular, the corresponding arrangement of the connection means 30 may depend on the structure of the heat pump 20 and / or on the configuration of the hydraulic circuit 4. That said, according to one embodiment particularly advantageous, which is implemented in the embodiment considered here, the connection means 30 are arranged through the rear face 12 of the frame 10: as clearly visible in Figure 2, the connection tubes 31 and 32 thus pass through the rear face 12 of the frame 10. In this way, the hydraulic connection between the heating device 2 and the spa 1 is particularly discreet, while being effective, in particular by limiting pressure drops and losses. of heat for the water circulating between the heat pump 20 and the hydraulic circuit 4.

When heater 2 is in service and connected to spa 1, as in Figures 1 and 2, heat pump 20 is concealed inside frame 10. User can access spa 1 by walking successively on levels N1, N2 and N3 of the stepped shape of the upper face 14 of the frame 10: thus, when the user wants to enter inside the casing 3 of the spa 1, he climbs on the upper face 14 of the frame 10, the way one climbs a staircase; when the user wants to come out of the casing 3, he climbs, from the inside of the casing 3, to the highest level N3 of the upper face 14 of the frame 10, then descends to the ground by walking successively on level N2 and level N1, the way you descend a staircase. In addition, the spa water is heated by the heat pump 20. In practice, the control of the heat pump 20 by the user, in particular the adjustment of its setpoint temperature, can equally well be done directly at the level of a control system, typically electronic, of the heating device 2, via a dedicated interface which is carried by the frame 10 or remotely deported, that be provided through an interface of the spa 1 by means of the interconnection between the spa control system 1 and the heater control system 2.

Various arrangements and variations on the bathing installation 1 described so far, in particular its heating device 2, are also possible. For example:

- the number of levels of the stepped shape of the upper face 14 of the frame 10 is not limited to three as in the example considered in the figures; in particular, two levels are sufficient, but more than three levels is possible; in practice, the number of levels is linked to the height of the side wall of the casing 3 from the ground, so that, for most bathing facilities, this number of levels is preferably two or three;

- although arranged in the internal volume V10 of the frame 10, the heat pump 20 can advantageously be raised above the ground, typically a few tens of millimeters, thus making it possible to control the flow of condensates produced by the heat pump 20, in particular by sending these condensates into a drainage circuit equipping the spa 1;

- for installation and maintenance, one or more accesses to the internal volume V10 of the frame 10 can be provided by making certain external parts of the frame 10 removable, in particular at the level of one and / or the other of the side faces 17;

- The power supply to the heat pump 20 can be provided either through the spa 1, or independently from the latter;

- rather than the heating device 2 is connected to the hydraulic circuit 4 of the spa 1 and benefits from the entrainment of water through its heat pump 20 by the pump 5 of this hydraulic circuit, the heating device 2 can to be connected to the spa 1 so that its connection means 1 open directly into the casing 3 of the spa 1, that is to say without the water sent from the casing 3 of the spa 1 to the heat pump 20 then returned from the latter inside the casing 3, does not pass through the hydraulic circuit 4; in this case, a pump for driving the water between the casing 3 and the heat pump 20 is then necessary, by being advantageously integrated into the heating device 2, in particular housed inside the frame 10, in particular in the internal volume V10 of the latter; and or

- As mentioned at the beginning of this document, the spa 1 described with reference to the figures is only an example of an above-ground swimming pool with which the heating device 2 can be used.

Claims

1. Device (2) for heating the water of an above-ground swimming pool (1), such as a spa or an above-ground swimming pool, this heating device comprising:

- a frame (10) which has:

- a bottom (1 1) which is provided for, when the heating device is in service, rest on the ground,

- a rear face (12), which rises from the bottom (1 1) and which is adapted to, in service, be pressed against the pelvis (1),

- a front face (13), which rises from the bottom (1 1), being opposite the rear face (12), and

- an upper face (14), which connects the rear (12) and front (13) faces and which generally has a stepped shape having at least two levels, which, in use, are at different respective heights and whose level the highest (N3) opens onto the rear face (12) while the other level (s) (N1, N2) are distributed substantially evenly between the base (1 1) and the highest level (N3), from so that, in service, a user can access the pool (1) by walking successively on the levels of the stepped form, and this by climbing these levels (N1, N2, N3) from the ground to enter the pool and descending these levels to the ground to exit the basin,

- an air-water heat pump (20), which is suitable for transferring heat from the air to the water in the pool (1), the heat pump being arranged in an internal volume (V10) of the frame ( 10), which is delimited between the bottom (1 1) and the rear faces (12), front (13) and upper (14), and through which circulates air from outside the chassis, and

- means (30) for connecting to the basin (1), suitable both for bringing water from the basin from outside the frame (10) to the heat pump (20) and for returning the water heated by the heat pump to the outside of the frame to supply the pool.

2. Heating device (2) according to claim 1, wherein there are provided two or three levels (N1, N2, N3) for the stepped shape of the upper face (14) of the frame (10).

3. Heating device according to one of claims 1 or 2, wherein the heat pump (20) is arranged essentially vertically in line with the portion of the upper face (14) of the frame (10), located at the highest level (N3) of the stepped form.

4. Heating device according to any one of the preceding claims, wherein the connection means (30) are arranged through the rear face (12) of the frame (10).

5. Heating device according to any one of the preceding claims, in which the frame (10) has perforated walls (18A, 18B) to allow air to pass between the exterior of the frame (10) and the internal volume ( V10) of the chassis,

which perforated walls include at least a first perforated wall (18A) which is arranged on the front face (13) of the frame (10) and / or on the part or parts of the upper face (14) of the frame, located (s) between two consecutive levels (N1, N2, N3) of the stepped shape,

and which perforated walls also include at least a second perforated wall (18B) which is arranged on one and / or the other of the side faces (17) of the frame (10).

6. Heating device according to claim 5, wherein the heat pump (20) includes a fan (25) adapted to drive, in the internal volume (V10) of the frame (10), the air from which the heat is transferred. to the pool water (1) by the heat pump, this fan being configured, at the same time, to bring in air from the outside of the chassis to the interior of the internal volume of the chassis, via the first perforated wall (s) (18A), and for discharging air from the internal volume of the frame to the outside of the frame, via the second perforated wall (s) (18B).

7. Heating device according to any one of the preceding claims, wherein the frame (10) comprises stair treads (15.1, 15.2, 15.3) which constitute the levels (N1, N2, N3) of the stepped shape of the upper face (14) of the frame.

8. Heating device according to claim 7 taken in combination with one of claims 5 or 6, wherein the frame (10) also comprises risers (16.1, 16.2, 16.3), which are respectively associated with the staircase steps (15.1, 15.2, 15.3) and which incorporate the first perforated wall (s) (18A).

9. Bathing facility, comprising:

- an above-ground bathing basin (1), this basin comprising an envelope (3) intended to contain water for bathing therein, and a hydraulic circuit (4) suitable for sucking up the water contained in the envelope (3), treating the water thus sucked in, and returning the water thus treated to the envelope, and - a heating device (2), which conforms to any one of the preceding claims, of which the rear face (12) of the frame (10) is contiguous against the outer face of a side wall of the casing (3) ), and whose heat pump (20) is connected to the hydraulic circuit (4) so that water circulating in this hydraulic circuit is sent to the heat pump to be heated there before being returned to the hydraulic circuit.

10. A bathing installation according to claim 9, wherein the basin is a spa (1).