Introduction

A heating system's circulation pump is responsible for moving heated water or steam through the system. The pump must be strong enough to overcome the system's resistance to flow, but not so strong that it causes waterlogging or poor heat transfer.

CHOOSING A CIRCULATION PUMP FOR A HEATING SYSTEM

The circulation pump is the most important element of any heating system. It maintains the operating pressure and the required fluid pressure in the heating circuit. Thanks to the operation of the circulation pump, otherwise called the pump, it is possible to achieve a significant reduction in energy costs, since the coolant, actively circulating through the system, enters the boiler less cooled than without using the pump. In a system of great length, several pumps are usually installed, one of which is located in the boiler, the rest are in pipes. However, for a small cottage, private or country house, it is enough to install one pump, which will help the coolant circulate and ensure the uninterrupted operation of the entire heating system. The main thing is to correctly calculate its required power and other technical characteristics.

CIRCULATION PUMP SELECTION CRITERIA

The choice of any equipment always comes down to the calculation of its performance and operating conditions. Choosing a pump for a heating system is no exception. What features and qualities to pay attention to when buying it?

Performance. Perhaps the most important criterion. Some mistakenly believe that the more performance, the better. In this case, this principle does not work - it is not advisable to buy a pump with a "power reserve", as it will consume excess energy and make extra noise. You can calculate the pump performance using a simple formula. To do this, it is enough to divide the power of the heating boiler by the temperature difference of the coolant at the outlet of the boiler and in the return pipes. The latter value usually fluctuates around 20°C when using a conventional one-pipe system and 5°C if underfloor heating is installed in the house.

Pressure. Simply put, this indicator indicates the pressure of water that the pump can lift up. The rate of circulation of the coolant through the system directly depends on it. To calculate the required head, you should use the data from the design documentation for pipes, fittings, locking elements.

Operating conditions . Here it is necessary to take into account the total length of the pipes and their diameter, the frequency of use of the circulation unit and other conditions. It is worth noting that antifreeze, which has a high viscosity, is increasingly being used as a heat carrier. Therefore, the pump must also have optimal power for pumping liquid. Modern circulation pumps have several speeds (usually 3), which allow you to adjust the conditions for transporting the coolant through the system. In simpler models, this speed is set manually, in the rest - automatically.

The reputation of the manufacturer

The choice and installation of any heating equipment requires a professional approach, and this rule works when analyzing the price factor. Today, circulation pumps are widely represented on the market both from unknown Chinese companies and from popular European manufacturers. The former, as a rule, have a lower price, but do not differ in quality and long service life. Therefore, it is worth choosing units that are more expensive, but have exceptional reliability and are designed to serve for many years. In cheap models of pumps, the main element, the rotor, quickly becomes unusable, and its replacement or repair is often comparable to the purchase of new equipment.

TYPES OF CIRCULATION PUMPS

There are two types of circulation pumps, the main difference of which lies in the operating conditions:

• Dry type pumps
• Wet pumps

Both types of devices have their advantages and disadvantages. So, in devices of the "dry" type, the rotor does not come into contact with coolants and is insulated with a special ring, which increases its efficiency up to 80%. The main disadvantage of the device is the increased level of emitted noise. The design features of the "dry" pump make it commonly used in industrial plants or installed in a heating system that serves several buildings.

Devices of the "wet" type are silent on the one hand, but reduced efficiency - on the other. This is due to the fact that the rotor is completely in the water. However, the performance of the “wet” type pump is quite enough for pumping the coolant in the heating system of a summer house, a private house or a country cottage.

Thus, the circulation pump overcomes the hydraulic resistance of pipes, radiators and valves, which allows the coolant to actively circulate through the heating circuit and heat the premises more efficiently.

Conclusion

An important factor in choosing the right circulation pump for a heating system is the head loss. Head loss is the difference in pressure between the inlet and outlet of the pump. The head loss should be less than the static head of the system. Another important factor is the flow rate. The flow rate should be greater than the system's design flow rate.