Which pump is better for heating a private house. Choosing a circulation pump for a heating system: calculation of pump performance and recommendations from professionals. Calculation of the power of the circulation pump for the heating system

In order to mount a water heating system with forced circulation, it is necessary to correctly select and install a circulation pump in it, which will provide it. Currently, there is a wide variety of models of different designs and with different characteristics. Which one and how to choose? In this article, we will look at how to select a circulation pump for a heating system on our own.

Main selection criteria

In order to select a circulation pump for a heating system, it is necessary to determine its main characteristics that will be required during its operation: the working head (pressure) and the flow (flow) that it must provide. And in order to determine them, it is necessary to know both the power of the heating system itself and its hydraulic resistance. Both of these indicators can be calculated more accurately, using complex calculations, or simplified, using a calculation that almost anyone can do. We will consider it.

Heating system power and required flow

As we have already said, when selecting a circulation pump for a heating system, first of all, it is required to determine its thermal power. It must correspond to the amount of heat required to heat the building, which, in turn, is determined by its area and the level of thermal insulation of external structures (walls, floors, ceilings, windows, doors). To calculate this indicator accurately, it is necessary to take into account their thickness, material, design and other factors.

In order to simplify the calculation, you can take an average of 100-150 W of thermal energy for every 1 m 2 of a room, with a ceiling height of up to 3 m. If the building is insulated well enough, you can take a lower value. So, for example, a well-insulated house with an area of 100 m 2 will require heating with a thermal power of 10 kW. If the circulation pump is to be installed in an already existing system with natural circulation, then its power can be found from the technical characteristics of the boiler that is installed.

Now, knowing the required heating power, you can determine the required performance (flow) of the circulation pump using one of the following formulas:

P \u003d Q / (1.16 x ΔT),(kg/h)

Q- thermal power of the heating system (W);
∆T- the temperature difference between the supply and return pipes (for two-pipe systems it is usually taken within 20 ° C, and for a warm floor - about 5 ° C);
1,16 is the coefficient of specific heat capacity of water, Tue× h/kg× °С(for other types of coolants, this indicator will be somewhat different and can be found in reference literature or on the Internet).

Another formula by which you can calculate the required performance:

P \u003d 3.6 x Q / (c × ΔT),(kg/h)

Where: With– specific heat capacity of the coolant (for water is 4,2 kJ/kg×°С).

For example, for the heat power of 10 kW considered above and a two-pipe water heating system, according to the first formula, we obtain:

P \u003d 10000 / (1.16 × 20) \u003d 431 kg / h or 0.43 m3/h(for heat carrier-water 1kg=1l).

Hydraulic resistance and required head

In order to make the selection of a pump for a heating system according to this parameter, it is necessary to calculate the hydraulic resistance that it will need to overcome in order to ensure the normal circulation of the coolant (water). You can use the following formula to calculate:

J = (F+R× L)/p× g(m)

L– length of the system to the most distant radiator (m);
R- hydraulic resistance of the straight section of the pipe (Pa / m);
p- heat carrier density (for water - 1000 kg / m 3);
F– resistance of connecting and stop valves (Pa);
g– 9.8 m/s2 (gravitational acceleration).

For accurate calculation of the value R And F can be found in the reference literature. For a simplified one, you can take the averaged data obtained experimentally:
R— within 100-150 Pa/m;
F- depending on the type:

in each connecting fitting, an additional 30% is lost to the losses in the straight pipe in this section;
in a three-way mixer or similar devices - additionally up to 20%;
in thermostats - up to 70% of the losses in a straight pipe.

In addition to the above, you can use another formula proposed by experts from the well-known German company Wilo:

J=R× L × k, m

Where: k- coefficient taking into account the resistance in shut-off and control valves and which has the following values:

1.3 - for simple systems without complex fittings;
2.2 - with control valves;
2.6 - for more complex ones.

If one pump will circulate in a heating system with several circuits (branches), then for its selection it is necessary to take into account their total resistance. If it is planned to install a separate pump for each circuit, then each such branch of the line must be calculated separately, both in terms of thermal power and hydraulic resistance. At the same time, the number of storeys of the building, when calculating the pressure, does not play a big role. Since in a closed system the liquid columns of the supply and return lines are balanced.

How to choose a circulation pump according to the data received

Having now calculated and knowing the main required parameters of the characteristics of the circulation pump, you can easily select the required option using the performance graphs that are in the instruction manual or passport of any model. As a rule, such graphs have two axes: head (pressure) and flow (flow).

Rice. 1 Example of a circulation pump curve

We can plot the results obtained earlier on the existing chart, plotting their values along the corresponding axes, and at their intersection get a working point, which should be slightly below the line IN graph showing the characteristics of a given pump (the best option is A2). If the point is above ( A3) - such a pump is not suitable, it will not be able to provide the necessary circulation. If the operating point is significantly below the graph ( A1), this is also not very good, since it will provide circulation, but having too much supply, it will consume more electricity, and its cost will also be higher than a pump with more modest characteristics.

Rice. 2 Selection of the pump according to the graph of its characteristics

If the model has not one, but 2 or 3 speeds, then there will be 2 or 3 lines on the performance graph, respectively. In this case, it is necessary to select a pump for the heating system according to the schedule of the speed at which it is supposed to operate.

Other factors influencing the choice

The selection of a circulation pump for a heating system, in addition to the main characteristics discussed above, is also influenced by other factors, such as: reliability, workmanship, operating temperature, cost, connection method, etc.

Workmanship, reliability, and durability tend to be directly related to cost. Manufacturers that offer reliable and high-quality models, such as Grundfos (Denmark), Wilo (Germany), DAB, Lowara, Ebara and Pedrollo (Italy), evaluate their products accordingly.

wilo circulation pump in a heating system

Domestic or Chinese models are cheaper, but the guarantee of their quality, respectively, is lower. Here, everyone must make a choice himself, choose a quality product at a higher price or buy a cheaper circulation pump, with the knowledge that it may soon have to be changed.

If you want to save money, you can also buy used Grundfos or Wilo, they can often work normally longer than new Chinese ones, but it’s better to buy them from familiar, trusted specialists who give a certain guarantee.

In addition, when choosing, it is necessary to pay attention to the type and diameter of the connection between the pump and the pipes of the system. Some models are equipped with connecting elements such as "American", and some will have to be selected independently.
Another parameter that you need to pay attention to is the temperature regime for the operation of the circulation pump, which should be in the passport. This is especially important if it will be installed on the supply pipe in a system with a solid fuel boiler. In this case, the maximum allowable temperature must be at least 110°C. If, however, the pump will be installed on the "return", then this is not so important, since the temperature at the boiler inlet rarely exceeds 80 ° C.

When addressing issues with the organization of heating their own homes, the vast majority of homeowners prefer a water heating system. Methods for generating heat can vary depending on the availability of energy sources, the types of fuel prevailing in the region, the cost-effectiveness of one or another approach. That is, in fact, the boiler can be installed depending on the circumstances, gas, electric, solid fuel - long burning or with automatic fuel supply, diesel, etc. But the distribution of thermal energy in rooms in in most cases is done through circulating through the pipe circuits - water or a specially selected technical fluid.

When designing a water heating system, independently or with the involvement of specialists, it is necessary to competently approach the choice of all units, assemblies and components, from the boiler and radiators to pipes and the last valve - everything must fully comply with the planned parameters of the system being created. One of the key roles is played by the water pump for heating, as the system Equipped with forced circulation device, it always has stable performance and high efficiency. Therefore, this publication will be completely devoted to the nuances of the design of pumps, the criteria for their selection and the basic installation rules.

Do I really need a circulation water pump for heating?

Surely, many of the economical owners will wonder - is it possible not to "bother" with the pump at all. Indeed, in a small house with slightly branched circuits, it can be organized according to the scheme of natural circulation.

Yes, of course, there is such a possibility. To do this, it is necessary to correctly position the expansion tank, select pipes of the appropriate diameter and mount them with a certain slope, optimally arrange the heating radiators. In a word, when one speaks of the simplicity of a system with natural circulation, this statement is highly doubtful.

The main advantage of natural circulation - non-attachment it to the electrical supply (unless, of course, the boiler itself is non-volatile). In all other respects, it is significantly inferior to forced circulation.

Thermotechnical calculations show that even with the most optimal conditions - high efficiency of the boiler, rational placement of all components, clean pipes not overgrown with deposits and a minimum of shut-off or other reinforcing elements, a natural increase in pressure due to temperature differences and creating a slope will be within 0.6 atmospheres. This is clearly not enough to overcome strong hydraulic resistance in an extensive network, or even in case of force majeure circumstances - a narrowing of the internal clearance or even a short stop of the gas boiler can lead to imbalance heating systems, and it will take a long time to “bring to life”.

So, we summarize the advantages and disadvantages of natural and forced circulation:

1. The advantages of natural circulation, as already mentioned, include only complete energy independence and the relative simplicity of tying the boiler itself. But the disadvantages are a whole list:

- The need to use pipes of different, including sufficiently large diameters, which leads to an increase in the cost of the project and to difficulties in installation. The system requires very careful heat engineering calculations, with precise observance of slopes, with the obligatory consideration of the excesses of the location of some elements over others and with other nuances.

- The transfer of thermal energy over considerable distances (heights) is simply impossible. Both the height and the length of the created outline are limited.

- The low rate of natural movement of the coolant leads to completely unnecessary energy losses, uneven distribution of heat throughout the premises, and hence to a decrease in the overall efficiency of the system and its efficiency.

- A system with natural circulation is very difficult to make any fine adjustments, optimization of heat flow distributionby by house placements.

2. And now - about forced circulation in the heating circuits.

Its disadvantages are attributed to dependence on availability - in the event of a power failure, the heating system stops.

- Well, firstly, nothing prevents organizing the entire system in such a way that it can work in both modes - it is enough to install the pumping unit on the " return" before entering the boiler. For example, the figure reproduces the same scheme, but indicating the location of the tie-in of the circulation pump. The binding procedure will be discussed below.

- Secondly, we agree that now is still not the "dawn of the electrification of the country." And, hand on heart, let's give ourselves an honest answer to the question - how often, how regularly and for how long in a particular area (city, village) turn off the electricity. If these are just annoying episodes associated with some emergency situations, then everything can be solved by installing an uninterruptible power supply system. The power consumption of circulation pumps is usually very small, and even a small UPS will make it easy to keep the entire heating system in working order.

If, of course, there are still places where interruptions in the supply of electricity are systematic and prolonged, then in these settlements, of course, it is better to organize heating according to the natural circulation scheme.

The forced movement of the coolant in the water heating system is provided by a circulation pump capable of pumping liquid with a temperature of 110 ... 115 ° C. In private houses and apartments with individual heat sources, low-noise devices of the household series with coupling connection are used, equipped with a “wet” rotor (the engine armature is washed and cooled by flowing water).

If you decide to choose a pump for heating yourself, consider 3 main criteria:

Specifications - performance, working pressure.
Connecting and overall dimensions.
Product price, brand popularity.

Consider the points on how to choose the right circulation pump for the radiator system, underfloor heating and the primary boiler circuit.

The most "running" models of pumping units

Manufacturers offer a wide range of equipment of different capacities, designed for pumping liquid media with different parameters. But we are only interested in flow models operating in home heating and hot water networks.

How to distinguish circulation units from centrifugal and other types of pumps:

in form - the electric motor and the impeller are installed in one housing, the pipes go out on the sides of the lower part (not in the middle);
by the presence of a "wet" rotor, which significantly reduces the noise of rotation of the impeller;
2 standard sizes with mounting length 130 and 180 mm;
conditional passage of branch pipes - 15, 20, 25 and 32 mm, accession - coupling (threaded);
passport pressure - 0.4, 0.6 and 0.8 bar.

These parameters are easy to find on the labeling of the product. Example: the numbers in the name Wilo Star-RS 15/4 indicate the inner diameter of the connecting pipes 15 mm (DN 15) and the pressure of 4 m water column (0.4 bar). Second example: Grundfos ALPHA2 25-60 is connected to DN 25 pipes and develops a pressure of 0.6 bar (6 meters).

Reference. Typically, manufacturers produce extended product lines. The German brand Wilo offers circulation blowers with a head of 2, 4, 6, 7 and 8 m of water. Art. But the "running" models still remain "fours" and "sixes", less often - "eights".

Wet rotor pump device

Of course, there are more powerful pumps, whose pressure reaches 1 ... 10 bar, but they are not used in private homes. Small units 130 mm long with ½ and ¾ inch nozzles are usually placed inside the boilers, large ones (18 cm, 1 and 1 ¼") - crash into the heating mains.

Pump selection methods

The most correct way is to make a full-fledged hydraulic calculation and accurately determine the main parameters of the pump - the developed head and performance. This is how the centralized heating supply of apartment buildings and industrial buildings is designed.

Not all craftsmen involved in the installation of autonomous water systems are proficient in engineering calculation methods, to say nothing of ordinary homeowners. How can I choose a circulation pump for heating in a simpler way:

In the case of replacing an old worn-out unit, a new one with similar parameters is purchased. The price and quality of the product comes to the fore.
Order a project for a home heating system to a heating engineer. Below we will explain the advantages of this option.
Calculate the required pump pressure yourself using a simplified method.
Believe in many years of practice and buy the device, guided by their advice.

Boiler room made by our expert Vladimir Sukhorukov. Easy access to all equipment, including pumps

Expert recommendations. In country houses and apartments up to 250 m², a household pump is enough, developing a pressure of 4 m of water column or 0.4 bar. For a square of 250 ... 500 m², it is better to buy a more powerful unit with a head of 6 m (0.6 bar), over 500 m² - 8 m of water. Art.

Ordering engineering calculations and developing a circuit costs money, but it will pay off with interest. When you install heating yourself or hire workers, components and equipment are purchased with a decent margin - just in case. An intelligent designer will clearly justify why it is necessary to install a low-power pump and a smaller diameter pipe. As a result, there will be savings on materials, and in the future - on electricity costs.

Types of pumps used in autonomous heat supply schemes

If you trust only numbers or want to check the installers, choose the heating pump according to your own calculations, using the method below. Do not forget to compare the design characteristics of the unit with the recommendations of experts - the result will certainly come out the same.

Calculation of pump characteristics

Heating works efficiently when all radiators or underfloor heating circuits receive the required amount of heat. That is, the pumping unit must provide the required flow rate of the coolant in each section of the system, overcoming the hydraulic resistance of pipes, fittings and fittings.

G is the mass flow rate of the coolant, kg/h;
Δt is the difference between the temperature of the water in the supply and return lines, in calculations it is usually assumed to be 20 °C.

Reference. Since the density of water changes little when heated within 100 degrees, in simplified calculations, the mass flow is assumed to be equal to the volume flow. Example: G = 300 kg/h = 300 liters per hour.

For example, heating a two-story house with an area of 200 m², located in the middle lane, will require 22 kW of heat. From here it is easy to calculate the coolant flow rate and the required pump capacity: G = 0.86 x 22000 / 20 = 946 kg / h = 0.95 t / h = 0.95 m³ / h.

It is immediately proposed to find out the cross section and diameter of the main line coming from the boiler where it is planned:

F is the cross-sectional area of the pipe, m²;
ʋ - the speed of water movement, taken 0.5 ... 1 m / s.

The lower the water flow rate, the lower the resistance to friction against the walls of pipes, fittings and fittings.

We take a value of 0.6 m / s and determine the cross section of the line: F = 0.95 / 3600 x 0.6 = 0.00044 m². Further, using the circle area formula, we calculate the diameter of the passage - 0.024 m or 24 mm. Accordingly, the internal size of the pipe and the connecting fittings of the pump is 25 mm.

Having found out the required performance of the pumping device, we proceed to the calculation of the available pressure. We will carry out calculations separately for the radiator network, floor heating and the boiler piping circuit.

Heating circuit with batteries

The task of the pump is to push the required volume of coolant through the pipes from the first to the last radiator. It is prevented by the force of friction of the liquid against the walls, resistance from the narrowing of the flow in the control valves and turns on the fittings.

To find out the amount of resistance that the circulation unit must overcome, we suggest using a simplified formula:

H is the desired pressure drop in meters of water column;
R - specific friction resistance, is considered in m. of water. Art. per 1 meter running pipeline;
L is the length of the longest heating branch, measured from the heat source to the last radiator;
Z is the coefficient of local resistance.

Comment. The formula is greatly simplified, the engineering calculation of hydraulics is much more complicated. But it allows you to choose the right heating pump for domestic conditions. We checked an alternative option - online calculators posted on various Internet resources. Having received a difference between the results of 30%, we conclude: it is better to calculate the pressure manually.

The length of the branch is measured from the outlet of the boiler to the last battery installed on the 2nd floor. With a two-pipe scheme, the result is doubled

How the calculations are made:

Advice. The length of the line of dead-end and ring circuits is considered the same - plus the length of the supply and return. For a single-pipe "Leningrad" we take the total length of the ring. If there is no scheme at the time of calculation, the length is determined by the internal dimensions of the house: the size of the 1st floor + the height of the ceiling + the width of the 2nd floor.

Let's calculate the pressure according to our example. The length L according to the dimensions of the building is (10 + 3 + 10) x 2 = 52 m, Z = 2.2. The required pressure will be 0.015 x 52 x 2.2 = 1.716 ≈ 1.7 m. Let's add a margin of 1 m for the unaccounted resistance of the boiler itself and additional equipment, we get 2.7 m of water column.

On the graph attached to the pump passport, we mark the performance and pressure line, then select the appropriate model, in this case, the Wilo Star-RS 25/4 brand.

As you can see, the results of the calculations do not contradict the advice of experts: a pump with a pressure of 0.4 bar is enough to make water circulate through the heating network of a two-story house with an area of 200 square meters. For a better understanding, we suggest watching the progress of the calculations on the video:

An important point. In modern injection devices, 3-7 operating modes are often provided, and the same number of graphs are drawn in the instructions. To calculate, select the characteristic corresponding to the average speed (second - third).

Underfloor heating hinges

Usually, the coolant is supplied to the floor circuits by a separate pump, which is paired with a mixing valve. At the same time, the maximum length of the loop does not exceed 100 meters, there are no shaped parts. Local resistances - manifold thermostatic valve and mixing three-way (or 2-way) valve.

The previous algorithm is quite suitable for the calculation:

We find out the number of circuits, the maximum length of the pipe and the total coolant flow through the comb. We have described everything in detail in a separate publication.
We take the longest loop and calculate the required pressure of the pumping unit from it, using the above formula. We substitute similar values for R, L and Z.
We select a pump for floor heating loops according to the schedule presented in the product passport.

Example. Let's take the same two-story house with a heat load of 22 kW and a water flow of 0.95 m³ / h, the maximum loop length is 80 m. The value of R is 0.015, Z is 2.2, then the head H = 0.015 x 80 x 2.2 = 2.64 m. take into account, since the boiler is equipped with its own pump. This means that the final pressure of the collector unit is at least 2.64 m.

Note that by increasing the length of the loops to 100 m, you raise the pressure bar of the pump, which will lead to an increase in energy consumption. We check: H = 0.015 x 100 x 2.2 = 3.3 m. Draw the corresponding horizontal line on the diagram and select any model whose graph is placed above. The nearest unit is Wilo Star-RS 25/6.

boiler circuit

An important nuance. The main thing is to ensure the required water flow in the main circuit, corresponding to the power of the heat generator. To select a pump model, follow the same path - find out the required volume of coolant from the boiler performance and calculate the available pressure. Detailed instructions are presented in the video:

Choice by size

You probably noticed that in the assortment of companies there are units with the same characteristics, but different dimensions and sizes of nozzles. How to choose pump external parameters:

For mounting on pipelines and floor heating mixing units, standard 180 mm blowers are used. "Shorty" 130 mm are placed inside heat generators or on highways in a very limited space.
The diameter of the connecting pipes is selected according to the cross section of the main pipeline. An increase in size is acceptable, a decrease is strongly discouraged. That is, a unit with 32 mm fittings can be installed on the Du 25 pipeline.
Pumps with nozzles Ø32 mm are used on primary rings and boiler circuits, as well as in modernized gravity systems.

The performance characteristics of the pumps do not depend on their installation length - 130 or 180 mm

Note. The dimensions of the ready-made bypasses sold in stores are adjusted to a standard pump with an installation length of 18 cm.

The number of supercharger speeds does not play a special role. At home, 3 modes are quite enough, the optimal speed is the second. The air from the units is bled through the side screw, so you should not buy products with a separate air vent.

Manufacturers and prices

Despite the wide range of pumps in stores, it is not easy to choose a truly high-quality product. The market is flooded with Chinese goods and fakes of famous brands. To begin with, we list manufacturers popular in the CIS:

The highest price category is Grundfos (Denmark), Wilo (Germany). Prices for the original "Germans" start from 75 euros, "Grundfos" UPS series - 65 euros.
The middle category is DAB, Aquario (Italy), Sprut (quality China). The cost of units of various models ranges from 40-100 euros.
Other cheap pumps (Oasis, Neoclima, Whirlwind, Caliber, and so on ad infinitum). Price - from 20 euros per piece.

The latest development is the Grundfos Alpfa-3 "smart" pump, which transmits information to a smartphone and helps to balance the system

Comment. It is likely that we did not include some very worthy products in the highest or middle price category. Here are the most popular brands.

What is the difference between inexpensive and counterfeit pumps from high-quality superchargers:

service life - 1 ... 3 heating seasons;
the product number is applied only on the sticker, the body of the unit is clean;
pumping devices from the same batch often come with the same numbers;
in terms of weight, the fake is noticeably different from the original (it is lighter);
a low-quality unit starts to make noise and squeak, having worked out 1 heating season, the case is very hot.

Sometimes fake heating pumps are indistinguishable from the original, only the price is half that. The secret is in the aluminum winding, which reduces the cost of the product. How to check: find the mass of the original model on the official website of the company and compare it with the market copy. Most likely, an informed seller will refuse to weigh a counterfeit device or immediately recognize the unknown origin of the goods.

Final Conclusion

When choosing a circulation pump for heating a house, it is important not to make a mistake with the characteristics and not to chase cheapness. Insufficient pressure will lead to weak heating of distant batteries, excessive - to the appearance of noise in the radiators and rapid wear of the blower unit. The last advice for choosing a manufacturer: if you want to save money, it’s better to find a used branded original, it will last longer than a new cheap “Chinese”.

From the author: hello dear readers! The issue of selection of heating pumps is very important for owners of houses without public heating. In modern apartments and houses with autonomous heating, the choice in favor of circulation pumps is very common.

After analyzing the proposed market range, you will not only save on electricity and increase heat transfer, but in the future you will be able to avoid the troubles associated with breakdowns. How to choose pumps for heating private houses? To get the best option, you need to know what criteria to pay attention to and how to install this equipment on your own.

The circulation pump provides a normal flow of its coolant - water or antifreeze. This is necessary to maintain a normal temperature in the rooms, and also saves energy, which, thanks to circulation, is distributed evenly throughout the system.

Using the right pump, you will significantly save on gas and wood, as well as reduce electricity costs.

Types of pumps

When buying a circulation pump, it is important to know that these systems are of three types. The main difference is energy sources - air, ground or liquid (water).

The ground energy system is efficient, but more suitable for private homes. The temperature of the soil is not subject to sudden changes, and therefore this method is considered stable.

Air pumps are often used in Russia, the implementation of this heating method will not be difficult.

A system with a water source of energy is the most efficient and popular today - a water supply system or even a reservoir can serve as a heat source.

Ground source of energy is a proven and reliable method, in the presence of a small land plot, ground energy is used for heating. The stability of the method lies in keeping the soil temperature practically unchanged for many years.

Principle of operation

To choose the option of the heating pump you need, it is important to know what type of design it belongs to. There are two types: wet and dry rotor devices.

A dry rotor is isolated from the pumped water and, compared to a wet rotor, has a higher efficiency. It is recommended to install it in a separate room due to the increased noise flow. It is quite large and, moreover, not easy to install.

The wet rotor is much smaller, easy to operate and easy to replace blocks. The device is immersed in water, which cools and lubricates the running engine.

Source: obustroeno.com

Pump design

It will be much easier to select a pump for heating if you understand the principle of its operation and understand what its design can be. The basic principle is the forced movement of water or another source of energy. Such a system provides fast heating, due to which the temperature in the room itself rises.

The pump casing consists of different materials and contains several elements:

rotor;
rotation rotor;
rotary shaft;
electric motor;
impeller.

The wheel consists of two discs connected by blades and located opposite to each other. The blades have two holes, thanks to which the liquid and the impellers move. There is also a hole on the body itself that converts water energy into pressure. Thus, the coolant cools and lubricates the rotor shaft, while moving in the right direction. The rotor is mounted on bearings and is isolated from the stator of the electric motor, which is located under the stainless steel tank.

The principle of operation of the circulation pump resembles a drainage pump. There is an impact on the liquid and direction to the pipeline. The wheel is in motion, and from this the suction pipe creates a vacuum and circulation of the coolant.

The efficiency of the circulation pump depends not only on which device you choose, but also on the correct installation and accurate calculations, which will be discussed later.

Criterias of choice

When choosing a pump, you need to pay attention to the following characteristics:

connection. Here the main point is the diameter of the pipe for mounting the pump itself. Usually it is 25 or 32 mm (1 or 1.25 inches). The kit also includes union nuts corresponding to the diameter of the inlet and outlet, which greatly facilitates the installation and dismantling of the pump;
pump power. This information can be found in the enclosed instructions for use. Typically, power readings are between 60 and 300 watts. In some embodiments, these values may be higher. This should be paid attention to immediately, as soon as the question arose of how to choose a pump for heating private houses. Based on these parameters, the temperature scheme of the entire heating system is built. In private houses, for example, it usually does not exceed 80 degrees;
performance. This is an indicator of the volume entering the pipeline for a certain time period. The flow depends on the power of the boiler, and the performance, in turn, on the cross-section of the pipes of the heating system and also affects its performance. The pressure is measured by the meter of water supplied by the pump;
pressure. For the correct calculation, you need to measure the length of all pipes and multiply the readings obtained by 100 Pascals. The result should be no more than 10 thousand. In the accompanying documents of the pump, sometimes not the pressure, but the lifting height may be indicated. For the average buyer, this criterion is more understandable. Based on it, it is easier to choose the right pump. When installing a heating system designed for several floors, pumps with low power and a lifting height of, for example, 4 meters may not be suitable.

After completing all the necessary calculations and having studied the technical documentation, you can decide which pump is best for you to choose.

Terms of use

If you hear extraneous noise, do not immediately worry about possible malfunctions. Most often, such noises are formed by stagnant air in the pipeline. This problem is easy to fix on your own.

Open the valves corresponding to the source of the noise.
Leave the pump on. Repeat the above steps.

Below you can open a video about buying a circulation pump and go through all the instructions point by point on how to choose a pump for heating private houses.

Power parameter

When choosing equipment, buyers often pay attention, first of all, to the power indicated in the characteristics, and try to purchase heaters with higher power readings - as they say, "in reserve". In reality, such a measure of foresight is undesirable and even harmful to the heating system. Circulation pumps are driven and are not designed to pump cubic meters of water to irrigate fields. Choosing a pump for a heat supply line will become much easier if you pay attention to some data:

the power of the boiler for heating must always be higher than the power of the pump;
the length and diameter of the pipes most often has a cross section of ¾ or 1 inch. With such indications, the heat carriers of the heating system with a power of 12 to 30 kW, designed to heat 120–300 sq. meters, are consumed at a rate of 15-30 liters per minute. For lengths exceeding 80 meters, a second pump is required.

The norm with a correctly selected and installed pump is:

the pressure of a ten-meter pipe is 0.5 meters;
the average temperature indicator of the coolant is 95 degrees at the outlet of the boiler and 65 degrees at the return entrance.

Technical engineers of thermal services at thematic meetings provided evidence that for heating a private house with an area not exceeding 100 meters, a pump with a power of 25 kW is enough.

Additional characteristics that you should pay attention to in order to choose the right pump:

nutrition. Pumps can operate both from an uninterruptible power supply with a power of only 12 volts, and from the mains;
ways to control air release. Pumps have manual and automatic control. The automatic mode completely eliminates the need for human intervention, which is a significant advantage, since it is usually necessary to seek the help of professionals to remove accumulated air.

Almost all types of pumps on the market have three speed settings for fast switching when climate conditions change. If the temperature drops, you can increase the speed of rotation of the rotor, due to which the coolant will enter the radiator of the heating system much faster.

From the above, it is clear that the selection of a pump for each private house is carried out individually. It is better to install a pump with a dry rotor on objects with a large area that are not intended for human habitation, or in separate premises. For a private house, you should choose a pump with a wet pump and low noise output, with the option of automatic air discharge. It is recommended to accurately calculate the power in accordance with the area of \u200b\u200bthe house, even if you have to pay a little more.

Basic requirements for installation

To install the circulation pump and its further most efficient use, several important rules should be considered:

the expansion tank is installed 1 meter above the highest point of the heating system;
all radiators must be equipped with an air vent system (using a Mayevsky crane or automatic);
all rooms should have a bypass to bypass the system in the event of a critical situation, such as a sudden power outage. The best option would be to install an uninterruptible power supply that excludes or minimizes such failures.

In addition, with self-installation, you should learn how to make accurate calculations, taking into account the following nuances:

the pump pumps approximately 1 liter of liquid at the rate of 1 kW of power;
A 10-meter circuit length consumes 0.6 m of water pressure, respectively, a device with a reading of 60 is required per 100 m;
the average velocity of the coolant is approximately 1.5–2 m/s.

When making calculations, do not forget about the diameter of the pipes, guided by the principle: the thinner the diameter, the higher the pump power.

Installing a pump in a heating system

Firstly, it is necessary to prepare the working area by freeing the system from liquid, as well as stock up on all the necessary materials and tools. Then threaded joints are made on the pipes in accordance with the diameter of the holes of the device.

Advice: before installation, a cleaning filter is installed in front of the device, which is recommended to avoid subsequent repairs due to the accumulation of sand and dirt.

For correct installation of the device, it is necessary to ensure that the arrow on the pump housing coincides with the direction of fluid movement.

It is important not to forget about the installation of valves at the inlet and outlet of the pipes (shut-off valves and a check valve), as well as a bypass to improve operating conditions and possible repairs.

Usually the pump is installed horizontally, and if this condition is recommended for dry rotors, then it is mandatory for wet rotors.

After direct installation, check the reliability of all available connections and carry out a test run of the heating system, having previously filled it with coolant using the lower pipe. Thanks to this method of filling, the air in the pipes will rise into the expansion tank, and from there it will be removed from the system.

The circulation pump is mounted both on the supply pipe, for gentle operation when exposed to high temperature conditions, and on the return pipe. At the same time, installation on the supply pipe is more efficient, since many modern devices can withstand very high temperatures, 10–110 degrees. Wet rotor pumps are installed on the supply pipe, and dry rotor pumps are installed on the return pipe.

Leading manufacturers

In the modern pump market, Grunfos and Wilo devices are considered the most popular and reliable. The latter have earned the trust of customers due to long-term operation without interruption and build quality. These devices are made in Germany and the price for them is quite high. The most popular models of this brand are RS 25/4 and Star RS-25/6.

Grunfos devices are also in demand due to their low price and good quality. These pumps are manufactured in Denmark and, if used properly, can last up to 10 years. The most popular models are UPS 25/40 and 25/60.

Pumps of these brands will serve you for a long time. You should not buy fakes from China, because the confidence in a warm and safe home is worth the money spent. In addition, the funds and forces spent on repeated repair work may exceed the cost of a high-quality pump, and as a result, the device may malfunction.

Important: choosing a good circulation pump will help you to take into account the maximum permitted load of the device for its operation in an acceptable power range. This will ensure good and long pump operation.

The following tips will help you distinguish the original from the fake:

a fake is always much cheaper than the original;
sellers of such devices will assure you of its reliable performance, which is in no way inferior to the original, but do not forget that with this purchase you will not receive a real warranty, which, in the case of the original, is at least 5 years.

By the way, sellers of fakes also provide a guarantee - however, often it does not exceed six months. To avoid buying a low-quality device, pay attention to a few differences:

the original paintwork must be even over the entire surface and without defects;
the country of manufacture must be indicated on the device;
the pump model is indicated on the packaging of the device;
the serial number of the pump must be the same both on the packaging and on the device itself;
The set includes an instruction manual and a warranty book.

Having studied the step-by-step instructions for the device itself and the advice of experts with the provided photos and videos, you got an idea of how to choose pumps for heating private houses. Following all the recommendations, you can independently choose the right place for installation, make calculations and install a circulation pump. All the best, and see you on the pages of our site!