The present invention relates to a floor heating system for hot water heating.

Today floor heating is a frequently applied means for heating buildings by hot water, such as certain rooms, in particular a living room, a kitchen and hallway in houses. Such a type of floor heating may be used instead of radiator heating or may be applied in addition thereto. Typically a floor heating system is a circulation circuit, which comprises a manifold having a supply inlet for hot water from a boiler of a central heating and a return outlet for water to the boiler, a number of flexible hoses or tubes, that are embedded in the floor, and the ends of which are connected to the manifold. Typically the flexible hoses are arranged in grooves that are cut in the concrete bottom floor and after inserting the hoses the grooves are filled with fresh mortar or concrete. Generally the flexible hoses are arranged in a pattern wherein parallel hose parts are spaced at a distance of typically 10 cm. Installing such floor heating systems requires a lot of labour intensive activities. In addition the existing floor heating systems do heat up the whole concrete mass of the floor during use. This results in relative long heat up times and waste of heat into the mass of concrete. In addition, due to the distance between the hoses the occupants and other users experience local temperature variations. Furthermore, this kind of floor heating is less suitable for application with relative thin supporting floors, such as wooden floors, which may be present in older buildings, or between storeys, due to the typical diameter dimensions of the hoses. Moreover, in such wooden floors it is complicated to fixedly mount the hoses. Also space for arranging the manifold may be hard to find.

KR101925952B1 discloses a modular floor heating system that is composed of floor members, each floor member having a plurality of flow paths. At one end a floor member is provided with a first cap member having a supply chamber that is in fluid communication with half of the plurality of flow paths, and a discharge chamber separated from the supply chamber that is in fluid communication with the other half of the plurality of flow paths. At the other end the floor member is provided with a second cap member having a single chamber in communication with all the flow paths of the floor member. A bottom opening in the discharge chamber of the first cap member is connected by a flexible hose to a bottom opening in the supply chamber of neighbouring first cap member. Thus in the system neighbouring floor members are arranged in series, such that the hot water flows serially through all the floor members.

KR101296606B1 also discloses a modular floor heating system wherein the hot water flows serially through a number of the floor modules. Similar arrangements are known from KR20110112194A and EP0783064A1.

From DE102014006864A1 a mat having capillary tubes, e.g. for heating purposes, is known, wherein the supply and discharge flow channels are arranged above one another.

A disadvantage of these known systems is that locally differing temperatures are experienced. The floor temperature at the entry side of the heating system is higher than towards the exit end. Thus the floor heating system does not provide the hot water flows serially through all the modules which may give rise to locally differing temperatures, as the temperature difference between the hot water and the floor to be heated becomes smaller towards the end of the system at the supply side of the whole system the hot water has a higher temperature than at the discharge side, where the hot water after heat exchange is recirculated to the heat water source. Furthermore the inner space of the return caps or modules is in communication with all the supply flow channels and discharge channels of the floor member, resulting in inadequate heat transfer and flow characteristics.

The invention aims at providing a floor heating system which is versatile such that it can be easily adapted and installed independent from the type of supporting floor and that allows for easy connection to existing pipework.

Another object is to provide such a system which enables to reduce the heat losses into the floor.

Yet another object is to improve the uniformity of the heat distribution over the floor area where a modular floor heating system is installed.

According to the invention a floor heating system for hot water heating is provided that is constituted by interconnectable plastic modules, comprising multiple neighbouring sets of modules, each set comprising a connector manifold module, at least one basic module and a return module, wherein

- the connector manifold module comprises a supply channel, at least one supply manifold channel, a first end thereof ending up in the supply channel and a second end thereof being configured for connecting to a basic module, a return channel, at least one return manifold channel, a first end thereof being configured for connecting to a basic module and a second end thereof ending up in the return channel;

- the at least one basic module comprises a body having at least one supply channel, and at least one return channel, wherein the at least one supply channel is configured to be connected at its ends to a channel of an adjacent module in the set of modules, and wherein the at least one return channel is configured to be connected at its end to a channel of an adjacent module in the set of modules; and - the return module comprises a body having at least one return channel, which return channel at one end is configured to be connected to the respective supply channel of the adjacent basic module and at the other end is configured to be connected to the respective return channel of the adjacent basic module; wherein the supply channel of at least one connector manifold module in the system is configured to allow connection to a supply conduit from a hot water source and the return channel of at least one connector manifold module in the system is configured to allow connection to a return conduit to the hot water source, and wherein the ends of the supply channel of the connector manifold module are configured for connecting to the respective supply channel of the connector manifold module of an adjacent set of modules, and wherein the ends of the return channel of the connector manifold module are configured for connecting to the respective return channel of an adjacent connector manifold module.

The floor heating system according to the invention comprises multiple neighbouring sets of three main modules that are arranged adjacent to one another, such that the adjacent sets of modules are in parallel flow to one another in operation. Each set is constituted by a connector manifold module that is typically arranged at an edge between the floor on which the modules are positioned and an upstanding wall, typically at the position of a plinth if any, one or more basic modules supported by the floor and extending from the connector manifold module in the direction of an opposite wall, and a return module arranged at the opposite wall. In the context of this specification an “adjacent module” is a module next to another module within the same set of modules, The term “neighbouring” is used to indicate different sets or modules of different sets, which modules are arranged next to one another The respective channels of a module are at their ends connectable to the corresponding channels of an adjacent module in a fluidly tight manner. Likewise the ends of the supply channel and return channel of the connector manifold module are connectable to the respective ends of a neighbouring connector manifold module in a fluidly tight manner. The connector manifold module of a set of modules receives hot water from a central heating unit such as a boiler or heat pump and returns water after circulation through the one or more basic modules and return module to the central heating unit. The ends of the supply channels of neighbouring connector manifold modules of neighbouring sets are coupled to one another. In a similar manner the return channels of neighbouring connector manifold modules of neighbouring sets are coupled. The supply channel of a connector manifold module is connected via the supply manifold channel to each supply channel of the adjacent basic module. Likewise is each return channel of the adjacent basic module connected via the return manifold channel to the return channel of this connector manifold module. The basic module comprises at least two, but preferably a plurality of channels such as 6-12, wherein half of the number of the plurality of channels acts as a supply channel and the other half acts as a return channel. The number of supply and return manifold channels in the connector manifold module is the same as the number of the supply and return channels in the adjacent basic module. The at least one supply channel of the basic module is at its inlet end connected to the supply side of the adjacent connector manifold module, that is the respective end of the supply manifold channel, and at the opposite side to the inlet end of the respective return channel of the adjacent return module. On its turn the outlet end of the return channel of the return module is connected to the at least one return channel of the adjacent basic module and via this return channel via the return manifold channel to the return channel of the adjacent connector manifold module. At least one of the connector manifold modules in the system is connected to the hot water source, from which hot water is received and to which water after circulation through the modules is returned. Typically this is one and the same connector manifold module.

It will be understood that if a module set comprises more than one basic module the supply channel of the basic module adjacent the connector manifold module is at its upstream end connected to the supply manifold channel and at its downstream end to the inlet end of the adjacent basic module. The downstream end of the supply channel of the basic module adjacent the return module is connected to the inlet end of the return channel in the return module, while the outlet end of the return channel is connected to the downstream end of the return channel of the basic module adjacent the return module, which return channel is connected to the inlet end of the return channel in the adjacent downstream basic module. Thus in the floor heating system according to the invention the circulation path(s) of hot water in a set provided by the supply manifold channel, the supply channels of the one or more basic modules, the return channels of the return module, the return channels of the basic modules and the return manifold channel in the connector manifold module are arranged in parallel flow, and also the sets themselves are fed in parallel, contrary to the above prior art system where at least some of such sets are in series, because the end of the return channel in a connector manifold module is connected to the end of the supply channel of the neighbouring connector manifold module. As a result in the invention the temperature differences between ingoing and outgoing water in each set are more uniform than in the prior art systems having serially arranged sets of modules.

The plastic modular floor heating system according to the invention can be easily applied on existing floors, whether made from concrete, wood or other material, without the need for cutting grooves for inserting hoses or tubes. The plastic basic modules can be easily manufactured in one piece by extrusion at a standard length and can be cut to size in situ.

The connector manifold module can be prepared by injection moulding and the like of its constituting parts, which possibly are assembled together. Also the return manifold may be manufactured by this technique. 3D printing may also be used for manufacturing the modules. The plastic modules can be connected using any kind of plastic joining or welding. Preferably the plastic is a thermoplastic allowing mirror welding to connect the end of the channels of the basic module to those of the connector manifold module and the return module in order to establish the leak tight circulation loops comprised of the respective channels in the modules. Polyurethane is a preferred starting material in view of strength, rigidity and expansion coefficient. The internal surfaces of the channels may be coated, e.g. with an oxygen barrier coating in order to avoid diffusion of oxygen through the plastic into the circulating water, which would result in a flow of corrosive oxygen-rich hot water through the system including the hot water source and (metal) connecting pipework. Another example is a heat transfer improving coating such as a thin metal coating.

In a preferred embodiment the channels in the basic module and return module have a flat configuration. In other words these channels have a cross-section, which is typically rectangular, having a width that is larger than the depth, advantageously the depth is much smaller than the width. The thickness of the upstanding walls that delimit the channels in the depth direction is determined by the strength required and are designed as small as possible. The flat configuration of the channels due to their width offers a large heat exchanging surface covering substantially the whole floor surface in a contiguous way without the presence of large gaps between spaced apart hoses according to the prior art, thereby preventing local temperature difference. The system according to the invention also allows to operate the warm water source at a lower temperature compared to a floor heating system based on embedded hoses, because the system according to the invention does not need to heat up the concrete mass and because of the large heat exchanging surface. During operation of the system according to the invention the channels having a flat configuration, and the total of channels covering the whole surface of the respective floor a large volume of water (compared to prior art systems with hoses) is circulating. Such a large volume of water is favourable for use with a heat pump in view of stable operation thereof as well as optimal use of its heating and/or cooling capacity. The heating efficiency may further be enhanced by applying a suitable isolation such as a flattening underfloor for example from felt or cork, upon which the floor heating system according to the invention is positioned. The thickness of the module according to the invention in a flat bottom embodiment is preferably 7 mm or less.

The thickness of the module according to the invention having supporting legs as explained below is preferably less than 10 mm. The total thickness including the isolation is less than 15 mm, such as 12 mm. Typically a further floor covering, such as carpeting, floor laminate or wooden floorboards, is laid on top of the floor modules according to the invention.

The supply channels of adjacent connector manifold modules can be connected by a connector, e.g. a short piece of straight tubing having embedded seals, such as O- rings, at both ends that are to be inserted in the supply channel ends of adjacent modules to be connected. The return channels can be connected in a similar way.

At least one of the connected connector manifold modules is connected to the hot water source. In renovation where the system according to the invention replaces conventional radiator heating the connections of existing supply and return pipes can be used. Typically the connector manifold module in the neighbourhood of these existing conduits is provided with additional connectors for connecting thereto, which connectors are in fluid communication with the supply channel and return channel of the respective module. Thus advantageously the supply channel of at least one connector manifold module is provided with an additional supply connector, which is configured to be connected to a hot water supply conduit from the hot water source. Similarly the return channel of at least one connector manifold module is provided with an additional return connector, which is configured to be connected to a return conduit to the hot water source. Depending on the position of these existing conduits the additional connectors may be provided as top connectors, side connectors or bottom connectors. Angled e.g. 90° (knee bend) connectors may be inserted in the ends of the supply channel and return channel if desired. Non-active ends of the supply and return channels of the connector manifold module can be easily blinded by inserting a suitable plug or stopper.

In a preferred embodiment the connector manifold module comprises a bottom portion and an upstanding portion, wherein the supply channel and the return channel are arranged parallel and preferably above one another in the upstanding portion, and the at least one supply manifold channel and the at least one return manifold channel extend through the upstanding portion and the bottom portion wherein the ends configured to be connected to the basic module are arranged in the bottom portion. In this way the supply channel and the discharge channel are easily accessible for mutual coupling to adjacent connector manifolds using straight connector parts as explained above, while the bottom portion can be connected by mirror welding to the respective adjacent basic module.

In order to allow easy assembling and mutual positioning, in a further embodiment the basic modules are provided with couplings for interconnecting of these modules at the edges, typical the longitudinal sides, parallel to the channels in the basic modules, preferably tongue and groove couplings.

Similarly the return modules are provided with couplings for interconnecting of these modules at their edges. Preferably these couplings are also tongue and groove couplings. In yet a further embodiment the at least one return channel of the return module is a U- or V- shaped channel allowing a smooth bending of the flow of water. In an embodiment the outermost wall of the return channel is spaced apart from the rear edge allowing to adjust this void part by suitable machining such as cutting to unevenness in the neighbouring wall, such as a horizontally sloping wall

Generally the basic module and return module are panels having a flat upper face, upon which a further floor covering can be laid. This also holds for the bottom portion of the connector manifold module. When no separate insulating underfloor is used, the opposite bottom face of the various modules is preferably provided with supporting legs, more preferably at the positions of the upstanding walls of the channels, which walls separate adjacent channels, whether adjacent channels in the same module or in a neighbouring module. The supporting legs allow to balance any unevenness of the floor on which the system according to the invention is arranged. Furthermore the air volume that is present between the legs functions as an isolation layer preventing full area contact of the bottom face of the module with the floor, which also contributes to reduction of heat loss to the floor. In case a separate insulating underfloor is used, preferably the opposite bottom is flat.

It will be understood that the system according to the invention also can be used as a cooling system.

The invention is illustrated in more detail in the attached drawing, wherein:

Fig. 1 is a diagrammatic view of an embodiment of a connector manifold module of a floor heating system for hot water heating according to the invention;

Fig. 2 is a cross sectional view at a position of a supply manifold channel in Fig. 1;

Fig. 3 is a cross sectional view at a position of a return manifold channel in Fig. 1

Fig. 4 is a diagrammatic view of an embodiment of a basic module of an underfloor heating system for hot water heating according to the invention;

Fig. 5 is a cross sectional view of the basic module of Fig. 4;

Fig. 6 is a diagrammatic top view of an embodiment of a return module of an underfloor heating system for hot water heating according to the invention;

Fig. 7 illustrates the internal channels of the return module of Fig. 6;

Fig. 8 is a diagrammatic view of a second embodiment of a connector manifold module of an floor heating system for hot water heating according to the invention;

Fig. 9 is a cross sectional view at a position of an additional supply connector in Fig. 8;

Fig. 10 is a cross sectional view at a position of an additional return connector in Fig. 8;

Fig. 11 is a diagrammatic view of a third embodiment of a connector manifold module of an floor heating system for hot water heating according to the invention;

Fig. 12 is a cross sectional view at a position of an additional supply connector in Fig. 11 ;

Fig. 13 is a cross sectional view at a position of an additional return connector in Fig. 11; Fig. 14 is a diagrammatic view of a fourth embodiment of a connector manifold module of an floor heating system for hot water heating according to the invention;

Fig. 15 is a cross sectional view at a position of an additional supply connector in Fig. 14;

Fig. 16 is a diagrammatic view of an embodiment of a connector part for mutual coupling adjacent connector manifold modules; and

Fig. 17 is a diagrammatic view of a room, the bottom of which is provided with a system according to the invention.

In the drawing the same parts are indicated by the same reference numbers, except where indicated explicitly otherwise.

In Fig. 1 a diagrammatic view of an embodiment of a connector manifold module of an underfloor heating system for hot water heating according to the invention is shown. Fig. 2 and 3 show cross-sections at the position of a supply manifold channel, respectively at the position of a return manifold channel thereof. The connector manifold module is indicated in its entirety by reference numeral 10. The module 10 comprises an upstanding portion 12 and a bottom portion 14. The upstanding portion 12 comprises a supply channel 16 and a return channel 18, which both extend in the length direction of the module 10 and parallel to one another. At its respective ends 17 the supply channel 16 can be connected to an adjacent module, for example by means of a connection part as shown in Fig. 16. Similarly the ends 19 of the return channel 18 can be coupled to the end of the return channel in an adjacent module. In this embodiment the bottom portion 14 comprises ten channels, of which five adjacent supply manifold channels 20 (left hand side) are in fluid communication with the supply channel 16 via channels 22 and respective openings 24 in the upstanding portion 12. Similarly five adjacent return manifold channels 26 (right hand side) are in fluid communication with the return channel 18 via channels 28 and respective openings 30 in the upstanding portion 12. The channels 20 and 26 are separated by upstanding walls 32. These channels have a rectangular cross-section. As can be seen, the top face 34 of the bottom portion 14 is substantially flat and in this non-flat design the bottom face 36 is provided with supporting legs 38 at the position of the walls 32. At one side (left hand side) the bottom portion 14 has a groove part 40 and the opposite side (right hand side) is provided with a tongue part 42 for coupling to matching coupling parts of adjacent modules. In the embodiment shown the upper portion 12 comprises supporting legs 44 which carry the channels 16 and 18. Two supporting legs 44 are provided with slotted holes 46, which allow to fix the module 10 to a wall e.g. using a metal back support and screws (both not shown). In this embodiment the front faces 48 of the supporting legs 44 have projections 50 and recess 52 that extend in the width direction of the module 10. A further recess 54 is present in the top face 56. These projections 50 and recesses 52 and 54 can be used for coupling to a cover or plinth. In Fig. 4 a diagrammatic view of an embodiment of a basic module of an underfloor heating system for hot water heating according to the invention is shown. Fig. 5 shows a cross- section thereof. The basic module 60 has a panel like body 61 that corresponds to that of the bottom portion of the connector manifold module. The module 60 has a top 62 having a substantially flat upper face and - in the non-flat design as shown - a bottom 64 provided with supporting legs 66 extending over the length of the module 60 at the position of upstanding walls 68. These walls 68 together with the top 62 and bottom 64 delimit parallel internal channels 72 having a rectangular cross-section similar to the channels 20 and 26 of the module 10. Half of these channels 72 are supply channels 72’ that can be connected to the ends 21 of the supply manifold channels 20. The other half are return channels 72” that can be connected to the ends 27 of the return manifold channels 26. The longitudinal side 74 is provided with a groove part 78 defined by recess 79 between projecting edges 80 and 82 of the top 62 and bottom 64. The opposite side 84 has a tongue part 86 for insertion into a matching groove part of an adjacent module. Thus the recess 79 is configured to receive a matching tongue part 86.

In Fig. 6 a diagrammatic top view of an embodiment of a return module of an underfloor heating system for hot water heating according to the invention is shown. Fig. 7 illustrates the outlines of the internal channels thereof. The return module 90 has a panel like body 91 having an external configuration that corresponds to that of the basic module 60. The module 90 is provided with internal channels 92 separated by walls 94. The channels 92 have an inlet end 96 and outlet end 98 at the same side of the module 90, of which the cross-section corresponds to that of the internal channels 72 to receive the flow of water from the supply channels 72’ in the basic module 60 and to return the flow of water to the return channels 72” in the basic module 60. A return module 90 is provided with similar tongue and groove coupling means for coupling adjacent return modules. The rear end area 99, which is void of channels, can be adjusted to irregularities in the neighbouring wall, without interference with a flow path in the return module.

Figs. 8-10 show a second embodiment of a connector manifold module according to the invention, similar to Fig. 1. Similar parts are indicated by the same reference numerals. In this embodiment the supply channel 16 is provided with an additional upper connector 100 for coupling to a source of heat water such as a heat pump or boiler of a central heater. The connector 100 may for example have internal screw thread. Similarly the return channel 18 is provided with an additional upper connector 102 for circulating back the flow of water to the source thereof.

Fig. 11-13 show a third embodiment of a connector manifold module according to the invention, similar to Fig. 1 and 8, wherein however the respective additional connectors 100 and 102 are directed to the bottom of the module 10. Fig. 14-15 show a fourth embodiment of a connector manifold module according to the invention, similar to Fig. 1, 8 and 11, wherein however the respective additional connectors 100 and 102 project from the front of the upstanding portion 12 of the module 10. In this specific embodiment these additional connectors 100 and 102 have an end that is positioned where otherwise two openings and channels would have been situated. The number of internal channels is reduced to six, three as supply manifold channels 20 and three as return manifold channels 26.

Fig. 16 shows an embodiment of a connector part 110 for mutual coupling adjacent connector manifold modules 10 .The connector part 110 comprises a length of tubing provided at both ends 112 with a suitable seal, in this case circumferential recesses 114 in the outer periphery of the tubing for receiving O-rings (not shown). The ends 112 have a diameter that allows insertion in a sealing manner into the corresponding ends of the supply channels 16 and the corresponding ends of return channels 18 in adjacent modules that are to be coupled. For an end module an angled connector part, such as a 90° bend tubing may be a suitable alternative for the connector part 110.

Fig. 17 shows a diagrammatic view of a room, the bottom of which is provided with a system according to the invention. A series of connector manifold modules 10 of which the supply and return channels are interconnected using connector parts is arranged along a wall 110 of a room. The bottom portions of the modules 10 are arranged on the floor 114 of the room with possible interstation of an insulating layer 116 of cork and welded to the basic modules 60, thereby connecting the supply manifold channels and return manifold channels of the modules 10 to the corresponding channels in the basic modules. On its turn the other end of each basic module 10 is welded to the return module 60. As can be seen the connector manifold modules 10 and return modules 60 have a standard size, while the basic modules can be cut to size to achieve the required length. The connector manifold modules are fixed by screws on a metal back support profile to prevent the modules from being pushed apart by the water pressure.