Method for providing drinking water, drinking water supply assembly, and hot-water and flushing-function switching unit

Abstract

The growth of Legionella can be minimized by cold flushing at least one part of a TWW (hot drinking water) line as required. In particular, it is then not absolutely necessary to keep the temperature in the corresponding line parts above 50 °C over long periods of time, for example overnight or over weeks or months in vacation homes or buildings in vacation complexes or barracks, thereby wasting energy and leading to temperature ranges that are favorable to the growth of Legionella at the contact points between TWW lines and TWK (cold drinking water) lines, for example in the region of tapping points or at T-pieces which branch off into short stub lines. The cold flushing process can quickly and effectively reduce the temperature in the corresponding line parts so that the risk of growth of Legionella can be minimized while having a reduced energy requirement or an energy requirement which is as low as possible.

Description

Provision procedures for the provision of drinking water, Drinking water supply arrangement as well as hot water and flushing switching unit

[0001] The invention relates to a method for providing drinking water via a DHW (hot water) line and a DHK (cold water) line at a draw-off point. The invention also relates to a drinking water supply arrangement having at least one hot water source, at least one draw-off point, at least one DHW line connecting the hot water source to the draw-off point, and at least one hot water demand valve arranged between the DHW line and the draw-off point, as well as at least one DHK line. The invention also relates to a hot water switching unit and a flushing switching unit.

[0002] Such drinking water supply arrangements and corresponding provision methods for providing drinking water via a domestic hot water line and a domestic hot water line at a withdrawal point are known, for example, from DE 37 23 089 A1 and DE 102017 010893 A1 or also from DE 102004033 770 A1, from DE 102019 107 179 A1, from DE 20 2013 104 471 U1 and from DE 10 2018 208 662 A1. US 2019 / 0093904 A1 and DE 202012 012276 U1 also disclose such drinking water supply arrangements and provision methods.

[0003] In this case, DE 37 23 089 A1 and DE 102017 010 893 A1 disclose a circulation path between the DHW line and the TWK line, through which a circulation pump can pump drinking hot water from the DHW line into the TWK line in order to shorten as much as possible the time frame within which drinking hot water is provided at the point of use.

[0004] DE 102004 033 770 A1, DE 10 2019 107 179 A1, DE 20 2013 104471 U1, and DE 102018208662 A1, however, disclose a terminal flush in toilet cisterns or other flush outlets to quickly provide hot drinking water continuously or at desired operating times. This is also intended to reduce the risk of Legionella proliferation.

[0005] Legionella are ubiquitous bacteria found in water that thrive in temperatures between 25°C and 45°C. Therefore, significant accumulation can occur in domestic hot water (DHW) from drinking water supply systems, also known as domestic hot water installations (DWI), for example, in buildings. The species Legionella pneumophila is an important opportunistic pathogen that can cause pneumonia. At least 6,000 cases are estimated to occur in Germany annually. Transmission and infection occur primarily via aerosols.

[0006] For this reason, there are requirements in the technical regulations for domestic hot water or drinking water supply arrangements where there is a risk of aerosols being created, such as in showers, bidets, etc., with the aim of preventing the growth of Legionella: Short branch lines, minimum temperatures and intended use or flushing are provided for in this regard. In unused domestic hot water branch lines, stagnation and cooling cannot be avoided despite everything, which leads to critical temperature intervals. Therefore, regular replacement of drinking water, particularly if the temperature of cold drinking water deviates to above 25°C or hot drinking water to below 55°C, in all drinking water supply pipes and pipe components appears essential to ensure the quality of the drinking water. If this replacement is not sufficiently ensured, particularly through the use of drinking water, the drinking water must be replaced within the water supplying domestic hot water or drinking water supply pipes.DHW pipes are removed or flushed. During these flushes, often referred to as Legionella flushing or Legionella (protection) circuits, this water is subsequently drained, resulting in a significant additional consumption of unused drinking water. This is also disclosed in the aforementioned publications DE 10 2004033 770 A1, DE 10 2019 107 179 A1, DE 202013 104 471 U1, and DE 10 2018 208 662 A1, whereby the proportion of unused drinking water can be reduced by feeding it into toilet cisterns.

[0007] The Drinking Water Ordinance of June 20, 2023, explicitly states that the consumption of stagnant water should be avoided if, upon reaching the technical action value for Legionella spec., hazard prevention measures are ordered: ... ..the operator must... provide affected consumers with the necessary advice on drinking water consumption and use based on the measures taken, in particular on avoiding the consumption of stagnant water (Section 52, Paragraph 1).

[0008] Concepts for supplying cold and hot drinking water to water outlets such as showers, bathtubs, sinks, etc. are well known. Both centralized and decentralized solutions for domestic hot and cold water supply systems are common. Furthermore, various concepts for the design of the water supply pipe connections between a cold water supply and a hot water system and the corresponding water outlets are known, each of which has its own advantages and disadvantages.

[0009] A common example of this is the use of individual branch lines or series lines or combinations thereof to connect a central domestic hot water system or hot water source to the various water draw-off points. In such drinking water supply arrangements, the formation of Legionella within the water pipes can pose a major problem. In branch lines, the water in the pipes stagnates if it is not drawn off at one of the water draw-off points. This poses a major problem from a hygiene perspective, particularly with regard to the domestic hot water pipe. A hot water source should preferably provide domestic hot water at a temperature of at least 60°C, especially if it is designed in accordance with standards. This corresponds to a temperature above which no significant proliferation of Legionella occurs and Legionella bacteria die off in large numbers.However, this hot drinking water cools down over time due to the stagnation of water in the pipes when not in use. When the temperature ranges from 25°C to 45°C, optimal growth conditions exist, particularly for Legionella. As a result, all of the cooled hot drinking water would have to be regularly flushed from the pipes, usually when the temperature falls below 50°C. To this end, the pipes are currently flushed with freshly supplied hot drinking water at a temperature of at least 55°C, in accordance with regulations. During this flushing process, the cooled water is then fed into the drain or toilet cistern, as also disclosed in the aforementioned publications DE 10 2004 033 770 A1, DE 10 2019 107 179 A1, DE 20 2013 104 471 U1 and DE 10 2018 208 662 A1.

[0010] One approach to reducing the frequency of pipe flushing, or rather, the volume of pipes to be flushed, involves designing the domestic hot water pipes, or at least parts of them, as circulation pipes. In such circulation or ring pipes, the domestic hot water circulates continuously or regularly, preventing prolonged stagnation of the water. Furthermore, cooling of the domestic hot water can be significantly limited. However, at the end of the circulation cycle, the cooled water must be reheated to the required initial temperature of at least 60 °C to suppress Legionella growth. The domestic hot water is therefore repeatedly heated, even when not in use, which generates high energy requirements, especially in poorly insulated pipes in existing buildings. Despite these measures, temperatures in the peripheral DHW pipes, especially in existing buildings, rarely reach the required temperature level of at least 55 °C.

[0011] US 2019 / 0093904 A1 and DE 20 2012 012 276 U1 use the circulation for a sterilization or disinfection step by circulating warm water at a sufficiently high temperature, whereby DE 20 2012 012 276 U1 also suggests subsequently draining the hot water that has then been circulated several times in combination with a rinsing process, although the exact process and, above all, the type of drainage are left open.

[0012] The object of the present invention is to provide a supply method for providing drinking water, a drinking water supply arrangement and a hot water switching unit which minimize the growth of legionella with the lowest possible energy and water consumption.

[0013] The object of the invention is achieved by methods for providing drinking water, drinking water supply arrangements, and hot water switching units having the features of the independent claims. Further advantageous embodiments, possibly independent of these, can be found in the subclaims and the following description.

[0014] The invention is based on the fundamental insight that the growth of Legionella can be minimized if at least part of a DHW pipe is flushed with cold water as needed. In particular, it is then not absolutely necessary to maintain temperatures of over 50 °C in the corresponding pipe sections for extended periods, for example at night or in holiday homes, in holiday complexes or barracks for weeks or months, which is not only energetically pointless but also leads to temperature ranges at contact points between DHW pipes and DHK pipes, for example in the area of ​​withdrawal points or at T-pieces that branch off to short branch pipes, in which Legionella can preferentially grow. Cold flushing can be used in the corresponding Pipe sections can reduce the temperature quickly and effectively, so that the risk of Legionella growth can be minimized with reduced or as low an energy requirement as possible. [ 151 The unused DHW pipes can therefore be set to cold after a cold flush and left cold during periods of interruption in use. Only then, for example, every 72 hours, can the cold drinking water in the DHW pipes and, accordingly, also in the DHW pipes be replaced, if necessary, to simulate normal operation, for example.

[0016] In particular, a method for providing drinking water via a domestic hot water line and a domestic hot water line at a withdrawal point can be characterized in that at least one section of the domestic hot water line, which constitutes part of the domestic hot water line, is cold-flushed as needed in order to minimize the growth of Legionella bacteria while minimizing energy and water consumption, regardless of the other combinations of features described as advantageous here. The cold flushing can preferably be carried out by draining drinking water from the domestic hot water line section or after drawing off hot drinking water, before excessive proliferation of Legionella bacteria can occur.

[0017] Depending on the specific implementation, it may also be possible to cold flush parts of a circulation system, particularly a DHW circulation system, whereby, with a suitable process, these parts can then be set to cold accordingly. This can particularly be implemented in a cascading manner if circulation systems are planned one after the other or in parallel. Circulation systems that are not required can then be set to cold, while others can still operate according to the desired specifications. For example, in a school, the teaching room and toilets can be heated from 7:00 a.m. via the circulation system, while this happens for the showers in the gym, for example according to the timetable, when the teacher activates it at the start of sports lessons or via a trigger when the lights in the changing rooms are switched on, or similar. The individual circulation systems can then be cooled again in a staggered manner, whereby if necessary.A main circulation can also be set to cold if all subsequent circulations, for example the circulations for the toilets, the staff room and the showers, are or are set to cold.

[0018] It is understood that, depending on the ratio between cold drinking water and hot drinking water in the pipe sections flowing through during flushing, such cold flushing can also be achieved by means of suitable flushing circulation, as long as it can be ensured that, within a reasonable time window, the mean temperature in the DHW pipe sections and the TWK pipe sections, which is distorted due to the circulation, is below the critical temperature of 25 °C with regard to the growth of Legionella.This is ultimately excluded in the solution proposed by DE 20 2012 012 276 Ul, since there, cold drinking water is circulated together with the hot drinking water through the hot water source, taking the route through the previously cold TWK pipe sections, so that the water in the essentially cold and actually safe pipe sections and these cold pipe sections are also heated.

[0019] However, from a drinking water hygiene perspective, it may be advantageous to enforce a complete water exchange in the domestic hot water and domestic hot water pipes after defined periods of time, for example after 72 hours at the latest, even when flushing by means of a suitable flushing circulation.

[0020] On the other hand, it appears advantageous to drain the hot drinking water that is or is to be flushed out of the corresponding DHW pipe section, for example, into a flush outlet or a toilet cistern, in order to minimize the risk of recontamination, even if this means accepting a certain loss of drinking water. With suitable process management, an appropriate flushing process can be carried out before excessive process management, so that the contamination of the flushed rinse water with Legionella or other biological contaminants remains relatively low. This means that it can be used for secondary uses that are not subject to drinking water or the risk of aerosol formation, such as for irrigation purposes or in washing machines or dishwashers, without any hygienic concerns.In this respect, this procedure offers a significant improvement over the solutions of US 2019 / 0093904 Al and DE 20 2012 012 276 Ul, in which the legionella and other biological components, which can in particular lead to biofilms or deposits, are ultimately degenerated by heating and then discharged via the respective withdrawal points and thus made available as drinking water, which then - naturally - circulates and is loaded with corresponding residues of the degenerated components and in particular possibly more often the. critical temperature window. Furthermore, in the solution proposed by DE 20 2012 012 276 U l, at most the DHW pipe section is briefly cooled, whereby, since circulation through this DHW pipe section takes place via the DHK pipe through the hot water source, the DHK pipe is heated first and then the DHW pipe section is heated again, which leads to multiple passes through the critical temperature ranges and ultimately to an increased risk of contamination.

[0021] Cumulatively or alternatively to the other feature combinations described here as advantageous, a drinking water supply arrangement with at least one hot water source, with at least one withdrawal point, with at least one DHW line connecting the hot water source to the withdrawal point and with at least one hot water demand valve arranged between the DHW line and the withdrawal point as well as with at least one DHW line can be characterized in that a cold water flushing line is arranged between the DHW line and the DHW line, which provides cold drinking water to the DHW line and opens into the DHW line in order to minimize the growth of Legionella with the lowest possible energy and water consumption. With a suitable design of the drinking water supply arrangement, cold flushing of the DHW line or a corresponding DHW line section can then take place via this cold water flushing line.

[0022] In this case, this DHW pipe section, which can or should then be flushed with cold water as required, can be limited on the one hand by the cold water flushing pipe and on the other hand by a flushing outlet or a flushing circulation pipe, so that cold flushing can then take place from the cold water flushing pipe through the corresponding DHW pipe section to the flushing outlet or to the circulation.

[0023] In this context, a DHW pipe section is understood to be a section of a DHW pipe which, for example, is to be flushed with cold water as required. Ultimately, any section of a DHW pipe can initially represent a corresponding DHW pipe section. It is understood that although the possibility of an arbitrary definition of such pipe sections exists, pipe sections, and in particular DHW pipe sections, are generally defined or should be defined between connections, outlets, valves, branches, bends or similar special features of pipes in order to then be able to carry out certain measures together in the corresponding pipe sections, such as a flushing process. It is understood that in addition to In addition to DHW pipe lines, TWK pipes can also be divided into corresponding parts, i.e. TWK pipe sections, if this seems sensible.

[0024] Any known device for providing hot water can serve as a hot water source or domestic hot water heating system. In particular, these can include hot water storage tanks, which are heated and kept warm by heating systems, heat pumps, solar thermal systems, possibly with the aid of auxiliary electric heaters, or by other means. Instantaneous water heaters or direct gas or coal-fired boilers can also be used as hot water sources in the usual way.

[0025] Depending on the specific implementation or the specific structure of the respective drinking water supply system, even a conventional circulation system, by means of which hot drinking water can be provided at a sufficiently high temperature even over longer distances, especially across multiple floors, can be considered a component of a hot water source. This perspective does not change the fact that a hot drinking water source can provide hot drinking water, which can then be transported via a DHW pipe to a point of use and made available there as needed.

[0026] Any known domestic hot water pipe capable of delivering domestic hot water in a conventional manner over desired distances can serve as a domestic hot water pipe. Such domestic hot water pipes are generally made of copper, stainless steel, or other metals, or of other metal or plastic composite systems, or in the form of another device deemed suitable for transporting drinking water, especially domestic hot water. Such pipes, particularly in the form of pipes or hoses, are well known.

[0027] The same applies to drinking water pipelines, for which all known pipelines intended for cold drinking water can be used. Pipes and hoses made of metals, such as copper, or plastics are also well known. If necessary, other equipment that appears suitable for transporting drinking water, especially cold drinking water, can also be used.

[0028] Particularly in the case of extensive drinking water supply arrangements, especially if these have to bridge relatively large differences in height, these can also include, as is already sufficiently known, for example, from DE 102006006001 A 1, pressure boosting devices or storage devices (DEA) in order to be able to provide a sufficiently high water pressure at the extraction points in an operationally reliable manner.

[0029] In this context, any drinking water supply arrangements in which drinking water can be or is made available on demand are considered as withdrawal points. Such withdrawal points can be found, for example, in the usual way at sinks, showers, bathtubs, bidets, toilets, or individual water withdrawal devices, such as those well known for connecting garden hoses, washing machines, dishwashers, refrigerators, coffee machines, and the like.

[0030] Often, corresponding tapping points on the respective drinking water supply system include valves, such as hot water request valves or cold water request valves, which can be opened and closed to provide drinking water as required. For example, with washing machines or coffee machines, it is also conceivable that the corresponding tapping points do not have their own valves, but rather that these are provided by the corresponding equipment, which, however, can potentially lead to increased effort when replacing equipment. Therefore, at least one shut-off valve is usually provided at these points. Tapping points with mixing valves are also known, in which combined valves mix hot and cold drinking water and provide them on demand.

[0031] In particular, in addition to manually operated valves, electromotive, electromagnetic, pneumatic, or hydraulically controlled valves can also be used at the tapping points, or as hot or cold water demand valves, or as other valves used in a related context. To the extent that the valves are to be controlled, manually operated valves are essentially ruled out for practical reasons, even if manual operation following appropriate instructions, even if issued by a control system, seems conceivable to specifically control a valve.

[0032] Any device that can be used to control the flow of drinking water in the desired manner can be used as hot water demand valves or cold water demand valves, as well as the other valves explained in this context. In particular, screw valves, rotary valves, rotary slide valves, angle valves, straight-way valves, angle-seat valves, multi-way valves, and / or distribution valves can be used. In the area of ​​drinking water supply, disc valves, angle-seat valves, diaphragm valves, and ball valves are particularly well-known. It goes without saying that other known valve types can also be used accordingly.

[0033] Accordingly, a hot water demand valve can be virtually any valve suitable for drinking water that can be used to open or close an opening in a domestic hot water line. The term "cold water demand valve" therefore refers to a valve that can be used to open or close a domestic hot water line as needed.

[0034] In this context, any device by means of which cold drinking water can be brought from a domestic hot water line to a domestic hot water line can be considered a cold water flushing line. A cold water flushing line can also be used for other purposes if necessary. In this context, it is referred to as a cold water flushing line if it is suitable and intended to supply cold drinking water for the purpose of flushing a domestic hot water line or a section of that line. Depending on the specific implementation, the cold water flushing line can be in the form of a pipe, a hose, or any other device deemed suitable for transporting drinking water, particularly cold drinking water. In particular, the cold water flushing line can also be made of plastic, metallic materials, or composite systems, including metal-plastic composite systems.

[0035] Preferably, the DHW line section is rinsed with cold water after drinking water has been drawn, as already explained above, and then preferably cooled. This prevents the remaining hot water in the DHW line or DHW line section from cooling down to the point where the temperature window within which the risk of Legionella proliferation is particularly high is reached, maintained for an extended period, or passed through over an extended period.

[0036] In this context, it is clear that briefly reaching or maintaining this temperature window, especially if flushing occurs during or after it, does not leave time for excessive proliferation of Legionella, so that this can certainly be tolerated over shorter periods. In particular, it is possible to take the habits of the respective user unit into account through learning processes in order to, on the one hand, sufficiently flush the DHW pipe sections with cold water and, on the other hand, minimize the loss of drinking water. For example, it is conceivable that in the morning, showering, making coffee, using the toilet, and washing hands can be delayed until a flushing process is initiated.

[0037] In particular, cold flushing can be performed using cold drinking water from the drinking water line, as already indicated above, and for which the cold water flushing line can preferably be provided. Such a configuration enables a compact design of the overall arrangement. In particular, the length of the additional drinking water lines or drinking water lines that must be provided can be kept to a minimum.

[0038] In order to enable cold flushing as needed and thus minimize the growth of Legionella with the lowest possible energy and water consumption, a hot water switching unit can be provided cumulatively or alternatively to the other feature combinations explained above as advantageous, which is characterized by a hot water inlet flange and by a hot water pipe partial flange that is fluidically connected to the hot water inlet flange by a DHW arm, which can be optionally connected to the hot water inlet flange and to a cold water inlet flange of the hot water switching unit that is fluidically connected to a cold water flushing arm that opens into the DHW arm at an opening, wherein the opening can preferably be realized by a passive coupling of the arms or by a discrete directional valve, which can be implemented structurally easily with a suitable design.Such a hot water switching unit enables cold flushing of a DHW pipe section and thus minimises the growth of Legionella with the lowest possible energy and water consumption, unlike the thermostatic mixer with flushing function from DE 20 2014 105 702 Ul, also in terms of installation in the simplest possible way, since ultimately the DHW pipe section to be flushed as required only needs to be connected to the hot water pipe section flange, the cold water inlet flange to an inlet for cold drinking water, for example to the cold water flushing pipe, and the hot water inlet flange to the DHW pipe on the hot water source side in order to enable flushing as required.

[0039] Accordingly, the drinking water supply arrangement can be configured such that the hot water switching unit is inserted into the domestic hot water line via its hot water inlet flange and its hot water pipe section flange, and into the cold water flushing line via its cold water inlet flange. The cold water flushing line then preferably opens into the domestic hot water line within the hot water switching unit, which then enables flushing of the domestic hot water pipe section.

[0040] Flanges can be any of the known methods used to connect a drinking water unit, such as a hot water switch unit, to drinking water pipes, i.e. to DHW pipes or TWK pipes. The flange connection can, for example, comprise disc-shaped attachments attached to the pipe ends which are clamped or connected together. Loose attachment discs are also conceivable, which can seal pipe ends together via collars when clamped together. Connections between pipes can, as is well known, also be made in other ways, for example by means of screw connections, compression fittings, press connections, welded or soldered connections, adhesive connections, sliding sleeve connections, socket connections or plug-in or plug-in fittings.Grooved connections are realized, whereby two suitably prepared pipe ends are positioned relative to one another in a manner appropriate to the type of connection and then connected to one another. In the present context, the term “flange” preferably refers to any pipe end or hose end that is prepared accordingly for a selected type of pipe connection. If necessary, this can even be a simple pipe or hose end if the corresponding pipe connection is to be realized, for example, via a shrink clamp or shrink sleeve or a press connection. Accordingly, in the present context, the term “flange” refers in particular to any pipe or hose end that is suitable and intended for attachment to other pipes or hoses.

[0041] A hot water control valve can be arranged between the hot water inlet flange and the hot water pipe section flange or in the DHW arm (30) between the hot water inlet flange and the mouth of the cold water flushing arm in the DHW arm, so that the flow through the DHW pipe interrupted by the hot water switching unit or to the DHW pipe section can be interrupted or opened as required.

[0042] Accordingly, a hot water flush valve can be installed on the side of the cold water flushing line opening into the DHW line facing away from the hot water demand valve. be arranged so that - regardless of the presence of a hot water switching unit as a unit installed in the DHW line - the DHW line can be interrupted as needed before the cold water flush line joins the DHW line. Accordingly, the hot water flush valve, in particular, can be the hot water control valve, or the hot water control valve of the hot water switching unit can be used as the hot water flush valve.

[0043] The hot water switching unit can also comprise a cold water control valve arranged between the cold water inlet flange and the hot water pipe part flange or in the cold water flushing arm, by means of which cold drinking water can be selectively supplied to a DHW arm or a pipe part between the hot water inlet flange and the hot water pipe part flange or in particular the hot water pipe part flange.

[0044] Accordingly, a cold water flush valve can be installed in the cold water flush line, so that the cold water flush line or a cold water flush arm can be used optionally to supply cold drinking water to the outlet of the cold water flush line into the DHW line. Accordingly, the cold water flush line, in particular, can be connected to the DHW line via a cold water flush valve.

[0045] In this respect, the cold water control valve can in particular be the cold water flush valve or it can be used to flush the DHW line or the DHW line section.

[0046] The connectivity can be achieved in particular by suitable valves, for example, by discrete directional control valves, which are controlled or guided in such a way that there are no smooth transitions between flow and blocking, or this only occurs for a very short time, for example, only to avoid unwanted pressure surges. In this context, discrete directional control valves therefore describe the exact opposite of proportionally controlled or controlled directional control valves, in which different flow rates can be selected proportionally to an input signal and maintained over an extended period.

[0047] Depending on the specific implementation, the hot and cold water control valves or the hot and cold water flush valves can also be implemented together as a multi-way valve if this appears advantageous for structural or other reasons. For example, a discrete 2 / 3-way multi-way valve can be used to The DHW arm on the one hand and the cold water flush arm on the other hand can each be optionally connected to the hot water pipe flange, whereby this discrete 2 / 3 multi-way valve can then be provided at the mouth of the cold water flush arm into the DHW arm.

[0048] On the other hand, the outlet can also be realized through a purely passive coupling, for example, a T-piece. In this context, the term "passive" refers to hydraulic assemblies that do not offer any adjustment capability, such as pipes, hoses, branches, or connections, for example, in the form of T-pieces, crosspieces, or similar.

[0049] In order to enable cold flushing as required and thus minimize the growth of Legionella with the lowest possible energy and water consumption, a hot water switching unit can be used cumulatively or separately.As an alternative to the other feature combinations explained as advantageous here, a hot water inlet flange and a hot water pipe partial flange which is fluidically connected to the hot water inlet flange by a DHW arm, which can be connected selectively to the hot water inlet flange and to a cold water inlet flange of the hot water switching unit which is fluidically connected to a cold water flushing arm which opens into the DHW arm at an opening, can be provided, wherein a check valve opening in the direction of the hot water pipe partial flange can preferably be arranged between the hot water inlet flange and the opening in the DHW arm and / or in the cold water flushing arm, which can be implemented structurally in a simple manner with a suitable design.Such a hot water switching unit enables cold flushing of a DHW pipe section and thus minimises the growth of Legionella with the lowest possible energy and water consumption, also in terms of installation in the simplest possible way, since ultimately the DHW pipe section to be flushed as required only needs to be connected to the hot water pipe section flange, the cold water inlet flange to an inlet for cold drinking water, for example to the cold water flushing pipe, and the hot water inlet flange to the DHW pipe on the hot water source side in order to enable flushing as required and the check valves can reliably prevent uncontrolled flow in an undesirable direction.

[0050] In particular, such hot water switching units, unlike the thermostatic mixer with flushing function disclosed in DE 20 2014 105 702 Ul, are extremely flexible and versatile and can be used cost-effectively.

[0051] In particular, the combination of check valves and discrete hot and cold water flush valves, regardless of whether these are implemented separately in the respective arms or via a shared directional control valve, proves to be advantageous, as this provides hygienic redundancy. The flush valves alone can prevent unwanted backflow of flush water by closing them according to the specific process being implemented. However, the check valves can also prevent backflow in the event of a valve failure, thus ensuring hygienically perfect operation. Depending on the specific selection of the corresponding components, the check valves can also reduce the load on the hot and cold water flush valves, which can accordingly enable the use of cheaper components.

[0052] Depending on the specific design of the drinking water supply arrangement, a circulation line can branch off from the DHW line, as is well known in the art. Typically, such a circulation line is routed back to the hot water source, which allows for the provision of domestic hot water at a sufficiently high temperature through circulation through the hot water source to the branch of the circulation line, thus minimizing any demand times, particularly in the case of longer pipe runs. As already indicated above, such a circulation line can ultimately be considered a component of the heat source, unless special measures regarding circulation are also planned or desired.

[0053] With such a design, it is particularly advantageous if the cold water flush line flows into the DHW line between the branch of the circulation line and the hot water demand valve. If the DHW line only branches to a utility line and not into a circulation system, it can accordingly be advantageous if the cold water flush line flows into the DHW line between this branch and the hot water demand valve. In this way, the area of ​​the DHW line or the part of the DHW line not covered by the circulation system can be flushed, at least to a large extent, in accordance with the present explanations.

[0054] Preferably, the DHW line has a flushing outlet so that, as already explained above, the water in the DHW line or in the DHW line section Drinking water can be flushed out and ultimately leave the drinking water supply arrangement.

[0055] Such a flush outlet can ultimately discharge in a conventional manner, for example, into a toilet cistern, a siphon, or a floor drain. It is also conceivable to use the flushed drinking water for secondary purposes, such as cleaning or irrigation. However, due to the recommendations for avoiding the consumption of stagnant water (see Section 52, Paragraph 1 of the Drinking Water Ordinance of June 20, 2023), the flush water should no longer be used for consumption after passing through the flushing unit.

[0056] In particular, the flushing outlet can preferably be hygienically separated from the destination to which the drinking water, whether hot or cold drinking water, discharged or flushed through the flushing outlet is directed, in order to avoid any possible recontamination.

[0057] Alternatively, it would be conceivable to provide a flushing circulation for cold flushing, possibly in addition to the hot water circulation already explained above, which is optionally available. This seems particularly conceivable if a flushing circulation can be provided through the DHW pipe section or through the DHW pipe to be flushed, the cold water flushing line, the associated DHW pipe section and a flushing circulation line, the total water quantity of which, taking into account the amount of domestic hot water in the DHW pipe to be flushed or in the DHW power section, is sufficient to reduce the average temperature of the water to sufficiently below 25 °C or to a sufficiently low temperature so that there is no longer any risk of increased growth of Legionella. If necessary, the mass of the heated DHW pipe components or the DHW pipe components that also need to be cooled can also be taken into account in such considerations or in the associated calculations.DHW pipe components as well as the other pipe components involved are taken into account. For example, if only the water quantities are considered, 8 1 hot drinking water at 55 °C and 40 1 cold drinking water at 15 °C result in an average total temperature of less than 22 °C when the corresponding water quantities are mixed together. This can be ensured, if necessary, by appropriate flushing circulation, whereby the above DHW volume from the same usage unit can be considered a type of existing flushing volume.

[0058] If necessary, a cooling circulation system and / or a cooling flushing system for cold drinking water can also be provided, for example, using a suitable device, especially if there is a risk that the drinking water pipes will overheat due to structural conditions, such as existing insulation or nearby heating or domestic hot water pipes. For the cooling flushing system, an existing flushing outlet, connected to a cold water flushing outlet valve for the purpose of regular flushing after extended periods of inactivity, for example, after 72 hours, can be used.

[0059] Both cooling circulation and cooling flushing can, if necessary, lead to sufficient cooling simply by the movement of the respective water, as already disclosed with regard to cooling circulation, for example, in EP 1 845 207 A1, EP 3 037 591 A1, DE 20 2015 007 277 U1 or DE 20 2019 001 121 U1. In particular, a cold spot can also be provided if necessary, not only to distribute any locally present excess heat in the drinking water supply arrangement during cooling circulation or to flush it out of the drinking water supply arrangement during cooling flushing, but also to actively extract heat from the drinking water supply arrangement via the cold spot. The latter then enables longer downtimes until another cooling flush or cooling circulation must or should be carried out.

[0060] In this regard, any device that can specifically provide a temperature sink in a drinking water supply system can be used as a cold junction. For example, this could be the evaporator of a compressor chiller or a heat exchanger of another chiller.

[0061] Depending on the specific implementation, flushing can be performed as a combination of flushing processes with varying effectiveness. For example, both a temperature reduction and a water exchange for drinking water hygiene reasons can be performed. If this is desired in the form of circulation to save water, filtration and / or other germicidal or germ-reducing measures can also be provided.

[0062] On the other hand, corresponding flush outlets, for example in bathtubs, toilet cisterns or even in siphons, are well known and are also used for flushing purposes. desired, although the cold flushing of DHW pipes explained here is not known.

[0063] In particular, the flushing outlet can be opened and closed via a hot water flushing outlet valve so that flushing can be initiated in a targeted manner and under given circumstances.

[0064] In particular, cold flushing can then take place until the hot drinking water present in the DHW line section has been replaced by cold drinking water in a defined quantity at the flush outlet or at the draw-off point, for example if a flush outlet is provided into a siphon or if drinking water can be taken in via a toilet cistern. This quantity can be defined, for example, by taking into account the pipe volume of the DHW line and a correspondingly defined period of time. In particular, however, a temperature measurement is also conceivable, which can be used to determine whether the hot drinking water in the DHW line or in the DHW line section has been sufficiently replaced by cold drinking water.

[0065] Although it should ultimately be no problem for an installer to equip a domestic hot water line with a flush outlet and, if necessary, install a hot water flush outlet valve that can be opened and closed as needed, a flush switch unit also appears advantageous in this regard. This unit provides, on the one hand, appropriate flanges that allow easy installation into a drinking water supply system, and, on the other hand, includes any control devices, such as valves, etc., as well as additional electrical equipment, so that an electrical or signaling connection can be carried out relatively easily, and possibly even by personnel with electrical training. Appropriately provided connections can then certainly enable a relatively reliable and speedy electrical installation even for electrically trained personnel.

[0066] In this respect, regardless of the other combinations of features described here as advantageous, a flushing switching unit which is characterized by a hot water inlet flange which can be optionally connected to a flushing flange of the flushing switching unit via a passive coupling and / or via a discrete directional control valve, in particular in contrast to the thermostatic mixer with flushing function as disclosed in DE 20 2014 105 702 U1, enables a minimization of the growth of Legionella with the lowest possible Energy and water consumption. With a suitable design, such a flushing switch unit is relatively easy to install in a drinking water supply system via its hot water inlet flange and its flushing flange. In particular, the flushing switch unit can be connected to the DHW line of the drinking water supply system via its hot water inlet flange and to the flushing outlet via its flushing flange, so that the flushing switch unit, once the corresponding connections are closed, can immediately enable flushing, in particular of the connected DHW line.

[0067] Additionally, the flushing switch unit can have a cold water inlet flange, which can also be connected either to the hot water inlet flange or to the flushing flange. This design can be advantageous because it makes it possible, for example in barracks or holiday complexes, to flush both the cold DHW lines and the DHW lines on a regular basis during periods of often longer interruptions in use. According to the currently applicable standard, water should be replaced after 72 hours at the latest. Unlike the thermostatic mixer equipped with a flushing function from DE 20 2014 105 702 U l, this cold water inlet flange can also be connected to the flushing flange or to the hot water inlet flange, preferably via a passive coupling or via a discrete directional control valve, so that the most flexible use possible can be achieved at low cost.

[0068] Preferably, electrical or electronic devices or sensors can be provided in the flushing switching unit, such as a control unit, which can possibly also enable communication with the hot water switching unit or with a home computer.

[0069] However, in practice, the pipes for cold drinking water and hot drinking water (TWK pipes or DHW pipes) are often laid in close proximity to each other. In large or tall buildings, this is preferably done in riser shafts, for example, in main lines, which then branch off into sublines for individual apartments or floors. This type of installation is often also done together with the piping of the central heating system. This makes it conceivable that the cold drinking water in its TWK line is also heated through thermal crosstalk. [ 701 As a rule, the temperature of the cold drinking water in the inlet is approximately 15 °C to 20 °C. If the temperature of the cold drinking water is affected by contact with the DHW pipe or If the temperature in heating pipes is raised above 20°C, especially above 25°C, there is also an increased risk of Legionella proliferation. Consequently, it is recommended to flush the drinking water pipes in such installations at regular intervals, which should naturally preferably be done with cold water. This can also potentially result in high consumption of unused drinking water.

[0071] Flushing the TWK line or components of TWK lines can, as already explained above, serve to reduce the temperature in the corresponding TWK line or its components.

[0072] For such purposes, a cold water inlet flange or a cold water flush outlet valve for a corresponding flush outlet can also be useful.

[0073] In particular, the flushing switching unit can comprise a hot water flushing outlet valve arranged between the hot water inlet flange and the flushing flange, whereby an optional connection of the hot water inlet flange to the flushing flange can be implemented in a structurally simple manner.

[0074] When installed in the drinking water supply arrangement, the hot water flush outlet valve of the flushing switching unit can then represent the hot water flush outlet of the drinking water supply arrangement, so that the latter can be provided in a structurally simple manner.

[0075] In order to be able to connect the flushing flange or the hot water inlet flange optionally with the cold water inlet flange, the flushing switching unit can comprise a cold water flushing outlet valve arranged between the cold water inlet flange and the flushing flange or the hot water inlet flange, so that, if desired, additional cold drinking water can be provided through the flushing flange when such cold drinking water is required, for example, to fill a cistern of a toilet.

[0076] Above, the focus was primarily on cold flushing of the DHW line or line section in the direction of flow of the domestic hot water through the DHW line or DHW line section to be flushed. On the other hand, it is also conceivable to choose the opposite flushing direction, in which case the cold water flush line is preferably located at the ends of the DHW line or DHW line that are connected to the hot water source or a DHW inlet. Feeding of cold drinking water into the drinking water supply arrangement should be provided and these two lines should be connected at this point, which can be done, for example, via appropriate valves in order to be able to meet specific flushing requirements. In this case, it is correspondingly advantageous if the flushing outlet of the DHW line is provided from this end or from the cold water flushing line in the direction of the hot water source in the DHW line, whereby the arrangement of the flushing outlet or a circulation line used for flushing then determines the part of the DHW line that is to be flushed or the DHW Z -line section is defined accordingly.

[0077] If there is no flush outlet in the entire unit, it may be advantageous to provide this flush outlet in the hot water switching unit.

[0078] In particular, the flushing outlet can then be adjusted accordingly, for example, to the Wr The hot water switching unit can be connected or flanged if the hot water switching unit is equipped accordingly.

[0079] In this respect, cumulatively or alternatively to the other feature combinations described here as advantageous, a hot water switching unit which is characterized by a hot water inlet flange and by a hot water pipe partial flange fluidically connected to the hot water inlet flange by a DHW arm, which can be connected optionally to the hot water inlet flange and to a flushing flange fluidically connected to a flushing arm which opens into the DHW arm at an opening, makes it possible to minimize the growth of Legionella with the lowest possible energy and water consumption, wherein a check valve opening in the direction of the flushing flange can preferably be arranged in the flushing arm, which, with a suitable design, can be implemented structurally easily.Such a hot water switching unit enables cold flushing of a DHW pipe section, thus minimizing the growth of Legionella while minimizing energy and water consumption. Installation is also as simple as possible, since the DHW pipe section to be flushed as needed only needs to be connected to the hot water pipe section flange, the flushing flange to a flushing outlet, and the hot water inlet flange to the DHW pipe on the hot water source side in order to enable flushing as needed and to reliably prevent uncontrolled flow in an undesired direction via the check valve. In particular, such a hot water switching unit, unlike the one described in DE 20 2014 105 702 Ul. revealed thermostatic mixer with flushing function extremely flexible and versatile in its use, cost-effective.

[0080] Accordingly, cumulatively or alternatively to the other features which are explained here as advantageous, a flushing switching unit can be characterized by a hot water inlet flange which can be optionally connected to a cold water inlet flange of the flushing switching unit.

[0081] In this way, a cold water flushing line can be opened via the flushing switching unit, if it is installed in a drinking water supply arrangement, which then enables a reverse flushing with cold drinking water if the hot water pipe partial flange is connected to the flushing flange in the hot water switching unit, which can be realized, for example, by a corresponding valve.

[0082] By counterflowing, against the direction of the domestic hot water flow, the flush volume can be minimized if, for example, the temperature at the flush outlet, such as in the hot water switching unit, is measured. This allows the assumption that sufficient cold flushing has occurred if the temperature drops. Counterflow can minimize the water volume if not the entire section of the domestic hot water line or the entire length of the domestic hot water line being flushed has been heated during the domestic hot water drawoff. Counterflow can also reduce energy loss, especially when long domestic hot water lines are frequently flushed with cold water.

[0083] In the DHW line section or in the DHW line to be flushed with cold water as needed, a temperature measurement can be used, for example, by inserting a thermal marker near a flush outlet or on a flush circulation line to determine when and when a flushing process can be completed and, for example, a corresponding valve can be closed again. For this purpose, a target temperature can be specified, for example, via the flushing switching unit.

[0084] Such a target temperature, preset via the flushing switch unit, or a target flushing temperature derived or learned from user behavior, can eliminate the need for an additional permanent connection, such as an electrical signal line. If necessary, a warm-cold transition, such as that which naturally occurs during a cold flush of a domestic hot water line containing domestic hot water at a temperature above 45°C, can be used accordingly, referred to or used as a thermal marker. It is then possible to transmit such flush-stop signals along the domestic hot water lines or, if necessary, the domestic hot water lines without having to lay electrical signal lines or other separate signal lines, such as fiber optic cables, or exchange electromagnetic signals. This can prove particularly advantageous for retrofitting purposes, for example, by minimizing installation effort.

[0085] Pressure signals can be used cumulatively or alternatively for such signal transmissions. For example, a brief opening of a flush line or a flush outlet, which in one advantageous embodiment can be realized, for example, by fast-acting solenoid valves, can be measured as a corresponding pressure signal along drinking water pipes and interpreted accordingly. In this way, for example, a flush switching unit can signal the desire to initiate a flushing process, for example with cold drinking water, so that the hot water switching unit, which receives a corresponding pressure signal or a falling line pressure or a corresponding pressure marker, can provide cold drinking water to the DHW line section or the DHW line to be flushed.

[0086] Accordingly, the hot water switching unit can comprise a control unit which can, for example, control the hot water control valve or the cold water control valve or, if necessary, also another flushing valve provided additionally or alternatively as required.

[0087] The control unit can also include, for example, a request detection system that detects the request for hot drinking water. This can be done, for example, by a pressure sensor. A data input can also be used cumulatively or alternatively. The request detection system can, in particular, be designed to detect the request for flushing water, i.e., cold drinking water, in addition to the request for drinking water. This—as already explained above—can be implemented, for example, by a pressure sensor.

[0088] In particular, a corresponding request recognition can be provided via a data input to the control unit, wherein a corresponding data input can be implemented in particular electromagnetically or by cable.

[0089] On the other hand, the control unit of the hot water switching unit can also be operatively connected to a hot water flushing outlet valve of the drinking water supply system and, for example, issue a flushing signal to the hot water outlet valve. This can also be done via a cable, for example, by directly connecting the hot water flushing outlet valve. controlled by the control unit of the hot water switch unit. Alternatively, electromagnetic signal transmission can also be implemented in this regard. The positions of, for example, mixer tap levers can also be detected wirelessly, so that, for example, domestic hot water is only provided by the hot water switch unit when there is a specific request.

[0090] Insofar as the flushing switching unit is equipped with appropriate signaling technology, a corresponding flushing signal can also be sent from the hot water switching unit to the flushing switching unit in order to, for example, control a hot water flushing outlet valve or, if applicable, a cold water flushing outlet valve, which can possibly also serve for counterflow flushing.

[0091] In particular, the flushing switching unit can cumulatively or alternatively comprise a control unit, which in turn controls or can control, for example, the hot water flushing outlet valve or the cold water flushing outlet valve of the flushing switching unit. If necessary, this control unit of the flushing switching unit can also be used to directly control components of the hot water switching unit or the cold water flushing valve and / or the hot water flushing valve of the drinking water supply arrangement. It is also conceivable for the control unit of the flushing switching unit to act as a master and control a control unit of the hot water switching unit, specifying when normal operation or flushing operation takes place.

[0092] Conversely, the control unit of the flushing switching unit can be designed to receive a flushing signal from a home computer or the hot water switching unit or from a control unit of the hot water switching unit.

[0093] In particular, the flushing switching unit can be signal-connected to a hot water temperature sensor or to a cold water temperature sensor of the flushing switching unit, so that corresponding temperatures previously input to the flushing switching unit or learned by the flushing switching unit can be measured and, if necessary, also passed on as flushing start or flushing stop temperatures or for receiving thermal markers or for other purposes.

[0094] In particular, the DHW line can be fluidically connected to a circulation line, which enables circulation for individual usage lines branching off from a main line, so that domestic hot water can be brought as close as possible to any tapping points at the highest possible temperature. Especially in such In some cases, it may be advantageous to flush at least part of the circulation line with cold water as required, preferably together with the DHW line section, particularly if, for example, the corresponding line is not expected to be used for the extraction of domestic hot water, for example overnight or over a weekend.

[0095] Accordingly, a hot water switching unit can also comprise a circulation inlet flange which can be connected either to a flushing flange of the hot water switching unit or to a cold water inlet flange of the hot water switching unit. This makes it possible to flush the circulation line if the part of the DHW line to be flushed or the DHW line section is supplied with cold drinking water, for example via the cold water flushing line, and the flushing flange is fluidically connected to the circulation inlet flange and this connection to the flushing flange is open, which can be achieved, for example, by a flushing outlet valve which is correspondingly open. If, on the other hand, the circulation inlet flange can be connected to the cold water inlet flange, the DHW line orThe DHW pipe section must be connected to a corresponding flush outlet at a suitable location so that when the connection between the cold water inlet flange and the circulation inlet flange is opened, the cold drinking water provided there can have a flushing effect through the circulation line and the corresponding parts of the DHW line to the flush outlet. This will generally result in the flushing drinking water flowing in the opposite direction to the normal flow of the domestic hot water, thus resulting in the corresponding advantages already explained above.

[0096] In particular, the circulation inlet flange can preferably be fluidically connected to a circulation outlet flange via a circulation arm, so that the corresponding hot water switching unit only needs to be inserted into a circulation line.

[0097] In particular, a circulation valve can be arranged in the circulation arm, via which the circulation can be separated accordingly when flushing is to be carried out.

[0098] The drinking water supply arrangement may comprise at least one utility line branching off from a main line, in each of which a supplementary circulation line is provided, as already indicated above. In this circulation line A flushing outlet can be provided in such a utility line so that at least parts of the corresponding circulation line can also be flushed.

[0099] In particular, this flush outlet can also be opened and closed via a hot water flush outlet valve, so that flushing can be performed as needed. In particular, the hot water flush outlet valve can also be the flush outlet valve of the hot water switching unit, so that the former can be provided in a structurally simple manner.

[0100] Preferably, a circulation valve, in particular a circulation valve arranged in the hot water switching unit, is arranged on the side of the flushing outlet facing the main line in order to prevent backflow of cold drinking water or drinking water displaced during flushing into the main line-side circulation line or even into the hot water source.

[0101] The hot water switching unit can be inserted into the circulation line, in particular via its circulation inlet flange and its circulation outlet flange, which in particular enables easy installation of the corresponding hot water switching unit.

[0102] Depending on the specific implementation, the flushing direction can also be reversed if a cold flush includes the circulation line or parts thereof, as indicated above.

[0103] Particularly when flushing in a different direction, but also when flushing in a different direction, when a circulation line or parts thereof are also to be flushed, it appears advantageous to arrange the mouth of the cold water flush line and the flush outlet as close to each other as possible, for example in a tub water shut-off unit or in a flush switching unit, and to interrupt the short distance between the mouth of the cold water flush line and the flush outlet during flushing, for example by means of a corresponding valve, while the flush outlet is open, also for example by means of a corresponding valve. The cold drinking water provided by the cold water flush line can then drive flushing water to the flush outlet.The location of the cold water flush line outlet and the flush outlet, along with the corresponding valves, can ultimately be anywhere, as long as a corresponding circuit from the cold water flush line to the flush outlet can be maintained. However, an arrangement as close to the main line as possible seems particularly advantageous, regardless of whether the Cold water flushing line flows into the DHW line or into the circulation line, if the flushing outlet then branches off from the other of these two lines, i.e. from the circulation line or the DHW line.

[0104] Fundamentally, the technical capability of flushing a DHW pipe section with cold drinking water supplied via a cold water flush line as needed opens up the possibility of flushing this DHW pipe section with hot water as needed, since ultimately only the corresponding flush outlet needs to be opened and the control option for providing either cold drinking water or hot drinking water can be used accordingly. This then makes it possible to make this DHW pipe section hot or cold as needed. For example, after hot drinking water has been drawn from the DHW pipe section via a draw-off point, which can be detected, for example, by pressure and temperature sensors, it can be flushed with cold water, so that this DHW pipe section can then remain cold for an extended period.On the other hand, it is conceivable that, as a result of an external signal, such as a presence sensor, or based on other specifications, such as a time signal, the DHW line is flushed with hot water and thus also heated, so that domestic hot water is immediately available for use at the point of use without delay. Circulation systems can also, as already mentioned above, be flushed with cold or warm water, or heated or cold, as needed, if this seems advantageous or sensible. This applies in particular to circulation systems arranged in series or parallel.

[0105] It is understood that the features of the solutions described above or in the claims can also be combined if necessary in order to be able to implement the advantages cumulatively.

[0106] Further advantages, objects, and features of the present invention will become apparent from the following description of exemplary embodiments, which are particularly illustrated in the accompanying drawings. In the drawings: Figure 1 shows a first drinking water supply arrangement in a schematic representation; Figure 2 shows a schematic representation of a first hot water switching unit usable in the drinking water supply arrangement according to Figure 1; Figure 3 shows a schematic representation of a first flushing switching unit usable in the drinking water supply arrangement according to Figure 1; Figure 4 shows a schematic representation of a second hot water switching unit usable in the drinking water supply arrangement according to Figure 1; Figure 5 shows a schematic representation of a second flushing switching unit usable in the drinking water supply arrangement according to Figure 1; Figure 6 shows a schematic representation of a third hot water switching unit usable in the drinking water supply arrangement according to Figure 1; and Figure 7 shows a schematic representation of a third flushing switching unit usable in the drinking water supply arrangement according to Figure 1; Figure 8 shows a fourth hot water switching unit in a schematic representation; and Figure 9 shows a second drinking water supply arrangement in a schematic representation.

[0107] The drinking water supply arrangement 10 described by way of example in Figure 1 comprises a TWK (cold drinking water) line 80 and a TWW (hot drinking water) line 70, which are fed by a TWK (cold drinking water) feed 82 in a manner known per se.

[0108] Such drinking water supply arrangements 10 are well known in the art and typically comprise a main line 18, from which at least one utility line 19A, 19B, 19C branches off. In the present exemplary embodiment, three utility lines 19A, 19B, 19C branch off from the main line 18 to corresponding utility units. Depending on the specific embodiment and in particular depending on the capacity of the drinking water supply 82, multiple main lines 18 may also be provided.

[0109] To supply the domestic hot water line 70 with domestic hot water, the domestic hot water inlet 82 not only flows into the domestic hot water line 80, but also into a hot water source 11, which in this embodiment is designed as a heatable hot water tank. Any type of hot water source can be provided at this point, such as instantaneous water heaters, solar thermal systems, or heat pumps, possibly with additional electric heating, or a gas boiler.

[0110] Drinking water can be supplied to the drinking water supply arrangement 10 via withdrawal points 12, which, depending on requirements, include hot water demand valves 13 (numbered only as an example) and cold water demand valves 14 (numbered only as an example). in particular hot drinking water, cold drinking water or mixtures thereof.

[0111] If necessary, a sufficiently well-known increase in water pressure can also be provided, for example by appropriately arranged pumps.

[0112] In the present embodiment, the extraction points 12 are each provided in the usage lines 19A, 19B, and 19C, so that, if necessary, a separate usage calculation for the respective usage unit could also be carried out via separate and known individual meters (not shown here). Likewise, common extraction points 12 can be provided, which are fed directly from the main line 18.

[0113] In alternative embodiments, the main line 18 and the utility lines 19A, 19B, 19C may also be further branched. It is also conceivable that in alternative embodiments, several hot water sources 11 are provided in parallel, which may also supply separate main lines 18 with domestic hot water, especially if the capacity of the domestic hot water supply 82 is sufficient for this purpose.

[0114] Depending on the specific implementation, the main lines 18 and utility lines 19A, 19B, 19C can run horizontally or vertically, which ultimately depends on the arrangement of the extraction points 12, the TWK feed 82 and the hot water source 11 or the hot water sources 11.

[0115] In particular, the drinking water supply arrangement 10 shown as an example in Figure 1 can be provided for a three-story building, for example, in which the main line 18 runs vertically and the respective utility lines 19 for each floor run horizontally and the hot water source 11 and the TWK feed 82 are arranged in the basement.

[0116] When a hot water demand valve 13 of the usage lines 19B and 19C located further away from the hot water source 11 is requested, there may be waiting times until the hot water from the hot water source 11 reaches the respective draw-off point 12 and until appropriately tempered hot water is available at this draw-off point 12. To avoid this disadvantage, a circulation line 15 is provided, which branches off from the DHW line 80 at a branch 16 near the usage line 19C and is returned via a circulation pump 17 to the Hot water source 11, so that in the part of the DHW line 80 and the circulation line 15 extending from the hot water source 11 to the branch 16, a domestic hot water circulation can be maintained through the hot water source 11, which ensures that in the part of the DHW line 80 which lies between the hot water source 11 and the branch 16 of the circulation line 15, sufficiently tempered domestic hot water is constantly available.

[0117] For example, it can be ensured that the temperature in this circulation does not fall below 55°C by switching on the circulation pump 17 at regular intervals or depending on a temperature measurement.

[0118] In this way, it can be ensured for each of the usage lines 19A, 19B, 19C that sufficiently tempered domestic hot water is available at the associated branches 16A, 16B, 16C of the DHW line 80 to the individual usage lines 19A, 19B, 19C, so that the time until this then reaches the withdrawal points 12, which may request domestic hot water, can be kept sufficiently short.

[0119] While the circulation due to the circulation line 15 and the circulation pump 17 in the part of the DHW line 80 belonging to the circulation can maintain a sufficiently high temperature of the domestic hot water, which can limit or prevent the growth of Legionella, the parts of the DHW line 70 extending into the service lines 19A, 19B, 19C, or the DHW line sections 71 of the service lines 19A, 19B, 19C, respectively, heat up again with each demand for domestic hot water, only to then cool down again as long as no further domestic hot water is pumped. Therefore, the drinking water in these line sections frequently passes through a temperature range conducive to the growth of Legionella, so that flushing these line sections is considered advantageous, as is also known from the prior art.For example, it is known to provide warm water flush outlet valves 93 at the ends of service lines facing away from the main line 18, which correspond to service lines 19A, 19C. These flush outlet valves end in flush outlets 95, which may, for example, also end in a toilet cistern 92 of a toilet 91. Corresponding embodiments are shown by way of example in Figure 1 in service lines 19A and 19C.

[0120] For example, the flushing outlet 95 of the usage line 19A can open into a siphon below the withdrawal point 12 provided at the end of the usage line 19A. which may also apply to the flush outlets 95 of the service lines 19B, 19C. In other embodiments, it is known to lead such a flush outlet 95, for example, into a floor drain. Likewise, DE 10 2004 033 770 A1, DE 10 2019 107 179 A1, DE 20 2013 104 471 U1, and DE 10 2018 208 662 A1 disclose the possibility of allowing the flush outlet to open into a toilet cistern 92, in which case a supplementary cold water flush outlet valve 94 may be provided, by means of which the toilet cistern 92 may be completely filled if the flushed-out hot drinking water is insufficient to fill it. The same is also provided for the service line 19C of the exemplary embodiment according to Figure 1.

[0121] If necessary, the TWK line 80 can also be flushed via the cold water flushing outlet valve 94, for example to carry out a water exchange recommended for drinking water hygiene reasons or to specifically reduce the temperature in the TWK line 80 or parts thereof.

[0122] While according to the prior art, flushing of the DHW line sections 71, which flow into the usage lines 19A, 19B, 19C, leads to a renewed supply of high-temperature domestic hot water, in the present case a cold water flushing line 81 is provided, which flows between the extraction points 12 of the usage lines 19A, 19B, 19C and the associated branches 16A, 16B, 16C of the DHW line 80 to these usage lines 19A, 19B, 19C from the DHW line 80 into the DHW line sections of these usage lines 19A, 19B, 19C.

[0123] These cold water flushing lines 81 can be selectively opened, as will be explained below by way of example, so that if a flushing process known per se from the prior art for flushing with hot drinking water takes place, flushing can also be carried out with cold drinking water instead.

[0124] Insofar as this technical option, i.e., cold flushing or flushing with cold drinking water, is provided, it is advantageous that after a request for hot drinking water, the system is flushed with cold drinking water, so that the critical temperature range in which Legionella prefers to grow is only crossed for a very short time. It is understood that cold flushing is not absolutely necessary immediately after every request. If necessary, flushing can be carried out at an appropriate time, for example, when the If the temperature in the associated pipe sections drops too much or for too long due to a lack of demand for hot drinking water, it must first be initialised so that the consumption of drinking water can be minimised as much as possible.

[0125] By connecting the cold water flushing lines 81 to the DHW line 70, DHW line sections 71 can be defined, which extend from this opening to the ends of the respective usage lines 19A, 19B, 19C and, if a cold flush is to be carried out, can then also be flushed cold.

[0126] Any remaining pipe sections located between the mouth of the cold water flushing pipes 81 and the branches 16A, 16B, 16C are so small in size and are flushed with high-temperature hot water each time the corresponding utility line 19A, 19B, 19C is required, so that the risk of excessive Legionella infestation due to these pipe sections can be classified as low.

[0127] Finally, the above-described process sequence for cold flushing of the DHW line sections 71 or the parts of the DHW line 70 to be flushed in the individual utility lines 19A, 19B, 19C can be implemented manually or by individually installed components, such as corresponding valves and, if necessary, associated sensors and controls.

[0128] However, due to the expected installation effort, it may be advantageous to provide a hot water switching unit 20, as shown by way of example in Figure 2.

[0129] This hot water switching unit 20 comprises a hot water inlet flange 31 and a hot water pipe partial flange 33, which are fluidically connected to one another via a DHW (domestic hot water) arm 30, as well as a cold water inlet flange 42, which is fluidically connected to a cold water flush arm 40 and opens into the DHW arm 30 at an opening 49. Such a hot water switching unit 20 ensures that it can be inserted into the DHW line 70 with its water inlet flange 31 and the hot water pipe partial flange 33, so that domestic hot water can flow as desired. It is then also sufficient to simply connect the cold water flush line 81 to the cold water inlet flange 42, so that, if the associated fluidic actuators are arranged in the hot water switching unit 20, cold flushing is also easily possible as needed. The installation effort can be reduced to a minimum.

[0130] The respective flanges 31, 42, 33 are shown in Figure 2 by way of example as conventional flanges with flange rings, whereby these flanges 31, 42, 33 and also all other flanges shown here can be shaped according to specific requirements so that they can be connected in a suitable manner to the associated pipes, whereby in this regard all installation types known for drinking water supply regulations 10 can be used depending on the specific requirements.

[0131] A cold water control valve 46 is arranged in the cold water flush arm 40, which serves as a cold water flush valve 45 and can provide cold drinking water by opening and closing at the mouth 49.

[0132] Likewise, a hot water control valve 36 is provided in the DHW arm 30 between the orifice 49 and the hot water inlet flange 31, by means of which the flow through the DHW arm 30 to the orifice 49 can be controlled. This hot water control valve 36 serves here as a hot water flush valve 35.

[0133] In the present embodiment, the control valves 36, 46 are each driven by an electric motor. Depending on the specific implementation, other drive mechanisms may also be provided for these control valves 36, 46.

[0134] In this embodiment, the orifice 49 can be realized by a passive coupling in the form of a T-piece, since ultimately all control processes can be implemented by the control valves 36, 46. In an alternative implementation, suitable directional control valves, in particular discretely, i.e., non-proportionally, controlled or configured directional control valves, can be used at the orifice.

[0135] In the present embodiment, the control valves 36, 46 or, if applicable, a corresponding directional control valve are controlled via a control unit 21, which is also provided in the hot water switching unit 20.

[0136] To avoid undesired backflows, a check valve 34 is arranged in the DHW arm 30, preferably between the hot water inlet flange 31 and the hot water control valve 36, and a check valve 44 is arranged in the cold water flushing arm 40, preferably between the cold water inlet flange 42 and the cold water control valve 46.

[0137] For monitoring and control purposes, a DHW arm temperature sensor 22 and a DHW arm pressure sensor 28 are arranged in the DHW arm 30, preferably between the orifice 49 and the hot water control valve 36.

[0138] In particular, the DHW arm pressure sensor 28 can be used, for example, to detect a demand for domestic hot water based on a change in pressure, for example, if an unusually high pressure drop is recorded during a cold flush, which exceeds the pressure drop that occurs during flushing. In such a case, the control unit 21 can then close the cold water control valve 46 or the cold water flush valve 45 and release the hot water control valve 36 or the hot water flush valve 35 accordingly. Such a DHW arm pressure sensor 28 is accordingly advantageous in fluidic contact with a hot water pipe flange 33 of the hot water switching unit 20, regardless of the other specific configuration of the hot water switching unit 20.

[0139] The DHW arm temperature sensor 22 can be used to monitor the temperature profile of the DHW arm 30 and thus also of the DHW line 70 in the vicinity of the hot water switching unit 20. If this temperature falls below a given value, a cold flush of the DHW line section 71 can be initiated—possibly after a certain time.

[0140] In the present embodiment of the hot water switching unit 20, a TWK (cold drinking water) arm temperature sensor 23 is also arranged in the cold water flush arm 40, which can also be omitted if necessary. This TWK arm temperature sensor 23 can also be used for monitoring purposes. If necessary, its monitoring function can also serve only special purposes. For example, the aforementioned flush target temperatures or thermal markers can be monitored in their respective configurations. Thus, the corresponding hot water switching unit 20 can be used in a variety of ways or is only used in special cases, for example, when flush circulation is to be used for cold flushing.

[0141] Insofar as the control unit 21 is now enabled, for example via corresponding signal lines or corresponding control lines, to directly control the hot water flush outlet valves 93 or the cold water flush outlet valves 94. With suitable wiring or programming of the control unit 21, the hot water switching unit 20 can be enabled to carry out cold flushing as required or in accordance with requirements.

[0142] However, insofar as several trades, such as plumbing and electrical installers, may need to be involved, it may prove advantageous to also provide a flush switching unit 50, which in turn comprises a control unit 51 that can communicate, for example, via an electrical signal line or via electromagnetic signals with the control unit 21 of the hot water switching unit 20. Corresponding signal connections can generally be established by untrained personnel or even set up automatically if appropriate programming is available.

[0143] Such a flushing switching unit 50 is shown as an example in Figure 3.

[0144] The flushing switching unit 50 shown as an example in Figure 3 comprises a hot water inlet flange 61, a cold water inlet flange 62, and a flushing flange 63. The hot water inlet flange 61 is connected via a domestic hot water (TWW) arm 64 to a flushing arm 66, which in turn opens into the flushing flange 63. A cold water flushing arm 65 opens at the connection between the hot water inlet flange 61 and the flushing arm 66, which is fluidically connected to the cold water inlet flange 62. The connection is made as a passive coupling 67 in the form of a T-piece.

[0145] To enable flushing as needed, the flush switching unit 50 includes a hot water flush outlet valve 55, which can be selectively opened and closed by the control unit 51 to initiate flushing. It is understood that in alternative embodiments, the control unit 21 of the hot water switching unit 20 can also directly address the hot water flush outlet valve 55.

[0146] As is immediately apparent, the cold water flush arm 65 and / or the cold water inlet flange 62 can be omitted if a supplementary supply of cold drinking water does not appear necessary for the current use of this flushing switch unit 50. This can be particularly the case if the flushing of the drinking water lines is already ensured by another means, which can be carried out in a planned manner, for example, by self-flushing fittings.

[0147] However, if the flush switching unit 50 is to be connected, for example, to a toilet cistern 92 or to other devices which can also be sufficiently supplied with cold drinking water, which can also be a washing machine, for example, it proves to be advantageous to also provide a cold water flush outlet valve 56 in the flush switching unit 50 so that cold drinking water can be made available optionally, which can preferably also be done via the control unit 51 or, if necessary, also via an external control unit, such as the control unit 21 of the hot water switching unit 20.

[0148] For example, it is conceivable that the cold water flush outlet valve 56 is constantly open and is only closed during cold flushing, while the hot water flush outlet valve 55 is constantly closed and is only opened during flushing.

[0149] Depending on the specific implementation, some or all of the valves of this flushing switching unit 50 can also be replaced by a suitable directional control valve, in particular by a discrete or discretely controlled directional control valve, which can be provided instead of the passive coupling 67.

[0150] To avoid undesired backflows, check valves 54 are provided in the arms 64, 65, 66 of the flushing switching unit 50, this preferably being the case on the flange side of the respective arms 64, 65, 66.

[0151] In addition, the flushing switching unit 50 also has a hot water temperature sensor 52, which is arranged in the DHW arm 64. This hot water temperature sensor 52 can, for example, detect the arrival of cold drinking water at the flushing switching unit 50, which can be evaluated as a thermal marker or by which it can be recognized that sufficient flushing has taken place. The cold temperature sensor 23 of the hot water switching unit 20 can, if necessary, measure a temperature and the hot water switching unit 20 can, by means of a switching or active connection, pass on the information as to the temperature range in which the TWK of the flushing is to be expected to the flushing switching unit 50. On the other hand, it is conceivable that a corresponding evaluation or information processing of the detection of a flushing target temperature orsuch a thermal marker in the hot water switching unit 20, so that the flushing switching unit 50 merely receives corresponding information and then, if necessary, receives and executes instructions on how to react, for example, to the thermal marker.

[0152] If necessary, it can be provided that the cold flushing takes place for a little longer, even if the thermal marker has already reached the flushing switching unit 50, in order to ensure that the corresponding DHW line 70 or the DHW line section 71 has also cooled down accordingly in its material boundary, for example with its pipe wall.

[0153] The flushing switching unit 50 also includes a cold water temperature sensor 53, which, however, is not mandatory. However, a corresponding cold water temperature sensor 53 may be useful in special cases, such as when circulation is used for cold flushing or other special applications, so it may be quite expedient to already have this cold water temperature sensor 53 in the flushing switching unit 50.

[0154] It has already been indicated above that the DHW arm pressure sensor 28 can be used to detect certain situations, such as domestic hot water requirements or flushing processes, so that the hot water switching unit 20 can react accordingly.

[0155] Particularly in retrofitting situations in which flushing is provided at the ends of the utility lines 19A, 19B, 19C facing away from the main line 18, the hot water switching unit 20 can serve as a slave if it can distinguish between a flushing process and a request for domestic hot water via the different pressure drops.

[0156] Additionally, the pressure in the TWK line 80 can also be monitored for this purpose if necessary. Ultimately, any pressure sensor found in the TWK line 80 can be used for this purpose. However, it may also be advantageous to place this pressure sensor close to the switching event, since excessive distances to the pressure event could flatten the pressure flanks or weaken the pressure amplitudes due to material elasticities. [ 157| On the other hand, it is also possible to provide a TWK arm pressure sensor 29 in the hot water switching unit 20 in its cold water flushing arm 40, as shown by way of example in Figure 4, so that pressure changes in the TWK- Line 80 can be monitored or recorded. In this way, the demand behavior in the respective usage line 19A, 19B, 19C can be monitored in more detail in order to be able to initiate a cold flush at the most appropriate times if necessary.

[0158] In particular, it is conceivable to design the control unit 21 to be self-learning for this purpose or, if necessary, to link it information-technically with one or more central processing units which are designed to be self-learning in order to carry out the cold rinsing at the most advantageous times possible.

[0159] When retrofitting a hot water switching unit 20, it may prove particularly difficult to provide communication with hot water flush outlet valves 93 or cold water flush outlet valves 94 that are already permanently installed. This can be particularly difficult if electrical cables need to be laid.

[0160] The same applies to subsequently installed flushing switching units 50 if electromagnetic communication with the hot water switching unit 20 does not appear possible. Communication can be enabled via temperature sensors or pressure sensors, particularly within a utility line 19A, 19B, 19C, without the need for electrical or electromagnetic communication means.

[0161] Accordingly, a flushing switching unit 50, as shown by way of example in Figure 5, can also have a DHW arm pressure sensor 68 or a cold water pressure sensor 69. This also enables an evaluation of corresponding demand pressure signals, which, in particular, if necessary in conjunction with a corresponding hot water switching unit 20 and communication of the associated control units 21, 51 or through the evaluation in a central control unit, enables detailed statements about the respective requirement profile in the associated usage line 19A, 19B, 19C.

[0162] Even with such a flushing switching unit 50, self-learning effects, for example of the control unit 51 of the flushing switching unit 50, the control unit 21 of the hot water switching unit 20 or other control units, can be used to optimize the accuracy of the respective reactions to pressure and temperature changes depending on the respective usage lines 19A, 19B, 19C and the individual behavior of the respective users.

[0163] While the cold water pressure sensor 69 of the embodiment shown in Figure 5, as well as the TWK arm pressure sensor 29 of the embodiment shown in Figure 4, are each arranged on the side of the associated flange, i.e. on the side of the cold water inlet flange 42 or cold water inlet flange 62, the TWW arm pressure sensor 68 of the flush switching unit 50 shown in Figure 5 is located on the side of the TWW arm 64 of the hot water inlet flange 61 facing away from the hot water flush outlet valve 55. Depending on the specific requirements, it may also be expedient to provide the TWW arm pressure sensor 68 directly behind the hot water inlet flange 61, i.e., for example, in front of the check valve 54 and in front of the hot water flush outlet valve 55.

[0164] The DHW arm pressure sensor 28 can also be arranged between the orifice 49 and the hot water pipe flange 33 instead of directly behind the hot water control valve 36 if this appears to be advantageous from a measurement point of view.

[0165] It is also conceivable to carry out the cold flushing against the normal flow direction of the domestic hot water through the part of the domestic hot water line 70 to be flushed or through the domestic hot water line section 71, for which purpose the arrangements shown in Figures 6 and 7, i.e. the hot water switching unit 20 according to Figure 6 or the flushing switching unit 50 according to Figure 7, are particularly designed.

[0166] For this purpose, the hot water switching unit 20 additionally comprises a flushing flange 43, which is connected to the cold water flushing arm 40 via a check valve 38 and a flushing outlet valve 37, each provided in a flushing arm 41. The connection can also be made at the outlet 49 or at another location in the DHW arm 30 if necessary. In particular, the line section of the cold water flushing arm 40, which lies between the connection of the flushing arm 41 to the cold water flushing arm 40 and the outlet 49, can also be considered part of the flushing arm 41 or as part of both the cold water flushing arm 40 and the flushing arm 41. Depending on the specific implementation, the cold water flushing arm 40 and the associated cold water inlet flange 42 can also be dispensed with in this hot water switching unit 20, since ultimately, with this implementation, cold drinking water can be supplied from the flushing switching unit 50.On the other hand, leaving these assemblies in place allows the flexibility of use of this hot water switching unit 20 to be increased.

[0167] In this embodiment, the orifice 49 is also implemented by a passive coupling, whereby suitable directional control valves, in particular discrete or discretely controlled directional control valves, can also be used at this point if necessary.

[0168] If a cold flush is to be initiated, the flush outlet valve 37 of the hot water switching unit 20 is opened, while the hot water control valve 36 and the cold water control valve 46 are closed. Any cold drinking water, which is now available at the end of the respective utility line 19A, 19B, 19C facing away from the main line 18, can be guided through the hot water pipe partial flange 33 to the flush flange 41, where it can then be discharged via a correspondingly connected flush outlet (not explicitly shown here).

[0169] A corresponding backflow can also occur, for example, through the flushing switching units 50, as shown in Figures 3 and 5, if a valve is added to their flushing arm 66, which prevents unwanted outflow through the flushing flange 63 of these flushing switching units 50, as long as the counterpressure of the check valve 54 present in the flushing arm 66 is insufficient for this purpose. For safety reasons, an additional valve that performs a corresponding blocking function appears advantageous in any case.

[0170] In a structurally simple manner, the flushing switching unit 50, as shown in Figure 7, can realize a corresponding backflow by simply opening the cold water flushing outlet valve 56 when flushing is required. Particularly with such a simple design, it is conceivable that the cold water flushing outlet valve 56 is controlled directly by the control unit 21 of the associated hot water switching unit 20, i.e., in particular, by the hot water switching unit 20 according to Figure 6, which, as provided in the present exemplary embodiment, can be done via the control unit 51 using information technology, in particular via electromagnetic signals.

[0171] However, if a control line can be laid directly, the control unit 21 of the hot water switching unit 20 or a central control unit can directly address the cold water flush outlet valve 56, for example via an electrical line, so that a separate molded flush switching unit 50 can be dispensed with, since in such a case ultimately only the cold water flush outlet valve 56 is connected to a cold water flush line 81 provided at the end of the respective usage line 19A, 19B, 19C, which The DHW line 80 must be used to connect the DHW line 70 or the DHW line section 71. For safety reasons, the check valve 54 should also be provided in the cold water flush arm 65 to reliably prevent unwanted crosstalk of domestic hot water from the DHW line 70 into the DHW line 80.

[0172] To further increase comfort, circulation can also be provided in the utility lines 19A, 19B, 19C, as shown by way of example in Figure 9. Here, the extraction parts 12 and thus the essential structure of the drinking water supply arrangement 10 according to Figure 9 correspond to the embodiment shown in Figure 1.

[0173] However, circulation lines 15A, 15B, 15C are provided for each usage line 19A, 19B, 19C, which in particular makes it possible to dispense with flush switching units 50, flush outlets 95 and hot water or cold water flush outlet valves 93, 94, which lead into toilets 91 or similar.

[0174] On the other hand, with such a configuration, it may be advantageous to also flush the circulation lines 15A, 15B, 15C of the individual utility lines 19A, 19B, 19C with cold water, especially if longer downtimes are expected, for example, overnight or over a weekend, or even longer periods, such as in barracks. This allows energy losses to be avoided or minimized.

[0175] For such cold rinsing, the hot water switching unit 20A shown in Figure 8 can be provided, for example, which additionally has a circulation inlet flange 26 and a circulation outlet flange 27, which are connected to one another via a circulation arm 25.

[0176] In the circulation arm 25, a circulation valve 39 is also provided, which can be driven by a motor.

[0177] Between the circulation inlet flange 26 and the circulation valve 39, a branch to the flushing flange 43 is provided, which thus, unlike in the embodiment according to Figure 6, is not in direct fluidic connection with the DHW arm 30.

[0178] By closing the circulation valve 39 and the hot water control valve 36 on the one hand and by opening the flushing outlet valve 37 and the cold water control valve 46, a cold flushing of the DHW line section 71 and the respective circulation line 15A, 15B, 15C from the cold water flushing line 81 to the flushing flange 43 and to a flushing outlet 95 attached thereto, if desired. It is also possible, in a fluidic circuit not explicitly shown here, to carry out the cold flushing of one or all of the circulation lines 15A, 15B, 15C in the opposite direction to the normal flow direction.

[0179] This flushing process can be monitored, if necessary, by the circulation arm temperature sensor 24 or by the DHW arm temperature sensor 22, whereby one of these temperature sensors 22, 24 can also be omitted to avoid redundancies. List of reference symbols: 10 Drinking water supply arrangement 35 21 Control unit 11 Hot water source 22 DHW arm temperature sensor 12 Tapping point 23 TWK arm temperature sensor 13 Hot water demand valve 1 24 Circulation arm temperature sensor (exemplary number) 25 circulation arm 14 Cold water demand valve 40 26 Circulation inlet flange (exemplary number) 27 Circulation outlet flange 15 Circulation line 28 DHW arm pressure sensor 15A circulation line for the 29 TWK arm pressure sensor Usage line 19A 15B Circulation line for the 45 30 DHW arm Usage line 19B 31 hot water inlet flange 15C circulation line for the 33 hot water pipe flange Usage line 19C 34 check valve 16 Branch of the circulation line 15 35 Hot water flush valve from the DHW line 80 so 36 Hot water control valve 16A Branch of the DHW line 80 to 37 Flush outlet valve the utility line 19A from the 38 Check valve DHW line 80 39 Circulation valve 16B Branch of the DHW line 80 to the utility line 19B from the 55 40 Cold water flush arm DHW line 80 41 Flush arm 16C Branch of the DHW line 80 to 42 Cold water inlet flange the utility line 19C from the 43 Flushing flange DHW line 80 44 Check valve 17 Circulation pump so 45 Cold water flush valve 18 Main line 46 Cold water control valve 19A Usage line 49 Mouth of the cold water flush arm 19B Utilization line 40 into the DHW arm 30 19C usage line 65 50 Flushing switching unit 20 Hot water switching unit 51 Control unit 20A hot water switching unit 52 hot water temperature sensor 53 Cold water temperature sensor 15 54 Rucks chl ag ve nt il 70 TWW line 55 Hot water flush outlet valve 71 DHW pipe section 56 Cold water flush outlet valve 80 TWK line 61 Hot water inlet flange 20 81 Cold water flushing line 62 Cold water inlet flange 82 TWK feed 63 Flushing flange 64 DHW arm 91 Toilet 65 Cold water flush arm 92 Toilet cistern 66 Flush arm 25 93 Hot water flush outlet valve 67 passive coupling 94 cold water flush outlet valve 68 DHW arm pressure sensor 95 flush outlet 69 Cold water pressure sensor

Claims

Patent claims:

1. A method for providing drinking water via a DHW line (70) and a DHW line (80) at a withdrawal point (12), characterized in that at least one DHW line section (71) constituting part of the DHW line (70) is flushed with cold water as required.

2. Provision method according to claim 1, characterized in that the DHW line part (71) is rinsed with cold water after the withdrawal of domestic hot water.

3. Provision method according to claim 1 or 2, characterized in that the cold flushing is carried out using cold drinking water from the TWK line (80) and / or that the cold flushing is carried out until the hot drinking water present in the TWW line section (71) is replaced by cold drinking water in a defined quantity at a flushing outlet (95) or at the withdrawal point (12).

4. Provision method according to one of claims 1 to 3, characterized in that the DHW line is fluidically connected to a circulation line (15, 15A, 15B, 15C) and at least a part of the circulation line (15, 15A, 15B, 15C) is cold-flushed as required, preferably together with the DHW line part (71).

5. Provision method according to one of claims 1 to 4, characterized in that a thermal marker, preferably as a hot-cold transition or as a cold-warm-cold transition, is introduced into the DHW line section (71) to be flushed cold as required.

6. Hot water switching unit (20.20A), characterized by a hot water inlet flange (31) and by a hot water pipe part flange (33), which can each be connected optionally to the hot water inlet flange (31) and to a cold water inlet flange (42) of the hot water switching unit (20.20A) and / or to a flushing flange (43) of the hot water switching unit (20.20A).

7. Hot water switching unit (20, 20A) according to claim 6, characterized by a hot water control valve (36) arranged between the tub water inlet flange (31) and the hot water pipe part flange (33) and / or by a Cold water control valve (46) arranged between cold water inlet flange (42) and hot water pipe flange (33).

8. Hot water switching unit (20, 20A) according to claim 6 or 7, characterized by a hot water control valve (36) and / or the cold water control valve (46) controlling and / or receiving or outputting a flushing signal and / or connected to a Demand detection of the hot water switching unit (20,20A), which detects the demand for drinking water and / or cold drinking water, signal-connected control unit (21).

9. Hot water switching unit (20, 20A) according to one of claims 6 to 8, characterized by a circulation inlet flange (26) which can be connected selectively to a flushing flange (43) of the hot water switching unit (20, 20A) or to a cold water inlet flange (42) of the hot water switching unit (20, 20A), wherein the circulation inlet flange (26) is preferably fluidically connected via a circulation arm (25) to a circulation outlet flange (27), in which in particular a circulation valve (39) is arranged.

10. Flushing switching unit (50), characterized by a hot water inlet flange (61) which can be optionally connected to a cold water inlet flange (62) of the flushing switching unit (50) and / or to a flushing flange (6.3) of the flushing switching unit (50).

11. Flushing switching unit (50) according to claim 10, characterized by a hot water flushing outlet valve (55) arranged between the hot water inlet flange (61) and the flushing flange (63) and / or by a cold water flushing outlet valve (56) arranged between the cold water inlet flange (62) and the flushing flange (63) and / or the hot water inlet flange (61).

12. Flushing switching unit (50) according to claim 10 or 11, characterized by a control unit (51) which preferably controls the hot water flushing outlet valve (55) and / or the cold water flushing outlet valve (56) and / or receives or outputs a flushing signal and / or is signal-connected to a hot water temperature sensor (52) and / or cold water temperature sensor (53) of the flushing switching unit (50).

13. Drinking water supply arrangement (10) with at least one hot water source (11), with at least one withdrawal point (12), with at least one DHW line (70) connecting the hot water source (11) to the withdrawal point (12) and with at least one hot water demand valve (13) arranged between the DHW line (70) and the withdrawal part (12) and with at least one DHW line (80), characterized in that a cold water flushing line (81) is arranged between the DHW line (80) and the DHW line (70) and provides cold drinking water to the DHW line (70) and opens into the DHW line (70). Drinking water supply arrangement (10) according to claim 13, characterized in that the cold water flushing line (81) is connected to the DHW line (70) via a cold water flushing valve (45) and / or that a cold water flushing valve (45) and / or a check valve (44) are arranged in the cold water flushing line (81) and / or that a hot water flushing valve (35) is arranged on the side of the mouth of the cold water flushing line (81) into the DHW line (70) facing away from the hot water demand valve (13).

15. Drinking water supply arrangement (10) according to claim 13 or 14, characterized in that the cold water flushing line (81) opens between the hot water demand valve (13) and a branch (16) of a circulation line (15) from the DHW line (70) or a branch (16A, 16B, 16C) of the DHW line (70) into a usage branch (19A, 19B, 19C) in the DHW line (70).

16. Drinking water supply arrangement (10) according to one of claims 13 to 15, characterized in that the DHW line (70) has a flushing outlet (95) which can preferably be opened and closed via a hot water flushing outlet valve (93). Drinking water supply arrangement (10) according to claim 16, characterized in that the drinking water supply arrangement (10) comprises the flushing switching unit (50) according to one of claims 10 to 12, wherein the flushing switching unit (50) is connected via its hot water inlet flange (61) to the DHW line (70), via its cold water inlet flange (62) to the DHW line (80) and via its flushing flange (63) to the flushing outlet (95), wherein the hot water flushing outlet valve (55) of the Flushing switching unit (50) is preferably the hot water flush outlet valve (93) of the drinking water supply arrangement (10).

18. Drinking water supply arrangement (10) according to one of claims 13 to 17, characterized in that the drinking water supply arrangement (10) comprises at least one utility line (19A, 19B, 19C) branching off from a main line (18) with a circulation line (15A, 15B, 15C), in which a or the flushing outlet (95), which can preferably be opened and closed via a hot water flushing outlet valve (93), is provided, wherein preferably a circulation valve (39) is provided on the line (18) facing the side of the flush outlet (95).

19. Drinking water supply arrangement (10) according to claim 18 with the hot water switching unit (20A) according to claim 9, characterized in that the hot water switching unit (20A) is integrated into the circulation line (15A, 15B, 15C) via its circulation inlet flange (26) and its circulation outlet flange (27).

20. Drinking water supply arrangement (10) according to one of claims 13 to 19, characterized in that the drinking water supply arrangement (10) comprises the hot water switching unit (20.20A) according to one of claims 6 to 9, wherein the hot water switching unit (20.20A) is inserted into the DHW line (70) via its hot water inlet flange (31) and its hot water line part flange (33) and into the cold water flush line (81) via its cold water inlet flange (42).

21. Drinking water supply arrangement (10) according to claim 20 with the hot water switching unit (20, 20A) according to one of claims 7 to 9, characterized in that the cold water flush valve (45) is the cold water control valve (46) and / or that the hot water flush valve (35) is the hot water control valve (36). Drinking water supply arrangement (10) according to claim 20 or 21 with the hot water switching unit (20, 20A) according to claim 8 or 9, characterized in that the control unit (21) of the hot water switching unit (20, 20A) is operatively connected to the hot water flush outlet valve (93).

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