Hot water circulation pumps how to choose. Hot water circulation pump

Feeding devices hot water are called circulation pumps for domestic hot water. Prevent stagnation of water in the pipeline. Provide sufficient pressure at water points (faucets, showers).

1 PURPOSE OF DHW PUMPS

Devices are intended for water supply in systems of water supply. An auxiliary function of the aggregates is the prevention of diseases of the population. At water temperatures up to fifty degrees and a low level of circulation, bacteria of the Legionella species multiply. At a liquid temperature of sixty degrees and its circulation, the bacteria die. The device, dispersing the liquid, prevents the development and reproduction of these microorganisms. The liquid does not cool down and does not stagnate, which means it is safe for use by residents. And residents enjoy sufficient pressure in the taps of their homes.

Devices regulate the process of water supply, selecting an individual mode for the time of day and year. Thanks to the adjustment function, the devices make water systems energy efficient. maintain a constant temperature of the liquid by mixing the cooled water with hot. Water is supplied to the tap immediately and at the desired temperature.

2 TYPES OF PUMP FOR DHW

According to the type of rotor, the devices are divided into dry type of rotor and wet type.

Dry has a high level of efficiency - seventy percent. Noise level is higher than wet type pumps. To increase the comfort of use, it is necessary to place the device in a separate room. Not all users have the option to post.

The wet rotor runs quietly, with an efficiency of forty-five percent. The service life reaches fifteen years. Does not require Maintenance.

Circulation and recirculation abilities:

• circulation devices are characterized by an increase in the speed of movement of the liquid. Such devices do not have a filter for cleaning the liquid;
• hot water recirculation devices are used to increase the speed of the liquid and reuse it. The hot water recirculation pump is equipped with a cleaning filter. The recirculation pump supplies hot water from the heater to the faucet;
• hybrid mechanisms are used for fluid circulation and recirculation purposes. Equipped with a cleaning filter.

By location relative to the highway:

• working in a horizontal position;
• working in vertical position.

2.1 DIFFERENCES OF DHW APPLIANCES FROM DEVICES FOR HEATING

The design of both types of pumps are similar, but there are differences.

By temperature regime:

• hot water devices are operated at liquid temperatures up to sixty degrees;
• heating devices work with liquid temperatures up to one hundred and forty degrees.

Performance:

Production material:

• brass-housing material for hot water stations;
• cast iron is a material for heating stations.

Types of devices suitable for hot water supply:

• sump pumps are operated when the fluid source is contaminated. Water is pumped with particle sizes up to 1 cm. The drainage mechanism can be submersible and surface;
• hot water circulation booster pumps increase the pressure in the pipeline. The booster pump is installed without a foundation. Small dimensions, noiselessness and economical power consumption are the advantages of the devices. The pump for increasing the pressure is a centrifugal apparatus with two to three speeds of the operating mode. The booster pump is operated in clean water.

3 RULES FOR SELECTING APPARATUS FOR DHW

When choosing a pump for hot water supply, they take into account the operating conditions, design and requirements for the characteristics of water supply.

By design features hot water pumps are divided into dry and wet rotor.

Advantages and disadvantages of types of rotors:

• The wet type impeller is located in a water environment. Hot water is used as a lubricant and cooling agent. The operating period of the devices is fifteen years. The absence of noise effects during operation is another advantage of the mechanisms. Apparatuses of this type, according to the pricing policy, are more profitable than dry ones. They do not require maintenance and rarely fail. The efficiency is lower than that of dry devices and is forty-five percent. The device can only be installed horizontally;
• dry type devices do not come into contact with the liquid during operation. This feature negatively affects the performance of the mechanisms. Lack of lubrication and cooling causes frequent breakdowns. To prevent breakdowns, the pump is subject to frequent maintenance and completion of the design with a fan. The advantage of mechanisms in the efficiency of seventy percent.

Selection by characteristics:

Manufacturer's name:

exist a large number of manufacturers of pumps providing hot water supply with pressure. But not all manufacturers produce high-quality devices.

The main criterion for choosing a device by manufacturer is a name that has been proven over the years.

• Wilo: manufacturer specialized in pumps. Model Star-Z creates pressure in the faucet and shower;
• Grundfos manufactures pumps different types and models. The UP model is applied to water supply and heating system (twin model). The device is equipped with a wet rotor. The wet type rotor ensures a high service life without maintenance. The type of rotor ensures quiet operation of the device, while the efficiency is 45 percent. Fluid circulation reduces temperature loss;
• The German manufacturer Vortex is distinguished by maintainability and high performance. Model BM152 stands out for its small size, high performance and quiet operation;
• the Espa RA 1C model with a wet rotor is mounted in a vertical position. Pumps cold and hot water. Temperature regime working fluid up to one hundred and twenty degrees Celsius.

3.1 WILO STAR-Z NOVA DHW RECIRCULATION PUMP (VIDEO)

4 INSTALLATION OF THE HOT WATER PUMPS

The installation diagram is shown on the example of a circulation unit.

To provide the points with sufficient pressure, the apparatus is mounted on a direct supply pipe.

Installation steps:

During installation, observe the following rules:

• wet-look devices are mounted in a horizontal position;
• for comfortable use, the pump power is selected according to the needs of the system;

4.1 STARTING RULES

• the pipeline is filled with water and pressurized;
• air is bled from the pump with a screw;
• the boiler or boiler turns on;
• the device turns on. The process is controlled;
• after operating for four to five minutes, the air is vented from the disconnected device.

For system productivity and ease of repair and dismantling, the pump is mounted in a diverted pipe. When repaired, the plumbing will be fully functional.

To prevent breakdowns, follow the rules of operation:

• it is forbidden to use the pump dry;
• to prevent deformation of the blades, before starting, the pump is filled with liquid;
• the pump is used in compliance with the temperature regime;
• centrifugal pump for hot water cannot be operated in heating systems due to insufficient power.

Following the rules of operation, the hot water pump will last five to ten years without breakdowns and maintenance.

To ensure the circulation of hot water in large rooms and apartment buildings, DHW circulation pumps are used, which regulate the water supply according to closed circuit. Due to the ability to circulate and recirculate water in one circuit several times, the pump is also called recirculation.

The need for a pump

Circulation pump for hot water supply is used for the full operation of the entire heating system of the house, as well as cooling and air conditioning systems. The equipment is designed to prevent the accumulation of stagnant water in pipes. In the production of hot water recirculation pumps, designs are thought out that are protected from breakage and settling of calcified residue. To provide the necessary conditions for pumping hot water through a pipeline, the pump has a recirculation principle of operation, which allows you to increase pressure throughout the system.

Due to the fact that the DHW circulation pump operates silently, and are used Energy Saving Technologies, he can work on average data up to 13-15 years. The produced models are configured in such a way as to ensure uninterrupted operation of the system, equipped with the function of temperature control along the circuit.

The need to use a circulation pump for hot water is explained by the fact that at a temperature of 60 ° C, all pathogenic bacteria die. Even with a 25 W pump, pathogenic bacteria such as legionella can be killed. The installed equipment will not only be durable, but will also preserve the health of all family members.

The structures that are mounted in the DHW system are made of brass and of stainless steel, cast iron, bronze, they withstand exposure to water with large quantity salts. Ordinary pumps may not be suitable, so manufacturers provide the population circulation systems different types. Some models are equipped with thermostats, they keep the set temperature for the entire period of operation or for a certain period of time. Small water systems are equipped with a rotor that is easy to clean from calcium sediment.

Application area

The circulation pump alone can improve the functions of the pipeline circuit, ensure uninterrupted pressure supply. The devices are used when decorating houses or apartments with warm floors, since hot water circulation, pumping and pumping out, requires a lot of power.

Actual use of circulation pumps in large buildings and high-rise buildings, where there is an extensive network of circuits along the entire perimeter, tens of meters long. Heaters are inferior in functionality in that water quickly cools down in them, and the necessary energy is lost, in practice it drops from 55-60 degrees to 40-45.

Hot water systems with natural and forced heat supply have their pros and cons, which depend on the application for a particular area. natural circulation water in the heating system is carried out due to the forces of gravity, they cannot be regulated and used in hot water supply.

The forced system, exactly the opposite, is designed to work with DHW circulation pumps, since it can be adjusted. Thermal energy in this case it is used at full capacity, providing a high degree of comfort. In this way, it is possible to minimize the difference in the temperature regimes of the water leaving and entering the boiler.

There are also models industrial use having large sizes dimensions and significantly increased power.

Principle of operation

In a hot water supply system, the circulation pump has a design similar to those used for heating systems. The main purpose of creating equipment is to increase the pressure through the pipeline, maintaining the desired temperature.

Provision of hot water takes place in stages:

1. A closed-type pipeline is connected to the boiler, which runs throughout the house;
2. First, hot water is drawn into the tank, after which the pump creates the pressure necessary for the pipeline circuit;
3. Water with a temperature of 50-60 degrees circulates through pipes, near the taps of the apartments. Thus, a person immediately receives pressurized water in the shower or kitchen faucet.

If the water has not been completely consumed, then it returns to the boiler or boiler through the return pipeline. If the system does not function according to sanitary standards, the water flow will become slower, this will cause insufficient heating.

Types of pumps

In order to choose electric pumps for a hot water supply system, you should know their types.

Classification by rotor type:

• Wet rotor models are popular for being durable and quiet in operation. In addition, the pressure part of the unit is located in the pumped medium, in which the rotor is constantly lubricated and cooled if necessary. The wet rotor pump does not need constant diagnostics and is inexpensive. The disadvantage of the unit is the low efficiency rate of up to 45% and the fact that it is mounted only horizontally, it can maximize the pressure up to 3 atmospheres;
• Models with a "dry rotor" differ from the previous version in that the main power plant is outside the pumped medium. The disadvantage of such a mechanism is problems with lubrication and cooling, as it constantly remains dry. The solution to the problem is to regularly inspect the equipment and install a fan. A more powerful apparatus, compared to a wet rotor, can raise the pressure through the pipeline up to 5-10 atmospheres, which explains its high cost.

Based on speed switching, hot water pumps are classified:

• With one speed, the devices are suitable for any living conditions, have low productivity. Easily built into the system and does not require special care;
• Multi-speed units can be configured in such a way that it is possible to switch operation algorithms. They are most often installed for plumbing systems.

The selection of the circulation pump is carried out in accordance with the requirements:

1. First you need to choose required pump by performance, calculating its performance with minimal operation;
2. The unit is selected according to desired pressure, with a wet or dry rotor;
3. The pump should be selected according to the parameters of the heated room and the temperature of the pipeline liquid;
4. The device is selected according to the noise level, giving preference to silent options;
5. Unlike which room will be connected to hot water supply, they buy equipment with different levels difficulties.

The main task of the pump on re DHW circulation is to ensure a constant pressure through the pipeline, so that you can know the temperature of the water on the return.

For the further operation of the pump, the selection criteria are important:

• The speed of the water pressure, which makes it possible to assess the pressure on the centrifugal flows of water and the return;
• The amount of water consumed;
• Heat transfer of the DHW system, determined by the area of ​​\u200b\u200bthe room and heat losses.

When choosing a circulation pump, preference is given to devices with a "dry rotor", despite their high cost. Compared to "wet rotor" DHW pump"dry" have a performance of up to 75%.

Circulation pump installation

Before installing a DHW recirculation pump, you should be sure that it will be carried out in accordance with the manufacturer's instructions and the house design scheme, and all liquid from the pipeline must also be drained.

The equipment is installed step by step:

1. First of all, the installation site is selected, it should be on the return line, located in front of the boiler. The location on the return line prevents oxygen from entering the station, which can lead to equipment shutdown. The coolant will rest against the boiler, creating a vacuum space, ensuring it is completely filled with water;
2. Then a bypass or bypass is selected, which is intended for the uninterrupted operation of the pump in the event of a power outage and water supply to the taps. It is important that the diameter of the main pipeline is larger than the diameter of the bypass pipe. AT without fail the pump shaft is installed in a horizontal straight line so that it is completely in the water;
3. In front of the storage tank, install check valve, additional shut-off valves will also be required before and after the station;
4. For the system, the installation of a filter must be thought out in order to avoid the ingress of small particles into the pump structure. To be able to release air locks, an automatic or manual valve must be installed;
5. The pump is connected to the UPS to avoid power outages;
6. Before starting the electric motor, additional pressure movement valves and distribution manifolds are installed.

Starting the system and doing a test run is allowed only after the pump is installed in DHW system, and the water circuit is filled. Regardless of the heating area in the house, a DHW circulation pump is installed for private and multi-storey buildings.

First of all, it must be remembered that the circulation and booster pumps are completely various appliances. The circulation pump does not change static pressure system, but only ensures the movement of the coolant through the pipes.

The main characteristic of any circulation pump is the operating curve, which in the case of the DHW recirculation variant usually consists of a single curve, since it usually does not have switching speeds (Fig. 1). It can be seen from the graph that as the volume of the pumped liquid increases, the pressure drops. Conversely, with an increase in the height of the rise, the flow decreases. At the extreme point with maximum pressure, the flow zero, at the point with the maximum flow, the head is equal to zero.

The physical meaning of this curve is very conveniently illustrated by the example of an open system (Figs. 1 and 2). If the length of the pipe H is equal to H max, water will not flow out of it, since at this pressure value the flow V 0 is equal to zero. If you shorten the pipe to length H 1, water will flow out of it at a speed V 1. Removing the pipe altogether, we will get a flow at the outlet V max, since the pressure H 0 \u003d 0.

The situation described above is only true for open systems. AT closed system the pressure created by the circulation pump is designed not to overcome the height of the liquid rise, but to compensate for pressure losses caused by the resistance of pipes and fittings.

Operating point of the DHW circuit

In a circulation circuit, pressure loss and volumetric flow are closely related. There is an equilibrium between the pressure loss in the system, which must be converted into a head loss, and the pump head. This means that the system losses are the same as the pump head at the duty point.

Since each value of the pump head corresponds to a single flow value, the volume of water circulating in the system is directly related to the resistance of pipelines and fittings. To determine the operating point, the DHW circuit curve must be superimposed on the circulation pump curve.

There are frequent cases when neither the curve of the system nor its operating point are known. In this case, the required pressure losses in the system and the required volume of hot water for circulation can be determined arithmetically by calculating the resistances of individual sections of the system.

At the same time, it should be borne in mind that it will be possible to achieve the design characteristics only if all circulation branches tied to one pump are hydraulically balanced using control valves, mechanical or thermostatic. The purpose of balancing is to maintain optimum speed flow in the entire system, regardless of the length of the pipes and their diameter, in order to prevent an excessive decrease in the temperature of the water returning to the boiler. Ideally, the difference between the supply pipe at the outlet and the recirculation line at the inlet to the water heater should be 2-3 K for small systems less than 200 m long and 7-10 K for large ones (more than 200 m in length).

In the standard case, with equal diameters of all circulation pipelines, in the branches located closer to the pump, the resistance must be increased to such an extent that it corresponds to the pressure loss in the distant branches. Away from the pump, on the contrary, it is required to create an increased flow so that the circulating water does not have time to cool down much.

The diameter of the circulation pipe depends on the diameter of the supply pipe. Unfortunately, the Russian SNiP 2.04.01-85 * “Internal water supply and sewerage”, unfortunately, does not have clear recommendations in this regard, so let's turn to the German DIN 1988, part 3 (Table 1).

Working point calculation

We now proceed to determine the operating point of the system. To do this, we need a flow V c and a pressure loss (head) Δp c . The flow that needs to be provided depends on the total volume of water circulating in all branches. To prevent excessive cooling of the liquid, the pump must provide such a speed that all the water in the pipes does not have time to cool too much. It should also be taken into account that the maximum speed should not exceed 0.5 m/s for copper pipes and 1 m/s for pipes of other materials.

The pressure is determined by the sum of the resistances of the longest circulation branch, if we count from the connection of the circulation pipeline to the supply line to the inlet to the water heater. The operating point must be selected in such a way that the temperature of the hot water in the pipes does not fall below 55-60 ° C to prevent the growth of bacteria.

Exist different techniques calculation. We offer here one of them, quite simple, based on some averaged data. Of the disadvantages of this method, one can only note the possibility of its use for relatively small systems with a circulation pipe diameter of different areas from DN 10 to DN 20 and, accordingly, the flow area of ​​the pump is not more than 3/4ʺ.

First, we determine the heat loss in the pipelines. If there is no data from the manufacturer of pipes and thermal insulation, for a well-insulated pipe we accept: q tp.neot = 11 W / s per 1 m of pipe laid in unheated room(for example, a basement), as well as q tp.ot \u003d 7 W / s per 1 m of a pipe laid in a heated room (for example, a plumbing box, kitchen, bathroom). The heat losses of fittings (valves, meters, etc.) can be ignored due to their insignificant influence on the overall result. Thus, total losses heat in the system is:

Qtp = Σl tp.neot q tp.neot + Σl tp.ot q tp.ot, (1)

where Σl tp.neot and Σl tp.ot is the total length of pipelines laid in cold and heated rooms, respectively.

The maximum allowable temperature difference between the supply and circulation lines is taken equal to Δt tp = 2 K. Based on these data, we can now calculate the required flow rate:

where ρ is the density of water, equal to 1 kg/l; c is the specific heat capacity of water, equal to 1.2 W*h/(kg*K). So you can find the required water speed in individual branches.

If there is only one branch, then the flow in it is equal to the total flow. But this rarely happens, since the circulation line covers all draw-off points, therefore, it is replete with branches.

At the nodal points, the duct is divided into the main duct and the additional duct. The flow in the main part is equal to:

and in the extra:

or V add \u003d V c - V main. (5)

The pressure component of the working point is determined, as mentioned earlier, by the longest branch with a coefficient for bends and joints K = 1.2-1.4. The more tortuous the pipe, the greater value coefficient should be accepted. The channel in this case at each nodal point is divided into main and additional. If, after branching, none of the pipes goes directly to the draw-off point, the one in which the volume of water is less is considered additional. They also take into account the resistance of various fittings that are not included in the calculation of heat losses - valves, valves, etc.:

Δp c = KΣl tr R tr + ΣR arm. (6)

The pressure and flow calculated in this way represent the operating point of the system. Consider an example (Fig. 3). In table. 2 shows the main characteristics of the hot water supply system of a three-story building with five risers: the length of the metal-plastic pipelines laid in the basement and in the heated rooms, the inner diameter of the pipes, the type of flow when dividing at nodal points, and heat losses are calculated in each segment. After that, we find the common duct according to (2):

at Δt tp = 2 K.

Calculation of the required flow rate for each pipe section based on those determined in Table. 2 heat loss is given in table. 3. The heat losses of the main and additional sections are summarized in the column "Total heat losses", and the corresponding values ​​of the flow are calculated using formulas (3) and (4).

In table. 4, based on SP 41102-98, the speed of the coolant and the pressure loss due to friction are calculated (if the pipes are plastic or copper, then you need to use SP 40101-96 or SP 40108-2004, respectively). The longest branch: 10-8, 8-7 , 7-6, 6-1, the pressure loss in it is 1271.27 Pa. According to formula (6), we find the pressure at the working point:

Δp c \u003d KΣl tr R tr + ΣR arm \u003d 1.4 × 1271.27 + 200 \u003d 1979.78 Pa,

at K = 1.4 and R arm = 200 Pa. In terms of meters of pressure, 1979.78 Pa = 0.2 m.

According to the available in the table. 4 data, it is also necessary to adjust the control valves.

So, for this system, a pump with a duty point V c \u003d 189.17 l / h, Δp c \u003d 0.2 Pa is suitable. With such insignificant parameters, almost any of the DHW circulation pumps available on the market can easily cope.

1. Brochure VORTEX Brauchwasserpumpen. Technische Broschu..re. Trinkwasserzirkulation mit VORTEX Pumpen // 09de0090 11/09.

2. SP 41102-98. Design and installation of pipelines for heating systems of buildings using metal-polymer pipes.

3. SP 40101-96. Design and installation of pipelines made of polypropylene "random copolymer".

4. SP 40108-2004. Design and installation of pipelines internal systems water supply and heating of buildings from copper pipes.

Whoever gets up early is the first in the shower. Turn the faucet knob and wait for hot water to pour out of the watering can. The usual situation for a private house. During the night, the water in the pipes managed to cool down, and until you get the right temperature, you will have to watch how the liters flow into the sewer. Clean, by the way drinking water. In general, complete disrespect for nature, and for your own wallet. But we'll fix it.

Hot water in a private house, as you know, has its own circuit. And there is nothing surprising in the fact that the liquid cools down in the pipes while you sleep, or no one from the household is at home for a long time. But for thrifty owners who are used to counting every ruble, flushing cold water, waiting for hot water, this is a luxury. In order not to wait and save money, you can solve the issue by installing a circulation pump in the DHW system. But which one and how to choose it?

Devices can be either permanent or automatic. With "wet" or "dry" rotors. Be that as it may, the main parameters when choosing it are flow and pressure. Plus, in units designed for the DHW system, there is one more important indicator- power. It depends on how much electricity the pump will consume.

It is best to entrust the selection to a specialist. Of course, the consumer can independently calculate everything, having spent time on this. For example, use the rules and standards of the set of rules (SP), building codes and rules (SNiP), Santekhproekt standards and even DIN (German Institute for Standardization). Each of them calculates the instantaneous water consumption at the current time in a different way. Therefore, in our country, specialists use those standards that are closer to them.

However, when choosing a pump for hot water supply, it is necessary to know the height and length of the pipeline in order to understand what hydraulic resistance will be in the system along the length, as well as local resistance. The power of the pump and its ability to overcome resistance depend on this so that water reaches each of the draw-off points. We must not forget the maximum permissible value outlet pressure. As a rule, this is no more than 4.5 atmospheres for hot water supply in the plumbing area. Otherwise, the pressure will break your faucet, shower or faucet.

So. Which pump to choose? It is difficult for the consumer to understand the wide selection of models on the market. Professionals recommend starting from one criterion. And this is quality. Reliable, having thousands positive feedback, and besides, not expensive - this is, without a doubt, a pump from the company GRUNDFOS (Russia). The manufacturer can offer several excellent models for high-quality hot water supply to your home.

First of all, the UP type pump with asynchronous electric motor. The device has a built-in timer and thermostat. It is enough for the user to set the time 15 minutes before the time at which he usually takes a shower, for example, 7 am, and nothing else to worry about. The pump itself will turn on at 6:45 and drive hot water through the system. By the time the tap is turned on, hot water will already be circulating throughout the system. But the thermostat is responsible for maintaining the desired water temperature in the system. If it has become colder than usual, the pump will automatically start to work and will do this until a value that is comfortable for the person is reached.

Even more interesting model from GRUNDFOS - UP PM pump with motor on permanent magnets and its modification U.P.M. with AUTO function ADAPT. This is a unique feature developed by engineers from the Danish concern GRUNDFOS. Her main feature in that the electronic unit of the pump remembers the schedule of hot water consumption of the people living in the house and builds work based on it.

How does it work in practice? After installation - the pump must be installed on the return pipe, and the external temperature sensor on the hot water supply pipe - the device works for two weeks in temperature regime. During this time, all events with cranes are recorded. Namely, how many times a day, and at what time the draw-off points were involved. Whether it is the frequency of hot water consumption on weekdays, or how consumers use hot water on Saturday and Sunday. After this time, the received information is analyzed. Considering all possible nuances, electronics determines optimal model work. In the future, the pump starts working 15 minutes before the expected opening of the tap. Thus, the pump turns on only when it is really needed and provides an instant supply of hot water. Thus, it is achieved real savings energy resources and money.

Separately, it must be said about the UP PM engine. Compared to asynchronous UP, a permanent magnet motor consumes much less electricity. If UP consumes 25 watts, then UP PM only 8. Three times less! In addition, it complies with European energy efficiency requirements EuP 2015. It is virtually silent and durable. The engine is able to work effectively with water, the hardness of which is estimated at 4.99 degrees of hardness. It has a spherical rotor and a self-adjusting bearing that is lubricated by the pumped liquid. The body of pumps of this series is made of a material that is most suitable for working with drinking water - brass. Models with built-in check and shut-off valves are available for sale.

The manufacturer also made sure that the consumer does not experience inconvenience during the preventive examination and cleaning the pump elements from scale and other debris. It is not necessary to dismantle the equipment for this. Enough to shut off the water stopcocks and separate the electronic part of the pump with the impeller from the pump volute. This is not difficult to do, since the connection is threaded. In addition, inspection on models with built-in check and shut-off valves is even easier - no installation is required. stopcocks. The valves will independently limit the access of water to the pump.

Circulation pumps for hot water systems from GRUNDFOS (Russia) meet the highest safety and energy efficiency requirements in Europe. By purchasing any model of equipment, the consumer receives comfort, convenience, practicality and savings for a reasonable price. That is why the purchase of Grundfos pumps should rather be seen as a good investment that will soon pay for itself.

It remains to add that Grundfos (Russia) is one of the few companies on the market that takes care of customers throughout warranty period equipment. The project of the company "SERVICE 24" will help solve everything possible difficulties when operating the pumps. In case of problems, the buyer just needs to call " hotline” and the operator will solve your problem by phone. If this is not possible, on specified address Departure of a specialist from the nearest service center. The expert will find out the cause of the problem. a little problem repaired on site, and in case of significant damage, the pump will be replaced with a new one. Of course, all work for the client is free of charge. But only on condition that the case is recognized as a guarantee. Today the Service 24 program operates in 33 Russian cities. In the future, it is planned to expand the territorial zone.

The water pressure in the boiler itself may not be sufficient to provide a summer residence hot water. To recirculate hot water through, it is necessary to properly install the DHW system with the installation of a circulation pump.

In large country houses experts recommend installing a hot water supply system (DHW) of a centralized method of heating water, through an electric column (you can also use a single-circuit gas boiler). In this case, to ensure the necessary supply of hot water, a boiler must be installed in this system. indirect heating.

The volume of the boiler is calculated taking into account all the people living in the house (for a family of 4 people, a boiler of 100-150 liters will be enough). Water in the DHW system is heated using a heat exchanger, which is connected to a heating source (boiler, column).

The DHW boiler has several inputs and outputs. The design feature of indirect heating boilers is that a coil is mounted in it in the form of a spiral metal tube through which hot water from the boiler passes. Due to the heat exchange between the hot water in the coil and cold water in the boiler, the liquid inside the boiler is heated. This creates a preliminary supply of hot water for human needs.

The entire DHW system has a closed cycle of operation. If hot water is not used for a long time, it starts to cool down. When a person wants to use hot water, he will surely face the problem of the initial absence. When the tap is turned on, the system itself is activated and the water heating starts. But before the time when it heats up to the desired temperature, it may take several minutes.

In order to be able to use hot water immediately after opening the tap, they are mounted in the system, which ensures the recirculation of water around the circuit constantly, regardless of whether the person uses hot water or not.

Uninterrupted recirculation of water through the boiler is carried out using the installation additional equipment: expansion tank, reverse and safety valves, air bleed valve.

Thus, the recirculation of hot water through the boiler takes place with the help of a circulation pump, a heat exchanger and additional equipment, which is mounted in a single DHW system. As a result, a person does not have to wait until the water heats up, passing water for some time.

Boiler piping with recirculation

One of the most important and complex processes installation of a hot water supply system is a piping of a boiler with recirculation, but it is quite possible to do it yourself.

One of the most economical and efficient water heaters for home and summer cottages, experts consider an indirect heating boiler. The source of water heating can be gas, electricity or a heat exchanger. It is the heat exchanger that ensures the cost-effectiveness of using a DHW system with an indirect heating boiler.

The further functioning of the entire system depends on the correct piping of the boiler. The concept of strapping can be defined as a feature of the installation and connection of the DHW system to a source of water heating.

When installing the boiler and the entire system with recirculation, you need:

• Set a recirculation point. It is usually located in the center of the heating tank;
• supply cold water produced in the lower opening of the boiler;
• The hot water outlet must be mounted at the top of the boiler;
• The heat carrier pipe is connected from above and goes down (the water circulation of the heat exchanger will pass through the circuit, the inlet of which will be at the top of the boiler, and the outlet at the bottom).
• Pipes should be connected to the energy source in accordance with the rules for installing materials, and connected using adapters. Valves and faucets.

You should know that the efficiency of the DHW recirculation system depends on the heating system of the house. This improves the efficiency indirect water heater(boiler) by 35%.

The piping of the boiler with recirculation is carried out standard set materials: taps, pvc pipes, adapters, fittings, pumps. You need to choose only high-quality certified products from durable materials. The use of corrugated hoses and powder metallurgy material is strongly discouraged.

Boiler recirculation scheme

Recirculation of water in the DHW system is necessary in order to provide hot water to any point in the system without additional spillage. To do this, a circuit is installed through which water flows from the boiler throughout the system, and then returns back to the boiler. Recirculation is carried out using a small pump that runs completely silently. Such a system helps maintain a stable temperature of hot water anywhere in the house.

Among the common recycling schemes, there are several main options:

The choice of the method of heating water and heating, as well as the methods of its recirculation through the boiler, must be carried out in accordance with clear calculations of all consumers and the power of the coolant. Boilers with three-way or servo valves have an advantage among the main schemes.

Video about the organization of hot water recycling