Background The present invention relates to a method for operating a shower device for recirculating shower water, the shower device comprising;

- a support area for supporting a person taking a shower,

- a catchment basin for collecting water,

- a drain at a bottom level of the catchment basin,

- a pump for circulating a circulating shower flow, and

- a water intake fluidly coupled with the pump for taking in water from the

catchment basin.

Such a methods is known from US5353448 which relates to a water circulation system for use in recycling water from a water catchment basin, e.g. of a shower and reissuing the same through a dispensing head along with an intermittent mixing of fresh water from a supply source. Such a water recycling system is for use in shower facilities enabling the user to increase both the time duration of a shower and the quantity of water experienced by a user, by maintaining water in a semi-closed system, while both maintaining water and energy conservation. The system operates with fresh and recirculated hot water. The system utilizes spent hot shower water located in the catchment area of a shower or tub and recycles this water to a spray head. A selected water temperature can be maintained by periodically introducing fresh water or continuously introducing the fresh water at a very low flow rate from a fresh water source, and mixing that water with the recycled water from a water catchment area. Recycled water can also be re-heated and issued again. The known system uses a pump at the bottom of the catchment area. Further, the pump may alternatively be located outside of the shower stall and attached to a wall, hung or suspended from existing hardware, or otherwise integrated into the supply stem of the fresh hot water source, however such alternative location of a pump is not shown and it is unclear if and how this may function.

The known water circulation system has a disadvantage in that it is not as efficient as desired. It is even doubtful if this known water circulation system can even compete with a standard eco shower since the entire floor acts as catchment area and therefore a considerable volume of water is buffered. This huge volume and outer surface of the mass of water undermines efficiency and causes considerable heat loss. In addition, as a consequence performance with respect to hygiene is poor because the person taking a shower stands with his feet in the water to be circulated. Moreover, a person taking a shower may disturb the caught water in the catchment area and therefore harm the continuity of the recycling water flow.

Summary of the invention The invention aims to provide a method for operating a shower device which method consumes less water and energy and still meets demands concerning hygiene and enjoys acceptance by users.

Another object of the invention is to improve a prior art method for operating a shower device in that a problem associated with said prior art method is at least partly solved.

Yet another object of the invention is to provide an alternative method for operating a shower device.

According to a first aspect of the invention this is realized with method for operating a shower device for recirculating shower water, the shower device comprising;

- a support area at a support area level for supporting a person taking a shower,

- a catchment basin below the support area level for collecting water,

- a drain at a bottom level of the catchment basin,

- a pump arranged above the support area level,

- a water intake fluidly coupled with the pump and arranged for taking in water between the bottom level of the catchment basin and the support area level, and wherein,

the method comprises the steps;

- initial filling the catchment basin from a fresh water supply through the pump and the water intake until a desired showering water volume is in the catchment basin, - activating the pump and taking in water at the water intake for circulating a circulating shower flow between the catchment basin and a shower head which dispenses at the support area.

The filling of the small catchment basin with fresh water through the pump provides the possibility of improved control of the volume of the circulating shower flow also because of the separation of the support area and the catchment basin. This separate catchment basin also enables improved control of the volume and facilitates isolation of the caught water. In addition, it ensures a better controlled start of the circulating shower flow in that the drawing in of water by the pump is improved because the supply conduit to the pump from the catchment basin is already filled with water. In addition, the method allows for complete drainage of the shower device once showering is finished. This avoids still water being present in the shower device which still water would undermine hygiene and requires drastic cleaning like e.g. with overheated water. This complete drainage of the shower device importantly includes complete drainage of the pump. Known systems do maintain water in the pump and even require to maintain water in the pump in view of starting a recycling flow.

The pump is arranged above the support area level for allowing drainage of the pump. The pump is preferably entirely arranged above the support area level.

Preferably, the catchment basin is completely filled from a fresh water supply through the pump and the water intake until a desired showering water volume is in the catchment basin. However, it is conceivable that the catchment basin is partly filled otherwise, like with a conventional shower head.

In an embodiment of the invention, the method comprises the step, after finishing showering, draining the entire shower device via the drain at the bottom level of the catchment basin for preventing any still water left behind. The entire shower device includes at least all circulating water carrying parts.

In an embodiment of the invention, the method comprises the step refreshing the circulating shower flow with a refreshment flow at a flow rate of about half a litre per minute for controlling water temperature of the circulating shower flow and total refreshment of the circulating shower flow every 4 to 6 minutes. According to a further aspect of the invention this is realized with an assembly of a catchment basin (10) for collecting water and a support area (14) for supporting a person taking a shower, wherein the support area extends at a support area level and the catchment basin is arranged (10) below the support area level for collecting water, the assembly comprising;

- a drain (12) at a bottom level of the catchment basin, and

- a water intake (13) for taking in water from the catchment basin, which intake is arranged between the bottom level of the catchment basin and the support area level.

This arrangement of the water intake provides the possibility for complete drainage of the shower device, in particular a pump fluidly coupled with the water intake, once showering is finished. This avoids still water being present in the shower device which still water would undermine hygiene.

The catchment basin being below the support area level for collecting water importantly ensures that the person standing on the support area and taking a shower needs not standing in water of the circulated water flow because a separate catchment basin is provided. Standing in own water to be circulated is found to be perceived as unhygienic and found to be a barrier for enjoying a circulated shower flow.

Furthermore the separate catchment basin ensures that a person standing on the support area can move or walk while taking a shower without disturbing water intake to the pump which would undermine continuity of the circulating shower flow.

In an embodiment of the assembly, the support area extends at an angle with respect to the horizontal for dewatering in the catchment basin. This promotes a prompt dewatering of water towards the catchment basin which enables to have a small volume catchment basin and facilitates maintaining water temperature of the circulating shower flow.

In an embodiment of the assembly, the catchment basin and support area are mutually arranged such that water caught in the catchment basin is visible from point of view of a person supported by the support area for taking a shower. This reassures the person taking a shower in that he or she receives direct visual feedback concerning the freshness of the circulating shower flow and cleanliness of the catchment basin. In an embodiment, the assembly comprises an overflow outlet for determining a basin water level and which overflow outlet is therefore aligned with the support area. This even more assures a separation of the support area and the catchment basin.

In an embodiment of the assembly, the catchment basin is isolated to prevent loss of heat. This promotes efficiency even more. This isolation is facilitated by the catchment basin having a relatively low volume. Preferably the support area is isolated as well to promote efficiency even more.

In an embodiment of the assembly, the volume of the catchment basin is between 2 and 5 litre.

In an embodiment of the assembly, the volume of the catchment basin is about 3 litre.

According to a further aspect of the invention this is realized with a shower device (1) for recirculating shower water and for use in the method according to a the invention, the shower device comprising;

- an assembly according to the invention,

- a pump (7) arranged above the support area level,

wherein the water intake (13) is fluidly coupled with the pump. The pump is arranged above the support area level for allowing drainage of the pump. The pump is preferably entirely arranged above the support area level.

In an embodiment, the shower device comprises a course intake filter arranged at the water intake for preventing ingress of dirt towards the pump. Preferably the circulating water flow is filtered only by a filter, like said course filter, which filter involves no still water once showering is finished.

In an embodiment of the shower device, the course intake filter comprises a replaceable filter element which is easily replaceable by a person taking a shower. In an embodiment, the shower comprises a course pump filter arranged downstream with respect to the pump, preferably arranged between the pump and a mixer tab where fresh water is taken in. The pump filter arrangement enables cleaning of the course pump filter once the circulating shower flow is finished. The course pump filter may have a separate outflow which debouches in a sewer and which outflow is controllable by e.g. a valve.

More particular it is preferred that the shower device comprises a conventional shower system separate from the circulating shower flow for providing a drainable shower flow. In practice the shower system provides a shower flow for soaping and rinsing which is separate from the circulating shower flow to avoid pollution of the shower device. Subsequently this shower flow is drained where after the circulating shower flow may start after closing the drain at the bottom level of the catchment basin preferably by a controllable valve for closing said drain.

In an embodiment, the shower device comprises a relief valve for allowing the entire shower device to drain at the bottom level of the catchment basin for preventing any still water left behind. This even more ensures complete drainage of the shower device once showering with the circulating shower flow is finished.

In an embodiment, the shower device comprises a controllable valve arranged for closing the drain at the bottom level of the catchment basin, wherein the controllable valve is operationally coupled with the pump for closing the valve in connection with activating of the pump. This facilitates use of the shower device.

In an embodiment, the shower device comprises a UV filter for filtering the circulating shower flow.

In an embodiment, the shower device comprises a substantially closed cabin for preventing loss of heat, the cabin accommodating at least the support area the catchment basin, the drain at a bottom level of the catchment basin, and the water intake fluidly coupled with the pump. In an embodiment, the shower device comprises a panel wall, preferably all cabin walls, made of a material selected from the group aluminium, stainless steel, and glass.

In an embodiment of the shower device, a cabin surface, preferably all cabin surface, is coated for preventing accumulation of dirt on the cabin surface.

In an embodiment of the shower device, the entire cabin is isolated for preventing loss of heat. The invention further relates to a device comprising one or more of the

characterising features described in the description and/or shown in the attached drawings.

The invention further relates to a method comprising one or more of the characterising features described in the description and/or shown in the attached drawings.

The various aspects discussed in this patent can be combined in order to provide additional advantages.

Description of the drawings

The invention will be further elucidated referring to an preferred embodiment shown in the drawing wherein shown in:

Fig. 1 a schematic side view of a shower device according to the invention;

fig.2 a schematic perspective view of a further embodiment of a shower device according to the invention;

fig. 3 a perspective view of an assembly of a support area and a catchment basin of the shower device;

fig. 4 schematic side view of an assembly of a support area and a catchment basin of the shower device; and

fig. 5 and 6 graphs of estimated savings of the shower device according to the invention. Detailed description of embodiments

In the figures a shower device 1 according to the invention is shown as well as an assembly 2 of a support area 14 and a catchment basin 10. The invention will now be described referring to the embodiments in fig. 1 and 2 referring to all figures.

The first embodiment shown in fig. 1 is a shower device 1 which is shown in a schematic way. The shower device 1 comprises a support area 14 at a support area level for supporting a person 30 taking a shower. The support area extends at an angle a with respect to the horizontal for dewatering in the catchment basin 10. The support area 14 is suitable for supporting a person taking a shower. Both the support area 14 and the catchment basin 10 are isolated by an isolation layer 32 to prevent heat losses.

The shower device 1 comprises a catchment basin 10. The catchment basin 10 extends below the support area level for collecting water from the support area 14. The catchment basin 10 and support area 14 are mutually arranged such that water caught in the catchment basin 10 is visible and easy cleanable from point of view of a person supported by the support area 14 for taking a shower. Here, the volume of the shown catchment basin 10 is about 1,8 litre, the catchment basin being dimensioned circa 4 cm in depth, 90 cm in length, and 5 cm in width. This small volume of the catchment basin 10 facilitates isolation of the basin by isolating material 32 known per se.

The catchment basin 10 has an overflow outlet 11 which determines the basin water level 31. Surplus of water is drained via the overflow outlet 11 which enables to refresh the circulating shower flow at a desired rate and also aids in control of the volume of the circulating shower flow, and assures a strict separation of support area 14 and catchment basin 10. The overflow outlet 11 is therefore aligned with the support area 14. Surplus of water is drained via the overflow outlet 11 and the outlet pipe 18 into the sewer 19. The shower device 1 comprises a drain 12 at a bottom level of the catchment basin

10. The drain 12 may be a conventional type of drain which can be manually closed off, however it is conceivable for the drain 12 to be equipped with a valve (not shown) which can be closed automatically once the circulating shower flow starts. The drain 12 debouches in a sewer 19.

The shower device 1 comprises a pump 7 for pumping a circulating shower flow. Here, the pump 7 has a pump housing 8. In this case, the pump 7 is arranged entirely above the support area level. Important is that the pump 7 is arranged above the drain

12 such that the pump 7 may drain completely. Thus, arranged "entirely above" here means that the pump 7 is able to completely drain in the catchment basin 10.

The shower device 1 comprises a water intake 13 which is fluidly coupled with the pump 7 for circulating the circulating shower flow between the catchment basin 10 and the shower head 3. The intake 13 is arranged with respect to the catchment basin 10 such that is takes in water between the bottom level 34 of the catchment basin 10 and the support area level 35. The water intake 13 here is arranged a few millimetres from the bottom of the catchment basin 10. The water intake opening 36 of the water intake

13 faces downwards towards the bottom of the catchment basin 10 for taking in water in a substantial vertical upward direction.

The shower device comprises a course filter (not shown) arranged at the water intake 13 for preventing ingress of dirt towards the pump 7. In particular the course filter comprises a replaceable filter element (not shown) which is easily replaceable by a person 30 (partly shown) taking a shower.

The shower device comprises a thermostatic mixer tab 4 with a control means 6 for manually setting the temperature and volume of the circulating shower flow. The thermostatic mixer tab 4 is coupled with a fresh hot water supply 9 via a hot water input of the thermostatic mixer tab 4. The thermostatic mixer tab 4 is coupled with the pump for taking in a circulating shower flow at the cold water input of the thermostatic mixer tab 4. Between the pump 7 and the thermostatic mixer tab 4, a course pump filter 22 is arranged upstream with respect to the thermostatic mixer tab 4 for filtering the circulating flow before entering the mixer tab 4. The mixer tab 4 is accommodated in a mixer tab housing 5.

The shower device 1 comprises a relief valve (not shown) for allowing the entire shower device 1 to drain at the bottom level of the catchment basin 10 for preventing any still water left behind in the shower device 1. Therefore any check valve normally present in the mixer tab 4 has been removed for allowing the shower device 1 to drain such that circulated water is not present anymore in the shower device 1. Thus, the thermostatic mixer tab 4 is modified in that the not-return valve, also check valve, is removed such that the shower system 1 is able to drain entirely.

The draining of the shower device 1 beneficially cleans the course pump filter 22 and the pump 7. The course pump filter 22 and the pump 7 may also be actively washed with water directly from the fresh water supply 9 without a circulating shower flow being present. When actively washed, the course pump filter 22 and the pump 7 may drain via the catchment basin 10 and the drain 12. However as shown as an option the course pump filter 22 and the pump 7 may drain may drain via respective pipes 15, 16 to the sewer 19.

The shower device 1 comprises a controllable valve (not shown) arranged for closing the drain 12 at the bottom level of the catchment basin 10. The controllable valve is operationally coupled with the pump 7 for closing the valve in connection with activating of the pump 7.

During use of the shower device 1 the following steps are taken. Initially, the catchment basin 10 is filled from a fresh water supply 9 through the pump 7 and the water intake 13 until a desired showering water volume is in the catchment basin 10. During filling of the catchment basin 10, the pump 7 is idle. Subsequently the pump 7 is activated and water is taken in at the water intake 13. Then, the taken in water is pumped towards the shower head 3 for circulating a circulating shower flow between the catchment basin 10 and the shower head 3 which dispenses at the support area 14. Finally, after finishing showering, water from the entire shower device 1 is drained via the drain 12 at the bottom level of the catchment basin 10 for preventing any still water left behind. During use it is experienced that the shower device according to the invention consumes up to between 50% and 90%> less water and energy compared with known circulating shower systems.

The second embodiment shown in fig. 2 is a shower device 1 which is shown in a schematic way. In general only differences compared with the first embodiment are elucidated. The shower device 1 comprises here a conventional shower system 17. The conventional shower system 17 is separate from the recycling shower system. The person may use a conventional shower system 17 for soaping and rinsing and a recycling shower system for enjoying a comfort shower. A comfort shower is regarded here as a shower which is not necessarily from hygienic point of view. In practice it has been experienced that the recycling shower system according to the invention only uses 10% of water and 10% of energy compared with the conventional shower system 17 while offering 10 times more water/minute.

The conventional shower system 17 uses a thermostatic mixer tab 23 well known per se. The mixer tab 23 is coupled with a hot 25 and cold 24 fresh water supply. Here, the initial filling of the catchment basin 10 is done by reversing the mixed flow from the mixer tab 23 towards the pump 7 which is then still idle.

Here, the circulating shower flow passes a thermostatic safety valve 21 which valve provides safety in that water above a set temperature may not contact the person taking a shower.

In this case, the circulating shower flow passes an uv- filter device 28 for filtering the circulating shower flow.

Additional safety may be provided bay a safety valve 26, like a electromagnetic valve, which valve prevents leakage of so called grey water to fresh water.

The shower device 1 comprises a water intake 13 which is fluidly coupled with the pump 7 via water intake pipe 20 for circulating the circulating shower flow between the catchment basin 10 and the shower head 3. The water intake 13 here is arranged a few millimetres from the bottom of the catchment basin 10. The water intake opening faces downwards towards the bottom of the catchment basin 10 for taking in water in a substantial vertical upward direction. This is also shown in fig. 4. The low water intake 13 guarantees complete drainage of the pump 7 once comfort showering is finished, and guarantees a stable intake of water at all conditions of movement of persons on the support area 14 or even water movement in catchment basin 3.

The shower device 1 comprises a relief valve 37 for allowing the entire shower device 1 to drain at the bottom level of the catchment basin 10 for preventing any still water left behind in the shower device 1. The shower device 1 comprises a controllable valve (not shown) arranged for closing the drain 12 at the bottom level of the catchment basin 10. The controllable valve is operationally coupled with the pump 7 for closing the valve in connection with activating of the pump 7.

During use of the shower device 1 the following steps are taken. Initially, the catchment basin 10 is filled from a fresh water supply 9 through the pump 7 and the water intake 13 until a desired showering water volume is in the catchment basin 10. Subsequently the pump 7 is activated and water is taken in at the water intake 13. Then, the taken in water is pumped towards the shower head 3 for circulating a circulating shower flow between the catchment basin 10 and the shower head 3 which dispenses at the support area 14. Finally, after finishing showering, water from the entire shower device 1 is drained via the drain 12 at the bottom level of the catchment basin 10 for preventing any still water left behind.

Fig. 5 and 6 graphs of estimated savings of the shower device 1 according to the invention. The total saving is shown versus years. The saving is the difference between the cost of a shower device according to the invention (thin line) and the cost of a commonly used shower (bold line). Fig. 5 shows the saving for a 4 person household using a walk in shower consuming 10 litres per minute with an average shower duration of 10 minutes. Fig. 6 shows the saving for a 4 person household using a shower with a shower curtain, the shower consuming 12 liters per minute with an average shower duration of 12,5 minutes.

It will also be obvious after the above description and drawings are included to illustrate some embodiments of the invention, and not to limit the scope of protection. Starting from this disclosure, many more embodiments will be evident to a skilled person which are within the scope of protection and the essence of this invention and which are obvious combinations of prior art techniques and the disclosure of this patent.