Hot water supply in modern world is an integral part of comfort. Proper organization water supply systems will not only provide comfort, but also save money on installation and operation.

Hot water systems

When arranging a water supply system, it is necessary to take into account that there are two completely opposite connection methods. This is an open (open, dead-end) and closed (closed, ring) layout of pipelines and equipment. Moreover, the second option is much more popular than the first. This is due to the possibility of adjustment and complete control over the condition of the water and its temperature.

The open scheme has been used less and less in recent years. The reason was its complete organizational lag behind advanced technologies and user needs. Although, it is worth recognizing, at the cost of direct installation open system much cheaper.

When choosing an open scheme, you should adhere to a detailed technically and economically sound design. In addition, the arrangement of such systems has high requirements for technical specifications coolant, which will also be used as hot water. An open hot water supply system has proven itself best in small networks, or under conditions where the resource is constantly being dismantled.

When installing such a system, you should first of all take into account the principle of operation. In fact, the water that is heated for the heating system is supplied to dismountable points (mixers). This results in one general outline. Technologically, it looks like supply and return pipelines with the arrangement of any type of water heater (electric, solid fuel, gas). Constant pressure in such a network is achieved exclusively hydraulically ( hot water squeezes out the cold one, gradually cools down, becomes cold and then squeezes out a new volume of hot water).

This simplicity is considered one of the advantages of an open circuit. An open hot water supply system is beneficial due to the maximum level of thermal energy transfer at very low coolant costs. Also, such equipment has a low price, because there is no need to install additional pumps, heat exchangers, expansion tanks, etc. And the absence of all this makes for easy operation during the winter and inter-heating periods.

In addition, an important factor is more low level final costs of operating the system. In addition, an open hot water supply system has increased safety and reliability indicators, and if drinking water is used as a coolant, significant improvements in the efficiency of networks in the future are possible.

But, undoubtedly, there are a lot of disadvantages to an open hot water supply system. Firstly, in the absence of frequent analysis, hot water cools faster and warms up worse, which disrupts natural circulation (in areas connected to mixers). Due to such moments, the heating system may also “suffer”. But in winter, when there is severe frost outside, the heating warms up more, which also increases the temperature of the supplied hot water. Therefore, there is a clear negative relationship in the general contour.

Secondly, the quality of the water itself. Again, due to dependence, it is necessary to use either water that is too pure for heating, or a coolant for hot water supply, whose sanitary parameters are far from the required standards. Accordingly, an open water supply system leads to additional costs due to the use deaeration and chemical cleaning water. Carrying out these works is necessary in any case, as they eliminate the formation of scale and corrosion.

And thirdly, the lack of hot water in summer period. At a time when it is warm enough outside, it is very unprofitable to operate the circuit. After all, both heating and hot water supply will work actively in this case.

Open circuit optimization.

To optimize the use of an open system, some sections of the mains are closed with shut-off valves, which facilitates preventive and renovation work and allows you to drain water from a small section of the pipeline, instead of draining the entire volume. For added protection, open hot water systems are equipped with float sensors and relays for measuring pressure in pipes.

Hot water supply systems can be connected directly (in open heating systems) or independently through water heaters (in closed heating systems). The type of heat supply system (open or closed) is determined during the design, and the choice of one or another system is determined by technical and economic indicators.

Direct connection to the supply and return pipelines (a). Hot water of the required temperature is prepared by mixing it using a thermostat from the supply and return pipelines. In the thermostat, the pressure of the water coming from the supply pipeline is throttled to the pressure of the return pipeline (and its amount depends on the temperature of the water in the return pipeline). In accordance with SNiP 41-02-2003 "Heating networks", the temperature of the heated water at the outlet of the water heater into the hot water supply system should be taken equal to 60 o C. Therefore, when the temperature in the return pipeline is above 60 o C, the water comes completely from the return pipeline , and when the water temperature in it is below 60 ° C - from the return and supply; at a water temperature in the supply pipe equal to 60 °C - completely from it.

At independent accession heating systems (6) leaks are replenished from the hot water supply system after the displacement unit. If the pressure in the return pipeline of the heating network is insufficient to supply water to the hot water supply system, install a pressure regulator (pressure) with sufficient total pressure or a booster pump, which can also be a circulation pump. Circulation can be carried out using throttle washers installed on the return pipeline heating system(winter mode) and on the circulation pipeline ( summer mode). If there is a pressure regulator (pressure), the throttle washer for winter mode is not installed.

Direct connection of a hot water supply system (open circuit)

a - to the feeder and the returner; b - to the supply and return pipelines with independent connection of the heating system;
c - to the return pipeline; g - to the supply pipeline;
1 - mud trap; 2 — mixed water temperature regulator; 3 — regulator temperature sensor; 4 - water riser;
5 - circulation pipeline; 6 — heating system elevator; 7 - booster circulation pump;
8 — make-up water pipeline; 9 — heating water heater; 10 - circulation pump of the heating system;
11 — throttle washer; 12 — hot water heater; PP - flow regulator; RD - pressure regulator

Direct connection to the return pipeline is shown in Fig. c. If the water consumption for hot water supply is significant, p > 0.3, the hot water supply system is connected only to the return pipeline, and the water is heated to the standard temperature in a water heater. This connection makes it possible to reduce misadjustment of the heating system, since the amount of water withdrawal will not affect the water flow in the heating system.

Direct connection to the supply pipeline is shown in Fig. d. With this connection, part of the water is taken from the city water supply, heated in a water heater, then mixed using a regulator with water taken from the supply pipeline of the network. The purpose of the scheme is to reduce water consumption for hot water supply at thermal power plants. However, this results in the loss of the main advantage of a system with direct water supply - protection of the system from internal corrosion. Additive tap water will cause corrosion of the hot water supply system of buildings. For this reason, the hot water supply system cannot be connected to a return pipeline to ensure circulation in it, as this will lead to corrosion of the heating network pipelines.

Independent connection with the inclusion of a hot water supply water heater in a parallel circuit. The heating fluid (mains water) branches into two parallel flows: one enters the water heater, the other goes into the heating system. Therefore, such inclusion is called parallel. The parallel circuit is used for very low thermal loads of hot water supply in relation to heating (r m< 0,2) или очень больших (р > 1,0).

Switching on a hot water heater in a parallel circuit

1 - mud trap; 2 - water heater; 3 — heated water temperature regulator;
4 - circulation pump; 5 - distribution pipeline; 6 - water riser;
7 — circulation riser; 8 - circulation pipeline; 9 - heating system;
10 — constant flow regulator; 11 — elevator

In the absence of storage tanks, due to uneven consumption of hot water, significant fluctuations in flow rate are observed network water, which affects the parallel connected heating system. Therefore, to stabilize the water flow in the heating system, a constant flow regulator is installed in front of it.

Independent connection with inclusion of a hot water supply water heater according to a mixed scheme. The heating coolant (mains water) branches into two parallel flows: one enters the second stage water heater, the other goes into the heating system. From the heating system, network water flows into the first stage water heater. Heated tap water first enters stage I, where it is heated by coolant supplied from the heating system and from the water heater of stage II, and then into stage II until it is heated to the required temperature.

Switching on the hot water heater using a mixed scheme

1 - mud trap; 2 - temperature controller; 3 — stage II water heater;
4 - flow regulator; 5 - distribution pipeline of the hot water supply system;
6—circulation pipeline; 7 — circulation pumps; 8 — heating system;
9 — elevator; 10 — water heater stage I

Since one water heater is connected in parallel with the heating system (stage II), and the other in series, this scheme is called mixed. A mixed scheme is used if p m =>0.2-1, if heat is supplied according to heating schedule or if heating systems are equipped with elevators with adjustable nozzle. A mixed scheme is also used when connecting public buildings with a ventilation load of more than 15% of the heat consumption for heating. Here, as in the parallel circuit, fluctuations in the consumption of network water are observed due to the uneven consumption of hot water. Therefore, to stabilize the water flow in the heating system (in the absence of heat release regulators), flow regulators are installed.

Independent connection with the inclusion of hot water supply water heaters according to a sequential circuit.

The heating fluid (mains water) passes sequentially through the hot water supply water heater of the second stage, then through the heating system and then through the hot water supply water heater of the first stage. The heated tap water first enters stage I, where it is heated by the coolant supplied through the heating system, and then into stage II for heating to the required temperature. Thus, both hot water heaters and the heating system are connected in series.

The sequential scheme is used at a value of p m = 0.2 - 1 and heat supply according to the total load of heating and hot water supply (increased schedule). Distinctive feature sequential circuit is the constant consumption of network water in heating point, which makes it possible to maintain stable hydraulic mode in the heating network. The specified constant flow rate is maintained by a flow regulator, which changes the flow rate of network water at the jumper depending on the flow rate for the period of hot water supply.

Turning on the hot water heater according to a sequential circuit

1 - mud pan; 6 - temperature regulator; 3 — stage II water heater; 4 - flow regulator;
5 - distribution pipeline of the hot water supply system; 6 - circulation pipeline;
7 - heating system; 8 - circulation pumps; 9— elevator; 10 — jumpers for the summer period;
11 — water heater stage I

To ensure a sufficient level of comfort and improvement in the house, it is necessary to establish a water supply. Laying a hot water supply complex requires careful design and implementation at the required technical level. At the design stage, an important task is choosing the type of water supply. The article will talk about the advantages and capabilities of an open water supply system.

Any type of water supply requires the presence of a water source, a pump used to lift water, laying pipelines, collectors that distribute water through pipes, and a water heater is additionally installed for hot water.

Water supply can be carried out using an open or closed circuit. The main difference between the schemes is that in closed cycles water circulates in a closed circuit, and the consumer does not have access to it. IN open device, capable of consuming, are connected to itself. Therefore, an open hot water system requires constant replenishment from a water source. In them, water is the coolant.

So, when installing an open type of water supply, it is necessary to correctly place all its elements:

1. In order to ensure a uniform and constant supply of water, a pump is installed, with its help the required water pressure is established throughout the entire circuit. They can be submersible or external. The location of their installation depends on this;
2. to distribute liquid and heat throughout the house, pipes are installed through which the coolant will be distributed;
3. since water from the very entrance to the house is distributed between two schemes - cold and hot water supply, then for this purpose it is installed distribution manifold. The wiring diagram will also contain tie-ins for consumers - taps, showers, baths, sinks, etc. Their number and placement will depend on the layout of the house and the needs of the residents;
4. Further, in order to function, an open hot water supply system requires installation water heating devices– storage or flow-through, this provides heat supply to the building. The peculiarities of their functioning are explained by their name: the storage type first collects water and then heats it, while the flow type heats it directly in the pipe. For large buildings, one water heater is not enough, so a central heating station is usually built - a central heating point, which plays a major role in ensuring the functioning of the heating and hot water supply of the house;
5. For different needs, various additional devices can be installed - various automatic devices, filters, relays, etc. Their number and composition depend on the complexity of the project as a whole.

An open heating and water supply system may differ in the type of circulation. The previous description shows a forced circulation scheme, i.e. The movement of liquid through the pipe is carried out by a pump. But installation is also possible without a pump, the so-called. scheme with natural circulation. The advantage of an open natural circulation hot water system is that it is economical, since no electricity is required to circulate the water.

Advantages and disadvantages

An open hot water supply circuit has advantages as a heat supply system, especially its energy independence in a natural circulation circuit. Although In recent years, such schemes have been used less and less, since they lag behind the growing needs of the user and advanced technologies, but another advantage is their low cost of installation.

More open circuit The water supply system is simpler in design compared to a closed one. Filling it does not require complex manipulations or devices - water can simply be poured in and drained. In addition, such a water supply scheme is less “aired” than closed circuit hot water As soon as the open tank with water begins to fill, the air automatically leaves the pipes.

Although water is taken directly from the system for consumers, it is not difficult to control its replenishment. But here lies the main drawback of such heating systems - it is necessary to regularly check the liquid level.

For such heat supply systems high level resistance to pressure changes, and the overall pressure is not so high. Therefore, leaks do not affect its performance so much.

Another disadvantage, or rather, difficulty, is that an open hot water supply system requires precise calculations. In order to correctly select the volume of the storage tank, pump power and the number of other elements, you need to know how much water is consumed on average. For heating systems with such a design, this will depend on the number of people who will consume water, on the volume of water consumption in the bathroom, when washing dishes and other activities that require hot water. Knowing how much water is required per day, you can easily determine the required volume of water for heating systems of any type.

So, having your own water supply system with a heating unit is convenient, because thanks to this the house becomes autonomous system, independent of utilities or some other factors. But the installation of such systems requires careful calculation and certain costs, which will depend on the layout of the house and the required level of improvement.

A closed hot water supply system is a set of equipment, pipes and devices that must solve the problem of heating, incoming cold water and its subsequent distribution to consumers. The operating algorithm of such a system is as follows:

1. Cold water enters the heater.
2. The pump supplies the heated water to the pipeline system through which it is supplied to consumers.

Basic principles of operation of a closed hot water supply system

The method of heating water determines its type - open or closed. The system during operation of which the consumer receives hot water is called closed. A closed DHW system is built on the following principles:

• Water supplied from the water supply goes to an additional heater where it receives thermal energy and then served to consumers. In this case, water and coolant are separated from each other. Such a system implies that the hot water supplied to the consumer has the same parameters as that pouring from a cold water tap.
  It should be noted that when using a closed hot water system, the pipes through which hot water is supplied are more susceptible to corrosion.
• The closed DHW system includes two pipelines - supply and return. Water circulates through them in the system. This allows several consumers to use hot water simultaneously without a drop in water pressure. In addition, the closed hot water system is easy to adjust the temperature regime.
• This system allows you to save money; the whole point is that it maintains a constant temperature. This is especially true if the building is connected to a central water supply system. By the way, the use of a closed hot water system allows you to connect heated towel rails. But those who have installed a heated towel rail are faced with the following problem - in the summer it will be constantly hot, and this will lead to an increase in the temperature in the room. But this problem can be solved by installing shut-off valves that regulate the supply of heated water.

Any water supply system requires calculations of the required amount of hot water. Their results are influenced by certain factors. They are determined primarily by the number of residents living in the house. To carry out calculations it is necessary to take into account:

• predicted water temperature;
• number of residents;
• parameters, sanitary equipment used and a number of others.

Differences between open and closed water supply systems

The use of a closed system implies that to heat cold water coming from a centralized water supply, coolant supplied from the heating network will be used.

In an open hot water system, hot water is taken directly from the heating network. It can only be used to satisfy household needs, for example, for washing dishes or laundry. Such water can have a temperature of up to 75 degrees. It should be noted that the main advantage of a closed hot water system is the quality of the water. As a rule, if all design requirements are met and there are no violations during its installation, the water fully meets the requirements of GOST R 51232-98.

Equipment required for network operation

A closed hot water system is a rather complex engineering and technical system and to ensure uninterrupted, and most importantly safe work a set of certain equipment is required.

Water flow metering unit

It is through it that water is supplied to the house water supply. A water flow meter is installed on it. In addition, the design of the unit provides for the possibility of turning off the water supply during repairs of pipeline fittings, both scheduled and emergency. The following components are installed in the water metering unit:

• magnetic or mesh coarse filter;
• taps and valves through which cold water is supplied;
• measuring instruments - pressure gauges, thermometers;
• bypass - a bypass pipeline that is used while servicing the water metering unit.

Of course, to ensure the operation of the hot water system, a pipe system is involved; it can be divided into three groups:

• bottlings;
• risers;
• carts.

Through bottlings located in the basement of the building, water moves to the risers. Through them, it is supplied directly to apartments and through supply lines to end consumers - sanitary equipment, Appliances, heated towel rails, etc. There are many layouts of pipes for each group. For example, through risers located in one apartment, water can be supplied to neighboring housing.

The diameters of the pipes are determined during the design of the building, but as a rule the following dimensions are maintained:

• Bottlings from 32 to 125 mm;
• Risers from 25 to 40 mm;
• Eyeliners within 15 - 20 mm.

When developing a project for a closed hot water system, the following materials are used:

• metal-plastic;
• pipes made of food grade stainless steel;
• galvanized pipes.

When ordering pipes, please remember that metal-plastic pipes can be designed for different pressures and different operating temperatures. By the way, during overhaul, unscrupulous contractors install pipes that do not meet the requirements of the working documentation, the same applies to pipeline fittings.

Basic malfunctions of a closed hot water system

Hot water supply can sometimes fail or be unstable. This is determined by a number of subjective and objective factors. In particular:

• errors made during the design and installation of the system;
• leaks and noises arising in pipeline fittings. As a rule, this is caused either by wear in the valve shutter or by the installation of defective products;
• lack of heating of the heated towel rail, most likely all of it is caused by air pockets.

As a rule, the water supply system is accepted according to an act and the company that installed the hot water supply system must deal with it for several years warranty service transmitted management company networks. That is, to eliminate defects in DHW networks it is necessary to call specialists from the management company or from the contractor company.

Estimated standards for hot water consumption

It should be noted that there are many standards for calculating resource consumption; in the housing sector, there are no standards for water use per person without the use of a water meter. This is due to the fact that population density varies greatly in different regions of our country. In other words, each region has its own regulations. In accordance with the rules, a certain amount of water is supplied to the populated area. At the same time, they take into account the volume of water used by residents of those apartments in which water meters are installed.

From the total volume of water supplied, the volume that passed through the metering devices is calculated. The resulting difference is divided by the number of people registered in a given residential area. It is these people who bear the cost of used water. This situation has arisen largely because there are many places of unauthorized water consumption and water meters are not installed everywhere, by the way, unlike countries with developed economies. Consumption rates are calculated using a multiplying factor.
When making calculations, it is necessary to take into account the condition of plumbing fixtures and the presence of installed water heaters.

The water consumption coefficient in different regions differs because in each region water is consumed in different volumes. In this case, it is necessary to take into account the climate and the price of fuel intended for heating water.

The average rate of water consumption per person has been derived. During the daytime, this figure is 200 liters of cold water and 100 liters of hot water. An ordinary bathroom holds 250 liters of water, and if the resident does not take a bath every day, then it makes sense for him to think about installing water meters.

An installed meter will allow you to significantly save on water bills. The fact is that unauthorized water withdrawals, leaks, water consumption for the needs of the Ministry of Emergency Situations and much more are included in water bills in one form or another.

A little about the regulatory framework

Any modern man understands perfectly well that without the majority utilities, including the presence of hot water, life is not at all comfortable. And often the central water supply system does not always provide consumers with access to hot water. But if you read the regulatory documentation, namely sanitary standards and rules (SanPiN) 2.1.4.2496-09, then the requirements for hot water temperature in a city apartment will become clear. The maximum temperature should not exceed 60 - 75 degrees. This level is mandatory at all consumer connection points. Maintaining this temperature is necessary to prevent the spread of bacterial and other infections that can harm the health of people living in the house.

How often do you call a plumber?

Provide hot water multi-storey building not easy, because the hot water supply system must contain water under a certain pressure and at a certain temperature. This is the first. Second: hot water supply apartment building– this is a long path of water itself from the boiler room to consumers, in which there is a huge amount of different equipment, devices and devices. In this case, the connection can be made according to two schemes: with upper or lower wiring.

Network diagrams

So, let's start with the question of how water gets into our homes, meaning hot water. It moves from the boiler room to the house, and is distilled by pumps installed as boiler equipment. Heated water moves through pipes called heating mains. They can be laid above or below ground. And they must be thermally insulated to reduce heat losses the coolant itself.

Ring connection diagram

The pipe is brought to apartment buildings, from where the route branches into smaller sections that supply coolant to each building. A pipe of smaller diameter goes into the basement of the house, where it is divided into sections that deliver water to each floor, and from that floor to each apartment. It is clear that such an amount of water cannot be consumed. That is, all the water pumped into the hot water supply cannot be consumed, especially at night. Therefore, another route is laid, which is called the return route. It moves water from the apartments to the basement, and from there to the boiler room through a separately laid pipeline. However, it should be noted that all pipes (both return and supply) are laid along the same route.

That is, it turns out that the hot water itself inside the house moves around the ring. And she is constantly on the move. In this case, the circulation of hot water in an apartment building is carried out from the bottom up and back. But in order for the temperature of the liquid itself to be constant on all floors (with a slight deviation), it is necessary to create conditions under which its speed was optimal, and it did not affect the decrease in temperature itself.

It should be noted that today apartment buildings can be approached separately by routes for hot water supply and heating. Or one pipe will be supplied with a certain temperature (up to +95C), which in the basement of the house will be divided into heating and hot water supply.

DHW wiring diagram

By the way, pay attention to the photo above. A heat exchanger is installed in the basement of the house according to this scheme. That is, water from the route is not used in the hot water supply system. She just heats up cold water, coming from water supply network. And the domestic hot water system itself is a separate route, unconnected with the route from the boiler room.

The house network is circulation. And the water supply to the apartments is carried out by a pump installed in it. This is by far the most modern scheme. Its positive feature is the ability to control temperature regime liquids. By the way, there are strict standards for the temperature of hot water in an apartment building. That is, it should not be lower than +65C, but not higher than +75C. In this case, small deviations in one direction or another are allowed, but not more than 3C. At night, deviations can be as low as 5C.

Why this particular temperature?

There are two reasons for this.

• The higher the water temperature, the faster pathogenic bacteria die in it.
• But we also have to take into account the fact that heat in a hot water supply system these are burns when coming into contact with water or metal parts of pipes or faucets. For example, at a temperature of +65C, a burn can be obtained in 2 seconds.

Water temperature

By the way, it should be noted that the temperature of the water in the heating system of an apartment building can be different, it all depends on various factors. But it should not exceed +95C for two-pipe systems, and +105C for single-pipe systems.

Attention! The law determines that if the water temperature in the hot water system is 10 degrees below normal, then the payment is also reduced by 10%. If it is at a temperature of +40 or +45C, then the payment is reduced to 30%.

That is, it turns out that the water supply system of an apartment building is available in type of hot water supply, This individual approach for payment, depending on the temperature of the coolant itself. True, as practice shows, few people know about this, so disputes usually never arise on this issue.

Dead-end circuits

There are also so-called dead-end circuits in the DHW system. That is, the water goes to consumers, where it cools down if it is not used. Therefore, in such systems there is a very large excess coolant consumption. Such wiring is used either in office premises, or in small houses - no more than 4 floors. Although all this is already in the past.

The best option is circulation. And the simplest thing is to enter the pipe into the basement, and from there through the apartments through a riser that runs along all floors. Each entrance has its own riser. Reaching the top floor, the riser makes a U-turn and goes down past all the apartments into basement, through which it is discharged and connected to the return pipeline.

Dead-end circuit

Wiring in the apartment

So, let's look at the water supply (WSS) scheme in the apartment. In principle, it is no different from cold water supply. And most often, hot water supply pipes are laid next to cold water supply elements. True, there are some consumers who do not need hot water. For example, a toilet, washing machine or dishwasher. The last two themselves heat the water to the required temperature.

Wiring diagram DHW pipes and HVS

The most important thing is that the distribution of water supply in an apartment (both hot water supply and hot water supply) requires certain standards for laying the pipes themselves. For example, if pipes of two systems are laid one above the other, then the top one should be from the hot water supply. If they are laid in a horizontal plane, then the right one should be from the hot water system. In this case, on one wall it may be deep in the groove, and on the other, on the contrary, closer to the surface. In this case, the laying of the pipeline can be hidden (in grooves) or open, laid on the surface of the walls or floor.

Conclusion on the topic

The apparent simplicity of hot water supply in apartment buildings determined by the inhabitants by the distribution of pipes inside the apartments. It's actually quite a wide variety. various schemes, in which pipes stretch for several kilometers, starting from the boiler room and ending with the mixer in the apartment. And, as practice shows, even in old houses today, hot water supply systems are being reconstructed using new, improved technologies that provide hot water and reduce heat losses.

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