How to choose a circulation pump for hot water. Choosing a circulation pump for a heating and hot water system

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, accustomed to counting every ruble, to lower cold water, expecting hot, this is a luxury. In order not to wait and save money, you can solve the issue by installing circulation pump. 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 DHW systems, 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 working and will do this until a comfortable value for the person is reached.

Even more interesting model from GRUNDFOS - UP PM pump with permanent magnet motor 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 that the electronic unit of the pump memorizes the consumption schedule hot water people living in the house and builds work on its basis.

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 operates in temperature mode for two weeks. 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. Taking into account all possible nuances, electronics determines the optimal model of 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 casing of this series of pumps 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 be added that Grundfos (Russia) is one of the few on the market that takes care of customers throughout the entire warranty period of the 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.

We are all accustomed to the fact that in the hot water supply system, water moves solely due to the main pressure. On the one hand, this is not bad, but such a plumbing scheme has one significant disadvantage- opening the tap, we wait until it drains cold liquid, and only after that we enjoy the benefit of civilization called "hot water". Agree, a little wrong. It is this problem that the DHW circulation pump is designed to solve, which we will talk about in detail in this article - together with the site, we will talk about how it works correct system hot water supply in a private house.

Circulating pump for hot water photo

DHW circulation pump: what it is used for and how it works

The fact that by installing a pump for hot water, you will not wait until cold liquid flows from the tap, you already understood. The principle of operation of this pump remains not entirely clear. It is simple and consists in the device of a closed circuit, through which hot water constantly circulates. That is, a ring along which water makes an endless movement and is periodically heated to a predetermined temperature. A faucet or a mixer can be connected anywhere in this ring.

Anticipating your next question, I will say that hot water does not enter this circuit through a heating device that uses fuel to heat water. This circuit is powered from the heating boiler through a special heat exchanger, called - the water here is heated by. In fact, a battery (coil) is mounted inside such a boiler, upon contact with which water is heated. Is not instantaneous water heater- this storage boiler, which has at least five connection pipes. Two of them are used for connecting to heating, two for hot water circulation (supply and return, so to speak) and one for cold water inflow into the tank.

Recirculation pump for hot water photo

If you describe the cycle of operation of such a unit, then it looks like in the following way. When the tap on the mixer is closed, the water, thanks to the circulation pump, moves in a circle and is heated by the coil to the maximum temperature limit. As soon as you open the mixer, water flows - at the same time into the tank indirect heating fresh cold water comes from the water supply, which is immediately heated from the coil. In general, the same thing happens here as in a conventional electric one, only instead of a heating element, it uses a coil.

When and how it is advisable to use a circulation pump for hot water

Such a scheme of hot water supply in the house is not always appropriate - in short, in not big houses for 3-5 rooms it is unjustified. For such cases, the usual double-circuit is suitable - the short length of the hot water supply lines will not make you wait long for the heated water to flow from the tap. Another thing - big houses with several bathrooms and a sophisticated heating system. Here it shows itself one hundred percent with a circulation pump. What tasks are solved in this way?

1. First of all, the presence of hot water in the tap is constant - not a second of waiting until you get heated water.
2. The second point is the increase in pressure in the system. In large houses, as a rule, pipes stretch for a long distance - the result of a long pipe length is a weakening of the pressure in the system, which compensates for the hot water recirculation pump.

These are the main tasks of the hot water ring circuit. As a bonus, it provides a couple more benefits.

Among other things, the pump itself allows you to save resources. He can do this solely due to the possibility of programming the on-time. Let's just say that hot water is not used at night, which means that there is no need for a circulation pump for hot water supply. Therefore, you need to program it so that it turns on half an hour before you go to the bathroom. What is the savings here? In the termination of circulation - the water in the circuit heats up quickly, and the heat exchanger stops taking heat from the heating circuit. In turn, the coolant in it cools less, as a result of which less fuel will be needed to heat it up to a given temperature.

How to choose a hot water pump

First you need to understand the difference between a heating circulation pump and a DHW pump. It consists of three points. First of all, it is the ability to withstand a certain temperature of the coolant. If heating circulation pumps are able to work with a coolant heated to almost 100 degrees, then DHW pumps can only withstand heating up to 65 degrees. Secondly, pumps for heating are made of cast iron, and pumps for hot water are made of brass. And, thirdly, pumps for hot water supply at home have a smaller power reserve.

At first glance, it may seem that you can install an ordinary one in a hot water supply system - unfortunately, this is not the case. These two types of pumps are not interchangeable, which must be taken into account first of all when approaching the issue of choosing a circulation pump for a hot water supply system.

In addition, when choosing this equipment, it is necessary to take into account the following points.

Also, approaching the issue of choosing a circulation pump for hot water, one should also mention the double pumps for hot water - they simultaneously supply the coolant to the indirect heating boiler, and push the hot water heated by it through the pipelines. The thing is good, but expensive - separately, these two pumps will cost less.

And finally, I will say a few words about modern pump manufacturers who have already managed to establish themselves exclusively with positive side. Grundfos is considered the undisputed leader in this industry today - it supplies to the market economical pumps equipped with multiple protections. Pumps of this brand are protected against dry running and, as a rule, have built-in pressure sensors. Second manufacturer pumping equipment The one worth paying attention to is Wilo. German by origin, which offers circulation pumps for hot water, as they say, for every taste and color - in the range of these products you can find pumps with a mechanical timer, and with electronic control. As they say, for all occasions and for any budget. And an economy option called DAB - despite low cost, the company produces very high-quality equipment with rather big warranty period operation.

- a device designed to pump liquid through the hot water supply system at home. With this equipment, you can heat the room, supply all the taps hot water.

Using a circulation pump allows you to save on electricity and avoid water overruns. The main thing is to take responsibility for choosing a model, choosing a unit that can fully satisfy your needs.

The use of a circulation pump for hot water supply (DHW)

The essence of the operation of the circulation pump is the constant distillation of water through the system, which does not allow it to cool. The installation of such a device will significantly improve living conditions in a private house, if there is a need for constant availability of hot water, heating water in the pool or heating.

In homes where water heaters are installed to provide hot water, you have to drain a decent amount of liquid until hot water flows, and this significantly increases its consumption. The optimal way out is the selection of a circulation pump that minimizes the differences between centralized and autonomous water supply.

Thus, there are three main tasks that can be solved by installing this equipment:

• Hot water supply;
• Air conditioning;
• Heating.

The principle of operation of the circulation pump: the main closed-type pipeline passing through the entire building, with pipes extending from it to all water supply points, is connected to the boiler.

Hot water continuously circulates through the system, which allows households to get water at the desired temperature at any time, simply by opening the tap. They do not have to drain cold water, waiting for the liquid to heat up. A return pipeline is connected to the tank so that unused liquid flows back.

The circulation pump at high working capacity, has small size, affordable price, consumes little energy, does not make noise and is easy to install, which makes it more attractive to consumers.

What parameters should be guided by when choosing?

The pump should be selected according to its characteristic, which is the dependence of two indicators on each other:

pressure

The flow must be sufficient to ensure all water points good pressure , taking into account possible hydraulic losses. The greatest value of the hydraulic resistance of the system, which the pump is able to overcome is called the maximum head. Head is measured in meters of water column.

Performance

Before choosing, it is necessary to calculate the maximum load of the system and compare it with the pump performance. Usually in the house the value of hydraulic resistance is within 0.1 - 0.2 atm. The highest value of the pumped amount of coolant per unit of time is the maximum performance.

Not superfluous in the functions will be protection from lime deposits, low noise level during operation, low power consumption.

Also when choosing optimal model, it is worth considering the operating conditions: type of boiler for hot water, required liquid temperature, pipeline diameter, etc.

Optimal choice

Device design

There are two varieties this device: with dry and wet rotor.

Units of the first type are distinguished by large dimensions and noise, lack of natural lubrication, since the rotor remains dry (the device is separated from the pumped liquid). But pumps with a dry rotor are characterized by high performance (up to 70%), because the engine is less susceptible to heating from the coolant.

Wet rotor pumps, on the other hand, are small in size and practically do not make noise during operation. The impeller and rotor are installed directly in the pumped liquid, which provides both lubrication and cooling, and contributes to the absorption of operating noise.

Due to the accumulation of deposits on the surface of the device, the rotor may jam, you need to regularly inspect the equipment.

The temperature range at which the unit is able to function normally is much wider for pumps with a dry rotor than with a wet one. In connection with these "dry" are more often used in industry, and "wet" in private homes, especially since the latter are cheaper.

In addition, there is a division according to the type of connection: with a flange and a coupling connection.

Models in which the suction and discharge pipes are located in the same line can be embedded in the system. Fastening occurs with the help of special frames.

Unit Performance

Pay attention to the following factors:

1. You should not buy a unit whose performance is much more than the value you need. In this case, energy overexpenditure is possible. For a private house, a device with a pressure of 3-4 meters is enough.
2. It is worth choosing a model from proven and well-established manufacturers in the market.
3. When buying a device, consider the temperature environment, to prevent it from freezing, which will lead to malfunctions.
4. The larger the diameter of the pipeline, the more powerful the pump will be required.

If the unit is not intended to be used permanently (seasonally or as a make-up for the main system), do not apply great importance its power. The loads on it will be small, which means it makes no sense to overpay.

• the device must be installed on a pipeline of the diameter for which it is intended. Otherwise, you will have to sacrifice pressure;
• the presence of a timer will allow you to set the operating mode of the pump, and it will automatically turn on during the highest fluid consumption.

Modern models are equipped with special sensors that save water and energy: thermostat, timer, auto-settings.

Cost calculation

The circulation apparatus can be purchased from 5,000 rubles or more, depending on the technical characteristics and brand of the manufacturer.

Grundfos brand pumps - prices in the range of 8000 - 15000 rubles with a head of 1.20 m.w.st., DAB 7000 - 9000 rubles with a head of 1.60-5.70 m.w.st., Wilo 5000-7000 with a head 2-6 m.w.st. respectively. The price of consumed energy is approximately 720 rubles or 200 kW per year.

These small expenses will allow you to use hot water at any time, heat the room and even warm the water in the pool.

The use of a circulation pump can significantly reduce water consumption, because now you do not have to wait and drain the water until it warms up.

Learn more about the circular pump by watching the video:

Special functions allow not only to save fluid consumption, but also the use of electricity: various thermostats, timers, sensors allow you to control the operation of the device, turning it on and off at the right time.

Devices that provide 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 cause 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:

exists 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.

In order to ensure constant circulation of hot water in private homes, you should buy a modern pump. Most often, for these purposes, circulating equipment for water is used, which, providing a permanent movement of liquid along closed loops greatly enhances the comfort of life. Otherwise, such a pump is called a recirculation pump, because it has the ability to timely circulate and recirculate water in the same circuit many times. It is for this reason that such a pump is indispensable element heating systems, as well as hot water.

True, this equipment has a serious limitation - it cannot be used for pumping and pumping liquid, which is important when organizing drainage systems, as well as sewer structures. For pumping and pumping any (cold, hot, clean and dirty) water, you will most likely need a different type of pumping equipment - for example, a centrifugal electric unit. These devices are very actively used in the organization of drainage and sewer systems life support of buildings and household plots. For example, from the timely pumping and further pumping of rainwater from basements and from adjoining territory depends on their condition.

Why do you need a circulation pump?

So that you always have hot water in the tap at home, which will quickly flow from the faucet spout, you can choose the option that is best for you:

Buy and install household appliances at home electric water heaters, which will raise the water temperature to the desired user;

Buy a double-circuit boiler for heating systems, which has a second function - hot water;

Install a circulation pump in the water supply system, which increases the pressure and provides a quick supply of hot water, regardless of the remoteness of the draw-off point.

We suggest you go the last way, because modern circulation pumps are the most effective devices to solve such problems.

How can pumps differ from each other?

When choosing the right device, it is important to consider what it has specifications. First of all, pay attention to power. This parameter determines how low the consumption electrical energy the device will have, whether it is economical in maintenance, how much it will consume in order to pump a certain volume of liquid.

Other equally significant characteristics should also include performance indicators (what efficiency has the electric motor of pumping equipment).

What determines the reliability of the device?

The sale of electric pumps is a very common business, however, it is necessary to find not just a seller, but specialists who can correctly calculate the performance and power of the unit. For example, by contacting us for a purchase and consultation, you can be confident in the professionalism of the recommendations received and the quality of the purchased products.

It is important to correctly calculate the pressure that will be required in order for the pumping of water through the pipeline to be permanent. Max level potential pressure is 4.5 bar, and the minimum can be anything, the main thing is that the pumping device performs its function, and the water supply pipe is constantly filled with water.