Outdated home heating systems, in which the movement of water through pipes was organized by gravity, remain a thing of the past due to low efficiency. The emergence of new materials marked the beginning of the production of composite pipes. This has led to many owners seeking to choose circulation pump for heating in a private home, showing the best results compared to natural circulation.
- body made of metal or alloy, not subject to corrosion;
- electric motor;
- impeller, which is a wheel with blades.
- high productivity;
- ease of repair;
- long service life;
- Efficiency - up to 80%;
- can be installed in any plane;
- reliability;
- does not fail in the absence of coolant;
- low price.
- uniform and rapid heating of rooms;
- the track does not become airy;
- it is possible to mount a thermostat and heated towel rail;
- use of smaller diameter pipes.
- P- required quantity heat;
- S is the size of the room.
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Design and principle of operation
As the size of residential premises increases, it becomes more and more difficult to create a complex that allows increasing the temperature. As a rule, these are multi-circuit circuits that require precise calculation and design. The effectiveness of the solution also depends on the diameter of the pipes, which are large during the normal movement of water in them. Therefore, to ensure a constant flow of coolant, special pumps are installed different types, which increases productivity several times. The main parts of such a device are as follows:
After turning on the power, the motor rotor begins to rotate, which is transmitted to the supercharger blades. In this case, a vacuum occurs in the working chamber and enters the inlet line. Due to this, liquid is absorbed. It is affected by the centrifugal force that is created during torsion. The pressure increases, and water is pushed out with some pressure into the heating pipes through the discharge manifold. Circulation in the circuit and overcoming the friction force inside the line become possible due to the pressure of the coolant jet.
If you choose the right pump for the heating system, the rooms will warm up quickly. You can maintain a favorable temperature by adjusting the rotation speed of the device. In addition, resources are saved, the impact of which increases the degree of liquid.
In practice, it has been established that it is possible to save up to a quarter of the volume of gas consumed. This is possible due to the high speed of water passing along the route, which returns to the boiler not yet cooled down. Reheating it requires less energy.
11How to choose a pump for a heating system
Purpose and types
The main task of such equipment is to ensure maximum speed of coolant movement in the circuit. Design capacity in systems with forced circulation is achieved only under this condition. Side effect there is a slight increase in pressure in the circuit, which is not the main task of the device.
You can choose one of two types of units. Their design is different, but the set of tasks is the same. In order not to make a mistake in choosing which circulation pump to use for heating, you need to study the pros and cons of each of them.
The name is associated with the design features of the device. In working condition, only the impeller is immersed in water. The rotor is hermetically sealed in the housing by means of several sealing glands. Such pumps are characterized by the following positive features:
However, the attractiveness of such pumps is reduced by the high noise level and the need for regular maintenance, which consists of lubricating rotating mechanisms and replacing seals. Based on these characteristics, it becomes clear that such equipment will not be optimal for heating a private house. An example of such a design would be good in centralized networks.
How to choose a circulation pump
From the name it is clear that with this method of execution both the rotor and the impeller are located in the water. The electric drive part is housed in an impenetrable metal casing. The pump design has the following advantages:
The disadvantages include the presence of a constant coolant, low efficiency (no more than 50%) and an exclusively horizontal arrangement.
For installation in a private home, you should select a heating circulation pump of exactly this design. To summarize, the use of similar installations provides the following advantages:
Selecting parameters
Before you buy necessary equipment, you need to know the properties that a suitable model should have. This will ensure your home is warm in the coldest weather, and will also prevent you from spending extra money on purchasing a device with unnecessary characteristics.
How to choose a circulation pump
This indicator is decisive in choosing a pump. It refers to the volume that the pump is capable of pumping in a certain period of time. The unit of measurement is usually considered to be l/min, l/hour or m³/hour. For circulation unit the formula will be correct Q = P / (1.163 * (Tf - Tr)), Where:
There is another formula, Q = 3.6 * P/(C * (Tf - Tr)), in which C characterizes the heat capacity of water equal to 4.2 kJ/kg*C. You can calculate heat consumption depending on the heated area using the formula P = S * 173, Where:
Professionals advise purchasing a heating circulation pump 10-15% more powerful than the calculated value. This will allow you to avoid unforeseen circumstances in the event of abnormal cold weather.
This indicator determines the height to which the pump can lift water. It is measured in meters of mercury. Pressure is also an important characteristic for heating equipment. When calculating it, you need to take into account the losses that occur during the passage of coolant through branches, turns, narrowings and expansions of the heating main. The number of locking elements and fittings that are installed on it is also taken into account. Data on various types System pressure drops can be found in reference tables.
Calculate the pressure of circulation equipment follows the formula H = R x L x ZF / 10000, in which:
CALCULATION OF PRESSURE AND PERFORMANCE OF CIRCULATION PUMP
Additional features
One of the most necessary devices for turning the pump on and off automatically is a thermostat. Its operation ensures rational and efficient use of heating system equipment. Such devices start heating when the room temperature drops to a set point and turn off when comfortable conditions are reached. The difference in indicators can be adjusted within 2-10 °C.
Some equipment models have an “Anti-stop” function in the controllers, which allows you to avoid rotor stagnation during periods of long stoppage, for example, in summer. In addition, it is possible to turn on coolant circulation when the temperature reaches +5 °C. This option is called “Antifreeze”.
When installing automation devices, you should take into account the length of the cables with which the sensors are connected. The temperature relay is installed on the pipe and treated with thermal paste, which improves heat transfer. This ensures the accuracy of the controllers.
Installation location
The installation location is selected individually in each case, depending on the type of heating system and the number of circuits in it. If it is one or two pipes, then the pump is placed immediately behind the expansion tank and a bypass is provided. It is placed on the return line in front of the boiler.
If the owner has chosen a system with wiring at the bottom, then it becomes possible to gradually increase the number of batteries and installation additional equipment for forced circulation. This system is typical for installing a circuit in multi-storey buildings. For overhead wiring, installing a pump is not necessary. This method is intended for natural coolant circulation. In this case, the supply manifold is placed as high as possible above the heating radiators, and the return manifold is located below. Then the circulation device can be connected at an arbitrary point after the expander.
When equipping a low-rise building with a heated floor, pressure-increasing equipment is installed for each system separately. The exception is sets equipped with two electric motors. Special attention you need to pay attention to the direction of rotation, which is indicated by arrows on the pump body.
Heating circulation pump
Models of circular pumps
The cost of the equipment is determined by its main characteristics, country of origin and brand. The cheapest and not very reliable models are made in China. In order to ensure trouble-free operation for a period of time long term, it is better to pay attention to equipment from well-known companies, time-tested and recommended by the majority of buyers. The following pumps can be purchased:
Heating systems with forced circulation of coolant provide fast and uniform heating of all sections of the water circuit, regardless of the distance from the water heating unit.
Modern boilers from well-known European brands already have a circulation module installed. For modification of old heating systems and connection to energy-independent heating equipment, you will need a circulation pump for heating a private house.
Why do you need a pump in a heating system?
Circulation pumps for heating private houses are designed to create forced movement of coolant in the water circuit. After installing the equipment, the natural circulation of liquid in the system becomes impossible; the pumps will operate in constant mode. For this reason, high demands are placed on circulation equipment regarding:- Productivity.
- Noise insulation.
- Reliability.
- Long service life.
As practice shows, if you install the station in any system with natural coolant circulation, the heating efficiency and uniform heating along the entire length of the water circuit increases.
The only disadvantage of this solution is the dependence of the work pumping equipment from electricity, but the problem is usually solved by connecting an uninterruptible power supply.
Installing a pump in the heating system of a private home is justified both when creating a new one and when modifying an existing heating system.
Operating principle of the circulation pump
The operation of circulation pumps increases the energy efficiency of the heating system by 40-50%. The operating principle of the devices, regardless of type and design, is as follows:- The liquid enters a cavity made in the form of a shell.
- Inside the housing there is an impeller, a flywheel that creates pressure.
- The speed of the coolant increases and, through centrifugal force, the liquid is discharged into a spiral channel connected to the water circuit.
- The coolant enters the water heating circuit at a given speed. Due to the swirling of the water flows, the hydraulic resistance during fluid circulation is reduced.
The operating principle of a heating system with a circulation pump differs from circuits with natural circulation in that the movement of the liquid is forced. The heating efficiency is not affected by slopes, the number of installed radiators, or the diameter of the pipes.
The operation of circulation pumps may differ slightly depending on the type of design, but the principle of operation remains the same. Manufacturers offer more than hundreds of equipment models, with various performance and control parameters. Based on the characteristics of the pumps, stations can be divided into several groups:
- According to the type of rotor - to enhance the circulation of the coolant, models with a dry and wet rotor can be used. The designs differ in the location of the impeller and moving mechanisms in the housing.
So, in models with a dry rotor, only the flywheel, which creates pressure, comes into contact with the coolant fluid. "Dry" models have high performance, but have several disadvantages: it creates high level noise from the pump operation, regular maintenance is required.
For domestic use, it is better to use modules with a wet rotor. All moving parts, including bearings, are completely enclosed in a coolant medium, which serves as a lubricant for the parts that bear the greatest load. The service life of a “wet” type water pump in a heating system is at least 7 years. There is no need for maintenance. - By type of control - the traditional model of pumping equipment, most often installed in small domestic premises, has a mechanical regulator with three fixed speeds. Regulating the temperature in the house using a mechanical circulation pump is quite inconvenient. The modules are distinguished by high power consumption.
The optimal pump has an electronic control unit. A room thermostat is built into the housing. The automation independently analyzes the temperature in the room, automatically changing the selected mode. Electricity consumption is reduced by 2-3 times.
There are other parameters that distinguish circulation equipment. But for choice suitable model, it will be enough to know about the nuances listed above.
How to choose a pump for a heating system
The selection of a pump for a heating system begins with an analysis of the parameters of the room and the installed water heating equipment. Additionally, they determine what functions, in addition to increasing the coolant speed, the installed module should perform.There are several types of circulation pumps offered by different manufacturers. When choosing, you should focus on the quality and reliability of the product, as well as performance parameters.
When choosing a circulation pump for heating a private house, consider the following points:
- Power.
- Equipment manufacturing company.
- Functionality.
How to calculate the power of a circulation pump
An accurate selection based on the area of the house is made only after a thermal audit of the room and heating system. Often, the procedure is expensive, it is carried out for industrial facilities and apartment buildings. For domestic buildings with a relatively small area, there is a method for calculating a pump without formulas.You can independently select the power of the circulation pump as follows:
- According to boiler performance. The calculation of the circulation pump for the heating system of a private house is carried out, taking into account that 1 kW of water heating equipment power corresponds to the coefficient bandwidth equal to 1 l/min. Accordingly, for a 25 kW boiler, you will need to install a pump with a rating of 1500 l/hour.
- Calculation of the pressure of the circulation pump of the heating system. The technical documentation indicates the pressure parameter in meters of water column. Using this parameter, you can determine the length of the water circuit and calculate the required number of pumps in the system.
It is believed that for 10 l.m. pipeline, 0.6 m of water column pressure is required. The optimal choice of pump for a 1-story building is standard models from 6 m. Art. The stations are suitable for premises with a pipeline up to 100 running meters.
If the pressure is not enough, install a second pump or select a more powerful model. The same calculation principle is used when choosing a pump for a 2-story house.
Which brand of circulation pump to choose
The cost of a circulation pump, productivity, and operating time directly depend on the manufacturer of the equipment. It is wrong to focus only on price. When choosing a model, it would be a good idea to find out about consumer reviews regarding quality, technical and industrial characteristics.Judging by the number of sales, the following companies offer the best circulation pumps:
- – the world's largest manufacturer of pumping equipment. According to recent estimates, about 50% of all products sold belong to this brand. Grundfos models are distinguished by high reliability and performance. The company has developed and implemented several energy-saving technologies. German pumps are guaranteed to operate for at least 10 years.
- - another leader in the production of circulation equipment. The German company currently has factories located in several countries, which, however, does not affect the quality of the products. Wilo's product range includes domestic and industrial stations, as well as electronically controlled models.
- is an Italian company with many years of experience in the production of circulation equipment. Since 2002, the operating principle of DAB pumps has been improved at the company’s factories, which has led to an increase in the reliability and performance of the equipment, and also reduced noise.
- UNIPUMP is a Russian competitor to well-known foreign brands. The equipment is manufactured by Subline Service. The product range includes submersible and surface pumps. The main advantage of UNIPUMP is considered to be the low cost of equipment and complete adaptation to domestic operating conditions.
- Oasis is a model that is often offered as Russian product, actually comes from China. It has factory assembly and quality. The cost, even compared to Russian analogues, is approximately 30% cheaper, which explains the high popularity of the brand. Oasis models are guaranteed to last their entire service life. The equipment is inferior in performance and thermal characteristics to previous manufacturers.
- Wester is another brand that is promoted as English, but actually belongs to the Impulse group of companies. Sufficiently reliable models for heating and hot water systems. Wester pumps are suitable for domestic and industrial use, the only drawback is the limited range of products.
What functionality should you pay attention to?
When choosing a suitable model, you need to pay attention to a few more points:- Pump control – the most convenient and economical pumps with automatic switching on and off. The automation is connected to the room thermostat. The pressure and circulation speed of the coolant are adjusted automatically. The electronically controlled pump is already equipped with a temperature sensor mounted in the housing. Stations with mechanical switching of operating modes are cheaper. The work intensity is selected manually.
- Air removal and pressure relief - an additional bonus will be the presence of a built-in air vent, as well as a function that prevents the engine from starting at idle. Some models are additionally equipped with a pressure relief valve. When there is a power outage, the coolant quickly heats up to the boiling point. The valve prevents emergency situations.
The use of circulation pumps with an electronic control unit is most justified in heating systems of two-story residential buildings, as well as when several water circuits are simultaneously connected.
How to properly install a heating pump
A detailed pump installation diagram is included in the operating instructions. Proper installation begins with a thorough study of the manufacturer's recommendations.Connecting a pump to a heating system with your own hands is only possible with special equipment and technical skills. Any violations lead to denial of warranty service, reduced productivity and reduced service life.
- Installation closed system heating a house using circulation pumps is carried out with the obligatory connection of a backup power supply. The minimum time of autonomous power supply is at least 4-6 hours.
- One- and two-pipe heating systems with a circulation pump require the installation of a bypass. When the electricity is turned off, the forced movement of fluid in the system is replaced by natural movement. Systems with combined coolant circulation are a good solution for frequent power outages in a building.
- It is prohibited to turn on the device at idle speed in a system not filled with coolant. To check the functionality of the electric pump in the heating system, the water circuit is first filled with liquid. Then turn on the pump. If the station is selected correctly, the surface of the radiators will heat up evenly, regardless of their distance from the heating device.
- The optimal pipe diameter is indicated in the technical documentation. Narrowing the cross-section of the water circuit reduces the performance of the pump.
- Connection to the electrical network is made using special terminal connections. There is no need to connect a stabilizer. At the same time, an autonomous power supply for the circulation pump is installed. Read about choosing a UPS.
- Models with a wet rotor are mounted exclusively in a vertical position.
- A coarse filter is installed in front of the pump.
- To carry out repair work, the installation location of the pump in the system is made accessible.
If the length of the water circuit exceeds the specified capacity, the heating system is made with two circulation pumps. An additional station is installed on the coolant supply, approximately in the middle of the water circuit.
Where to put the heating pump
The installation location of the pump in the heating system is determined individually, in each individual case. The location is affected by:- Type of heating system.
- Number of circuits.
A heating system with bottom wiring has a huge advantage - the ability to gradually add radiators and install additional circulation equipment. The decision to install a system with a bottom supply of coolant is often made when installing a water circuit in a multi-story building.
A heating system with overhead wiring is usually not necessarily equipped with circulation equipment. The design is designed for natural coolant movement. The circuit is assembled so that the supply pipe is as high as possible above the radiators, and the return pipe is below them. The pump is connected to a pipeline with top wiring anywhere in the circuit, immediately after the expansion tank.
Installation autonomous heating with circulation pump in one or two-story house, with the simultaneous connection of heated floors, is carried out by installing pumping equipment on each heating system separately (with the exception of models with two electric motors). The station for heated floors is placed in a special mixing unit. Installation is carried out according to the arrows engraved on the pump body and frame.
Pump installation methods are determined individually, depending on the selected heating system and other factors.
What circulation pump speed should I choose?
Provided the performance is correctly calculated, the radiators are properly connected and the heating system is installed, in most cases it is possible to set the minimum pump speed. In this mode it is consumed less electricity, mechanical parts are subject to less wear.The pump must operate in a mode that best matches the parameters of the heating system and boiler performance. You can check the settings as follows:
- Each pump is soundproofed. During operation, the module itself makes a slight noise, comparable to a quiet hum. But, when switching to high speed, the turbulence of the water flows, when passing through the water circuit, creates unpleasant sounds. Recommended speed 1-2 switch position.
The third speed mode is used briefly to push through air pockets when filling the heating system with coolant. - Uniform heating. Adding speed is required in cases where the difference in heating temperature of radiators installed at the beginning and end of the water circuit is more than 1-2°C.
Pumps with installed electronic control automatically select the coolant speed, focusing on the supply and return temperatures, as well as the intensity of heating of the room. To select the optimal operating mode, you just need to press the start key.
After installing a circulation pump in the heating system of an individual house, economic efficiency increases by 30-40%. Such indicators make the installation of equipment not only recommended, but rather a mandatory measure.
Smooth and safe operation of the heating system country cottage- one of the first and most important issues that must be addressed during design engineering systems. Therefore, it is very important to know how to choose a circulation pump for heating a private house, what parameters need to be taken into account, and how to avoid pitfalls during operation.
When is a circulation pump needed?
The circulation pump provides a given energy flow rate in autonomous system heating (in the central system this role is performed by industrial units). The need for it arises already in the presence of one of the following factors:
wiring of 2 or more circuits;
route duration is more than 50 m;
at least with 1 level difference;
the presence of a complex circuit (warm floor system);
heating 2 or more floors;
installing a boiler in the basement;
in a heating system with free movement of energy when the temperature difference between the incoming flow and the return flow is more than 15-20 ºС;
when the temperature difference is more than 1-2 ºС in the radiators of one system.
The circulation pump creates in a short time desired speed coolant movement in all circuits, ensuring uniform distribution temperature. The difference between the outlet and inlet temperatures, when installed correctly, should be about 10 ºС, which saves fuel and ensures careful operation of the boiler. The efficiency of the system increases by an average of 20-50%, which becomes noticeable both in stable room temperature and in saving money.
Operating principle
Circulation pumps for heating private houses are a closed structure consisting of an electric motor and a working element - a flywheel or rotor.
Water enters the cavity (recess) of the pump, where it is given centrifugal motion by moving blades. Next, the water enters the spiral channel and, by inertia, with the already acquired speed, a spiral flow that reduces hydraulic resistance, flows further. At this point, a vacuum is created, into which a new portion of water is sucked in.
Pump modifications and technical parameters
Based on the design features, the pumps are characterized by the productive power of the engine, the type of rotor and control.
Engine
Accurate calculation of engine parameters is carried out for a specific heating system, but general rule The selection is simple - the power is proportional to the performance (size) of the working part.
Rotor or flywheel
There are 2 principles of rotor operation:
Dry. The rubbing parts and the rotor itself are located in a hermetically sealed housing - only the blades that create the flow come into contact with water. Such models are characterized by high power and efficiency, but are more sensitive to mechanical pollution energy carrier. It is required to undergo annual technical maintenance of the electric motor. In addition, their installation should be carried out away from living rooms due to increased level noise.
Dry rotor circulation pump – motor and blower are located in separate housings
Wet. The most common type due to its ease of maintenance, cost and variety of models. In an open design, moving parts (bearings, shafts, rotor, etc.) are in water, which is both a lubricant for them and a coolant for the engine. Appropriate stainless alloys and gaskets made of waterproof materials are used. The system is less sensitive to mechanical impurities in the energy carrier, and its service life is household appliance designed for 7 years.
In a glandless pump, the motor and blower are located in the same housing
Work management
Pump control is the choice of speed modes, on which the efficiency of the entire system depends. For heating, the minimum mode is used, while at low temperatures, rapid heat removal requires an increase in speed. To regulate this process, 2 types of control are used:
Mechanical. The speed selection is made independently, and switching is done manually. This control is effective for small circuits where the response to speed changes occurs quickly. Heating pump in a private house, most often, is purchased with such control due to its low cost and higher maintainability.
Smart upgraded models controlled by an automation system, which, depending on the temperature of the coolant, regulates the flow rate. They cost more, but when installing multi-component systems with collectors, they are indispensable. In addition, they increase energy efficiency by 25-35%.
Each manufacturer uses its own developments that promote trouble-free operation during the shelf life, so prices for models with the same characteristics differ, as well as the quality of the equipment.
The cost reduction in cheaper companies occurs due to the minimum safety margin. Most often, this means reducing the thickness of non-critical elements of parts, using less durable and cheaper materials, which are only sufficient for the specified service life. The choice of manufacturer largely determines quality characteristics products. You can navigate them by reading reviews or delving into the study of the materials used for parts.
On our website you can find contacts construction companies who offer house insulation services. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
What to consider when choosing
How to choose a circulation pump for the heating system of a private house, and what parameters you need to know for this. Since the pump is a power unit, the first selection criterion will be its power. Next, we determine the type of rotor, and lastly, the type of control.
To determine the power, you need to know the parameters of the heating system. For large objects: industrial, multi-story, measurements are taken. In private homes such accuracy is not needed, so it is enough to know:
Boiler performance. The calculation is made theoretically using the formula: W thermal boiler * K throughput (1l/min=60l/hour). For 25 kW 25*60= 1500 l/hour; for 40 kW 40*60= 2400 l/hour.
Pressure. Indicated in meters of water column. For this calculation, you need to measure the total length of the contour and multiply by a factor of 0.6 (10 linear meters correspond to 0.6 m w.s.). For contours one-story house standard equipment of 6 m w.c. is sufficient, while 2;- and more floors require the installation of a station or several pumps.
Rotor type. Affects cost and subsequent maintenance. Increased efficiency allows it to be used in complex systems. But taking into account the possibility of remote installation and regular maintenance.
Control. It also affects the cost of the unit itself, but convenience and efficiency more than make up for this drawback. In complex systems it is recommended to use only this type of control.
Pressure and air relief valve. It is not installed in all models, but you can overpay for this function, since it prevents the pump from turning on “dry” and ensures trouble-free shutdown during a power outage (the water heats up to a critical temperature, the pressure increases and the outlet valve opens).
Manufacturers
Pumps in this category, regardless of the company, must be replaced after the end of their service life, since there is a high probability of stopping due to sudden breakdowns. The units are divided by manufacturer, since each of them focuses on performance, cost and reliability, and the final characteristics of the pump differ.
European - as a rule, all work in the middle or high price segment and offer high quality. The price reduction occurs due to optimal constructive solutions and marketing policy, including the transfer of production to China.
The German manufacturer stands out for its high quality and efficiency Grundfos– these models are equipped energy saving technologies. The declared service life is at least 10 years.
Company Wilo also produces high-quality industrial and household models, mainly with electronic control.
DAB- Italy. With regular maintenance, the pumps work flawlessly. The company spends a lot of money to eliminate noise in dry-type pumps.
Chinese - in addition to the price, you should pay attention to the company.
The company's models have proven themselves well Oasis. First of all, this is the cost, which is 30% less than Russian and European analogues. At the same time, operation is guaranteed throughout the declared service life.
Russian ones, like other participants, work in accordance with European GOSTs and comply with all safety requirements.
Among Russian manufacturers, the most famous company is the Subline Service brand. UniPump. Manufactures pumps of various types. The models are characterized by their low cost and the use of the most efficient technologies.
Wester belongs to the company "Impulse". Produces products in a limited range. The pumps are distinguished by good assembly and the use of parts with a high margin of safety.
Company Gilex models " Master" And " Compass" The line includes pumps for small circuits and 2-3 storey systems.
Where to install the pump correctly
When installing pump for heating private houses, how to choose installation location is no less important question than the direct characteristics of the equipment. Here you need to take into account the operating principle of the unit, the type of system and the number of its circuits.
One of the options for connecting a circulation pump to the heating system
The pump can be installed both at the inlet and outlet, providing convenient access to it for technical inspections and maintenance. In most cases, they prefer to install pumps at the inlet so that the pump pumps water at a lower temperature, but the main criterion is still ease of maintenance.
Video description
You can see the installation of supply or return pumps in the video:
Important! Installing a pump between radiators or in front of the expansion tank creates vortex flows that disrupt the direction of movement, creating temperature differences in different parts of the system. It is therefore very important that the pump is located between the boiler and:
radiator system;
collector;
expansion tank.
In a double-circuit system, with the connection of “warm floors”, a separate pump is installed for each circuit.
Installation of the system, which includes a circulation pump, is carried out with the connection of a backup power supply with a operating reserve of 4-6 hours.
For 1;-2-circuit systems, the installation of a bypass is mandatory, since in the event of a power outage it will ensure the natural movement of energy flow in the system.
For reference! A bypass is a bypass, a small section of pipe with a shut-off or adjustable fittings, sometimes with a check valve. It is built to bypass the circulation pump and, when it stops, ensures free flow movement.
The operation of the pump can only be checked when the system is full. Main indicative correct installation– uniform heat distribution between all radiators.
Pumps with a wet rotor type are installed in a vertical position.
Installation of a coarse filter is required, and installation of a fine filter is desirable.
The pump must be located in a place accessible for maintenance.
After all the calculations, add 20% of the rated power, so you will ensure gentle operation of the equipment in the optimal mode of 85-90%, excluding operation at the limit of possibility.
Solid fuel boilers
This type requires separate consideration. When the electricity is turned off, the pump stops, but heating of the energy carrier in the boiler continues: it is impossible to quickly extinguish burning wood or coal, after 3-5 minutes the temperature will reach critical levels and the pressure relief valve will operate. If the pump is installed on the outlet pipe, the reset occurs after 4-6 minutes, while its installation on the return pipe increases this time to half an hour.
Video description
You can see the installation of a pump in a system with a solid fuel boiler in the following video:
Price factor
When choosing a circulation pump, the cost of the device itself and its efficiency in operation are important. As a rule, the operation of the pump is justified by savings on fuel consumption, and the cost of the model itself is determined by its performance. In Moscow, the price range for pumps is very large. Conventionally, they can be divided into 3 categories:
For 3.5-7 thousand rubles you can buy basic functions, with a minimum operating life and most often one-time use;
Devices costing 7.5-20 thousand are “workhorses” that accurately provide the declared characteristics, with a service life no less than that specified by the manufacturer and with several degrees of protection and an optimal safety margin;
VIP systems with full automation, dialing additional functions, a high safety margin and the ability to provide heat to a large volume will cost from 20 to 45 thousand rubles.
Video description
And some more thoughts about circulation pumps in the following video:
Advantages of a separate pumping unit
The use of pressure equipment is justified from the point of view of saving fuel and increasing boiler efficiency, which is why many companies integrate pumping units into boilers. But installing the unit separately has its advantages: quick replacement without removing the boiler, the ability to control the process in case of emergency situations (for example, using a bypass). In addition, the pump can be installed in a system not provided for by the project at the initial stage.
Conclusion
Despite the apparent simplicity of the choice, the parameters of the pump must be technically justified, for which mathematical calculations are carried out taking into account the laws of heat engineering, the individual characteristics of the system, therefore the exact choice must be made by a specialist who takes into account all factors based not only on theoretical knowledge, but also on practical experience.
Operation modern systems heating systems that use forced movement of coolant through heating circuits would be impossible without a circulation pump.
It is this device that ensures the movement of coolant along the lines of the heating system, underfloor heating system, and hot water recirculation system. In complex multi-circuit systems of houses with a large area and number of floors, there may be several such pumps.
The effective heat transfer of a heating system directly depends on the compliance of the parameters of the circulation pump with the parameters of the system as a whole. To navigate the topic , how to choose a circulation pump for a heating system, let’s get acquainted with its structure and main parameters.
Pump device
Let's look at the cross-section of the pump. It consists of the pump itself and an electric motor with a control unit. The body material can be: stainless steel, bronze, aluminum, cast iron. An impeller made of stainless steel or technopolymer, fixed to the motor shaft, by its rotation creates a forced movement of fluid through the pump. The axes of the inlet pipe and the outlet axis are usually located along the same line. The bearings and shaft of modern circulation pumps are made of ceramic, which has a beneficial effect on the noise level and durability of the device.
Technical parameters of the circulation pump
The functionality of the device can be found in its technical data sheet. Knowledge of the following parameters will help you choose a circulation pump for heating:
- Pump flow (flow, productivity) is a volumetric value (unit - m 3 / h), numerically equal to the maximum volume of water that the pump can pump through itself in one hour.
- The pressure of the circulation pump is the maximum value of hydraulic resistance that all elements of the heating circuits provide to the movement of liquid, and which the pump is able to overcome (at its flow rate = 0). Measured in m (meters).
- Pump characteristic is a derived quantity determined by the relationship between the pump pressure and its performance. So for a single-mode (single-speed) pump there is only one characteristic, for two or more - respectively two and... What can we say about pumps with continuously variable output?..
Classification of circulation pumps
Circulation pumps from different manufacturers do not differ significantly from each other. All of them are classified by rotor type. There are:
- wet rotor pumps
- pumps with a “dry” rotor.
Devices of the first type are distinguished by the fact that the rotor is in a liquid, and its chamber is separated from the stator by a stainless steel sleeve. The advantages of such a pump include: its compactness and noiselessness, no need for lubrication (the coolant plays the role of a lubricant, as well as a cooling medium). However, such devices are characterized by lower efficiency compared to “dry” pumps.
Dry-type pumps do not have direct contact of the rotor with the coolant of the system. Waterproofing is provided by sealing rings made of stainless steel, carbon agglomerate or ceramic. The high level of “fit” of the rings to each other and their rotation leads to the formation of a thin film of water between them, ensuring sealing of the electrical part of the pump. The pressure spring constantly tightens the rings as they wear, ensuring their “self-fitting”.
And before you select a circulation pump for the heating system, you should remember that it is advisable to “register” such a pump in a separate room. Distinctive feature“dry type” devices have a fairly loud operating sound.
Marking of circulation pumps
After the name of the pump brand, numbers are indicated on its body. For example, Grundfos UPS 25-50.
The first two numbers are the diameter of the connecting pipes. In our case, 25 mm (1 inch) is the thread diameter of the nuts supplied with the circulation pump.
The second number means maximum height rise of coolant in the system. In our example, the lift height is 5 m, that is, it can create excess pressure of up to 0.5 atm.
According to these values, a circulation pump for heating is selected after theoretically calculating the pressure of the circulation pump and calculating the power of the heating circulation pump.
By the way, the power consumption of the pump is adjusted in steps (3 positions) or smoothly (electronic control of the pump motor). You can find out about the current consumption at a certain output power from the plate attached to the pump body.
Pumps equipped with an electronic control unit are more economical and are able to independently regulate their performance characteristics by analyzing the flow and pressure of water in the system.
The circulation pump is calculated based on the need building structure in heat - this value is the base point when calculating the circulation pump for heating. The value is taken to correspond to the coldest time of the year. According to SNiP 2.04.07-86 “ Heat networks” for one- or two-story buildings per 1 m2 of total area 173-177 W/m2 at an “overboard” temperature of -25 - 30 °C. Houses with three or four floors have indicators from 97 to 101 W/m2, respectively.
By multiplying this “norm” by the number of “squares” of the heated room, we obtain the amount of heat required by the building.
Also, the calculation of the parameters of the circulation pump can be performed based on the power of the boiler.
The required value is calculated using the formula:
$$Q=\frac(N) (t_2 — t_1)$$
\(Q\) - calculated value corresponding to the pump flow rate, (liters/h);
\(N\) - power of the main heater (boiler), (W);
\(t_2\) - temperature of the coolant at the inlet to the supply pipe (at the outlet of the boiler), (°C);
\(t_1\) - temperature of the coolant in the “return” (at the entrance to the boiler), (°C).
Substituting the necessary parameters into the formula, we obtain the required pump flow.
The temperature of the coolant “leaving” the boiler is usually in the range from + 85 to 95 °C, the “return” temperature is in the range of 60-70 °C.
The amount of pressure required to overcome hydraulic resistance is determined using special formulas. For a simplified selection, you can use the following information:
- straight sections of pipes have a resistance of 100-150 Pa/m, which is equivalent to the required pump pressure - 0.01-0.015 m for each meter of the main pipeline.
Attention! The calculations take into account the total length of the circuit (supply and return pipes).
- Fittings take up to 30% of the calculated “direct” resistance;
- Three-way mixer - 20%;
- Thermostatic valves - 70%.
This is interesting!
When calculating the hydraulic resistance of the entire heating main, the height (number of floors) of the building is not taken into account. That is, the height to which the pump will have to raise water does not play a role here!
This is explained by the fact that the system is closed. Therefore, the height of the supply line is equal to the height of the return line - the columns of liquid in them are balanced with each other.
The total hydraulic resistance is determined only by the sum of the resistances of all turns, tees, valves...
Using the calculated pressure and flow data, determine necessary characteristics pump, which is then selected from the catalog.
Since when selecting a circulation pump for the heating system we operated on the maximum data on the load on the pump, for its daily operation it will be enough to choose a less powerful option. It will be “quieter” at a lower cost, and will “eat” less electricity.
Installation features
When installing pumps, the following rule must be taken into account: “The pump shaft must be horizontal!”
Such devices “pump” the coolant in only one direction. Therefore, when installing the pump, it is necessary to observe the correct direction of its installation.
You can choose a circulation pump for heating with natural circulation. In this case, the existing heating system with natural circulation of coolant is modernized by installing a circulation pump. A pump “embedded” in such a system makes it possible to improve the uniform heating of all radiators. In addition, gas savings of 20-30% have been practically noticed when integrating such a pump into heating circuits.
The pump is installed on a bypass, embedded in the “return” of the system, and it is necessary to install in the main pipe check valve, which will allow the system to function even in the event of a sudden power outage.
To uniformly heat all rooms of the house, special equipment is needed to ensure the movement of coolant through the pipeline.
This important element is circulation pumps for heating private houses, which increase heating performance.
It is necessary to select the correct parameters that correspond to the needs of the heating system of the house.
Technical Parameters
Pumps supply coolant by rotating blades located inside its body. When considering circulation pumps for heating systems and technical characteristics, the following must be taken into account:
- productivity - the amount of liquid passed per hour of its operation. It is measured in cubic meters per hour and is determined by the hydraulic resistance of the pipeline;
- pressure – the parameter indicates the maximum height to which the pump raises a column of water;
- maximum temperature. Since the device will pump heated water in the system, it must withstand temperatures up to 110 degrees Celsius. When choosing, you need to make sure that the equipment is designed for it;
- Pumps with nozzle diameters of 25 or 32 mm are often used.
Usually the calculation is made using the first two parameters.
The need for room heat
Before choosing a circulation pump for heating http://ovk.dp.ua/nasosy/, you need to calculate the heat demand of the heated room. Professional designers produce it using special formulas. When it is not possible to access them, you can select the required value approximately, taking into account the size of your room.
According to building rules and regulations, in the Moscow region for single- and two-story houses sufficient power is 173 kW/sq.m, and for three to four floors - 98 kW/sq.m. The total heat consumption is found by simply multiplying this value by the area of the entire room.
Equipment performance
To calculate it, use a simple formula: G = Q / (1.16 x ΔT), where Q is the previously found heat demand; ΔT is the difference between two temperatures: supply and return. For a conventional two-pipe system this is 20 degrees C, and for a heated floor - 5 degrees C.
For a house with an area of 100 sq.m., the calculation will be as follows:
Q = 173 x 100 = 17300 kW.
G = 17300 / 1.16 x 20 = 745.689 = 746 cubic meters/hour.
Pressure
Calculation of a circulation pump for a heating system includes calculating the pressure required to overcome the resistance of the line. You can find its value in various ways, depending on whether a new system is being installed or the pump will be built into an existing one.
For a new one, this value is calculated using certain formulas using the values specified for fittings, pipes, etc.
For an already installed system, the exact value of this parameter is difficult to find; it is calculated approximately:
- the passage of 1 m of heating pipeline requires 0.01-0.015 m of pressure;
- heat loss in fittings is approximately 30% of the previous parameter;
- the non-return valve, as well as the three-way valve, prevent the normal circulation of the coolant, therefore they are estimated at 20%;
- thermostatic valves installed to regulate room temperature.
The value is calculated as follows: H = R x L x ZF, where:
R is the resistance of straight sections (it is better to take into account the maximum value of 0.015 m);
L – the length of the pipes forming the heating system (two-pipe – the return is also taken into account);
ZF is a coefficient: if conventional ball valves and fittings are installed, it will be 1.3 (indicated 30% losses), and if a thermostatic valve or throttle that breaks the circuit is 1.7.
Necessary calculations
For example, it is necessary to calculate a circulation pump for heating a square house with an area of 100 sq.m - for a single-pipe heating system.
Chokes or thermostats are installed directly on heating devices, and rupture of the main ring is excluded.
The length of each wall is 10 m. The total length of the pipes in the circuit will be 10 x 4 = 40 m. Substituting the values into the above formula, you can find the required pressure: 0.015 x 40 x 1.3 = 0.78. It is also necessary to take into account that the selected pump must have a headroom of at least 10%.
Nuances of choice
Having calculated the required values (the combination of these parameters is called the operating point), the desired model is selected. In principle, any of them is suitable, the technical characteristics of which are no worse than those calculated. However, before choosing circulation pumps for heating systems, you need to take into account the following nuances:
- Usually when calculating productivity, they take into account heaviest loads, which can occur at the lowest temperatures of the season. However, the heating system rarely operates in this mode - only a few days throughout the year. Therefore, if it seems that the pump power is more than necessary, it is better to choose a model whose parameter in question is slightly less;
- try to find the position of the calculated operating point on the flow-pressure characteristic curve for each of the proposed pumps. Choose a device where the operating point is located closest to the graph;
- you should carefully select such equipment, because a model with insufficient power will not be able to provide the required pressure, as a result, the radiators will not heat up to the required temperature;
- however excess capacity is also not needed, since electricity consumption will increase, and the noise level may also increase;
- It is undesirable for the diameter of the pump nozzles to be smaller than the diameter of the pipes - otherwise it will not be able to maintain the required pressure.
By calculating the power, you can choose the model that is most optimal for economically heating your home.