The circulation in the heating system can be carried out both by force and naturally. To create a forced circulation, install pumping equipment. Installing a circulation pump for heating will ensure uniform temperature and space heating. The choice of this device should be approached responsibly, since an incorrectly selected pump will create either too sluggish or too intense circulation of the coolant in the system. What subsequently will cause uneven heating of the room.
Design and principle of operation
The circulation pump for heating (price - in the range from 3,500 to 15,000 rubles) is the main element of the system with forced circulation of the coolant. In this case, there is no need to mount large pipelines and install the boiler at the lowest point of the system. In addition, the time period for heating radiators is noticeably reduced, which allows for a short time to increase the air temperature in the room. The main characteristics of pumping equipment are its pressure and performance.
The pressure created by the pump must overcome the hydraulic resistance of the system. With significant hydraulic resistance and low pressure equipment will require the installation of a circulation pump for heating, which has other characteristics.
Reliability and long-term functionality of pumping units largely depend on correctly performed calculation of operating parameters at which it is planned to heat the premises, as well as on how well the installation is done. For example, Wilo or GrundFos circulation pumps installed in the heating system, which are a closed environment, are able to operate under high pressure of several atmospheres. Thus, in order to fill the system, pressure equipment is installed, which is connected to heating or to a water supply system with significant pressure. Then testing is carried out.
Varieties
There are two main types of these devices:
Each of these types has its own disadvantages and advantages; we will consider them in more detail.
Dry Type Benefits
- In the process, such equipment does not interact with the pumped medium. This provides a long service life.
- The structures are carefully docked and processed. As a result, the installation of a circulation pump for heating of the “dry” type will further prevent leakage of the coolant from the system.
- Efficiency is almost 80%.
- O-rings do not require replacement within 2.5-3 years of operation, unlike stuffing box packing, which needs to be updated before the start of each heating season.
- Equipment of this type may be mounted both vertically and horizontally. At the same time, his position in no way affects the quality of work.
The disadvantages of the "dry" type
- During operation, a lot of noise is created. For this reason, the installation of a circulation pump for heating “dry” should be provided in a separate room.
- These units are very sensitive to the quality of the coolant. For long and high-quality work in network water there should be no pollution and impurities.
- O-rings need periodic lubrication.
Wet Type Benefits
- Easy maintenance and installation.
- Long service life.
- Low noise.
- The relatively low cost of spare parts and the unit itself.
- When operating the pumping equipment, lubrication is not required, which protects it from overheating. This function is carried out by the heat carrier which cools and also lubricates the pump shaft.
The disadvantages of the "wet" type
- Low efficiency, about 30%.
- Installation of "wet" type heating circulation pumps must only be done in a horizontal position.
- The possibility of leaks from the heating network through leaks of pumping equipment.
Circulation pump for heating: how to choose
When choosing pumping equipment, the following characteristics must be taken into account: performance, flow rate and pressure. As a rule, they are indicated in the passport.
Pressure
In order to correctly select the circulation pump for heating with the required pressure value, it is necessary to calculate the hydraulic resistance of the system. It depends on the length and diameter of the pipelines, as well as on the number of local resistances (narrowing, rotation angles, etc.). The pressure of the pumping equipment must be selected so that it overcomes the resistance of the entire system.
A well-chosen pump is a guarantee of optimal circulation speed, as well as the flow of coolant to all rooms.
Consumption
The selection of a circulation pump for heating based on the flow rate of the coolant should be oriented to the load of the system. The load is calculated in several ways: by actually installed heating devices or by the external volume of the building. The flow rate can be calculated by the formula, where in addition to the heating load, it is necessary to know the operation mode of the boiler.
Equipment power is determined in accordance with regulatory documentation. According to Western standards, about 1 Watt should fall on 1 m 2 of area. However, focusing on local weather conditions, equipment with a capacity of at least 120 watts should be installed on 1 m 2 .
Additional factors
The power of the pumping equipment is directly related to the diameter of the pipelines. Some believe that the larger the diameter of the pipeline, the greater the amount of heat will enter the room. At the same time, it is important to take into account the fact that a large amount of coolant moves over large diameters and, accordingly, circulation pumps are required for heating, whose power characteristics are very impressive. This will ensure high-quality circulation.
The location of the pump unit has a significant impact on power consumption and its performance. A pump installed in a cold room always functions uneconomically and is much worse, unlike the one installed in a building with heating.
The power of the equipment also depends on the expected operating time. If, for example, the main part of the time the circulation in the heating system is natural, and the pump starts only to quickly warm up the room or adjust the pressure, then a lot of power will not be required for this.
Expense calculation
Circulation pumps for heating private homes have a number of features that determine their functional potential. Flow and pressure are the main indicators of pumping units. These parameters are reflected in the equipment passport. The flow rate of the pump unit should be calculated using the following formula:
Q = N / (t 2 -t 1 ), where:
- N is the power of the heat source (boiler, gas column).
- t 2 is the temperature of the coolant located in the supply pipe and leaving in the direction from the heat source. Almost all boilers are set to an operating mode of 90-95 ° C.
- t 1 is the temperature of the coolant in the return pipe, as a rule, its temperature is 60-70 ° C.
This parameter allows you to determine whether the circulation pump is suitable for heating, how to choose it correctly will no longer be a difficult question for you.
Manufacturers
Currently, the best manufacturers of pumping equipment are European companies, as they are characterized by high quality materials and assemblies, as well as cost-effectiveness.
German Wilo circulation pumps have been represented on the heating equipment market for several years. During this time, they have established themselves as durable and high-quality equipment. A wide range of pumping units with a wide selection of characteristics is offered to customers' choice. For installation in an individual heating system, the most optimal circulation pump for heating (price - from 12 000 rubles) Wilo-Stratos ECO. The pressure created by this unit is 5 m water column, productivity is 2.5 m 3 / h, and power consumption is only 59 W. Such a device can function both in automatic and in manual mode. You can also adjust the speed and engine power.
Mounting
Before you install the heating circulation pumps, you should pay attention to the fact that it does not matter what material the system will be made of. It is preferable to connect the equipment not directly to the pipeline, but on a bypass line.
Another pipe in the form of a wide letter "P" is soldered or welded to the main pipeline of the heating system with a pump installed in the middle. On both sides of it are mounted locking devices that are necessary for the following purposes:
- Overlapping one of the taps will restore the natural circulation of the coolant in the system.
- Overlapping both faucets will help repair or replace the circulation pump for heating (expert reviews confirm this) without draining the coolant.
During installation, it is necessary to pay attention to the direction of movement of the coolant. As a rule, it is indicated by an arrow on the device.
When connecting to the mains in a heating system with natural circulation, it is recommended to use an automatic fuse with a flag. It will simultaneously act as a switch and a fuse. The automatic fuse should be installed at a distance of at least 0.5 m from the radiators.
To connect an additional pump to a forced circulation system, it is necessary to take into account the moment that one is already installed and starts when the thermal relay is triggered. In order for the circulation pumps for heating private houses to work synchronously, the additional unit should be connected to the main device or thermal relay through a parallel connection.
In heating systems with an electric boiler, pumping equipment can be connected directly to the boiler. In this case, the circulation unit will only function at the time of heating the coolant.