FR3150221A1 - Set comprising a basin and allowing water storage and thermal storage - Google Patents

Abstract

Title: Assembly comprising a basin and allowing water storage and thermal storage The invention relates to an assembly (1) comprising a basin (2) arranged in a cavity (4) of a terrain (5) and a backfill zone (3) located between a wall (21) of the basin and a wall (41) of the cavity. The backfill zone comprises a backfill (30) configured to ensure mechanical support of the basin or the cavity, a waterproof membrane (31) surrounding the backfill so as to define a water retention zone (32) and a drain (33) configured to circulate a heat transfer fluid therein. The assembly comprises a thermal insulation layer (6) located between the basin and the backfill and a fluid circuit (7) communicating with the drain and comprising a device configured to transfer the heat transfer fluid or heat from the heat transfer fluid to an external environment. Figure for the abstract: Fig.1.

Description

Set comprising a basin and allowing water storage and thermal storage

The present invention relates to the field of construction, more precisely the field of construction of basins, for example swimming pool basins. It is of particular interest in the sector of bioclimatic construction.

STATE OF THE ART

The construction of a home is now accompanied by numerous technical, regulatory and budgetary constraints, especially when it is accompanied by the construction of a pond or swimming pool.

In particular, when building a swimming pool or a planted pool, it is necessary to ensure that the structure is properly mechanically supported. Certain types of pools, such as so-called "hard" pools, whose perimeter is made of concrete or sheet metal for example, do not necessarily require additional mechanical support. However, the material providing the mechanical support of the whole, typically concrete, is expensive, has a very poor carbon footprint and is not environmentally sustainable. Shell pools, which are less expensive, often require the construction of a mechanical support area around the pool.

Furthermore, the construction of water retention basins has become a regulatory requirement in certain municipalities when building a home to limit or even eliminate the impact of soil artificialization during heavy rains. Retention basins allow at least a delay in the flow of water and thus not saturate public networks, thus avoiding the well-known flooding phenomena, particularly during Cévennes episodes. The construction of buried and invisible masonry retention basins so as not to disfigure real estate projects requires the implementation of costly construction techniques (suitable earthworks, construction of masonry elements, supply of necessary aggregates, etc.) representing approximately €150 to €200 per m² of artificialized soil depending on the region (i.e. for example a budget of €25,000 for artificialization of 150m² on the ground in Aix en Provence).

In addition, the question arises when building a home about its heating and air conditioning. When building a bioclimatic home, low ecological impact solutions are preferred, including geothermal solutions such as Canadian wells and geothermal heat pumps. However, building a Canadian well to recover air tempered by the ground requires excavation to a depth of at least 1.50m and over a length of at least 50m, installing an air circulation network based on 30cm section pipes and ventilation to recover the air tempered by the well. These various works and the necessary equipment generate installation costs of around €10,000. Furthermore, building a geothermal system on a water table with a heat pump using vertical drilling requires drilling to a significant depth to access a water table. The budget for this is estimated at €60,000 for a 150m² house. It should be noted that this technique does not always meet the needs of the habitat because the water table is not always available. Finally, the construction of a geothermal system on a probe with a heat pump in a horizontal installation requires earthworks to be carried out on a very large area of land at least 1.50m deep. The budget is estimated at €50,000 for a 150m² house.

It is therefore understandable that the construction of a home and an accompanying swimming pool involves very heavy and very costly work in order to meet the needs of mechanical maintenance of the pool, water retention, and heating and air conditioning of the home.

An objective of the present invention is therefore to propose a solution making it possible to reduce the disadvantage of existing solutions, in particular their cost.

SUMMARY

1. Un remblai configuré pour assurer un maintien mécanique d’au moins l’une parmi la paroi du bassin et la paroi de la cavité.
2. Une membrane étanche entourant au moins partiellement le remblai de sorte à définir une zone de rétention d’eau au sein de la zone de remblai, l’ensemble étant configuré pour qu’une première partie au moins de la zone de rétention d’eau recueille de l’eau de pluie s’écoulant sur le terrain et/ou provenant du bassin.
3. Au moins un drain configuré pour faire circuler en son sein un fluide caloporteur, une partie du drain étant située dans la zone de remblai et étant configurée pour permettre un transfert thermique entre la zone de remblai et le fluide caloporteur.
4. Au moins une sortie fluidique configurée pour extraire le fluide caloporteur présent dans la zone de remblai.

To achieve this objective, a first object of the invention relates to an assembly comprising a basin arranged at least partially in a cavity of a terrain and a backfill zone, the backfill zone being located at least between a wall of the basin and a wall of the cavity, the backfill zone comprising:

1. A backfill configured to provide mechanical support for at least one of the basin wall and the cavity wall.
2. A waterproof membrane at least partially surrounding the embankment so as to define a water retention zone within the embankment zone, the assembly being configured so that at least a first portion of the water retention zone collects rainwater flowing onto the land and/or coming from the basin.
3. At least one drain configured to circulate a heat transfer fluid therein, a portion of the drain being located in the backfill area and being configured to allow heat transfer between the backfill area and the heat transfer fluid.
4. At least one fluid outlet configured to extract the heat transfer fluid present in the backfill zone.

1. Une couche d’isolation thermique située entre ladite paroi du bassin et le remblai et configurée de sorte à former une barrière thermique pour les échanges de chaleur entre de l’eau contenue dans le bassin et le remblai,
2. Un circuit fluidique comprenant :
   • une entrée pour un fluide caloporteur présent dans la zone de remblai,
   • un dispositif connecté à ladite entrée et configuré pour transférer à un milieu externe l’un parmi le fluide caloporteur et de la chaleur du fluide caloporteur.

The set also includes:

1. A thermal insulation layer located between said basin wall and the backfill and configured so as to form a thermal barrier for heat exchanges between water contained in the basin and the backfill,
2. A fluid circuit comprising:
   • an inlet for a heat transfer fluid present in the backfill area,
   • a device connected to said input and configured to transfer to an external medium one of the heat transfer fluid and heat from the heat transfer fluid.

The presence of the embankment makes it possible to support the basin and/or the land adjoining the embankment area, thus responding to the problem of mechanically maintaining the basin in its environment.

Furthermore, thanks to the waterproof membrane, the embankment area plays a role in water retention and therefore responds to the problem of desaturation of public networks. The water stored in the embankment area can possibly be taken and used for different consumption items (watering, washing vehicles, supplying toilet flushes, washing floors, washing clothes, etc.). The consumption of water from the public network of a home can thus be divided by 2 to 4, depending on the dimensions of the retention area, the regions and the uses.

Finally, the rainwater stored in the retention zone and the air in the embankment zone, above this water, can both be used for heat exchange with an external environment. The embankment is in fact cooled in summer and heated in winter by the land adjoining the embankment zone. The embankment then transmits its heat or coolness, depending on the season, to the water and air with which it is in contact. The embankment zone thus has a very effective heat storage function, particularly when the material constituting the embankment has a high thermal inertia. The energy consumption of a home can be divided by 2 to 6 thanks to this, depending on the region in particular. The thermal insulation layer associated with the embankment zone reduces heat transfers between the water contained in the basin and the embankment. In fact, the thermal inertia of the water in the basin is much less than that of the ground and therefore of the embankment of the embankment zone.

The invention thus proposes a solution that addresses the three issues raised in the introduction and greatly improves the environmental impact of a habitat. It also allows significant savings, both during the construction and operation of a basin.

In more detail, the invention makes it possible to simultaneously meet the following three needs: land maintenance, water storage and thermal storage. This solution makes it possible to meet these three needs for a total cost significantly lower than the sum of the costs of the solutions currently used to meet each of these needs.

A second subject of the invention relates to a habitat comprising the assembly according to the invention and a heat exchange system, for example a radiator or a fan coil.

BRIEF DESCRIPTION OF THE FIGURES

The aims, objects, as well as the features and advantages of the invention will become more apparent from the detailed description of one embodiment thereof which is illustrated by the following accompanying drawings in which:

There represents the assembly according to the invention and in particular shows the basin, the backfill zone and the land in which the assembly is located.

Figures 2A to 2C show different embodiments of thermal extraction from the backfill area to an external environment.

There illustrates one embodiment of the extraction of water stored in the retention zone.

There illustrates a simplified top view of the assembly according to the invention.

The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily to the scale of practical applications. In particular, the dimensions are not representative of reality.

DETAILED DESCRIPTION

Before beginning a detailed review of embodiments of the invention, optional features which may optionally be used in combination or alternatively are set out below:

According to one embodiment, the assembly is configured so that the rainwater collected by at least the first part of the water retention zone comes from the basin, in part or only, by overflowing from the basin.

According to one embodiment, the assembly is configured so that the rainwater collected by at least the first part of the water retention zone comes from the basin, in part or only, by overflowing and being conveyed from the basin.

According to one embodiment, the assembly is configured so that the rainwater collected by at least the first part of the water retention zone comes from the basin by overflowing from the basin and/or by being conveyed from the basin.

According to one embodiment, the portion of the drain located in the backfill area is configured to circulate the heat transfer fluid in a sealed manner relative to the backfill area.

In one example, the part of the drain located in the backfill zone is made of a material allowing heat exchange between water contained in the water retention zone and the heat transfer fluid.

According to one embodiment, the heat transfer fluid is water contained in the water retention zone and in which the drain is configured to allow evacuation of said water contained in the water retention zone towards the external environment.

Preferably, the water retention zone extends over at least 60% of the height of the backfill zone, preferably at least 80% of the height of the backfill zone, preferably 100% of the height of the backfill zone.

According to one embodiment, a portion of the backfill area is configured not to accommodate water, in which the heat transfer fluid is air contained in said portion of the backfill area and in which the at least one drain allows said air to be evacuated to the external environment.

According to one embodiment, comprising at least one secondary drain allowing heat exchange with the water contained in the water retention zone.

Advantageously, the backfill has a specific thermal capacity less than or equal to 860 J.kg.^{- 1}.K^-1and/or a thermal conductivity of less than 2 W.m^-1.K^-1. This allows the embankment to maintain a temperature close to that of the ground 5 adjoining it while cooling or heating the water or air in contact with it. The embankment can thus cool or heat a large quantity of water or air.

In one example, the backfill contains crushed stone, the crushed stone having a grain size greater than 4 cm. In one example, the backfill contains crushed stone, the crushed stone having a grain size between 2 and 4 cm (crushed stone type 20/40, 20 corresponding to the width in millimeters of the smallest aggregates and 40 to the width in millimeters of the largest crushed stone).

For example, the crushed material has a grain size of less than 10 cm.

In one example, the backfill is made from a material derived from asbestos recycling, such as Cofalit®. Cofalit® is a material derived from asbestos recycling and is completely neutral for the environment. By using this material, we therefore convert waste, asbestos, into a resource. Cofalit® also has a very high thermal inertia, which is advantageous in the context of the invention. Its thermal storage capacity is very high: one ^m3 of Cofalit® can store 2.8MJ when its temperature increases by 1°C. Finally, Cofalit® is inexpensive (around 8 to 10 euros per tonne).

In one example, the membrane is based on ethylene-propylene-diene monomer (EPDM) rubber. However, any waterproofing membrane that is inert over time is possible.

Advantageously, the thermal insulation layer has a thermal conductivity of less than 0.035 Wm ^{- 1} .K ^-1 .

In one example, the backfill area comprises gabions, with the backfill being arranged in the gabions.

For example, the external environment is a habitat.

In one example, the assembly comprises a plurality of drains, at least two of the plurality of drains preferably being arranged in parallel. The assembly preferably comprises at least three drains. Advantageously, all of the drains are arranged in parallel, for example at different heights of the backfill area.

According to one example, the backfill area forms a perimeter around the basin, said perimeter extending over a length L _zr taken in projection in a horizontal plane, and the drain extends, in the backfill area, over a length L _d , taken in projection in the horizontal plane, such that L _d ≥ 0.5 * L _{z r} , preferably L _d ≥ 0.7 * L _{z r} , preferably L _d ≥ 0.8 * L _{z r} and preferably L _d ≥ 0.95 * L _{z r} .

For example, the heat transfer fluid forms the primary fluid of a heat pump system, a Canadian well or a hydraulic underfloor heating system.

For example, the set also includes a heat pump, a Canadian well or underfloor heating.

According to an advantageous embodiment, the assembly further comprises at least one second fluid outlet, and a control device configured to selectively control an extraction of rainwater contained in the water retention zone by the second fluid outlet.

According to an advantageous embodiment, the assembly further comprises water distribution equipment in communication with the second fluid outlet. The assembly is configured such that the water distribution equipment can be supplied by rainwater extracted by the second fluid outlet.

According to one embodiment, the water distribution equipment being taken from a tap, household appliances, automatic garden watering.

According to an advantageous embodiment, the assembly further comprises a settling tank, and the second fluid outlet communicates with said settling tank.

According to one example, the assembly further comprises a pump for extracting water from the retention area through the fluid outlet and delivering it to the water distribution equipment.

According to an advantageous embodiment, the assembly further comprises a fluid drain configured to convey rainwater from the retention zone to the fluid outlet.

Advantageously, the fluid drain is placed at the bottom of the retention zone.

According to an advantageous embodiment, the assembly further comprises a device for controlling the discharge of water contained in the basin towards the water retention zone.

Preferably, the water discharge control device is configured to control the discharge of water contained in the basin to the water retention zone according to at least one of the following parameters: a water level in the basin, a water level in the water retention zone, the season, data relating to the weather for the coming days, rainfall forecasts, activation by a user of a command to fill the water retention zone, a set temperature of the water in the basin.

Preferably, the basin has a volume V _b and the water retention zone has a volume V _retention , with V _retention /V _b ≥3.

A reference frame comprising the X, Y, Z axes is shown in Figures 1, 2A and 3. This reference frame is applicable by extension to the other figures. The plane defined by the X and Y axes is designated the horizontal plane. In this application, we may speak of a “ground plane” which will be assumed to extend parallel to the horizontal plane. It is understood, however, that the ground in which the basin is buried may be inclined.

In this patent application, we will preferably speak of thickness for a layer and of height for a structure or a device. The height is taken perpendicular to the horizontal plane XY. The thickness is typically taken in a direction normal to the main extension plane of the layer. The relative terms “on”, “under”, “underlying” preferably refer to positions taken in the Z direction.

The terms “substantially”, “approximately”, “of the order of” mean “within 10%, preferably within 5%”.

A layer or membrane can also be composed of several sub-layers of the same material or of different materials.

Set 1 will now be described in more detail with reference to the .

Set 1 first includes a basin 2. This basin 2 is typically the basin of a swimming pool. In the case of a shell pool, the "basin" is most often referred to as the shell itself. In the case of a concrete pool, the basin is generally composed of concrete blocks or shotcrete giving the pool its shape. The basin can also include or be formed from a fiber, resin or metal shell. Basin 2 can also be an ornamental basin or a leisure pond. For example, it can be a planted basin. It is preferably an ecological basin.

The basin 2 typically has a plurality of sides, for example four sides in the case of a basin having a rectangular shape in projection in the plane of the land 5.

Basin 2 is located in a cavity 4 of a plot of land 5, for example plot 5 of a garden.

The basin 2 is at least partially buried in the cavity 4. By the fact that the basin 2 is “partially buried” in the cavity 4, it is meant that a portion of the basin 2 may protrude relative to the ground 5. As a result, the basin 2 may not be buried in the cavity 4 over its entire height. Preferably, the basin 2 is buried in the cavity 4 over at least 80% of its average height. The average height of the basin 2 is defined as the average over the ground surface of the basin 2 in the plane of the ground 5 of the local heights of the basin 2.

Furthermore, the pool 2 may not be buried in the cavity 4 on all its sides. One or more of its sides may not be bordered by the land 5 or may only be bordered on part of its height by the land 5. This is particularly the case in the case of an infinity pool or a partially glazed pool.

The assembly 1 further comprises a backfill zone 3 also located at least partially in the cavity 4. Preferably, the backfill zone 3 is entirely buried in the cavity 4.

The backfill zone 3 is more precisely located at least between a wall 21 of the basin 2 and a wall 41 of the cavity 4. Preferably, the backfill zone 3 extends between several walls of the basin 2 on the one hand and several walls of the cavity 4 on the other hand. In other words, preferably, the backfill zone 3 borders more than one side of the basin 2. Advantageously, the backfill zone 3 borders the entire periphery of the basin 2.

In the case where certain sides of the basin are glazed, the backfill zone 3 is preferably positioned so as not to obstruct these glazed sides.

Backfill zone 3 includes backfill 30. Backfill 30 is typically a set of aggregates of a mineral material, commonly referred to as “crushed”.

The backfill 30 is advantageously placed in boxes or gabions, preferably gabions made of braided iron wire. As will be seen further on, these gabions may come into contact with water. Gabions made of a stainless or inert material will therefore be preferred. Generally speaking, the backfill 30 can be placed in cages made of non-putrescible woven or molded materials.

These gabions or cages give the backfill zone 3 a better hold, and in particular make it possible to maintain the backfill 30 in a desired volume. In particular, the gabions make it possible to prevent the backfill 30 from sagging over time and make it possible to reinforce its vertical stability. They thus make it possible to ensure that the backfill zone 3 maintains the same height and width over time.

Due to its weight and mechanical rigidity, the backfill zone 3 makes it possible to ensure the mechanical maintenance of the pool 2 within the land 5. More specifically, the backfill 30 makes it possible to ensure the mechanical maintenance of the walls of the pool 2 and/or of the cavity 4 that it borders. Concerning the mechanical maintenance of the pool 2, this is particularly useful when the wall(s) bordered by the backfill zone 3 correspond to at least part of the shell of the shell pool. Concerning the maintenance of the walls of the cavity 4, it is understood that the mechanical maintenance is effective on at least part of the land 5, this part extending from the wall(s) of the cavity 4 bordered by the backfill zone 3.

The backfill area 3 also comprises a waterproof membrane 31 at least partially surrounding the backfill 30. Preferably, the waterproof membrane 31 surrounds the backfill 30 over its entire height taken vertically. Preferably, the waterproof membrane 31 envelops the backfill 30 over at least 60% and preferably over at least 80% of the height of the cavity 4 taken vertically. This waterproof membrane 31 is impermeable to fluids, in particular to water, and thus defines a water retention area 32. This water retention area 32 makes it possible to collect rainwater coming in particular from runoff on the ground 5 and/or from an overflow from the basin 2. Indeed, the rainwater falling into the basin 2 can finish filling the basin 2 and end up overflowing from the latter. The excess water contained in the basin 2 can then flow into the water retention zone 32 located in the backfill zone 3 adjoining the basin 2. Advantageously, an overflow management system 22 is provided, configured to convey the excess water from the basin 2 to the backfill zone 3, or even directly to the water retention zone 32.

In order to allow the flow, in the water retention zone 32, of water running off from the land 5 or of water overflowing from the basin 2, it is provided that the waterproof membrane 31 does not completely cover the upper face of the backfill zone 3. It may be provided that the waterproof membrane has an opening. This opening may be left free. It may also be provided that it is provided with a filter, for example a filtering textile, for example a geotextile or a non-putrescible and/or stainless grid, in order to filter the water flowing into the retention zone.

The waterproof membrane 31 prevents water from flowing outside the backfill zone 3, particularly into the ground 5. By collecting the runoff rainwater in this way, the flow of water is delayed, which helps to relieve congestion in the public drainage networks and therefore limit flooding.

Additionally or alternatively, the water collected in the water retention zone 32 can also have several uses. On the one hand, this water can be used for the needs of a home, and for different functions: watering, washing vehicles, supplying toilets, washing floors, washing clothes, etc. On the other hand, because it is stored with the backfill 30, in the cavity 4 of the land 5, the temperature of this water is standardized with that of the backfill 30. The backfill 30 itself has a temperature substantially equal to that of the portion of the land 5 located at the same depth and of the portion of land 5 below. Thus, in winter, the cold rainwater flowing into the retention zone 32 is heated by the embankment 30 and by the ground 5, and in summer the hot rainwater flowing into the retention zone 32 is cooled. The water contained in the retention zone 32 can therefore serve as a thermal storage zone. The thermal collection systems from the water stored in the retention zone will be detailed further below.

It should be noted that the capacity of the basin 2 is typically greater than that of the retention zone 32. Furthermore, in winter, the water 20 contained in the basin 2 is typically colder than the portions of land 5 heating the water contained in the retention zone 32. Similarly, in summer, the water 20 contained in the basin 2 is typically warmer than the portions of land 5 cooling the water contained in the retention zone 32. The water contained in the basin 2 could therefore, undesirably, cool the water contained in the retention zone 32 in winter and, in summer, heat it. In order to prevent a thermal bridge that is too damaging for the thermal applications of the invention from being created between the water contained in the basin 2 and the water contained in the retention zone 32, the presence of a thermal insulation layer 6 is advantageously provided between the wall(s) of the basin 2 that the backfill zone 3 adjoins and the backfill 30. The thermal insulation layer 6 may be a membrane, for example a flexible one, or alternatively be formed of one or more rigid panels or sheets. This thermal insulation layer 6 forms a thermal barrier between the water contained in the basin 2 and the backfill 3. By “thermal barrier”, it is meant that the thermal insulation layer 6 makes it possible at least to reduce the heat transfers between the water contained in the basin 2 and the backfill 3. Advantageously, the thermal insulation layer 6 has a thermal conductivity of less than 0.035 Wm ^{- 1} .K ^-1 .

Although the presence of such a thermal insulation layer 6 is particularly advantageous for the implementation of the invention, it is however possible to do without it.

Advantageously, there is no thermal barrier between the embankment 30 and the ground 5. Indeed, it is often preferable to promote heat exchanges between the ground 5 and the embankment 30 so that the embankment 30 benefits from the thermal inertia of the ground 5. The waterproof membrane 31 preferably does not form a thermal barrier. Furthermore, the thermal insulation layer 6 which is advantageously present between the embankment 30 and the basin is not present between the embankment 30 and the ground 5. In particular, the thermal insulation layer 6 does not continue on the vertical wall between the embankment 30 and the ground 5. Preferably, it also does not continue between the bottom of the cavity 4 and the ground 5, as illustrated in FIGS. 1 to 2.

In certain situations, in particular in the case where the ground 5 is at temperatures not suited to the storage needs in terms of temperature, thermal inertia or any other factor which could interfere with the operation of the assembly 1, it is however possible to thermally isolate the backfill 30 from the ground 5. This is then referred to as independent thermal storage.

It should be noted that basin 2 can in fact serve as a thermal lock for rainwater before it flows into retention zone 32. Indeed, in winter, rainwater is at a very low temperature, for example around 0°C. The water contained in basin 2 is at a higher temperature. More precisely, the water at the bottom of basin 2 has a temperature close to that of the underlying portion of land 5, and the water on the surface has a temperature fairly close to the outside temperature, for example around 5°C. The rainwater falling into basin 2 can thus take at least the temperature prevailing on the surface of the water contained in basin 2. Due to the convection imposed on the water contained in basin 2 in order to prevent it from stagnating, it can be hoped that the rainwater will take on an even higher temperature. The water flowing into the retention zone 32 from the basin 2 is therefore less cold than if it had not passed through the basin 2. The warming by the ground 5 of the water in the retention zone 32, typically to temperatures of approximately 10°C, is therefore faster. This reasoning applies mutatis mutandis to a summer situation, where the rainwater is high (for example approximately 25°C) and will undergo an initial cooling due to its passage through the basin 2 before being collected in the retention zone 32 and being cooled by the ground 5, for example to temperatures of approximately 15°C to 20°C.

It is advantageously provided that the assembly 1 contains a system for controlling the discharge of water from the basin 2 to the water retention zone 32. This control system comprises, for example, temperature sensors: at a minimum, a sensor for determining the temperature at the surface of the water contained in the basin 2, and a sensor for determining the temperature of the water contained in the water retention zone 32, for example at the bottom of this zone. The control system advantageously performs a comparison of these temperatures. Based on this comparison, the control system actuates an element within the overflow management system 22 in order to allow or prevent the discharge of water from the basin 2 to the water retention zone 32. Preferably, the control system also actuates this element based on at least one, and preferably several parameters taken from: the season, data relating to the weather for the coming days, rainfall forecasts, activation by the user of a command to fill the water retention zone 32.

For example, in summer, if embankment 30 and land 5 have allowed effective cooling of the water contained in water retention zone 32, it may be counterproductive to allow water to discharge into retention zone 32 from basin 2, since the water in the basin could lead to heating the water in retention zone 32. Thus, if the control system detects that the temperature at the surface of the water in basin 2 is higher than the temperature of the water within water retention zone 32, this discharge will be prevented. If, on the contrary, a summer storm has allowed the recovery at basin 2 of very cool rainwater, and in particular colder than the water contained in retention zone 32, then the control system will allow this discharge. A similar operation of the control system takes place in winter, to only authorize the discharge of water when it is warmer than the water contained in the retention zone 32. It should be noted that it is expected that, if the assembly 1 contains such a control system, it can be activated or not. Thus, if one seeks to prioritize water storage over the optimization of thermal storage, the control system can be deactivated to authorize the passage of water without condition. The thermal storage will certainly be less optimized, but it will still be guaranteed to a satisfactory extent thanks to the properties of the embankment 30.

Furthermore, the user can choose to force the discharge of water from the basin to the retention zone 32, for example when a significant water requirement is a priority or when it is desired to avoid wasting water when an intervention in the basin requires it to be partially emptied.

Exploitation of the phenomenon of stratification of the temperature of the water contained in the basin

As schematically illustrated in the , according to an advantageous example, it is provided that the assembly 1 contains means for conveying water contained at the bottom of the basin 2 (for example up to 1%, 5%, 10%, possibly up to 100% of its height) to the retention zone 32. In this way, the phenomenon of natural stratification of the temperature of the water 20 contained in the basin 2 described above is exploited: these means in fact make it possible to take as a priority from the most appropriate temperature zone of the basin water that is temperate relative to the desired temperature in order to add it to the storage zone. This extraction of water 20 from the basin 2 to the retention zone 32 via the bottom of the basin 2 can be implemented in parallel with an extraction by overflow as described above, at the surface of the water 20 contained in the basin 2. It can also be the only technique for extracting water from the basin 2 implemented. It is also possible to envisage that water extraction from basin 2 to retention zone 32 is only done by overflow.

As schematically illustrated in the , the means for conveying water from the bottom of the basin 2 to the retention zone 32 advantageously comprise a valve 27 and a non-return valve 28. The non-return valve 28 prevents water contained in the retention zone 32 from returning to the basin 2. The valve 27 is advantageously controlled by a second control system 29 for adjusting whether water can flow from the basin 2 to the retention zone 32 and if so, at what flow rate. This second control system 29 can operate in an automatic mode, that is to say according to instructions defined beforehand and according to different predefined parameters, in a manual mode in which it is controlled by a user, or in a hybrid mode.

The exploitation of the phenomenon of natural stratification of the water temperature can even be pushed further. In particular, according to an advantageous embodiment, it is provided that the assembly 1 contains several sets of means for conveying water from the basin 2 to the retention zone 2, these different sets of means being located at different height levels of the basin 2. This provides different water extraction points, each of these extraction points making it possible to take water contained in the basin 2 being at a different temperature. It is advantageously provided that sensors make it possible to determine the temperature of the water at each of these extraction points. This makes it possible to choose, manually or automatically, through which of the extraction points the water will be extracted from the basin 2. In this embodiment, it is provided that each of the sets of extraction means contains a valve, preferably a second control system and possibly a different pump(s) in order to be able to selectively draw water from one level or another of the basin 2. A general control system, in communication with the second control systems, can manage in real time at which extraction point(s) the water is conveyed from the basin 2 to the retention zone 32. It is understood that the general control system, like each of the second control systems, can operate according to an automatic, manual or hybrid operating mode.

The multiplicity of water extraction points from the basin 2 to the retention zone makes it possible to better control the temperature of the water stored in the retention zone 32 and can also allow thermal optimization of the basin 2 itself. It is for example possible to select, automatically or manually, the extraction points by which water is actually extracted from the basin 2 in order to keep the water 20 of the basin 2 at a set temperature.

It therefore appears that the water retention zone 32 allows efficient thermal storage which can be used to heat or cool an external environment 8, as will be described in more detail.

Furthermore, the backfill area 3, when not completely filled with water, contains air which is also heated or cooled, depending on the season, by the ground 5. It is therefore possible to reserve a space within the backfill area 3 which is not filled with water in order to use it as a thermal storage area. In order to limit the water level to a certain height in the backfill area 3, several options are possible. For example, it is possible to include a water level detection mechanism which evacuates excess water beyond a previously set threshold. According to another example, the water level in the backfill area 3 is regulated using a gravity drain, comprising for example an overflow device.

It is possible to operate one or both types of storage simultaneously, namely thermal storage in water and thermal storage in air.

With a view to promoting thermal exchanges between the water and/or air contained in the backfill zone 3 and the ground 5, it is advantageous to provide that the waterproof membrane 31 has a thermal conductivity facilitating these exchanges.

The means of thermal extraction from the water or air contained in the backfill zone 3 to an external environment 8 will now be described in more detail with reference to FIGS. 2A to 2C.

Example of closed loop heat extraction with heat pump

According to an embodiment illustrated in , the assembly 1 comprises at least one drain 33 located at least partly in water contained in the retention zone 32 and allowing the circulation of a heat transfer fluid in a sealed manner relative to the backfill zone 3. In this embodiment, the heat transfer fluid is for example one of a chlorofluorocarbon (CFC), a hydrochlorofluorocarbon (HCFC) and a hydrofluorocarbon (HFC). In this embodiment, the drain 33 does not have openings allowing fluid communication with the retention zone. The drain 33 has the function of thermal drainage only.

The drain 33 is configured to allow heat transfer between the water contained in the retention zone 32 and the heat transfer fluid, which allows the heat transfer fluid to be heated in winter and cooled in summer.

After passing through the retention zone 32, the heat transfer fluid is evacuated from the backfill zone 3 via an outlet 34. This outlet 34 communicates with, or even corresponds to, an inlet 71 of a fluid circuit 7 into which the heat transfer fluid (cooled or heated depending on the case) is injected. The fluid circuit 7 comprises a device 72 for transferring the heat from the fluid to a secondary heat transfer fluid, or on the contrary for transferring the heat from the secondary heat transfer fluid to the heat transfer fluid. In the context of this embodiment, this device 72 is typically a heat pump, which can preferably operate both as heating and as air conditioning (reversible heat pump). After having been used to cool or heat the secondary heat transfer fluid, the heat transfer fluid is rerouted to the drain 33. It is understood that this circulation between the drain and the device 72 is in reality continuous, with heat transfer fluid permanently found in the drain 33 and heat transfer fluid in the device 72. The secondary heat transfer fluid is itself routed to an external environment 8. It can be used to supply thermal emitters (radiator, heated floor, fan coil, etc.) located within the external environment 8.

The assembly consisting of the drain 33, the means for conveying the heat transfer fluid from the device 72 to the drain 33 and from the drain 33 to the device 72 is commonly referred to as the “primary circuit” 73. The circuit located between the device 72 and the external environment is referred to as the “secondary circuit” 74. The arrows shown in the illustrate the direction of circulation of the heat transfer fluid and the secondary heat transfer fluid within the primary circuit 73 of the fluid circuit 7, the secondary circuit 74 of the fluid circuit 7, and the drain 33.

The heat transfer fluid being physically separated from the backfill 30 and the water contained in the backfill zone 3 by the drain 33 and from the ground 5 and the external environment 8 by the fluid circuit (i.e. its circulation is done in a sealed manner), this embodiment is said to be “in closed loops”, the primary circuit and the secondary circuit each constituting a closed loop.

As in all embodiments of the invention, it is advantageously provided that the assembly contains several drains in order to maximize its energy efficiency. Advantageously, it is provided to place at least one drain 33 at the bottom of the water retention zone 32 and at least a second drain 33 approximately halfway up the water retention zone 32. The drains 33 can in particular be installed in layers within the backfill zone 3. In order to prevent the drains 33 from being deformed and damaged by the weight of the backfill 30, it is advantageous to provide that they have significant intrinsic mechanical resistance or that they are arranged in protective sheaths.

There illustrates a top view of the assembly 1 according to the invention, particularly in the case of the embodiment currently described. This figure represents in particular the way in which the drain(s) 33 can extend, in projection in the horizontal plane XY, within the backfill zone 3. In the example illustrated, the backfill zone 3 defines a perimeter around the basin 2 extending in the horizontal plane XY over a length L _zr . It should be noted that the perimeter can be closed, as in the , or not. The drain 33 extends over a length L _d . In order to maximize the exchanges between the heat transfer fluid and the backfill zone 3, it is advantageous to ensure that the length L _d is at least greater than or equal to 50% of L _zr .

This embodiment using a heat pump allows efficient heat exchange between the retention zone 32 and the external environment 8. It is estimated that the coefficient of performance of this embodiment is between 5 and 6.

Example of closed loop heat extraction without heat pump

According to another embodiment not illustrated, the fluid circuit 7 does not include a heat pump but a simple pump, and the drain 33 and the fluid circuit 7 together constitute a single closed loop. The heat transfer fluid passing through the drain 33 and through the fluid circuit 7 can be pure water, salt water, glycolated water or even one of a chlorofluorocarbon (CFC), a hydrochlorofluorocarbon (HCFC) and a hydrofluorocarbon (HFC). In this embodiment, the drains allow an exchange of calories between the fluid present in the retention zone 32 and the fluid present inside the drain(s) 33. On the other hand, these drains 33 do not allow a passage of the fluid through their wall. They are for example formed of a conduit whose walls are sealed, that is to say not having openings.

The heat transfer fluid heated or cooled by the backfill 3 is, in this embodiment, conveyed directly to a ground heating or air conditioning system acting as a heat emitter in winter and a cold emitter in summer. The pump and the ground heating or air conditioning system thus together allow a heat transfer between the backfill zone 3 and a habitat 8.

Example of thermal extraction by “Canadian well”

According to another embodiment illustrated in , the thermal extraction from the backfill zone is done by suction of the air circulating in the backfill zone 3, according to the principle of a Canadian well. In this embodiment, the drain 33 is a conduit or a pipe having one or more openings on its wall, thus allowing air to enter the conduit. These may for example be openings obtained by radial perforations. The drain 33 therefore allows in this embodiment both fluid drainage and thermal drainage.

In this embodiment, the drain 33 communicates with a fluid circuit 7 comprising controlled mechanical ventilation (CMV) making it possible to capture the air located in the backfill zone 3 via the drain 33. The CMV makes it possible to convey the captured air to the external environment 8, typically a habitat.

Advantageously, the fluid circuit 7 is thermally insulated from the ground 5 that it crosses in order to limit the thermal exchanges between the air circulating in the circuit 7 and the ground 5. Indeed, the areas of the ground 5 closest to the surface could in winter be at a lower temperature (in summer higher) than the temperature reached in the backfill zone, and cool (in summer heat) the air being conveyed to the external environment 8, which would be counterproductive.

This VMC is typically located within the habitat itself 8 or at least is not buried in the land 5 in order to facilitate its maintenance.

As in the embodiment described above, the backfill zone 3 has an outlet 34. The air is evacuated through this outlet, which communicates with, or even corresponds to, an inlet 71 of a fluid circuit 7.

The arrows shown on the illustrate the direction of air circulation within the fluid circuit 7 and the drain 33.

The coefficient of performance of this embodiment is estimated to be around 2.

Example of thermal extraction by water extraction from the retention zone

According to another embodiment illustrated in , thermal extraction from the backfill area is done by taking water from the retention area 32. This water cooled or heated by the backfill 3 and ground 5 can typically be used to supply a hydraulic ground heating or air conditioning circuit of an external environment 8, typically a habitat 8.

In this embodiment, the drain 33 is a conduit or a pipe having one or more openings on its wall, thus allowing the water contained in the retention zone 32 to enter the conduit. These may for example be openings obtained by radial perforations. The drain 33 therefore allows in this embodiment both fluid drainage and thermal drainage.

As illustrated in , the drain 33 communicates with an outlet 34 of the backfill area itself communicating with, or even corresponding to, an inlet 71 of the fluid circuit 7. This fluid circuit 7 comprises a pump 75, making it possible to collect water contained in the retention area 32 via the drain 33. The water heated or cooled by the backfill 3 and the ground 5 is typically conveyed by the pump to a ground heating or air conditioning system 76 acting as a heat emitter in winter and a cold emitter in summer. The pump 75 and the ground heating or air conditioning system 76 thus together allow a heat transfer between the backfill area 3 and a habitat 8.

The arrows shown on the illustrate the direction of water circulation within the fluid circuit 7 and the drain 33. These last two together constitute an open loop, since a fluid exchange takes place between the drain 33 and the backfill zone 3.

Advantageously, the fluid circuit 7 is thermally insulated from the ground 5 that it crosses in order to limit the thermal exchanges between the water circulating in the circuit 7 and the ground 5. Indeed, the areas of the ground 5 closest to the surface could in winter be at a lower temperature (in summer higher) than the temperature reached in the backfill zone, and cool (in summer heat) the water being conveyed to the external environment 8, which would be counterproductive.

1. Un fluide caloporteur circulant dans la zone de remblai 3 et isolé fluidiquement de l’eau et de l’air contenus dans la zone de remblai 3,
2. De l’air puisé dans la zone de remblai 3,
3. De l’eau de pluie puisée dans la zone de rétention 32.

The heat transfer fluid can therefore be, depending on the chosen embodiment:

1. A heat transfer fluid circulating in the backfill zone 3 and fluidly isolated from the water and air contained in the backfill zone 3,
2. Air drawn from backfill zone 3,
3. Rainwater collected from retention area 32.

As previously expressed, it is possible to implement one or more of the embodiments of the thermal extraction from the backfill zone 3 within the same assembly 1. The assembly 1 may in particular comprise the elements necessary for the implementation of several of these embodiments and be used either simultaneously or successively for the implementation of the different types of thermal extraction.

In all the embodiments described above, it is possible to provide an outlet from the water retention zone 32 in order to draw water for any type of use, for example domestic.

Examples of basin and backfill area sizing

The following paragraphs aim to present an example of the dimensioning of basin 2 and the surrounding embankment zone 3. It has been shown that these dimensions make it possible to obtain very satisfactory results in terms of thermal and water storage, while corresponding to standard formats of basins for particular use. These dimensions are naturally given as an example and other dimensions can perfectly be used for the design of the basin and the embankment zone.

1. Une longueur L_bsensiblement égale à 8 mètres,
2. Une largeur l_bsensiblement égale à 4 mètres,
3. Une hauteur h_bsensiblement égale à 1,68 mètres.

Basin 2 can have the following dimensions:

1. A length L _b approximately equal to 8 meters,
2. A width l _b approximately equal to 4 meters,
3. A height h _b approximately equal to 1.68 meters.

Basin 2 then has a surface area in the horizontal XY plane of 32 m².

In a completely conventional manner, the basin 2 can have a shell 25 (for example in “rice grain” type gravel) with a thickness of approximately 7 cm.

1. Une longueur L_{z r}sensiblement égale à 8 mètres,
2. Une largeur l_{z r}sensiblement égale à 4,6 mètres,

The backfill zone 3 can extend around the basin 2, over its entire perimeter, over a width l _r of 60 cm. The backfill zone 3 then has the following dimensions:

1. A length L _{z r} approximately equal to 8 meters,
2. A width l _{z r} approximately equal to 4.6 meters,

The backfill zone 3 then has a volume of 26.6 ^m3 . It is this volume which is at least partially occupied by the backfill 30. The filling rate of the backfill zone 3 by the backfill 30, depending in particular on the grain size of the backfill 30, is typically 50%.

Furthermore, the volume occupied by the shell 25 at the bottom of the basin 2 is in this example 2.2 ^m3 . The volume occupation within the shell of the gravel forming it can also be estimated at 50%.

Thus, the total volume available for water storage is 14.4 ^m3 .

Interest s water storage enabled by the invention

As previously expressed, the backfill zone 3 allows not only thermal storage and, simultaneously or alternatively, water storage. The water stored in the backfill zone 3 comes from the surplus water in the basin 2. It can also come from other types of discharges. Indeed, it can be provided that the retention zone 32 is supplied by at least one of: water flowing on the ground, rainwater from a roof, rainwater from a terrace with a waterproof coating, rainwater from a road or a path.

This water storage can have two objectives, which are not mutually exclusive. The first is simple water retention: the waterproof membrane 31 allows water to be stored, and an outlet orifice is advantageously provided in this waterproof membrane 31 in order to return the water to a public network or directly to the land 5. The dimensions of this orifice are chosen so that the return flow rate is adapted to the characteristics of the land 5. A second objective is storage for later use. In this case, it is advantageously provided that the assembly 1 includes a settling tank in which the water is filtered or even sterilized before use.

The waterproof membrane 31 advantageously comprises a fluid outlet 36 (also called a second fluid outlet 36) as well as a device for controlling the extraction of water stored in the retention zone 32. The control device allows control of the extraction of water via the fluid outlet 36 and of the parameters characterizing this extraction. For example, the control device can prevent any exit of water stored in the retention zone via the fluid outlet 36. It can also authorize such an exit. Advantageously, it makes it possible to control the flow rate by which the water exits via the fluid outlet 36. The control system can be configured to allow or prevent the exit of water via the fluid outlet according to predetermined parameters, and thus operate in an automatic mode. The existence of such an automatic mode does not, however, prevent manual operation, in which the control device is entirely controlled by the user, or hybrid operation.

A fluid drain 35 communicating with this outlet 36 can make it possible to collect the water located in the retention zone 32 to be extracted via the fluid outlet 36.

As illustrated in , the fluid outlet 36 can allow the collected water to be returned to the land 5. The fluid outlet 36 can also communicate with a conduit carrying the water to a public or private network. In both of these cases, we are then in the case of water storage for retention purposes only.

The fluid outlet 36 can also communicate with a conduit carrying water to a settling tank. This is then the case of water storage for the purpose of subsequent use of the stored water. It is understood that the waterproof membrane 31 can comprise two fluid outlets, one for each of these applications, or a single fluid outlet connected to two separate conduits.

As illustrated in the , according to an advantageous embodiment, the assembly 1 comprises water distribution equipment 37. This equipment 37 can take different forms, depending on the uses chosen for water recovery. It can for example be a tap, household appliance, or even an automatic garden watering system. It should be noted that it is possible for the same circuit to be used to convey water to the external environment 8 for water consumption needs and for thermal needs of the external environment 8, in particular in the case where water storage is provided within the external environment 8.

This water distribution equipment 37 is in communication with the fluid outlet 36, possibly via a settling tank as previously described.

Advantageously, the assembly 1 comprises a pump 38 for collecting water contained in the retention zone 32 and conveying it to the water distribution equipment 37.

Exploitation of the phenomenon of stratification of the temperature of the water and/or air contained in the backfill zone

The phenomenon of stratification of the water temperature, described previously with reference to the water 20 contained in the basin 2, is also observed within the retention zone 32. This phenomenon can also be exploited at this level: it is advantageously provided that the thermal extraction from the backfill zone 3 towards the external environment 8 can be done at several heights of the backfill zone.

In particular, according to an advantageous embodiment, it is provided that the assembly 1 contains several fluid outlets located at different heights of the backfill zone 3. These fluid outlets may be fluid outlets allowing extraction of a heat transfer fluid having circulated within the backfill 30, of water contained in the retention zone 32, or of air contained in the backfill zone 3, according to any one of the embodiments described above for thermal or water extraction from the backfill zone 3.

In this way, different thermal and/or water extraction points are obtained, each of these extraction points making it possible to collect water or air contained in the backfill zone 3 which is at a different temperature. Advantageously, provision is made for sensors to determine the temperature of the water or air at each of these extraction points. This makes it possible to choose, manually or automatically, through which extraction point(s) the water or air will be extracted from the basin 2. In this embodiment, it is provided that each of the fluid outlets is associated with a different valve, as well as preferably with a third different control system and possibly with a different pump in order to be able to selectively take water or air at one level or another of the backfill zone 30. A general control system, in communication with the third control systems, can manage in real time at which extraction point(s) the water or air is conveyed from the retention zone 32 to the external environment 8. It is understood that the general control system, like each of the third control systems, can operate according to an automatic, manual or hybrid operating mode.

The multiplicity of thermal or water extraction points at the retention zone 32 makes it possible to better control the temperature of the water and/or air extracted from the retention zone 32. This makes it possible to improve the efficiency of the heating or air conditioning system of the external environment 8, or to choose the temperature of the water that one wishes to recover for a specific subsequent use. It is for example possible to select, automatically or manually, the extraction points by which water or air is actually taken from the retention zone 32 in order to temper the external environment 8 to a set temperature.

The following paragraphs aim to show the effectiveness of the water storage system according to the invention with quantified results.

In France, Brittany and Bouches-du-Rhône, the annual rainfall is 1.2 m/year/m² and 0.55 m/year/m² respectively. Thus, for a pool of 8x4 meters, 38 ^m3 and 17.6 ^m3 of rainwater fall on this pool each year respectively.

Considering that the backfill zone 3 extends over a width l _r of 60 cm all around the basin 2 in the horizontal plane XY, its storage capacity is approximately 15 m ³ , which allows, for a basin of 8x4x1.68 m ³ , to contain enough to renew more than a quarter of basin 2.

Thus, by using rainwater to rinse the filters of basin 2 and/or to replenish basin 2 after possible evaporation or overflow of water from basin 2 during its use, the latter is completely water neutral for regions with annual rainfall greater than 380 mm/year/m², which is the case in the majority of European countries.

If we consider an embankment area 3 with a width l _r of 90 cm instead of 60 cm around basin 2, the water storage capacity rises to 22 m ³ , which allows, for a basin of 8x4x1.68 m ³ , to contain enough to renew approximately 40% of basin 2. Thus, by using rainwater to rinse filters of basin 2 and/or to replenish basin 2 after possible evaporation or overflow of water from basin 2 during its use, basin 2 becomes neutral in water consumption in regions with annual rainfall greater than 250 mm/year.

In addition to the issues of water retention and recovery, the storage of water within the retention zone 32 makes it possible to further improve the mechanical maintenance of the basin 2 and/or the land 5 provided by the backfill zone 3. Indeed, the weight of the water is added to the weight and mechanical rigidity of the backfill, and, possibly, of the gabions. The backfill zone 3 is therefore all the more resistant to the forces exerted on it by the wall(s) of the basin 2 and/or the land 5.

Furthermore, the water stored in the retention zone 32 is a very important advantage for mechanically maintaining the wall(s) of the basin 2 when the latter is emptied.

The water stored in retention area 32 also constitutes a water reserve that can be used in the event of a fire or water shortage. This is also true for the water contained in basin 2.

The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

Claims (22)

Assembly (1) comprising a basin (2) arranged at least partially in a cavity of a terrain (5) and a backfill zone (3), the backfill zone (3) being located at least between a wall (21) of the basin (2) and a wall (41) of the cavity (4), the backfill zone (3) comprising:

• A backfill (30) configured to provide mechanical support for at least one of the wall (21) of the basin (2) and the wall (41) of the cavity (4),
• A waterproof membrane (31) at least partially surrounding the embankment (30) so as to define a water retention zone (32) within the embankment zone (3), the assembly being configured so that at least a first part of the water retention zone (32) collects rainwater flowing onto the land (5) and/or overflowing from the basin (2) and/or conveyed from the basin (2),
• At least one drain (33) configured to circulate a heat transfer fluid therein, a portion of the drain (33) being located in the backfill zone (3) and being configured to allow heat transfer between the backfill zone (3) and the heat transfer fluid,
• At least one fluid outlet (34) configured to extract the heat transfer fluid present in the backfill zone (3),

the set (1) further comprising:

• A thermal insulation layer (6) located between said wall (21) of the basin (2) and the backfill (30) and configured so as to form a thermal barrier for heat exchanges between water contained in the basin (2) and the backfill (30),
• A fluid circuit (7) comprising:
  1. an inlet (71) for a heat transfer fluid present in the backfill zone (3),
  2. a device (72) connected to said inlet (71) and configured to transfer to an external medium (8) one of the heat transfer fluid and heat from the heat transfer fluid.

Assembly (1) according to the preceding claim, in which the part of the drain (33) located in the backfill zone (3) is configured to circulate the heat transfer fluid in a sealed manner relative to the backfill zone (3). Assembly (1) according to the preceding claim, in which the part of the drain (33) located in the backfill zone (3) is made of a material allowing heat exchange between water contained in the water retention zone (31) and the heat transfer fluid. Assembly (1) according to claim 1 in which the heat transfer fluid is water contained in the water retention zone (32) and in which the drain (33) is configured to allow evacuation of said water contained in the water retention zone (32) towards the external environment (8). Assembly (1) according to any one of the preceding claims in which the water retention zone (32) extends over at least 60% of the height of the backfill zone (3), preferably at least 80% of the height of the backfill zone (3), preferably 100% of the height of the backfill zone (3). Assembly (1) according to claim 1 in which a part of the backfill zone (3) is configured not to accommodate water, in which the heat transfer fluid is air contained in said part of the backfill zone (3) and in which the at least one drain (33) allows evacuation of said air towards the external environment (8). Assembly (1) according to the preceding claim comprising at least one secondary drain (32') configured to circulate a second heat transfer fluid therein and being configured to allow a heat exchange between the water contained in the water retention zone (32) and the second heat transfer fluid. Assembly (1) according to any one of the preceding claims, in which the backfill (30) has a specific heat capacity less than or equal to 860 J.kg ^{- 1} .K ^-1 and/or a thermal conductivity less than or equal to 2 Wm ^-1 .K ^-1 . Assembly (1) according to any one of the preceding claims, in which the backfill (30) contains crushed stone, the crushed stone having a particle size greater than 4 cm. Assembly (1) according to the preceding claim in which the crushed material has a particle size of less than 10 cm. Assembly (1) according to any one of the preceding claims in which the backfill (30) is based on a material resulting from the recycling of asbestos, for example Cofalit ®. Assembly (1) according to any one of the preceding claims in which the membrane (31) is based on an ethylene-propylene-diene monomer (EPDM) rubber. Assembly (1) according to any one of the preceding claims in which the thermal insulation layer (6) has a thermal conductivity of less than 0.035 Wm ^{- 1} .K ^-1 . An assembly (1) according to any preceding claim wherein the backfill area (3) comprises gabions, the backfill being arranged in the gabions. Assembly (1) according to any one of the preceding claims, in which the external environment (8) is a habitat. An assembly (1) according to any preceding claim comprising a plurality of drains (33), at least two drains among the plurality of drains (33) preferably being arranged in parallel. Assembly (1) according to any one of the preceding claims in combination with claim 2 in which the backfill zone (3) forms a perimeter around the basin (2), said perimeter extending over a length L _{z r} taken in projection in a horizontal plane (XY), and in which the drain (33) extends, in the backfill zone (3), over a length L _d , taken in projection in the horizontal plane (XY), such that L _d ≥ 0.5 * L _{z r} , preferably L _d ≥ 0.7 * L _{z r} , preferably L _d ≥ 0.8 * L _{z r} and preferably L _d ≥ 0.95 * L _{z r} . Assembly (1) according to any one of the preceding claims further comprising a system taken from a heat pump, a Canadian well or a heated floor. Assembly (1) according to the preceding claim in which the heat transfer fluid forms the primary fluid of said system taken from a heat pump, a Canadian well or heated floor. Assembly (1) according to any one of the preceding claims further comprising:

• At least one second fluid outlet (36),
• A control device configured to selectively control an extraction of rainwater contained in the water retention zone (32) by the second fluid outlet (36).

Assembly (1) according to the preceding claim further comprising water distribution equipment (37) in communication with the second fluid outlet (36), the assembly being configured so that the rainwater extracted by the second fluid outlet (36) supplies the water distribution equipment (37), the water distribution equipment (37) being taken from a tap, household appliance, automatic garden watering. Habitat comprising the assembly (1) according to any one of the preceding claims and a heat exchange system, for example a radiator or a fan coil.