GB2323610A

GB2323610A - Lavatory ventilation system

Info

Publication number: GB2323610A
Application number: GB9805840A
Authority: GB
Inventors: Roger Edward Flaherty
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-03-19
Filing date: 1998-03-19
Publication date: 1998-09-30
Anticipated expiration: 2018-03-19
Also published as: GB9805840D0; GB2323610B

Abstract

In a lavatory having a fan 10 for extracting air from the volume of lavatory and expelling it outside the lavatory, the fan intake is also coupled via a conduit 18 to ducting means 26 of a lavatory bowl 20 or sluice conventionally provided for the supply and distribution of flushing water, so that air may be extracted directly from the lavatory bowl. The conduit 18 is shown as coupled to the downpipe between cistern 22 and bowl (or to a pumped water supply pipe for a marine lavatory), but it can also be coupled to a purpose provided connection to the bowl, or to the cistern or siphon in cases where the siphon is arranged for passage of air from the bowl. A variable louvre 21 may enable air extraction selectively from the bowl, or from bowl and lavatory, and the fan speed may be controlled accordingly. Various sensors may control fan actuation/speed.

Description

Lavatorv Ventilation System In this specification a room, closet or compartment in which a lavatory bowl (or sluice) is fitted will be referred to as a "lavatory", and the term "air" should be taken as meaning air including any undesirable odours.

The present invention relates to a ventilation system which significantly reduces the egress of foul odours from a lavatory bowl or sluice into the lavatory.

Lavatories are commonly provided with means for forced ventilation in the form of a large diameter fan, normally at a high level in a wall or in the ceiling, which evacuates the air from the volume of the room to an external location. Such a fan normally operates on mains voltage and provides an air flow at a rate which not only creates a substantial heat loss, costing money to reheat the inducted air, particularly in winter time, but also incurs a significant cost in terms of electricity, since the fan must, invariably, run-on for some time after the room has been vacated.

Systems have also been proposed for directly venting odours from the lavatory bowl. Some of these have included complex duct systems either present as an additional arrangement situated between the top rim of the lavatory bowl and a seat or associated with the lavatory seat itself. Typical examples of such proposals may be found in GB2136030 and US3585651.

Furthermore, conventional modern installations comprise ducting means for supplying water for flushing the bowl, the ducting means including water supply ducting moulded within the top rim of the bowl itself, and so other known systems for venting the bowl itself involve a duct system coupled to the ducting means at an appropriate location for extracting air from the bowl, at least when flushing is not taking place. Examples of such systems occur in GB 2290315, GB 2237825, GB 2209356, GB 2182368, GB 2135353, GB 2091772 and GB 1054919.

In either type of known bowl venting system, the ducting system includes some form of extractor fan which is vented through the lavatory wall to the outside, or to the soil pipe. The fan is specifically provided for this purpose, and since the aim is venting only of the lavatory bowl, rather than the whole lavatory, it may provide a relatively low flow rate. Also, in view of its association with the lavatory bowl, it may well be operated at low voltage. Naturally, such a system could occur in conjunction with a fan arrangement as mentioned above for ventilating the whole lavatory.

According to a first aspect, the present invention provides a lavatory which includes a lavatory bowl or sluice and a fan arranged for the extraction of air via its intake from the volume of the lavatory for expulsion outside the lavatory, wherein the intake is also coupled to extracting means for extracting air directly from the bowl or its immediate vicinity.

The extracting means may be any means known in the prior art, such as in the specifications noted above. In a preferred form, the lavatory bowl (or sluice) is of the type having ducting means therein for the supply of flushing water for flushing the bowl (or sluice), and the extracting means removes air via the ducting means, for example via a fan conduit which is coupled (a) to a separate connection provided in the bowl or sluice which connection is coupled to the ducting means; or (b) to a downpipe or siphon for supplying water to the ducting means. In the latter case, the extracting means may provide a path from a portion of the siphon normally free of water via a fan conduit to the fan, optionally via the air space in a closed cistern and the overflow connection in the cistern.

An advantage of ventilating the bowl via the ducting means is the creation of a negative pressure gradient towards the bowl, so entrapping the aerosol plume which occurs when the bowl is flushed and reducing the chance of infection by water borne diseases.

According to a second aspect the invention provides a kit of parts for adapting a lavatory of the type comprising a lavatory bowl or sluice, a downpipe for supplying water to flush the bowl (or sluice), and a fan arranged for the extraction of air via its intake from the volume of the lavatory for expulsion outside the lavatory, the kit comprising a conduit, an adaptor for covering the intake of the fan, said adaptor providing a first intake for coupling to the volume of the lavatory, and a second intake coupled, or couplable, to a first end of the conduit, and connection means adapted to enable coupling of the second end of said conduit to said downpipe.

Contrary to all prior art systems referred to previously, the present invention advantageously utilises a single fan both for the ventilation of the entire lavatory volume and for the direct venting of air from the lavatory bowl. This can eliminate complexity and expense associated with earlier proposals. Furthermore, appropriate control of the fan can lead to retention of a lower energy requirement for direct venting of the bowl (i.e. a lower air flow rate) when it is unnecessary to vent the whole lavatory.

Normally the fan will be situated within a wall or ceiling of the lavatory, but is would be possible to site it wholly within or without the lavatory provided suitable couplings were made to its intake or outlet.

Other features of the invention will become clear upon a consideration of the appended claims, to which reference should be made, and also from the following description of exemplary embodiments when read with reference to the accompanying drawings, in which: Figures 1 and 2 show a first embodiment of ventilation system for use in a lavatory according to the invention in side and front view respectively; Figure 3 shows a detail of the first embodiment; and Figure 4 shows a detail of another embodiment of ventilation system.

In the drawings, the same or closely similar features are given a common reference numeral.

Figures 1 and 2 show part of a lavatory fitted with a high level extractor fan 10 for expelling air from the volume of the lavatory through an outlet 12 which passes through a wall of the lavatory to the exterior. As will be seen in more detail in Figure 3, the intake side of the fan 14 facing the lavatory comprises a junction unit 16, which may be an integral part of the fan, or an adaptor secured to an existing conventional fan.

The junction unit 16 serves to receive air both from the room and also, from the upper end of a fan conduit 18, from a lavatory bowl 20, for expulsion to the exterior.

As shown, air from the room enters the unit through a louvre 21 which is selectively operable to allow or prevent air from the room from entering the unit.

At its upper rim the lavatory bowl 20 comprises a ducting 26 of known type for the supply and distribution of flushing water to the bowl. The ducting is coupled to the downleg of a siphon in a cistern 22 through a downpipe 24 in known manner. The fan conduit 18 is connected at its lower end to the downpipe 24 using a Tpiece in known manner, to permit the fan to draw air from the lavatory bowl via the ducting 26.

The louvre 21 of Figure 1 may be a fixed louvre, which could be replaced by some equivalent air admitting cover for the front of the junction unit 16. In such a case, air can only be drawn from simultaneously from the room and from the bowl, in a ratio determined by the flow resistances of the two paths as determined from dimensions and design of the components in the paths.

Preferably, however, the louvre can be selectively opened and closed as required. It may, of course be replaced by any equivalent air flow valve or controller. Again, when the louvre is open, the flow ratio will be determined by the relative flow resistances of paths from the room and from the bowl, but when it is closed, air is drawn mainly through the bowl.

Operation of the louvre or other flow controller could be manual, or automatic , Switching of the fan could be manual or automatic. A time delay may be built to permit the fan to run on for a limited time after deactuation.

Automatic operation of the louvre and/or automatic actuation or control of the fan could be in response to an output of a sensor or combination of sensors, for example, in response to: (a) operation of a light switch associated with the lavatory (e.g. to turn on bowl and/or entire lavatory ventilation); (b) a switch sensing pressure on the lavatory seat 28 (e.g. for bowl ventilation); (c) a pressure sensor in the floor at the front of the bowl(e.g. for bowl ventilation); (d) operation of the flush, for example a pressure sensor in the water supply, or the sensing of operation of the flush handle (e.g. for bowl ventilation);; (e) lifting of the bowl seat cover (e.g. to turn the bowl ventilation on); (f) lifting of the seat (e.g. to turn the bowl ventilation off); (g) a humidity sensor in the volume of the lavatory (e.g. to turn ventilation of the entire lavatory on); (h) sensing the use of a hot water supply in the lavatory, for example by a pressure switch in the supply to a tap and/or a shower unit(e.g. to turn on bowl and/or entire lavatory ventilation - different switches could have different functions).

Switching of the fan could be responsive to manual or automatic operation of the fan airflow controller (e.g.

the louvre). Actuation of the louvre and fan could be in response to the output of the same sensor(s) or the outputs of different sensors.

Where there is more than one sensor or sensing operation, the outputs thereof may be logically combined to control the fan and/or louvre. When the logical combination controls one of the fan and louvre only, the other may be controlled directly by a sensor output. When both are controlled, this may be according to the same or different logical outputs of the combination as desired.

In particular, it would be possible to provide a fan having at least two speeds which are selected according to the sensed conditions. Ideally, the fan operates at a higher speed when it is extracting air from the volume of the lavatory, and at a lower speed when air is being drawn only from the bowl (thus a high speed may obtain when the louvre is manually opened, and a low speed in response to sensors for other conditions in the lavatory, such as pressure on the seat 28); also, the outputs of the sensors may be arranged so that air is drawn from the bowl over a longer period compared to ventilation of the volume of the lavatory. In an alternative embodiment, the fan may be arranged to run continuously at a low speed, and to be switched to a higher speed in response to one or more sensed conditions, e.g. of the type listed above.

In one preferred arrangement, the lavatory comprises at least a humidity sensor, and a switch operated when the seat cover is lifted. The arrangement is such that at low room humidity lifting of the seat cover will cause the fan to operate at a first speed, with the louvre or other flow controller remaining closed. Attainment of a critical humidity level will cause the louvre or other flow controller to be opened for room ventilation, and the fan to be run at a second speed greater than the first, regardless of any indication as to whether the seat cover is lifted.

In an embodiment where a cistern is close coupled to the bowl, with the water supply aperture of the cistern sitting directly on top of a rear portion of the lavatory bowl a supporting collar can be provided between the water supply aperture of the cistern and the water supply inlet to the bowl. The collar has a side air extraction spigot for connection to the fan conduit as in the embodiment described with reference to Figures 1 to 3. In this embodiment, the lavatory bowl water ducting is again utilised to extract air via the bowl water inlet, the collar and spigot, the fan conduit and fan. A seal may be provided between the seat and the bowl, and a switching pressure sensor may be incorporated therein for control of the fan.

In a variation of the system of Figures 1 to 3, the downpipe 24 is uninterrupted and the bowl is provided with an additional external fan conduit connection for coupling the bowl to the fan conduit 18. The fan conduit connection may extend laterally from the bowl, as may the connection between the downpipe and the bowl, although either or both could extend in other directions, e.g.

vertically from a region at the rear of the bowl and seat. Similarly, in the close coupled embodiment, the collar may be omitted leaving the water supply aperture of the cistern coupled directly to the water supply inlet of the bowl, if an external fan conduit connection is formed in the bowl for coupling the bowl to the fan conduit. In either case, the external fan conduit connection is preferably coupled to the interior of the bowl via the ducting, or on a level therewith.

Figure 4 shows an embodiment in which a siphon 40 in a cistern 22 is adapted to provide the path for air from the lavatory bowl. The siphon comprises the normal water (first) and down (second) legs 42 and 44, the latter being coupled to the water supply ducting of the bowl in known manner. The cistern also comprises a conventional overflow aperture 52 in a wall 54, and has a lid 56.

In this embodiment, the aperture 52 is used for connecting the lower end of the fan conduit 18 to a horizontal portion 50 of a third leg 48 of the siphon.

The horizontal portion 50 extends to a vertical portion 48 which enters the downleg 44, which is free of water unless flushing is proceeding, near the base of the latter. In the drawing the connection between the lower end of the fan conduit and the portion 50 is shown as being effected by a sleeve 56, but any known method of effecting this connection may be used.

If the cistern has only one overflow aperture available, the conventional cistern overflow pipe cannot be used in this embodiment. In Figure 5 this problem is overcome by providing vertical leg portion 46 with a U tube extension 58 terminating in an open end slightly above the normal water level 60. The junction between the U tube 58 and the portion 48 is also preferably slightly above the level 60, although it need not be so long as water in the tube does not completely leave by siphonic action.

Under normal circumstances, the water remaining in the U tube provides a seal between the space 62 above the level 60 and the leg portion 48, thereby preventing the fan acting directly on the space 62. Should the cistern overfill, water will enter the U tube and descend via portion 48 to the lavatory bowl. This action also provide a visible indication that overfilling is taking place.

An alternative overflow connection 64 to portion 48 is shown in dashed lines. In this case, the fan will tend to draw some air from the space 62, but this can be limited by suitable sizing of connection 64. However, it is likely that a compromise will have to be reached as regards the overflow rate which can be accommodated.

Other alternatives are to have a pipe extending from the generally horizontal portion 50 to a point below the normal water level. The portion should slope downwards either for drainage back to the bowl or to the aperture 52. In the latter case, a suitable downwardly extending T-junction to a trap and external pipework could provide a path for overflow water while permitting the fan to work effectively on air from the bowl or room. Where the trap consists of a U-tube or the like depending on a liquid seal, this is preferably filled with a nonevaporable material such as a mineral or vegetable oil which is replaced in the rare event of the overflow being used.

In a variation of Figure 4, the coupling between the coupling between the third leg and the fan conduit is broken, and the fan conduit extracts air from the third leg via the space above the water level. A seal is preferably provided between cistern lid and the body of the cistern. By breaking the link between conduit and the third leg, and adjusting the height of the top of the third leg, it is possible to arrange either that this leg also provides an overflow path to the bowl, or that the overflow connection functions as a passage for both air from the bowl and overflow water from the system.

Advantageously, the end of the third leg is extensible or deformable to enable the height of its top to be varied and a choice to be made between these two arrangements, e.g. the third leg may comprise a corrugated portion of known type, which can be extended or compressed as desired, or a slidable end portion.

When the overflow connection is arranged to take both air and water, a convenient arrangement would be to insert a T-coupling close to the cistern with an upwardly extending leg for coupling to the fan, and a horizontal (or downwardly) extending leg for the overflow water.

Although, to a certain extent, the sizing of connections can achieve the same purpose, preferably the path for the overflow water would contain a one-way valve, such as a flap valve, or a U-tube, to prevent outside air from passing to the fan and so reducing the efficiency of air extraction from the bowl or room.

The embodiments of Figure 4 and its variation can be used whether the cistern is close coupled to the bowl or coupled by a downpipe. A further modification would be to make the connection of the third leg to the siphon to a point above normal water level, e.g. at or close to the top of the siphon (in this case, care needs to be taken with sizing so that the third leg does not destroy the siphonic action - also the overflow 58 of Figure 4 would need to couple to the down leg 44, while in the variation care would be needed to ensure that the outflowing water and the extracted air follow different paths - e.g. as discussed above, by a passage for the water which is normally sealed by a flap valve or U tube to maintain air extraction.) In an alternative form, the water supply to the bowl or sluice may be pumped through a water pipe, as in a marine toilet, in which case the fan conduit may be coupled to such water pipe.

It will be understood that while systems according to the invention may be provided as an entity when installing a lavatory, they may also be provided by suitable adaptation. As far as the intake from the bowl is concerned, this may mean a simple connection into the downpipe, as in Figures 1 to 3, or replacement or adaptation of a siphon, as in Figure 4. As far as the fan is concerned, this may be purpose made with an integral junction unit 16, or the latter may be provided separately with fixing means, to adapt an existing conventional fan. Accordingly, the invention extends to a kit of parts for adapting an existing lavatory ventilation system.

Claims

1. A lavatory which includes a lavatory bowl or sluice and a fan arranged for the extraction of air via its intake from the volume of the lavatory for expulsion outside the lavatory, wherein the intake is also coupled to extracting means for extracting air directly from the bowl or its immediate vicinity.

2. A lavatory according to claim 1 wherein the intake is capable of extracting air from the volume of the lavatory and from the bowl simultaneously.

3. A lavatory according to claim 1 arranged such that the flow rate of air extracted from the volume of the lavatory is substantially higher than that extracted from the bowl.

4. A lavatory according to claim 2 wherein the air flow paths to the fan are sized to ensure that for the same fan speed the flow rate of air extracted from the volume of the lavatory is substantially higher than that extracted from the bowl.

5. A lavatory according to any preceding claim, wherein the fan is provided with means for selectively hindering air from the volume of the room to pass to the fan.

6. A lavatory according to claim 5, wherein said selectively hindering means is responsive to the output of a sensor mounted in the lavatory.

7. A lavatory according to claim 6 wherein the sensor is a humidity sensor.

8. A lavatory according to any one of claims 5 to 7 wherein the fan is arranged to operate at different speeds according to whether air from the volume of the lavatory is passing to the fan.

9. A lavatory according to any preceding claim wherein operation of the fan is controlled by a sensor mounted in the lavatory.

10. A lavatory according to claim 9 wherein the sensor is a switch for sensing the opening of a seat of the lavatory bowl.

11. A lavatory according to any preceding claim wherein the lavatory bowl (or sluice) has ducting means therein for the supply of flushing water for flushing the bowl, and the extracting means comprises a fan conduit coupled between the ducting means and the fan intake.

12. A lavatory according to claim 11 wherein the ducting means comprises water supply ducting formed in the upper rim of the bowl and coupled to a water source.

13. A lavatory according to claim 12 wherein the ducting means is coupled to the water source by a pipe.

14. A lavatory according to claim 12 or claim 13 wherein the water source is a siphon.

15. A lavatory according to claim 11 or claim 12 wherein the water source is a siphon which is close coupled to the ducting means.

16. A lavatory according to claim 14 or claim 15, wherein an air conduit extends from a region within the siphon normally free of water.

17. A lavatory according to claim 16 wherein said region lies above the normal water level in the cistern, but said air conduit is sized so as not to destroy the siphonic action.

18. A lavatory according to claim 16 wherein said region is below the normal water level of the cistern in the downleg of the siphon.

19. A lavatory according to claim 18 wherein said region is adjacent the foot of the downleg of the siphon in the cistern.

20. A lavatory according to any one of claims 16 to 19 wherein said fan conduit is connected to said air conduit.

21. A lavatory according to any one of claims 16 to 19 wherein said cistern is enclosed and has an overflow water outlet connection, said air conduit and said overflow connection are both in fluid connection with the enclosed space above the water in the cistern, and said fan conduit is connected to said overflow connection.

22. A lavatory according to claim 21 wherein the height of the end of said air conduit in the enclosed space can be varied to lie below or above the overflow connection.

23. A lavatory according to claim 21 wherein the height of the end of said air conduit in the enclosed space is above the height of the water overflow connection.

24. A lavatory according to claim 21 wherein the height of the end of said air conduit in the enclosed space is below the height of the water overflow connection.

25. A lavatory according to claim 12 wherein the water source is a pump which is coupled to the water source by a pipe.

26. A lavatory according to claim 13 or claim 25 wherein the fan conduit is connected to the pipe.

27. A lavatory according to claim 12 wherein the water supply ducting is also provided with a dedicated air connection formed in the upper rim of the bowl and coupled to said fan conduit.

28. A lavatory substantially as hereinbefore described with reference to Figures 1 to 3, or Figure 4, of the accompanying drawings.

29. A kit of parts for adapting a lavatory of the type comprising a lavatory bowl or sluice, a downpipe for supplying water to flush the bowl (or sluice), and a fan arranged for the extraction of air via its intake from the volume of the lavatory for expulsion outside the lavatory, the kit comprising a conduit, an adaptor for covering the intake of the fan, said adaptor providing a first intake for coupling to the volume of the lavatory, and a second intake coupled, or couplable, to a first end of the conduit, and connection means adapted to enable coupling of the second end of said conduit to said downpipe.

30. A lavatory bowl comprising a first water connection for coupling flushing water between an external water source and the interior of the bowl and a second air connection for conducting air from the interior of the bowl to the exterior of the bowl.

31. A close coupled lavatory bowl according to claim 30, wherein the first connection is arranged to receive water from an immediately adjacent close coupled cistern.

32. A lavatory bowl according to claim 30 wherein both connections extend laterally from the bowl.