Installation of the pump for heating. How to choose and connect a pump

To ensure the efficient operation of the heating system, it is often necessary to choose between installing large-diameter pipelines or installing pumping equipment. The advantages of the latter option are obvious.

Heat pumps for heating - this is the most common mechanism in apartments and houses with a modern autonomous system. Choosing from the set of options on the market the most optimal, you can increase the heat transfer of the system, save energy, and prevent possible malfunctions and breakdowns. This article will discuss how to choose and how to connect the pump correctly.

Device and technology

So, before you buy pumping equipment, you need to find out its device. It consists of the following main elements:

• Compressor (powered by mains).
• Capacitor.
• Evaporator.
• Thermostat.
• Freon.

Under pressure, freon enters the evaporator, where it evaporates, taking heat from the internal grate of the evaporator. The evaporator, in turn, takes heat energy from the water or soil contour. The compressor raises the temperature of the refrigerant of the evaporator, compressing it. The compressed freon enters the condenser, where it transfers heat to the heating circuit and becomes liquid. This process is continuous.

Power source

In order not to make a mistake when choosing a circulation pump , it is necessary to take into account that such equipment is divided into three main types. Their difference is the sources of energy: liquid, air and soil.

Liquid

To date, a system with a source of energy, such as water, is particularly popular and effective. As a source can be used as a water supply system, and a reservoir - a reservoir, a lake, a river.

Air

In Russia, the most common equipment that operates at the expense of air. This option is easy to translate into reality.

Priming

The system, which functions at the expense of ground energy, is a rather effective option, it is preferable to apply to owners of private houses. It differs in stability, because the range of soil temperature fluctuations is practically not subject to strong changes.

Type of construction

To make the selection of the pump for heating correctly, it is necessary to pay attention to a criterion such as the type of construction. Pumps are divided into equipment with a wet and dry rotor.

Dry rotor

Devices with a dry rotor are isolated from the liquid, which is pumped. They are characterized by a high level of efficiency compared to a wet rotor. However, the installation of a pump for heating with a dry rotor has some difficulties. Due to the high noise level created by the operation of the dry rotor, it is necessary to install the pump equipment in a separate room. Also these devices have large overall dimensions.

Wet rotor

Unlike the previous version, the equipment with a wet rotor is much smaller. In this case, the pump is immersed in water, which simultaneously cools and lubricates the engine. The advantages include simplicity in operation and the absence of difficulties when replacing individual structural elements.

Main characteristics

When choosing a pump for heating, in addition to the manufacturer's warranty and various certificates, you should familiarize yourself with the following characteristics:

• Connection of the device, namely the diameter of the pipeline to which the pump is to be connected. In most cases, the diameter of the pipeline is in the range of 25 to 32 mm. In accordance with the diameter of the pipes, heat pumps for heating are equipped with nuts of the required size. This allows you to quickly make their installation and dismantling.
• Power. Information on this parameter is contained in the documentation for the pump itself. As a rule, this indicator is in the range from 60 to 300 W. Based on this indicator, the temperature graph of the heating system is determined. For private houses - up to 80 ° C.
• Performance. This is the volume of the heat carrier entering the pipeline by means of the pump for a certain unit of time. This indicator directly depends on the cross-section of the pipelines of the heating system and affects its main indicators.
• Head. This criterion is measured by the length of the jet that a water pump releases for heating.
• Pressure. To make a correct calculation, it is necessary to specify the length of all available pipelines, and then multiply the obtained data by 100 Pa. Most often, the total result is not more than 10 000. In the characteristics of pumps, pressure and altitude, for example, 8 meters, can be indicated. Thus, for a system designed to heat several floors, you should not choose low-power equipment with a lifting height of 4 meters.

Only after carrying out these calculations, it will be possible to consider various versions of pumping units, focusing on technical documents. Perhaps the calculation will show that the installation of the pump for heating is not required, and the coolant according to the laws of physics will circulate itself in a closed circle.

Criterias of choice

So, finding out the main characteristics of the heating pump, you need to go to the selection of the optimal unit. First of all, you need to pay attention to the level of performance. The calculation method is as simple as possible: the capacity of the boiler is equal to the volume of fluid passed per minute. For example, at a power of 35 kW, the volume of the coolant will be equal to 35 liters.

Further, the flow rate of the coolant is determined at a certain portion of the circulation. This will require data on the power of the heaters, which is equal to the total flow of the coolant.

To calculate the coolant flow in a pipeline system, you need to have a concept of the diameters used:

When calculating the average velocity of the coolant in the pipeline, take 1.5 m / s.

For example, to calculate the capacity of pumping equipment for a heating system on a length of 10 meters, you need a head with an indicator of 0.6 meters. Accordingly, for a normal operation of a 100-meter-long section, a head of 6 meters is required. And there is only the choice and the subsequent installation of the pump for heating, the technical characteristics of which will ensure the created conditions.

Pipelines with a small section are characterized by high hydraulic resistance, so in this case, you should install a powerful equipment. For large diameter pipelines, a high-performance pump can be neglected.

The above calculation is conditional, it can be applied only for heating systems with a simple and unhardened scheme. In all other situations it is more advisable to seek help from specialist heat engineers. If you are confident in your own abilities, you can use the formulas for calculations presented in SNiP 2.04.05-91.

Installation of the pump in the heating system

1. First of all, as already mentioned above, it is necessary to determine the choice of the pump unit. To do this, it is important to know that if there is a radiator heating system and a room area from 80 to 120 m ² in the house, the pump must process 0.4 m ^{3 of} heat carrier, while from 120 to 160 m ^{2 the} pump should be 0.5 m ³ .
2. Installation of the pump for heating should be carried out in such a way that the shaft of its engine is located in a horizontal position. Since vertical placement can lead to the accumulation of air. In this case, there is also a significant obstacle to the normal lubrication of the bearings of the pump unit. Incorrect installation of the pump will lead to a reduction in the operating life or even its failure.
3. In the radiator heating system, the pump is preferable to install near the boiler, and it is desirable to place it on the return pipeline. After that, the expansion tank is connected to the return line.
4. The boiler is then switched off, all the shut-off devices on the pump supply and return pipelines are closed. Unscrew the nuts to which the pump is screwed. Pump unit is recommended to be equipped with a threaded plug and filter. It is important that the filter and pump have identical diameters. If the heating system operates under pressure, a check valve must be purchased in advance.
5. After the bypass line is installed in the heating system, a non-return valve is installed, the terminal module must be located at the top. During the installation it is necessary to take into account the direction of the coolant movement, which is marked on the case of the device in the form of arrows. If an electric pump is used for heating, care should be taken to ground it.
6. Before starting from the pumping equipment, you need to remove all the air, the device itself can be turned on after 5 minutes after that. After switching on, it is necessary to remove the air again, only after that it will be fully ready for operation. If the pump is slightly warm, there's nothing to worry about.

Cost

On average, a circulation pump with a capacity of 30 W, with a coolant flow rate of 2 m ³ / hour and a head of 2 m is 4300-4500 rubles. When choosing these devices it is desirable to give preference to already proven companies. For example, the Danish pump for heating Grundfos, German equipment Wilo or Italian units from manufacturers such as DAB, Lowara, Ebara or Pedrollo. By and large, domestic manufacturers focus on the production of industrial pumps.

To date, consumers are more often choosing a pump for heating Grundfos and Wilo, since the units from these manufacturers have proven themselves in the best way.

It is not necessary to count on the fact that it will be possible to choose equipment, which will correspond to 100%. Since each heating system has its own nuances and features of functioning, and any equipment is focused on the average parameters and indicators.

Too powerful a pump during operation will create a lot of noise, and insufficiently powerful will not provide the required pressure in the system. For this reason, it is advisable to purchase a pump with a power that will exceed the required by no more than 7-10%. It is desirable to give preference to models with a customizable mode of operation, which will allow using the equipment as efficiently as possible.