WO2022002356A1

WO2022002356A1 - Window sill system

Info

Publication number: WO2022002356A1
Application number: PCT/EP2020/068295
Authority: WO
Inventors: Keith RIMMER
Original assignee: KSR Consultancy (NW) Limited
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2022-01-06
Also published as: EP4172449A1

Abstract

A window sill system is provided comprising a body that is configured to be arranged adjacent a bottom edge of the window. The body comprises an air input to draw in air, an air output to direct a stream of air across at least a portion of the surface of the window, and an air flow channel extending between the air input and air output. A heat source is arranged to heat the air within the body. For instance a heating element may be arranged to be mounted within the air flow channel.

Description

WINDOWSILL SYSTEM

Field of the Invention

The present invention relates to an improved window sill system (also called a window cill system) for a building window, and in particular, although not exclusively to an improved sill component.

Background

Typically, a building window comprises a wall opening of a building with a sill system and a glazed unit installed within the wall opening to provide a weatherproof closure of the wall opening. Building windows can take many shapes and sizes, with the sill system and glazed unit sized and shaped appropriately. A common building window has a square or rectangular wall opening and whilst examples herein are provided in relation to a rectangular building window, it will be appreciated that the window sill system can be adapted to suit different shapes and sizes.

Whilst there are various orders of construction, and the sill system is envisaged to be adaptable to many, commonly, a building window is installed after the window opening is formed through a fabric of the building, for instance in a cavity wall or the like. Again, various building constructions are available, for instance timber frame, monolithic walls, and emerging constructions such as insulated concrete form (ICF) and the window sill system and glazed unit can be suitably adapted. In relation to a cavity wall, the wall opening may include cavity closures and the like to close the cavity and provide a closed, peripheral box through the fabric of the building and in which the window sill system and glazed unit is installed. The closed box provides a lower, horizontal surface forming the base or bottom of the wall opening.

By way of example, the window sill system is installed on the lower horizontal surface of the wall opening. The window sill system has an exterior side and an interior side, relative to the glazed unit. Window sill systems serve to hold the glazed unit in place. Externally, the sill system provides a mechanism for the shedding of rain water away from the wall directly below the wall opening. Internally, the sill system functions as an aesthetic covering to hide the joins and gaps between the various parts and materials. It is known to form the window sill system from an exterior sill and an interior sill. Here, the exterior sill is formed from a similar material to a frame of the glazed unit. For instance an extruded UPC profile, but other materials are also common, and is mechanically fixed to the wall opening. The exterior sill has a projecting lip and a base upon which the glazed unit sits and is secured. The interior sill is typically a window board or the like such as an MDF board or other solid material that can be readily decorated and customised. The interior sill can be adhered to the wall opening or mechanically fixed if the fixings can be hidden.

It is well known and understood that glazing units have a lower thermal insulation than the building’s wall fabric. As a consequence, heat can transfer through a glass surface of the glazed unit and cause heat loss. If the external temperature drops below ambient room temperature, then temperature difference across the glass would further increase the heat loss from the room. Also, as warmer air from inside the building contacts the colder window surfaces, condensation can form which effects visibility and can lead to damp and mould. Damp and mould need to be cleaned up regularly to stop the damp causing damage and the mould growing. It is known and documented that problems associated with damp and mould include respiratory issues, allergies, asthma, and reduced immune system.

Previously, efforts to reduce mould and damp have been addressed within the industry by reducing the thermal transmittance (U-value) of the glazing unit. For instance, triple glazed window units are known to have a higher heat loss resistance rate (R-value, which is the reciprocal of the U-value) than single or doubled glazed window units. However, the replacement costs, time and disruption of replacing or installing high performance glazed units can be prohibitive. The configuration of a wall opening can also restrict the addition of an insulator and/or a building window with multiple glazing. Physical barriers are also used such as curtains and shutters that are arranged in front of (on the inside of) the glazed unit to provide an insulating barrier. However, these items must be closed and cover the window to provide an insulating effect, and so they block visibility.

The present invention has been devised in light of the above considerations. It is an aim of the present invention to overcome or at least mitigate one of the above or other issues. It is a further aim to provide a window sill system that reduces the formation of mould and damp on the inside surfaces of the building window. It is a further aim to provide a window sill system that can be retrospectively installed. It is a further aim to provide a window sill system that can improve the thermal efficiency (e.g. thermal resistance) of the glazing unit, the effects of which would be equivalent to decreasing the U-value (or increasing the R-value) of the building window.

Summary of the Invention

According to exemplary embodiments there is provided an internal sill, a sill system including the internal sill and a method of retrofitting the internal sill according the claims and as set out elsewhere in this application.

In the broadest form, the internal sill provides an air flow channel to divert rising warm air from a radiator mounted beneath the wall opening towards the glazed unit. The internal sill includes an air input provided on an underside of a nose that is arranged to project from the wall opening. Advantageously, the nose projects over the radiator. By shifting the flow of hot air towards the glazed unit, various improvements to the room temperature have been found relative to the same conditions and radiator performance through computational simulations and experimental data. It has been found that the temperature in the room raises quicker, the heat loss or leakage through the glazed unit is reduced and the energy needed to heat up the room is reduced. Furthermore, by shifting or diverting the hot air towards the surface of the glazed unit, local evaporation rate from the glass and the window frame would increase, leading to a reduction in condensation, which in turn reduces the possibility of mould formation. Moreover, by shifting the flow of hot air from the radiator towards the glazed unit, the computational simulations have shown that a thermal layer would be formed on the glazed unit which would reduce heat loss and undesirable draughts. In exemplary embodiments, the nose is arranged to extend over at least 50% of the depth of the radiator. Here, the extent of projection is determined by the position of a distal end of a nose of the internal sill determined in a vertical plane relative to vertical planes determined by two predominant faces or planes of the radiator. For instance a wall side face or plane and a room side face and plane. Suitably the nose extends between 50% and 100% of the depth of the radiator and more preferably between 75% and 100% of the depth of the radiator. In a particularly suitable embodiment, it has been computationally modelled that optimum conditions can be created with the nose extending substantially the full depth of the radiator. Here, the distal end of the nose is aligned in a vertical plane with the room side predominant face or plane of the radiator. In exemplary embodiments, the nose extends from the wall opening less than 105% of the depth of the radiator.

In exemplary embodiments, the nose of the internal sill is formed to extend from an air flow channel that extends through the internal sill to an outlet. Here, the airflow channel has an air inlet defined by a substantially vertical plane between upper and lower plates or walls that form the airflow channel. The nose projects from the upper wall of the airflow channel. Suitably, the nose is formed from an overhang. The overhang is suitably contiguous with the upper wall of the airflow channel. Thus, the overhang and upper wall may, as herein described, be an integral wall or plate. Preferably, the overhang comprises a planar section and a distal end wall. The distal end wall extends downwards from the planar section. Here, the distal end wall forms an internal angle with the planar section. The internal angle is measured between the underside of the planar section and the distal end wall. The angle may be around 90°. Alternatively, the angle may be between 90° and 150°. Preferably, the angle is between 120° and 140° and most preferably around 135°.

In the exemplary embodiments, a tip of the distal end wall forms the distal end of the nose. The tip of the distal end wall is arranged relative to the lower plate or wall of the airflow channel with respect to a horizontal plane. For instance, the tip is arranged to be at or lower than a mid-point between upper and lower extents of the airflow channel. However, optimum results have been achieved with the tip of the distal end wall arranged at or around the horizontal plane of the lower extent of the airflow channel. That is a face of the lower wall or plate internal to the airflow channel.

In the exemplary embodiments, the overhang from the airflow channel extends from the inlet at least a distance equal to a vertical height of the inlet. In some exemplary embodiments, the overhang extends less than 300% of the vertical height of the inlet and preferably between 150% and 250% and most preferably around 200% of the inlet height. Here, it is understood the inlet height, the vertical height between the upper and lower plates or walls of the airflow channel is a height of the airflow channel.

The internal sill comprises an airflow channel. The airflow channel is defined between upper and lower surfaces. The upper and lower surfaces are suitably, upper and lower surfaces of upper and lower plates or walls forming the airflow channel. Suitably, the upper and lower surfaces are planar. The planar surfaces are suitably parallel and spaced from each other to provide an airflow channel having a substantially constant height. The airflow channel extends from the air inlet to an air outlet. The air outlet is arranged to direct the airflow close to an inside of the glazed unit. The outlet suitably may be arranged in a horizontal plane. The height (in the vertical direction) and to some extent the shape of the outlet has been designed to induce ‘stack effect’ (or ‘chimney effect’) to further enhance the flow rate through the channel. Here, the airflow channel includes an elbow to change the direction of the airflow from being horizontal to being generally vertical. It will be understood the airflow channel shifts the or at least a portion of the airflow from the radiator to be closer to the glazed unit. For instance, by directing a portion of the airflow, typically being heated air rising from the radiator, through a horizontal portion of the sill and to the outlet. Here the airflow channel suitably has a length at least the depth of the window opening.

That is, at least a depth equal to a thickness of the building’s wall between an inside of the glazed unit or external sill and inside plane of the wall. However, as described herein, with the advantageous overhang and position of the distal end of the nose, the airflow channel suitably extends over the radiator. The airflow channel height is suitably between 5% and 15% of the length of the airflow channel. The airflow channel height may be greater than 5% or greater than 7% or greater than 10% of the length of the airflow channel. The airflow channel height may be less than 15% or less than 13% the length of the airflow channel. Suitably the airflow channel height may be around 12% of the length of the airflow channel. Here, the airflow channel length is determined between the air inlet and a portion of the airflow channel furthest from the air inlet in a horizontal direction (e.g. a direction parallel to a predominant longitudinal axis of the airflow channel between the inlet and outlet.

In the exemplary embodiments, the internal sill is a moulded component. The moulded component suitably has a generally consistent wall thickness. Side edges of the airflow channel are closed by respective side walls that extend between the upper and lower walls. In one exemplary embodiment, the internal sill is formed from a plurality of parts. Here at least one part is arranged to telescopically extend or contract relative to another part. For instance, one part may comprise one portion of the airflow channel and the other part may comprise a second portion of the airflow channel. One component may include or be connected to an upstand part comprising the outlet and the other component may include or be connected to the inlet. Suitably, one of the components (e.g. the first component) fits within the other component (e.g. the second component). It is suitable for the fit to be a tight fit, though sealing may be used. With the component being inserted into the other component, an overlap is created such that increasing or decreasing the overlap allows the length of the airflow channel to be adapted to fit different configurations of building wall thickness, radiator size and radiator mounting (e.g. distance from the building wall). Advantageously, the telescopic arrangement allows a modular design of the components such that one particular arrangement of the components can accommodate various ranges of design whilst still marinating the optimal configuration of the nose as herein described. Here, the optimal configuration is based on optimising airflow velocity through the airflow chamber and additionally or alternatively around the outlet. In addition, the telescopic arrangement acts as a control mechanism determining the extent of the overhang over the radiator, which in turn changes the volume of hot air to be diverted to towards the channel.

The internal sill is part of a sill system and combines or is integral to an external sill. The internal sill can be installed on top of existing window board, for instance when retrofitting the internal sill, or the internal sill can be used instead of or to replace the window board. Here suitably, the internal sill is installed underneath the window board or other suitable cover. Using a modular design, multiple internal sills can be installed in a series across the width of the wall opening. Additionally or alternatively, whilst it is envisaged the internal sill having an airflow channel will extend substantially across the width of the wall opening, spacers may be used to accommodate differences in wall opening width and sizes of the modular internal sill. For instance, the spacers may be cut from window board or the like. In the exemplary embodiments the window sill system includes a cover that is arranged over the top of the internal sill. The cover may be substantially a flat sheet of material that can be cut to size to cover the internal sill or sills to hide any joins in the internal sill or between adjacent internal sills. In one exemplary embodiment, the cover includes a lip that bends over the nose of the internal sill.

Exemplary embodiments relate to a window sill system for a building window, wherein the window sill system includes an internal sill configured to direct a stream of air across the window surface.

The window sill system comprises an internal sill having a body that is configured to be arranged adjacent a bottom edge of the wall opening. The internal sill or body forming the internal sill comprises an air inlet to draw in air, an air outlet to direct a stream of air across at least a portion of the surface, or at least near or adjacent the surface of the glazed unit, and an air flow channel extending between the air inlet and air outlet.

When the resulting air directed in a stream across the window has a higher temperature than the window surface, the stream of warmer air provides an insulating and heating effect on the cooler window surface. It is believed, this insulating and heating effect of the air stream counters heat loss through the window and the cooling effect of the cooler window surface. Any consequential cooling within a room of the building and the formation of cold spots is thereby restricted or at least reduced from the same configuration without the shifted airflow. The insulating and heating effect of the air stream also helps to raise the surface temperature of the glass and the window frame of the glazed unit (or prevent the interior surface of the window from cooling as far or as fast) so as to limit or at least reduce the formation of condensation.

The window sill system includes an internal sill arranged on an interior side of the building window. As such, the air inlet is configured to draw air from within an internal room environment and the air outlet is configured to direct the stream of air across at least a portion of an internal surface of the window.

The window sill system may include an external sill arranged on an exterior side of the building window. The external sill may be separate to the internal sill. The external sill may include a mounting for receiving, locating and fixing in position the glazed unit. Here, the internal sill may abut or be integral to the mounting. The window sill system may also include a further internal sill component, for instance an existing window board.

The internal sill, in some embodiments is formed from a body. The body may be a single body, for instance a unitary part such as a single piece moulding, or alternatively, the body may be formed from a plurality of component parts. Suitably, the body is formed from any suitable material, including recycled materials such as recyclable plastics.

The air inlet comprises an aperture formed in the body through which air can enter the body. The air inlet in some embodiments is envisaged as a plurality of apertures. For instance, a plurality of apertures separated from adjacent apertures by webs or the like extending between the upper and lower surfaces. The webs may be formed at discrete points or across the depth of the airflow channel to separate the airflow channel in to multiple channels. Here the webs can provide structural integrity or support the internal sill. Alternatively, the webs may extend the depth or a substantial depth non continuously. The air inlet is defined between upper and lower walls of the upper and lower surfaces of the airflow channel. As explained, the internal sill includes an extending nose that extends from the upper surface to overhang the lower surface. Here, an entrance plane to the airflow channel is created between a tip of the nose and a lower edge of the inlet. The inner or lower surface of the nose creates an air guide to guide air to flow to the inlet of the airflow channel.

The air outlet comprises at least one aperture formed in the body. The at least one aperture is configured to direct a stream of air drawn through the airflow channel to extend across at least a portion of the window surface. The air inlet may draw air from within the internal room environment having an ambient room temperature. Air is drawn in due to natural convection of higher temperature air, for instance from the radiator, rising. Suitably, the air inlet is therefore arranged adjacent a heat source external to the body and within the room, and configured to draw air heated by the external heat source into the air flow channel. For example, the air inlet may be arranged adjacent to a radiator to draw heated air rising by convection from the radiator into the air flow channel. Alternatively, the internal sill and therefore the window sill system may comprise an internal heat source mounted within the internal sill, for instance, within the body, to heat the air. Here, for instance, at least one heating element is to provide a heating effect. The at least one heating element may be arranged in the air flow channel. The heating element may be any suitable type of heating element. For example the heating element may be an electric-type heating element, a wet-type heating element or Thermoelectric system (i.e. Peltier device). Here, the internal sill includes connections, for instance electrical connections. The internal heat source could also be used to further enhance the performance of the internal sill in situations where, for example, there is excessive condensation and mould forming around the window frame.

The internal heat source may further comprise controls to control the heating element so as to heat the air and/or the surface of the window to a predetermined temperature and achieve a desired insulating and heating effect of the air stream. The controls may comprise a sensor to detect the surface temperature of the glazed unit and the controls may be configured to regulate and adjust the heating of the air by the heating element to achieve a predetermined glazed unit surface temperature. As such, the window sill system is able to optimise the insulating and heating effect of the air stream.

The window sill system may form a shelf or ledge with respect to the building window. Depending on the configuration of the window, the window may be mounted on a wall. In exemplary embodiments, the window sill system comprises a cover layer configured to extend over the body. Here, the cover layer provides an aesthetic and/or decorative finish. The cover layer may comprise a conventional window board. The cover layer may be formed form any suitable material include uPVC, MDF, natural stone, marble, man-made conglomerate and/or wood.

In exemplary embodiments, the internal sill is suitable for being retro-fitted with respect to a prior existing glazed unit, external sill and optional internal sill (for example a window board). If the prior internal sill is not removed, the internal sill is retro-fitted above (e.g. on top of) the prior window board. In this example, the nose of the internal sill is arranged to extend past a distal edge of the pre-existing internal sill. There is therefore provided a method of installing an internal sill to an existing window sill system. Here the method comprises arranging and securing the internal sill as herein described over and on top of an existing internal sill.

The window sill system may also be newly fitted with respect to a new window. In exemplary embodiments, there is therefore provided a method of installing an internal sill, the method comprising arranging a first internal sill in a wall opening. The method may comprise arranging second and further internal sills adjacent the first internal sill. Here, the first internal sill is as herein described with the advantageous airflow channel to shift the airflow closer to the glazed unit. The second and further internal sills may also be an internal sill with airflow channel or may comprise a spacer internal sill. Advantageously, the internal sill components can be configured to extend across the width of the wall opening using a modular set of internal sill component widths (e.g. the length across, and typically perpendicularly across the airflow channel). The method suitably further comprises extending or contracting a telescopic part of the internal sill to change the length of the airflow channel in order to arrange the nose of the internal sill appropriately relative to a radiator. Here, a cover is installed on top or over the internal sill components.

According to a further aspect, there is therefore provided a kit of parts comprising a first internal sill having the advantageous airflow channel to shift the airflow closer to the glazed unit as herein described and a second internal sill having the advantageous airflow channel to shift the airflow closer to the glazed unit as herein described. The first internal sill suitably has a first length between the sides of the airflow channel. The second internal sill has a second length. The first and second lengths are different. The kit of parts may further include a cover selected to be adjusted to a size of a wall opening. The kit of parts may further include one or more spacers. Here, the spacers are sized to have a similar profile to the internal sill. The spacers being selected to be cut to a width to fill between fixed length combinations of the first and second sill. The kit of parts may comprise third and further sills having the advantageous airflow channel to shift the airflow closer to the glazed unit as herein described each with third and further, different, widths. The kit of parts may comprise a plurality of first and / or second and / or third or further internal sills. The embodiments include the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

Summary of the Figures

Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which:

Figure 1 depicts cross-sectional view of a first embodiment of a window sill system;

Figure 2 depicts a cross-sectional view of a second embodiment of a window sill system; and Figure 3 depicts a perspective view of a kit of parts; and Figure 4 shows exemplary computational modelling results.

Detailed Description of the Invention

Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

With reference to the embodiments depicted in Figures 1 and 2, a building window is shown comprising a wall opening with a window sill system and glazed unit 40 installed therein. The window sill system is shown as an internal sill, but it will be appreciated, the window sill system may also include an external sill. Herein, the window sill system will be referred to as an internal sill. The internal sill is shown as a hollow body 1 . The body 1 may be a unitary, one-piece body or it may be formed from multiple component parts.

The body forms an air inlet 10, and air outlet 20 and an air flow channel 30 extending therebetween. The air inlet is defined by a plane extending, when the sill is installed, vertically between an extent of a lower wall forming the body and a wall forming the upper extent of the airflow channel. In the exemplary embodiments, a nose of the internal sill overhangs the air inlet. The nose forms an entrance plane defined between a distal end of the nose and the extent of the lower wall. The nose guides air from the entrance plane to the air inlet and combine to form an air input 10

In the embodiments depicted in Figures 1 and 2, the internal sill is arranged on the internal side of the glazed unit 40, adjacent to a lower internal edge 41 of the glazed unit. The internal sill extends substantially the length of the lower edge of the glazed unit. The internal sill is mounted on a wall 50 and it forms a ledge across the wall relative to the window. The wall 50 may be a cavity external wall as shown and as is known in the art. In the embodiments, the external temperature is less than the ambient internal room temperature.

In the first embodiment depicted in Figure 1 , a radiator 60 is mounted on the internal side of the wall, below the glazed unit and internal sill system to heat the room. The air input 10 comprises an entrance plane 11 in the body through which air can flow through the air inlet into the air flow channel. In the embodiment shown, the air input further comprises a hood 12 (also referred to as a nose) which forms a curving, overhanging lip of the body. The hood helps to guide the air towards the air flow channel. As shown in Figure 1 , the air input is configured to guide heated air that is heated at the rear of the radiator and rises towards the air input by convection.

The air flow channel 30 comprises a passage in the body that is configured to guide the flow of heated air towards the air output.

The air outlet 20 comprises at least one aperture 21 in the body that is configured to direct a stream of the heated air 70 across at least a portion of the internal surface of the glazed unit. The air outlet 20 has a larger height compared to the channel 30, to further help to push the flow through the outlet through a stack/chimney effect. The stream of heated air continues to rise upwardly across the internal surface of the glazed unit by convection. The stream of air spreads like a curtain across a window surface of the glazed unit 40. The aperture may comprise an elongate vent or multiple vent holes extending along the body to create the stream of heated air. The multiple vent holes may be defined by a grill or fins. As shown, air the outlet is configured to direct the air perpendicularly (e.g. vertical) to the predominant direction of the airflow channel (e.g. horizontal). Here the airflow channel includes an elbow to direct the airflow out of the air outlet that is sustainably planar and arranged in a horizontal plane. The elbow is created by a closed distal end of the air flow channel with the outlet arranged adjacent and above the closed end.

The stream of heated air forms an air curtain (or a thermal boundary layer) across at least a portion of the glazed unit. Due to the temperature differential between the stream of heated air and cooler window surface of the glazed unit, stream of heated air acts as an insulator and also heats the internal surface of the window. As a consequence, heat loss through the window is reduced and the cooling effect that would have previously been caused by the cooler window surface is reduced. Hence, the formation of cold spots in the room is limited. By raising the temperature of the internal surface of the window, the formation of condensation on the window surface is also reduced, thereby maintaining visibility through the window and avoiding damp.

Figure 2 depicts a second embodiment of the window sill system. In this embodiment, the air input 10 is configured to draw air from within the room, with an ambient room temperature. To optimise the insulating and warming effect of the stream of air on the internal surface of the glazed unit 40, the window sill system further comprises a heat source with multiple heating elements 80 located in the air flow channel. The heating elements heats the air so that the stream of heated air is able to raise the temperature of the internal surface of the window to a predetermined temperature and thereby restrict, preferably avoid heat loss, the formation of cold spots in the room and condensation on the internal window surface. The heating element is controlled by a sensor 81 detecting the temperature of the internal surface of the window and so that stream of air heats the surface of the window to a predetermined temperature. The heat source may be a wet heat source comprising heated fluid pipes and fluid control valves. The heated fluid pipes may be coupled to a wet heating system of the building. Alternatively, the heat source may be an electric heat source comprising a low wattage electric heating coil and thermostat or a Thermoelectric system (i.e. Peltier device).

In this embodiment, the window sill system includes a cover layer 90 configured to shroud the body. The cover layer is intended to provide a desirable aesthetic and decorative effect. The cover layer may comprise a conventional window board. The cover layer may be formed from any suitable material including for example, uPVC, MDF, natural stone, marble, conglomerate and/or wood.

Referring to Figure 3, there is shown an internal sill 100 including the advantageous airflow channel to shift the airflow closer to the glazed unit. Here, the internal sill is shown as comprising a plurality of parts. For instance, the internal sill is shown as having a first part 102 including a portion of the airflow channel and configured to be attached to a further component or components 104 that includes the outlet (though the further part/s may also be integral to the first part). And a second part 106 including a portion of the airflow channel and the air inlet and associated nose or hood. The first part and the second part are telescopically connected. That is, one of the parts is sized so as to fit and slide within the other. Thus, by extending or contracting the parts relative to each other, the length of the airflow channel can be adjusted. Thus, the position of the nose can be adjusted to fit different wall thickness and radiator designs and installations.

Figure 3 shows second and third internal sills 100b, 100c. The second and third internal sills have a different length (or width relative to the wall opening). Thus a kit of parts is provided. Installing the internal sill can therefore comprise selecting an appropriate sized internal sill or plurality of sills from the kit of parts and arranging the sill or plurality of sills adjacent each other across the wall opening so that the internal sill substantially extends across the wall opening. To accommodate wall openings having sizes between the sizes of the internal sills or combination, spacers can be used.

Figure 4(a) depicts a sample taken from the computational modelling of velocity contours and (b) a modelling of velocity vectors according to an optimised embodiment. It is envisaged that optimising velocity through the airflow channel provides an improved design by creating a stronger thermal layer on the glazed unit. Importantly, Figure 4(c) shows an optimised design for the internal sill obtained by computational simulations. The nose 120 is shown as a planar plate extending away from the air inlet shown as 112. The planar plate has a downwardly projecting lip 122. The downwardly projecting lip is angled to the planar plate, which has been modelled to provide an improved airflow through the airflow chamber. It is believed the angled lip provides an enhanced guide to the air and it is envisaged the underside of the angled lip and planar plate, although shown as suitably being planar (formed from thin walls), may be curved or the like. A distal end 124 of the downwardly projecting lip 122 defines an entrance plane 114 between the distal end of the lip and the distal end of the lower plate of the airflow channel. The downwardly projecting lip can be arranged to extend different extents. Here the lip, when viewed in a plane parallel to the predominant direction of the airflow channel (e.g. horizontally) can cover different extents of the airflow inlet. For instance, if the tip of the nose is arranged in a plane with the lower plate of the airflow channel, the air inlet is substantially fully covered. Suitably the tip of the nose is arranged to cover at least 50% or at least 75% of the air inlet. The airflow channel 130 has a length (L) and height (H). The height is defined by the gap between the upper and lower walls of the internal sill. It is envisaged, as shown the upper and lower plates will be parallel. The length of the airflow channel is defined between the air inlet and a closed end adjacent and beneath the air outlet 140. The air flow channel length may also be referred to as the depth of the internal sill, for instance, in the direction of the wall thickness. An end region including the air outlet is shown as projecting upwards from the top of the airflow channel. This allows a cover, such as a window board to be fitted without hindering the air outlet. Moreover, by stepping the height of the airflow channel at or around the outlet, the outlet can be arranged to encourage a chimney / stack effect. Here the step in height of the airflow channel extends substantially along the length of the internal sill. The step in height at the outlet may be about the same height as the predominant part of the airflow channel. For instance, the step in height may form a height of the airflow channel underneath the outlet about twice as height as the predominant part of the airflow channel. In the exemplary embodiment, the depth of the outlet, in a direction of the wall thickness (e.g. perpendicular to an internal-external direction) about the same as the height of the predominant part of the airflow channel.

As herein described there is therefore provided an improved internal sill that shifts the airflow closer to the glazed unit and thereby providing improved heating and insulating effect. For instance, quicker heating of the room, improved thermal insulation effect of the glazed unit, lower heating costs and energy consumption. There is also provided an internal sill having improved airflow characteristics through the internal sill to optimise the performance. There is also provide a window sill system that can be retrofitted and also a modular window sill system that can be installed to varying wall opening dimensions.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations. Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example +/- 10%.

Claims

Claims:

1 . An internal sill comprising a body suitable for being arranged adjacent a lower portion of a glazed unit, wherein the body comprises: an air inlet; an air outlet for being arranged adjacent the lower the lower portion of the glazed unit; an airflow channel extending through the body between the air inlet and air outlet; and a nose that extends away from the air inlet for forming an entrance plane and to act as an air guide from the entrance plane to the air inlet.

2. The internal sill according to claim 1 , wherein the body is formed from multiple component parts, and a first component part includes the outlet and a second component part includes the inlet, wherein the first component part is configured to move relative to the second component part to extend or contract a length of the airflow channel.

3. The internal sill according to any preceding claim, wherein the nose includes a downwardly extending portion that forms a distal end wall.

4. The internal sill according to claim 3, wherein a distal tip of the nose’s downwardly extending portion is arranged to be at or lower than a mid-point between upper and lower extents of the airflow channel.

5. The internal sill according to any of claims 1 to 4, wherein the nose extends away from the air inlet between 100% and 300% of a height of the airflow channel.

6. The internal sill of any of claims 1 to 5, wherein a height of the airflow channel is between 5% and 15% of a length of the airflow channel.

7. The window sill system according to any preceding claim, wherein the air outlet comprises an elongate vent or multiple vents arranged at an angle to a height of the airflow channel to create the stream of air, and wherein the height of the airflow channel is stepped in an end region of the body having the outlet.

8. The internal sill according to any of claims 1 to 7, wherein a heat source to heat the air is arranged within the body wherein the heat source comprises at least one heating element.

9. The internal sill according to claim 1 or 5, wherein the heat source comprises controls to heat the air to a predetermined temperature and/or to heat the air such that the surface of the window is heated by the stream of air to a predetermined temperature.

10. The internal sill according to any preceding claim, further comprising a cover layer configured to extend over the body.

11. A window sill system including the internal sill of any of claims 1 to 10 and an external sill.

12. A kit of parts comprising a first internal sill as claimed in any of claims 1 to 10 and having a first length and a second internal sill as claimed in any of claims 1 to 10 and having a second length, wherein the first and second lengths are different.

13. A method of fitting an internal sill as claimed in any of claims 1 to 10 or a window sill system as claimed in claim 11 or a kit of parts as claimed in claim 12, the method comprising fitting, to a lower edge of a wall opening through a wall, the internal sill and arranging the nose of the internal sill to be in a position relative to a radiator installed on the wall beneath the wall opening.

14. The method of Claim 13, wherein the method comprises extending or contracting a first component part of the internal sill including the outlet relative to a second component part of the internal sill including the inlet to arrange the nose to extend over at least 50% of the radiator.

15. The method of claim 13 or 14 when installing the kit of parts, wherein the method comprises installing one or more internal sills across a first partial width of the wall opening and installing one or more further internal sills across a second partial width of the wall opening.