WO2018130843A1

WO2018130843A1 - Heating system improvements

Info

Publication number: WO2018130843A1
Application number: PCT/GB2018/050086
Authority: WO
Inventors: Amir Daniel MIRFANI; Nigel BASSETT-JONES
Original assignee: International Innovation Services (Internacia Novigo Servoj) Ltd
Priority date: 2017-01-13
Filing date: 2018-01-12
Publication date: 2018-07-19
Also published as: GB201909857D0; GB201700654D0; GB2573226B; GB2573226A; GB2573674A; GB2573674B; GB201909858D0; WO2018130844A1

Abstract

The present invention provides a heat distribution system (1) for use with a radiator (11) positioned proximal to the inner surface of an external wall (16) of a room having an inner surface (16a), said system has a thermoelectric generator module (TGM) (52)working with an air duct (72) through which air from between the radiator and the external wall may be drawn. An electrically powered fan (43) positioned to move air through the air duct and the thermoelectric generator module (52) and the fan (43) are electrically connected such that electrical power generated by the TGM may drive the fan (43). The TGM has first (52a) and second (52b) spaced apart active surfaces. The TGM may be positioned between the radiator and the external wall with the first active surface (52a) in contact with the inner surface (16a) of the external wall (16) and the second active surface (52b) facing towards the radiator, thereby to generate electricity when there is a temperature differential between the radiator (11) and the inner surface (16a) of the external wall(16)and the generated electricity is supplied to the fan via the electrical connections (55) so that the fan draws air through the duct (72) from between the radiator (11) and the external wall (16).

Description

HEATING SYSTEM IMPROVEMENTS

The present invention relates to heating systems. More specifically, the invention relates to a heating system comprising a radiator, such as may often be found in a domestic setting, for example.

Radiators, such as wall radiators, are frequently used to heat rooms. Typically, such radiators use convection and radiation to transfer heat from the hot water circulating within the radiators into the room. The water is heated by a boiler located remotely from the radiators. Radiators are usually either wall-mounted or positioned close to a wall in the room. For optimal heating, a radiator is typically positioned underneath an external window. The main reason for locating radiators underneath windows is to create a heat (or "thermal") curtain to offset the chilling effect from the window. However, when a radiator is so positioned beneath an external window, or indeed adjacent to any external wall, a lot of heat is lost. The heat loss arises because the external wall is colder than the room, and there is a direct flow of heat through the wall behind the radiator to the outside environment.

This problem has previously been addressed by positioning heat-reflective sheet material, such as metallic foil, between the radiator and the wall, so as to reflect some of the heat back into the room. This is a rather crude response to the problem. Whilst it is better than nothing, an improved solution is desirable.

Another issue with a standard radiator heating system is due to the convection system set up in a room. Convection results in the displacement of warm air from next to a radiator upwards, creating a deficit of air adjacent the radiator that is equalised by drawing in colder air from the lower part of the room, thereby creating a circular current of air that over time warms the room. However, one result of convection, and the fact that heat rises, means that over time heat accumulates at the top of the room space, towards the ceiling. This is disadvantageous as occupants in a room tend to occupy the lower and middle tiers of the room space.

Existing documents that purport to at least partially address these problems include;

EP1369655 (GOLD), which illustrates the use of cowling around a radiator to collect warmed air, and fans to blow the warm air in directions other than in the direction of natural convection. Mention is vaguely made in here of the use of a "Peltier circuit" to provide at least part of the electrical power required to drive the fan, although the assumption is made that a "buffer battery" charged by the Peltier circuit is likely to be necessary.

WO2012/173580 (KOCAK), which shows a radiator or air conditioner with additional fan units. WO2016/030773 (XHABIJA), which is in essence a unit (a 'device'), placed on the top or bottom of a radiator, containing fans which can assist in the convective movement of air over the radiator and mentions the use of a thermoelectric circuit placed between the radiator and the device to assist in powering said fans.

US201 1/0253350 (BELLES), which is also aimed at enhancing the convective movement of air, this time over a heat exchanger, and mentions the possibility of use of a thermoelectric circuit to power fans.

WO2013/020936 (COSKUNOZ), which describes the addition of a heat sink to a radiator and the use of a fan to force convection by blowing air upwards over the fins of the heat sink. Here, a thermoelectric generator is connected between the radiator surface and the heat sink surface in order to provide a temperature differential and thus assist in powering the fan.

CZ20060232 (MINIB), which describes the use of a fan to blow air over a heat exchanger and posits the use of a thermoelectric generator where the 'cool' side of the generator is placed against the fan-cooled surface.

The present invention seeks to properly address the problems outlined above and also improve the efficiency of radiator heating systems.

Accordingly, there is provided; a heat distribution system (1) for use with a radiator (11) positioned proximal to the inner surface of an external wall (16) of a room, said system comprising;

a thermoelectric generator module;

an air duct through which air from between the radiator and the external wall may be drawn and blown into the room;

an electric fan positioned to move air through the air duct;

the thermoelectric generator module and the fan being electrically connected such that electrical power generated by the thermoelectric generator module may drive the fan;

said thermoelectric generator module having first and second active surfaces; Wherein the thermoelectric generator module is positioned between the radiator and the external wall with the first active surface in contact with the inner surface of the external wall and the second active surface facing towards the radiator, thereby to generate electricity when there is a temperature differential between the radiator and the inner surface of the external wall, and wherein the generated electricity is supplied to the fan via the electrical connections so that the fan draws air through the duct from between the radiator and the external wall and blows it into the room. The inventors have realised that where a radiator is placed adjacent to an external wall, the specific location of a thermoelectric generator module between the radiator and the wall, at appropriate times of year, in an environment where such an installation is typical, advantageously provides a suitable temperature gradient of sufficient magnitude to provide an efficacious driving force for the thermoelectric generator module. This is because at the typical time when a radiator is used, the outside environment is significantly colder than the desired temperature of an inside room. Accordingly, in a typical installation, a significant amount of radiated heat energy flows straight through the wall to the outside environment. Such a flow of heat can readily be seen by an infra-red image of a typical domestic dwelling, which shows 'hot spots' beneath the windows consistent with the placement of the radiators.

Further, by circulating (preferably) heated air drawn from adjacent, particularly behind, the radiator into the surroundings or room, the time required to heat a room to a given temperature may be reduced. Furthermore, the energy consumption required to sustain the room at the given temperature may also be reduced. The air blown by the fans may be directed simply away from the wall, or may be directed along the floor of the room. In an embodiment, the air is blown in a direction that is counter to the natural flow of convection in the room, to prevent the build-up of warm air in the upper region of the room and to more equalise the distribution of warm air vertically within the room.

The thermoelectric generator module may comprise a simple thermoelectric or more than one thermoelectric generator.

In an embodiment, there may be provided a thermoelectric generator module which comprises:

a panel, said panel comprising thermally insulative material and one or more cavities;

at least one thermoelectric generator for installation into at least one of the one or more cavities;

the thermoelectric generator having first and second active surfaces which, when the thermoelectric generator is installed in a cavity, correspond to the first and second active surfaces respectively of the thermoelectric generator module;

whereby when the thermoelectric generator module is positioned between the radiator and the external wall and in contact with the inner surface of the external wall, the sections of panel not comprising a thermoelectric generator insulate the contacted inner surface of the external wall from the radiator. In the circumstances as noted above, when the outside environment is cold and the radiator is On' with hot water flowing through it and heating the room, the transfer of heat from the radiator and to (and through) the external wall to the outside environment means that, over time, the section of wall 'behind' the radiator tends to warm up. Where a thermoelectric generator is placed between the radiator and that wall, with one active side against the inner surface of the wall and the other active side facing the radiator, the temperature difference across the active surfaces of the thermoelectric generator tends, over time, to decrease, as the inner surface of the wall warms up. The present embodiment provides a thermally insulative panel with a number of cavities. The panel may be in the form of a substantially flat plate with two or more cavities. Each cavity is sized and shaped so as to receive a thermoelectric generator. Such a thermoelectric generator may be a relatively standard commercially available product, and the cavities will be of a size and shape to snugly receive such a product. The panel may be of a thickness similar to that of such a thermoelectric generator. Aesthetically, the overall look of the panel, with thermoelectric generator(s) installed, may then be pleasing, and also the overall panel will then be relatively smooth so that installation of the panel behind a radiator may be facilitated. The panel may, however, be thinner or thicker than a thermoelectric generator. The thermoelectric generators may be advantageously placed such that one active side is in physical contact with the inner surface of the external wall. In such situation, the active side is likely to be 'flush' with the corresponding surface of the panel. The other active side of the thermoelectric generator(s), facing the radiator, and the corresponding surface of the panel, need not necessarily be so flush, so long as the active surface of the thermoelectric generator(s) is exposed to the radiator.

Advantageously, the presence of a thermally insulative panel behind the radiator reduces the warming effect of the radiator on the wall. Accordingly, the temperature differential between the inner surface of the wall and the radiator is maintained, and so therefore is the temperature differential across the active surfaces of the one or more thermoelectric generators that are installed in a cavity or cavities of the panel, maximising their electrical output potential. The panel thus comprises a thermoelectric generator module comprising one or more thermoelectric generators. In an embodiment, the panel may be sized so as to completely cover the 'footprint' of the radiator against the wall so as to minimise any heating effect of the radiator upon the wall.

Where the thermoelectric generator module comprises a panel with a number of cavities for the installation of thermoelectric generators, the number of thermoelectric generators may vary according to the power requirements of the remainder of the heat distribution system, primarily the fan. Where cavities are not fitted with a thermoelectric generator, these 'unused' cavities may simply be filled with 'blanks' of thermally insulative material. This material may be the same material of which the panel comprises.

In an embodiment, the panel may be further supplied with an electrical network. This network may be integrated or embedded within the panel. Each thermoelectric generator which is installable within a cavity of the panel may be provided with electrical terminals. Each cavity of the panel may be provided with complementary electrical terminals for connection with a thermoelectric generator when installed. These electrical terminals may be any common form of terminal known in the art, such as spade connectors, ring terminals, pin terminals, or bullet connectors, or may be essentially flat contacts which abut each other, on an outer edge of a thermoelectric generator and on the inner edge of a cavity. The electrical network may join together, electrically, a number of thermoelectric generators either in series or in parallel, or in a mixture of series and parallel, depending on the given output voltage/current of each generator and the desired voltage/current required to drive the fan of the system. In an embodiment, the electrical network may ultimately terminate in a collective terminal at which the combined output of all the thermoelectric generators is present in a single connector. This collective terminal connector may then be connected to a complementary connector from the fan. It will be recognised that in fact the collective terminal may in fact be a pair or wires or a collection of wires which may be directly connected to the fan, for example by soldering.

In an embodiment, the collective terminal connects to a Controller or the thermoelectric generator module comprises a Controller. The Controller may act as a regulator for the output from the thermoelectric generator module. The Controller may comprise a programmable processor or similar means known in the art. The Controller may act to activate the fan at certain times, for example in accordance with a schedule predetermined by a user, or in response to one or more certain conditions, such as the thermoelectric generator module producing a certain output level, or a temperature or plurality of temperature measurements in the room being at certain levels or varying by certain amounts. For example, if a temperature measured at the upper level of a room (for example, at the ceiling, or in the upper third of the room) reaches a temperature where it is 2 degrees Celsius or 3 degrees Celsius or some other quanta more than a temperature measured in the lower level of a room (for example, at the floor, or in the lower third of the room), then the Controller may then activate the fan or fans and thus create a flow of air into the room, away from the wall and/or against the natural convection flow of the room, thus acting to reduce the temperature differential.

The heat distribution system may comprise a further source of power such as a battery or mains power supply to supplement the power generated by the thermoelectric generator module. Power from the thermoelectric generator module may be used to charge a battery at times when the fan is not activated or at times when the module is generating a power surplus. The control and distribution of power from the module and/or from other sources may preferably be controlled by the Controller.

In an aspect there is provided A thermoelectric generator module for fitment between a radiator and an external wall, comprising: a plate comprising thermally insulative material and having a face and a face; said plate further comprising one or more cavities;

one or more thermoelectric generators for fitment into at least one of one or more cavities;

said thermoelectric generators having a first active face and a second active face such that when fitted into a cavity, the first active face is substantially flush with face of plate; whereby when the thermoelectric generator module is installed with face in contact with external wall and face in proximity to radiator and radiator is generating heat, a temperature differential is present across the first and second active surfaces and of the one or more thermoelectric generators such that electricity is generated by the one or more thermoelectric generators and the thermally insulative plate insulates wall from the radiator thereby to preserve the temperature differential.

In embodiments, at least one air duct is arranged to provide at least one channel for directing air from the air blower or fan into the surroundings is provided, for example wherein the air duct comprises at least one inlet arranged to receive air from adjacent the radiator, and at least one outlet arranged to distribute air into the surroundings. The air adjacent the radiator may be air from between the radiator and the inner surface of the wall, with an inlet provided between the radiator and the inner surface of the wall. The air duct may comprise a plurality of distinct channels for the passage of air flow, each channel having an inlet and an outlet. The air duct may at least in part be positioned between the radiator and an adjacent surface such that air from behind the radiator can be directed (or blown) into the at least one inlet.

In embodiments, the or an air duct may be integral with the radiator. The or an air duct may be arranged to pass through the radiator, with at least one of the inlet or outlet being arranged in the surface of the radiator. The at least one outlet may be arranged to distribute air into the surroundings from towards the bottom of, or from beneath, the radiator. The diameter or cross- sectional area of the at least one channel may increase or decrease from the inlet to the outlet. The at least one air duct may be located at an interface between the radiator and a surface to which the radiator may be attached or adjacently mounted (such as an external wall). If externally disposed, said air duct may comprise one or more channels arranged to provide an inlet behind the radiator and an outlet beneath the radiator. The air duct may be substantially V shaped, for example. The system may comprise a radiator having at least one internal air channel with an outlet in a surface or wall of the radiator, for example at or adjacent the base of the radiator, and this outlet may face into the room and away from an external wall. The fan or air blower may be integrated or disposed within the radiator. The fan or air blower may be arranged to direct air into the duct and/or air channel(s) from a position adjacent to or within the radiator. The fan or air blower may be situated at any suitable point relative to one or more air ducts, such as at or near an inlet, at or near an outlet, or at any point within the air duct(s) or air channel(s).

Where an air duct is provided that is mounted on, attached to or positioned adjacent to or in contact with a radiator, it may comprise heat conductive material. When the radiator is on, the duct warms up, and so air that passes through the duct or air channel(s) thereof, when the radiator is on, is therefore also warmed during transit before being directed or blown into the room. Where such an air duct is integral to the radiator, air drawn or blown through the duct is likewise warmed in transit when the radiator is on.

In an embodiment, a thermal bridge is provided between the surface of the radiator facing the wall and the second active surface of the thermoelectric generator module (that is, the surface of the thermoelectric generator module facing towards the radiator). The thermal bridge preferably comprises a thermally conductive material such as a metal. The provision of this thermal bridge provides for a direct conduction of heat from an On' radiator to the second active surface of the thermoelectric generator module (the first active surface facing or in contact with the relatively cold inner surface of the external wall). This means the temperature differential between the two active surfaces of the thermoelectric generator(s) is maximised. This is particularly helpful in the circumstance where the temperature of air between the radiator and the wall may be in effect reduced by the movement of warm air from between the radiator and the wall - either as a result of normal convective flows, or as a result of said warm air being drawn away and expelled into the room by the air duct and fan elements of the system. In an embodiment, the thermal bridge takes the form of a simple bent metal plate in a generally U-shaped or V-shaped configuration. The thermal bridge also in this form may be seen to provide a spring or biasing force - if the two 'arms' of the U (or V) are forced together, they will naturally tend to spring apart. This may be taken advantage of further, as an appropriately sized U-or-V-shaped thermal bridge will thus be able to be installed and hold itself in position between a radiator and a wall, or to enable further advantages as described above, between the 'back' surface of the radiator (which faces the wall) and the second active surface of a thermoelectric generator module. Yet more advantageously, the biasing spring force may also be used to hold the thermoelectric generator module in position in addition to the thermal bridge itself, thus obviating the requirement for fitting the thermoelectric generator module in place by other means, which may be difficult due to the presence of the radiator (for example, drilling holes into a wall for fitment of the thermoelectric generator module may necessitate initial removal of the radiator). It is however recognised that the thermoelectric generator module and indeed the thermal bridge may be fixed in place by any conventional fixings familiar in the art, such as screws, nails, glues, clamps, tape, and so on.

In an embodiment, the U-or V-shaped thermal bridge is positioned between the radiator and the wall/thermoelectric generator module in an 'upside-down' position such that the 'arms' of the U or V point downwards. Warm air that develops in between the radiator and the wall, when the radiator is on, is hence at least partially prevented from joining the standard convectional flow and is 'held' between the radiator and the wall. This produces a supply of warm air which can then be drawn by the air duct and fan elements from behind the radiator and thence blown into the room - as previously noted in one embodiment, advantageously against the flow of standard convection.

In an embodiment, there is provided a support member arranged to brace between the radiator and an adjacent surface, whereby the support member is configured to provide a heat conductive path between the radiator and the thermoelectric generator module. The support member may be an expandable brace member that is arranged to hold the thermoelectric generator module in position. The support member may act as a thermal bridge and may comprise or be formed from thermally conductive material. The support member may comprise a first portion arranged to brace against the radiator and a second portion arranged to brace against the adjacent surface, such as the wall. The first and second portions may be movably opposed such that the spacing between them can be adjusted. The first and second portions may be slideably opposed. As an alternative, the first and second portions may be biased apart elastically, whereby a compressive force can be applied to bring them closer together. This alternative may comprise a bent metal plate, which may be bent into a substantially U or V shape, and the 'arms' of the U or V may comprise the first and second portions. An interlocking mechanism may be arranged to inhibit relative movement between the first and second portions. Optionally, the thermoelectric generator module, or one or more thermoelectric generators, may be mounted to the support member (which may also comprise a thermal bridge), and the thermoelectric generator module or one or more thermoelectric generators may be mounted to one of either the first or second portions of the support member / thermal bridge.

In an embodiment, the fan comprises a so-called 'bladeless' fan assembly comprising an electric- motor driven bladed fan contained within a chamber having a chamber inlet and a chamber outlet, the chamber outlet comprising at least one slot and the chamber further defining an air passage through which air can be induced to flow when air is moved, blown or driven by the bladed fan so that it enters the chamber inlet, passes through the bladed fan blades, and exits via the chamber outlet. Such a bladeless fan assembly may comprise a part of the air duct noted in other aspects and/or embodiments of the present description, and may be integral to a radiator, a module for fitting to a radiator specifically designed to receive said module, or may be an 'aftermarket' or retrofittable module that may be applied to a radiator, either singly or in combination with or as part of a heat distribution system as elsewhere herein described. In other embodiments, the fan may be a simple electric-motor driven bladed fan that is placed within an air duct or air channel, or at or near an inlet or outlet to such an air duct or air channel.

Aspects and embodiments will now be described, by way of non-limiting example only, with reference to the accompanying Figures, in which:

Figure 1 shows a schematic side view of a radiator in a cross-section of a room, further illustrating typical convection air flow in a typical standard domestic arrangement and also radiated heat flow from the radiator both into the room and into an external wall adjacent the radiator.

Figure 2 shows a schematic side view of a heat distribution system, according to certain aspects and embodiments of the present application, as applied to a radiator in a cross-section of a room.

Figure 3 shows a schematic side view of a heat distribution system, according to certain aspects and embodiments of the present application, as applied to an integrated radiator system in a cross-section of a room.

Figure 4a shows an embodiment of an air duct for fitment between and beneath a radiator situated in proximity to a wall. Figure 4b shows another embodiment of an air duct as in Figure 4a, which for convenience and ease of installation is in two parts.

Figure 5a shows a view from above a radiator showing the placement of an air duct fitted behind and beneath a radiator.

Figure 5b shows a view from the front side of a radiator, showing the placement of an air duct fitted behind and beneath a radiator as shown in top view in Figure 5a.

Figures 6a and 6b show embodiments of a 'bladeless' fan module as may be installed in the integrated radiator of Figure 3.

Figure 6c shows a front view of an integrated radiator as in Figure 3 with a bladeless fan module as in Figures 6a and 6b installed.

Figure 7 shows a schematic view of a thermoelectric generator module in accordance with aspects and embodiments of the application, and Figure 7a shows a close-up view of a cavity of the thermoelectric generator module with a thermoelectric generator installed.

Figure 1 shows a radiator 1 1 in close proximity to external wall 16 of a room. The radiator is also positioned beneath window 15. The radiator, when on, warms the room via radiated heat as shown by arrows 12 as well as by the effect of heated air 14 rising. The heated air 14 ultimately creates a convection current, illustrated by arrows 13, by which means air circulates throughout the room. Heat energy also escapes from the room via conduction upwards through the ceiling as shown by arrows 17 and also into and through the wall 16 behind the radiator via radiated heat 18. As described herein, this standard arrangement tends to produce a room with a temperature profile that is hottest towards the upper reaches of the room, whilst the middle and lower reaches of the room, where occupancy is concentrated, may be 2, 3, or even 4 degrees Celsius cooler.

Figure 2 shows a radiator 11 as in Figure 1 but with a heat distribution system 1 in accordance with aspects and embodiments of the invention. A thermoelectric generator module 52 has a first active surface 52a in contact with the inner surface 16a of the external wall 16 and a second active surface 52b facing towards the radiator 1 1. L-shaped air duct 72 is placed behind and beneath the radiator 1 1. Within air duct 72 is an electric fan 43 connected to the thermoelectric generator module 52 by an electrical connection comprising wire 55. Heat is conducted directly to active surface 52b of the thermoelectric generator module 52 via thermal bridge 53 which consists of a substantially U-shaped bent metal plate which was installed in place by pressing together of the arms of the 'U' to facilitate insertion of the thermal bridge between the radiator and the thermoelectric generator module. Upon release, the arms expanded out and press against the radiator 11 and the thermoelectric generator module 52 surface 52b, providing good thermal contact - also thereby holding the thermal bridge in place and potentially also acting to hold the thermoelectric generator module in place. Electricity generated by a temperature difference across the active surfaces 52a and 52b of the generator module 52 powers the fan 43, setting up a flow of warm air from behind the radiator (at least some of which is prevented from rising with standard convection by the presence of thermal bridge 53), through the air duct 72 and out into the room, along the floor, against the normal flow of convection, in the direction of and as indicated by arrows 54 and 56. Such an embodiment can clearly be seen to be retrofittable to a standard radiator positioned adjacent a wall, merely requiring the positioning of a kit comprising an air duct with fan, a thermoelectric generator module and a thermal bridge.

Figure 3 shows an alternative embodiment wherein radiator 11 a is an 'integrated' radiator designed to comprise elements of the heat distribution system 1 described herein. As in Figure 2, thermoelectric generator module 52 has active surface 52a in contact with the inner surface 16a of external wall 16 and an active surface 52b facing towards radiator 1 1a. Thermal bridge 53 is installed between radiator 1 1a and thermoelectric generator module 52, in contact with active surface 52b and thus providing for direct conduction of heat from radiator 11a to surface 52b. In this embodiment, radiator 1 1a is provided with internal channels 61 which comprise part of the air duct of the heat distribution system. Also provided within the radiator 1 1 a is a further channel 62 for the fitment of a fan (not shown in Fig 3) comprising a fan module as detailed in Figures 6a and 6b. When the radiator is On', the temperature differential across active surfaces 52a and 52b of thermoelectric generator module 52 provides power via wire 55 to the fan module in channel 62. Warm air from between the radiator 1 1a and the wall 16 is drawn into air duct / internal channels 61 as indicated by arrow 54a and then travels internally through the radiator 1 1a through channels 61 as indicated by arrows 54b and ultimately blown out into the room across the floor as indicated by arrows 56, thus providing an anti-convective flow of warm airwhich warms up the room in a more even mannerthan by standard convection. It will be appreciated that the travel of air through air duct channels 61 , as the 'walls' of the channels are warm/hot radiator surfaces, will advantageously serve to warm the air as it moves through the radiator / air duct / internal channels.

Figure 4a shows a substantially 'L'-shaped air duct 72 for fitment beneath and behind a radiator 1 1 , as shown in Figure 2. Within the duct are a number of vanes 75. The duct 72 and the vanes 75 are composed of a thermally conductive material, in this case metal. Hence, when duct 72 is installed behind and beneath a radiator, and preferably in contact with the radiator, there is heat transfer into the material of the duct 72 when the radiator is on. Accordingly, air drawn through the duct 72 is exposed to a large surface area of heated metal and is warmed up as it transits through the duct. Figure 4b shows a variant of the air duct which comprises two sections, 72a and 72b. Section 72a is for fitting behind a radiator between the radiator and a wall, and section 72b is for fitting beneath a radiator between the radiator and the floor, and for convenience each section may be fitted individually, with section 72b slotting into open space 72c of section 72a. Conveniently, open space 72c may be bereft of vanes 75 and may then serve to provide an installation space for a fan or fan module. The fan module for fitting in duct 72 in the space 72c may be as described in relation to Figures 6a, 6b, and 6c.

Figures 6a and 6b show a fan module 43a. In this embodiment the fan module is a 'bladeless' fan assembly comprising an electric motor driven bladed fan 43 contained within chamber 64. Chamber 64 comprises a fan housing section 64a and an air passage section 64b. The air passage section 64b comprises a hollow rectangular passage which defines a tunnel 66, and further comprises slots 65 which are outlets from the chamber 64. The placement of slots 65 around the tunnel 66 means that when air is driven by fan 43 so that it enters the fan housing section 64a of fan module 43a via inlet 63, it is blown into air passage section 64b and then exits via slots 65. This flow of air out from slots 65, as indicated by arrows 67, in turn induces a further flow of air through tunnel 66, as indicated by arrow 68. In this way there is an 'air multiplier' effect as will be familiar to those skilled in the art. In an embodiment such as illustrated in Figure 3, such a fan module can be installed into an integrated radiator 1 1 a in a purpose-made channel 62. As an alternative, a fan module such as 43a may be installed into an air duct 72 as described in relation to Figure 4a and especially Figure 4b where the air duct may be broken down into two sections. In a further alternative embodiment, the fan module 43a may itself comprise an air duct in accordance with aspects of the invention and may, for example, be installed underneath a radiator proximate a wall, and comprise the means for drawing air from behind the radiator and blowing it into a room away from the wall, with or without further ducting or air tunnel structures. Figure 6c shows a front view of a purpose-built 'integrated' radiator in which fan module 43a is installed in complementarily sized and shaped passage 62. Dotted lines 57 represent the air duct / internal air passages 61 which are shown in side aspect in Figure 3, and show that each air passage 61 is defined by vanes 57 which serve to guide the airflow as well as warm the air passing through the passages 61 , as they are made of heat conductive material which warms up as the radiator warms up. Figure 7a shows a thermoelectric generator module 52 as shown in side view in Figures 2 and 3 and also in side view in Figure 7b. It comprises a plate 31 having a first side and a second side 31 a, 31 b made of material that is resistant to heat conduction. The plate has a number of cavities or moulded slots 32 comprising holes through the plate 31. Each cavity 32 may be filled either with a thermoelectric generator 33 or may be filled with a 'blank' composed of the same heat-conduction resistant material as the plate 31. Figure 7 shows the first active surface 52a for placing in contact with the internal surface 16a of an external wall 16, with two thermoelectric generators 33 in two of the moulded slots/cavities 32. The thermoelectric generators 33 have active surfaces 33a which lie, when installed, in a plane with active surface 52a of the thermoelectric generator module 52.

Figure 7a shows a close-up of installed thermoelectric generator 33 in a cavity 32. The thermoelectric generator 33 has electrical terminals/contacts (not shown) on its edge which are in contact with complementary electrical terminals 36 on the inner edge of the cavity 32. The module 52 has wires 35 embedded in the material of the plate 31. The wires 35 comprise an interconnected electrical network which connects the complementary electrical terminals 36 of all the cavities 32 via wire 55a to collective terminal 34.

Figure 8 shows an embodiment of a fan module 43b comprising a shrouded motor-driven bladed fan 43 inside a thermally and sound-insulated box 44, which drives air 67a out through slots 65a. In this embodiment an input terminal 34a is provided for connection with collective terminal 34 of the thermoelectric generator module 52 of Figure 7. The collective electrical output of the thermoelectric generator module 52 may thus be supplied to Controller 42 by connecting input terminal 34a to collective terminal 34. Controller 42 comprises a regulator and a programmable processor. The Controller 42 thus activates fan 43 at appropriate times, such as when sufficient power is being generated by the generator module 52 or according to a pre-programmed schedule input by a user. In this embodiment, the heat distribution system is also provided with a battery 46, connected to the Controller. Accordingly, at times when TGM 52 is generating surplus power, the Controller charges up battery 46, thus enabling the provision of back-up power should the circumstance arise that the fan 43 is called to operate according to user schedule or demand but the TGM be providing insufficient power. As a further back-up, the Controller is provided with a mains plug 47 so that the fan 43 may be activated even when the TGM 52 is not supplying power and the battery 46 is flat. It will be recognised that the heat distribution system may then be used as simply as an air distribution system to provide a cooling effect in a room at times of year when the ambient temperature is higher than comfortable for users. It will be appreciated that although not shown, a Controller 42 and/or a battery 46 and/or a mains plug 47 may equally be provided and present in the embodiments shown in Figures 2 and 3.

The embodiments given, especially in relation to the Figures, are to be understood as illustrative examples. A feature described in relation to one embodiment may be used alone or in combination with other features or in combination with other embodiments or features of other embodiments.

Claims

1. A heat distribution system (1) for use with a radiator (11) positioned proximal to the inner surface of an external wall (16) of a room having an inner surface (16a), said system comprising;

a thermoelectric generator module (TGM) (52);

an air duct (72) through which air from between the radiator and the external wall may be drawn;

an electrically powered fan (43) positioned to move air through the air duct; the thermoelectric generator module (52) and the fan (43) being electrically connected such that electrical power generated by the TGM may drive the fan (43);

said TGM having first (52a) and second (52b) spaced apart active surfaces; wherein the TGM is positioned between the radiator and the external wall with the first active surface (52a) in contact with the inner surface (16a) of the external wall (16) and the second active surface (52b) facing towards the radiator, thereby to generate electricity when there is a temperature differential between the radiator (1 1) and the inner surface (16a0 of the external wall (16), and wherein the generated electricity is supplied to the fan via the electrical connections (55) so that the fan draws air through the duct (72) from between the radiator (11) and the external wall (16).

2. A heat distribution system (1) as claimed in claim 1 wherein the thermoelectric generator module (52) comprises a thermoelectric generator.

3. A heat distribution system (1) as claimed in claim 1 wherein the thermoelectric generator module (52) comprises:

a panel (31) having a first side (31 a) and a second side (31 b), said panel (31) comprising thermally insulative material and having one or more cavities (32) extending through the panel (31);

at least one thermoelectric generator within at least one of the one or more cavities (32);

the thermoelectric generator (33) having first and second active surfaces (52a, 52b) which, when the thermoelectric generator (33) is installed in a cavity (32), correspond to the first and second active surfaces respectively of the TGM;

4. A system as claimed in claim 3, wherein:

the at least one thermoelectric generator is further provided with electrical terminals for the transmission of electrical power generated by the thermoelectric generator;

5 - the panel is further provided with complementary electrical terminals for the receipt of electrical power generated by the at least one thermoelectric generator when the at least one thermoelectric generator is installed in the one or more cavities;

the thermoelectric generator module being further provided with an electrical i o network connecting the complementary electrical terminals of each cavity;

said electrical network further comprising a collective terminal, said collective terminal capable of electrical connection to the fan; wherein the electrical network provides a collective electrical output from the at least one or more thermoelectrical generators installed in the one or more cavities of the 15 panel to the collective terminal.

5. A system as claimed in claim 4, wherein the complementary electrical terminals of the one or more cavities are connected in series via the electrical network.

20 6. A system as claimed in claim 4, wherein the complementary electrical terminals of the one or more cavities are connected in parallel via the electrical network.

7. A system as claimed in any preceding claim, wherein the air duct is shaped and positioned so that air drawn from between the radiator and the external wall and

25 through the duct by the fan is directed into the room away from the wall.

8. A system as claimed in any preceding claim, wherein the air duct is integral to the radiator or is in physical contact with the radiator such that when the radiator is at a higher temperature than the air, the air that passes through the duct is warmed by

30 passage through the air duct.

9. A system as claimed in any preceding claim, further comprising a thermal bridge located between the second active surface of the TGM and the radiator.

35 10. A system as claimed in claim 9, said thermal bridge comprising a substantially U- shaped bent plate of thermally conductive material.

1 1. A system as claimed in claim 10, said thermal bridge further comprising a spring for one or more of: installation and retention of the thermal bridge between the radiator and the inner surface of the external wall; installation and retention of the thermal bridge between the radiator and the second active surface of the thermoelectric generator module; installation and retention of the thermal bridge and the thermoelectric generator module between the radiator and the inner surface of the external wall.

12. A system as claimed in claim 1 1 , said spring comprising a substantially U-shaped bent plate which comprises an elastically deformable material.

13. A thermoelectric generator module (52) for fitment between a radiator 11 and an external wall 16, comprising: a plate (31) comprising thermally insulative material and having a face 52a and a face (52 b);

said plate (31) further comprising one or more cavities (32);

one or more thermoelectric generators (33) for fitment into at least one of one or more cavities (32);

said thermoelectric generators (33) having a first active face (33a) and a second active face (33b) such that when fitted into a cavity, the first active face (33a) is substantially flush with face (52a) of plate (31); whereby when the thermoelectric generator module (52) is installed with face (52a) in contact with external wall (16) and face (52b) in proximity to radiator (1 1) and radiator (1 1) is generating heat, a temperature differential is present across the first and second active surfaces (33a) and (33b) of the one or more thermoelectric generators (33) such that electricity is generated by the one or more thermoelectric generators (33) and the thermally insulative plate (31) insulates wall (16) from the radiator (11) thereby to preserve the temperature differential.