Where is the best place to put the pump on the supply or return?

Pump Selection Recommendations

The circulation pump installed in the heating system of a private house must perform its basic functions well. Each device has specific requirements.

The unit must have the necessary productivity or performance. The calculation of this parameter is carried out under conditions of minimum load on the device.
Another selection criterion is the pressure that provides the necessary pressure in the pipes and the entire system. In this case, the operating conditions must be taken into account. They depend on the volume of the premises, the type of liquid in the system, the ambient temperature and the coolant itself. Of great importance is the diameter of the pipes used.
When buying, it is imperative to take into account external factors related to the size of the unit, the noise level during operation, and the complexity of maintenance.

The right choice of the pump ensures its reliable and stable operation, long-term operation in difficult conditions.

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, it is determined what functions, in addition to increasing the coolant velocity, the installed module should perform.

There are several types of circulation pumps offered by various manufacturers. When choosing, you should focus on the quality and reliability of products, 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 the circulation pump

Accurate selection according to the area of the house is done only after a thermal audit of the premises and the heating system. Often, the procedure is expensive, it is carried out for industrial facilities and apartment buildings. For domestic buildings, a relatively small area, there is a method for calculating the pump without formulas.

You can independently select the power of the circulation pump as follows:

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 power of the water heating equipment corresponds to a throughput coefficient of 1 l / min. Accordingly, for a 25 kW boiler, you will need to install a pump with an indicator of 1500 l / h.
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 p.m. pipeline, 0.6 m head of water column is required. The optimal choice of pump for a 1-storey building is standard models with 6 m. Art. The stations are suitable for rooms with pipelines 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-storey building.

Which brand of circulation pump to choose

The cost of the circulation pump, performance, operating time, directly depend on the manufacturer of the equipment. Focusing only on price is wrong. When choosing a model, it will not be superfluous 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:

Grundfos is 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 work for at least 10 years.
Wilo is 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. The Wilo range includes domestic and industrial stations, as well as electronically controlled models.
DAB is an Italian company with many years of experience in the production of circulation equipment. Since 2002, on the basis of the company's plants, the principle of operation of DAB pumps has been improved, which has led to an increase in the reliability and productivity of the equipment, as well as reduced noise.
UNIPUMP is a Russian competitor of 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 the low cost of equipment and full adaptation to the conditions of domestic operation.
Oasis - a model that is often offered as a Russian product, actually comes from China. Has a factory assembly and quality. The cost, even compared to Russian counterparts, is approximately 30% cheaper, which explains the high popularity of the brand. Oasis models are guaranteed to work for the entire period of operation. The equipment is inferior in performance and thermal characteristics to previous manufacturers.
Wester - another brand that is promoted as English, is actually owned by the Impulse group of companies. Sufficiently reliable models for heating and hot water systems. Wester pumps are suitable for domestic and industrial applications, the only negative is the limited range of products.

Types of circulation pumps

The design of a typical circulation pump consists of a housing made of stainless metal, a ceramic rotor and a shaft equipped with a wheel with blades. The rotor is driven by an electric motor. This design provides water intake from one side of the device and its injection into the pipelines from the outlet side. The movement of water through the system occurs due to centrifugal force. Thus, the resistance that occurs in individual sections of the heating pipes is overcome.

All such devices are divided into two types - dry and wet. In the first case, there is no contact between the rotor and the pumped water. Its entire working surface is separated from the electric motor by special protective rings, carefully polished and fitted together. The operation of dry-type pumps is considered more efficient, however, quite a lot of noise occurs during operation. In this regard, separate isolated rooms are equipped for their installation.

When choosing such models, one should take into account the presence of air turbulences formed during operation. Under their influence, dust rises into the air, which can easily get inside the device and break the tightness of the sealing rings. This will lead to the failure of the entire system. Therefore, as a protection between the rings, there is a very thin water film. It provides lubrication, preventing premature wear of the rings.

Wet type circulation pumps have a distinctive feature in the form of a rotor that is constantly in the pumped liquid. The location of the electric motor is securely separated by a sealed metal cup. These devices are usually used in small heating systems. They are much less noisy during operation and do not require additional maintenance measures. Typically, such pumps are periodically repaired and adjusted to the desired parameters.

A significant disadvantage of these pumps is considered to be low efficiency due to insufficient tightness of the sleeve separating the stator and coolant.

When choosing the right model, you should pay attention to the fact that the pump has not only a wet rotor, but also a protected stator

The latest generations of circulation pumps are almost completely automated. Smart automation ensures timely switching of the winding level and significantly increases the performance of the device. Such models are most often used with a stable or slightly changing water flow. Thanks to the stepwise adjustment, it became possible to select the most optimal operating modes and significant energy savings.

Varieties of circulation pumps

The wet rotor pump is available in stainless steel, cast iron, bronze or aluminium. Inside is a ceramic or steel engine

To understand how this device works, you need to know the differences between the two types of circulation pumping equipment. Although the fundamental scheme of the heating system based on a heat pump does not change, two types of such units differ in their operation features:

The wet rotor pump is available in stainless steel, cast iron, bronze or aluminium. Inside is a ceramic or steel engine. The technopolymer impeller is mounted on the rotor shaft. When the impeller blades rotate, the water in the system is set in motion. This water simultaneously acts as an engine cooler and lubricant for the working elements of the device. Since the “wet” device circuit does not provide for the use of a fan, the operation of the unit is almost silent. Such equipment only works in a horizontal position, otherwise the device will simply overheat and fail. The main advantages of the wet pump are that it is maintenance-free and has excellent maintainability. However, the efficiency of the device is only 45%, which is a small drawback. But for domestic use, this unit is perfect.
A dry rotor pump differs from its counterpart in that its motor does not come into contact with the liquid. In this regard, the unit has a lower durability. If the device will work "dry", then the risk of overheating and failure is low, but there is a threat of leakage due to abrasion of the seal. Since the efficiency of a dry circulation pump is 70%, it is advisable to use it for solving utility and industrial problems. To cool the engine, the circuit of the device provides for the use of a fan, which causes an increase in the noise level during operation, which is a disadvantage of this type of pump. Since in this unit water does not perform the function of lubricating the working elements, during the operation of the unit it is periodically necessary to carry out technical inspection and lubricate the parts.

In turn, "dry" circulating units are divided into several types according to the type of installation and connection to the engine:

Console. In these devices, the engine and housing have their own place. They are separated and firmly fixed on it. The drive and working shaft of such a pump is connected by a coupling. To install this type of device, you will need to build a foundation, and the maintenance of this unit is quite expensive.
Monoblock pumps can be operated for three years. The hull and engine are located separately, but are combined as a monoblock. The wheel in such a device is mounted on the rotor shaft.
Vertical. The term of use of these devices reaches five years. These are sealed advanced units with a seal on the front side made of two polished rings. For the manufacture of seals, graphite, ceramics, stainless steel, aluminum are used.When the device is in operation, these rings rotate relative to each other.

Also on sale there are more powerful devices with two rotors. This dual circuit allows you to increase the performance of the device at maximum load. If one of the rotors exits, the second one can take over its functions. This allows not only to enhance the operation of the unit, but also to save electricity, because with a decrease in heat demand, only one rotor works.

How to install heating batteries

Location of radiators

Radiators are designed to transfer thermal energy from the coolant to the room. In fact, they compensate for heat losses in the building. Therefore, before installing a heating radiator, you should choose its location correctly.

The best option is the place of the greatest heat loss in a house or apartment - external walls and window structures. This must be foreseen at the design stage of heat supply. Then you should decide how to properly install the radiators and choose the connection method:

Upper. It is applied at vertical distributing of pipelines;
Side. The method is appropriate for horizontally located highways;
Lower. The best option for hidden installation of pipes.

Types of radiator connection

The efficiency of the battery depends on the correct choice of this parameter. The figure below shows how to properly install a heating radiator regarding the method of connection to the system.

Another important point is the location of the heater relative to walls and window structures. It is necessary to install a heating radiator so that it provides free air circulation. Almost all heat supply batteries work on the converter principle. Those. air flows must pass through the maximum area of the devices. In order to properly install heating batteries, you should follow these recommendations:

The distance to the window sill is at least 10 cm. At the same time, it should cover only 2/3 of the batteries.
The distance of the lower part of the radiator from the floor is 12 cm.

For proper installation of a heating radiator, it is necessary to first insulate the walls. You can increase the heat transfer rate using a reflective surface. Most often, foam with a foil layer is used for this.

Tying heat supply radiators

Strapping example

Ensuring the normal operation of radiators is possible only with proper piping. Its elements must perform the functions of protecting and regulating the degree of heating of the heater.

Correct installation of radiators depends on its type and design. Most often, manufacturers in the instructions indicate the optimal installation schemes. The following components are used to tie the batteries:

Mayevsky crane. Designed for the timely removal of air congestion;
Temperature controller. It is necessary to regulate the volume of coolant inflow;
Stop valve. With its help, you can disconnect the radiator from the general heating system for further repair or replacement.

At the end of the installation, the tightness of all nodes is checked and the device is pressure tested.

During installation, the radiator or battery must not be skewed. This can lead to air pockets, as well as degrade the performance of the heating system.

The video shows how to install a heating radiator yourself.

What are good pump heating systems

30 years ago, so-called steam heating was widespread in private houses, where a heat carrier was used, circulating through pipelines and batteries by gravity, and a gas boiler or wood-burning stove served as a heat source. Pumps for pumping water were used only in district heating networks. When more compact units appeared, they migrated to private housing construction, as they provided the following advantages:

The speed of movement of the coolant has increased. The heat generated by the boiler has become faster delivered to the radiators and transferred to the premises.
Accordingly, the process of heating the house is significantly accelerated.
The higher the flow rate, the greater the throughput of the pipe. This means that the same amount of heat can be delivered to the rooms through lines of smaller diameter. Simply put, pipelines have become half the size due to the forced circulation of water from the pump, which is cheaper and more practical.
Highways can now be laid with a minimum slope and make arbitrarily complex and extended water heating schemes. The main thing is the correct selection of the pumping unit in terms of power and pressure generated.
The domestic heating circulator made possible underfloor heating and more efficient pressurized closed systems.
We managed to get rid of the ubiquitous pipes passing through the rooms and not always in harmony with the interior. Increasingly, heating communications are being laid in walls, under flooring and behind suspended (stretch) ceilings.

Note. A minimum slope of 2-3 mm per 1 m of the pipeline is needed to empty the network in case of repair or maintenance. Previously, it was made at least 5 mm / 1 m.

Pumping systems also have disadvantages, where without them. This is the dependence on electricity and its consumption by the pumping unit during the heating season. Therefore, with frequent power outages, the circulation pump must be installed together with an uninterruptible power supply or connected to an electric generator. The second drawback is not critical, if you choose the right power of the device, then the electricity consumption will be acceptable.

For reference. Leading heating equipment manufacturers such as Grundfos (Grundfos) or Wilo (Vilo) have developed new models of units that can save energy. For example, if you buy and install an Alpfa2 circulation pump from the Grundfos brand, it will automatically change performance depending on the needs of the heating system. True, its price starts at 120 USD. e.

New generation products from Grundfos - models Alpfa2 and Alpfa2L

Pump device

Since the motor stator is energized, it is separated from the rotor using a glass made of stainless steel or carbon material.

The main elements that make up the circulation pump are:

housing made of stainless steel, bronze, cast iron or aluminum;
rotor shaft and rotor;
a wheel with blades or an impeller;
engine.

As a rule, the impeller is a construction of two parallel disks, which are connected to each other by means of radially curved blades. One of the discs has a hole for fluid to flow through. The second disk fixes the impeller on the motor shaft. The coolant passing through the engine performs the functions of lubrication and coolant for the rotor shaft at the place where the impeller is fixed.

Since the motor stator is energized, it is separated from the rotor by a cup made of stainless steel or carbon material. The walls of the glass are 0.3 mm thick. The rotor is fixed on ceramic or graphite sliding bearings.

2 Pump design, its advantages and disadvantages, manufacturers

The circulation pumps for the heated towel rail are equipped with a single-phase electric motor with a squirrel-cage rotor with a constant or variable speed of rotation.

The unit is made according to the "wet rotor" type. The impeller (impeller) of the pump and the rotor of the electric motor rotate in the pumped liquid. It also cools the electrical part and lubricates the bearings.

The "wet" working cavity, in which the impeller and rotor rotate, is separated from the motor windings by a hermetically pressed stainless steel cup.

Pump bodies intended for connection to heating risers are made of bronze or brass, and impellers are made of environmentally friendly polymer materials resistant to cavitation corrosion.

The shaft can be made of stainless steel or oxide ceramics, the plain bearing is made of graphite impregnated with synthetic resins.

Productivity in the range of 0.4-1.6 m 3 / hour, with a corresponding pressure of 1.4-1.9 m (0.14-0.19 kg / cm 2), provide complete and uniform heating of the heater in the bathroom room.

Operating voltage 220 V.

Pipe connection size ½˝.

Circulation pump in the heated towel rail circuit

2.1 Advantages and disadvantages of pumps with a wet rotor

small dimensions and weight: installation length 80-180 mm. Weight 1.2-2 kg;
the ability to install the pump directly on the pipeline;
long operating time without regular maintenance;
low power consumption: 7-40 W;
noiselessness at work.

The disadvantages include:

relatively low efficiency - up to 50;
indispensable installation of the pump only in the horizontal position of the axis of rotation of the rotor

The most famous manufacturers:

Carrying out installation work

The water pump is placed in the heating system through the bypass. Take a look at his drawing and familiarize yourself with the main elements:

The bypass connection scheme is good because it allows you to switch from natural circulation to forced circulation at any time. It will also help to replace the water pump without stopping and draining all the heating.

The circulation pump (1) is the main acting "person" in the system;
Shut-off valves (3) - disconnect the pump from heating;
Bypass valve (4) - ensures the movement of the coolant only through the pump or along both channels;
Mud filter (2) - provides coarse filtration from large mechanical impurities.

Let's see how to connect the pump to the heating boiler and what is needed for this. First, we inspect the installation site to find free space to accommodate the bypass. At the next stage, we assemble the bypass elements, prepare the taps, nuts, spurs and a mud filter. We also need a set of keys to connect individual nodes, and seals.

We start assembling the bypass - we form a section with a water pump by screwing a mud filter and taps to it. Next, we proceed to inspect the section of the pipe on which the tie-in will occur. We cut a piece for the bypass valve, take the section with the pump, cut holes for it. Next, we weld all the elements and only then tighten all the threaded connections with keys - this cannot be done before welding.

Having connected the water pump to a floor or wall-mounted boiler, we proceed to electrical work - we connect electrical wires with power to the terminals. Here it is recommended to put a separate RCD machine, choosing a sample for 1 or 2 kW.

The next step is to start the water pump. To do this, it must be filled with water, removing air from it. Removal of the air lock is carried out through the built-in bleeder or through the screw plug. We open all the taps, open the drain or unscrew the screw plug, wait for the air to come out and the water to flow. After that, we seal the system and try to start the water pump. If the device is noisy, it means that not all of the air plug has come out - we partially unscrew the plug screw and keep the system open until the air bubbles disappear.

Then it remains only to adjust the speed of rotation of the shaft so that the performance is slightly less than normal. There is nothing wrong with installing a water pump in the heating system with your own hands, no - you just need to be able to work with tools. In case of problems, consult with specialists.

The need for circulation pumps

Before we tell you how to properly install a circulation pump for heating your home, let's talk a little about why it is needed in the heating system. Thin plastic pipes have appeared on sale recently. Their predecessors are thicker metal pipes of large diameter. Possessing a solid margin of safety and increased throughput, they ensured the unhindered flow of the coolant through the heating system.

Water pumps were not previously needed, since thick pipes did not create serious hydrostatic resistance. The design of old heating appliances should also be noted - their impressive internal volumes did not create any special obstacles for the flow of coolant. Only now it was necessary to mount the contours according to a special scheme:

A high pipe was installed from the boiler, raising the coolant above all heating appliances;
An expansion tank was mounted at the highest point;
The supply pipe was mounted at an angle so that the coolant flowed unhindered towards the radiators;
The return pipe had to be mounted at an angle towards the heating boiler.

Such a scheme, which does not include water pumps, provided excellent heating performance.

Problems were created only if it was necessary to heat a large house. In this case, the coolant flowed through the system with difficulty, since the large circuit creates high resistance. The longer the pipes and the more heaters, the more obstacles. In two-story mansions, the resistance reaches the highest values at all. As a result, we see:

The voiced problems are solved in two ways - a more thorough study of the scheme of the heating system or the use of a water pump.

Uneven heating of the heating system;
Cold branches;
Boiler water overheating.