Comparison Wilo CronoLine IL-50/110-1.5/2 13 m

DN 50

340 mm

vs Grundfos UPS 50-180 F 13 m

DN 50

280 mm

The type of rotor the pump is equipped with.

— Wet. "Wet refers to rotors that are in direct contact with the pumped liquid. It achieves several advantages. The liquid provides lubrication and cooling of the rotor — which increases reliability, allowing the pump to work for a long time without additional maintenance, and reduces the noise level. The latter is especially important for residential premises, which is why they use wet rotor pumps. In addition, the units themselves are simple (in design and repair), compact and inexpensive. Their main disadvantage is a lower efficiency than in "dry" models — usually up to 50%. It is not critical for domestic use, but wet rotors are poorly suited for high-performance professional models.

— Dry. The name of such a rotor is because it does not come into contact with the pumped liquid. The key advantage of this design over the "wet" one is high efficiency — about 80%. On the other hand, dry rotors produce more noise and are not suitable for residential applications. Therefore, this option is typical mainly for high-performance units designed for industrial use.

The maximum flow of a pump is the amount of liquid it can pump in a certain amount of time.

Features of choosing the optimal performance option depend primarily on the purpose of the pump (see above). For example, for DHW recirculation models, the pump performance should not exceed the performance of the water heater. If the water heater is capable of delivering 10 litres per minute to the DHW circuit, then the maximum pump performance will be 10*60=600 L/h. The basic formula for calculating the performance of a heating system takes into account the power of the heater and the temperature difference at the inlet and outlet, and for the cold water system — the number of points of water intake. More detailed information about the calculations for each application can be found in special sources, and it is better to entrust the calculations themselves to professionals.

The highest pressure in the circuit at which the pump will be able to work normally.

Of course, this parameter cannot be exceeded — the unit may fail due to a breakdown caused by too high pressure (and even if this did not happen right away, it can happen at any time). However, it is worth choosing a model with some margin — so that the pump can normally withstand pressure surges, which are almost inevitable in any pipe.

The lowest fluid temperature at which the pump is capable of operating normally.

Almost all pumps can normally transfer cool water, regardless of the purpose (see above); therefore, for normal household use, this parameter is not critical and for some models, it may not be indicated at all. But if you need the ability to work with liquids with temperatures below 15 °C, you should pay close attention to the minimum temperature. Some models that can be used with antifreeze normally tolerate even temperatures below zero.

The highest liquid temperature that the pump is capable of operating normally.

The possibility of using the unit directly depends on this parameter (see "Suitable for"): for example, models for heating systems must tolerate a temperature of at least 95 °C, and for DHW supply — at least 65 °C. Well, anyway, this parameter should not be exceeded: an overheated pump will fail very quickly, and the consequences of this can be very unpleasant.

— Number of speeds. The number of speeds provided in the design of the pump. Each speed corresponds to its performance value (see above). The options could be:

• 1 speed. There are no adjustments in such models; when turned on, the pump can operate only at one speed. This is the simplest and most inexpensive option, due to the absence of additional elements (regulators) in the design. Of course, it is convenient only in cases where the unit must operate at full capacity every time it is turned on.
• 2 speeds. 2 speeds give the user some degree of choice: the pump does not have to be turned on at full power — when it is not required, the unit can be run at reduced power to save electricity and not wear out the mechanisms beyond what is necessary.
• 3 speeds. The largest number of adjustments found in modern pumps — it makes no sense to provide a larger number for many reasons. It gives even more options for setting operation parameters than 2 speeds.
• Stepless adjustment. This option implies the ability to set the regulator to any position from minimum to maximum (in some models, fixed settings may also be provided, but only as an additional option). It provides maximum freedom and precision in the choice of operating mode. However, it significantly affects the price; and the real need for smooth adjustment occurs quite rarely.

— Automatic operating mode.... The essence of this function differs depending on the purpose of the device (see above). So, in models for increasing the pressure of cold water, the automation turns on the pump when the tap is opened and turns it off when it is closed — a special sensor reacts to the movement of water. In models for heating and domestic hot water, automation is responsible for adjusting the operating parameters — for example, when screwing the valves and reducing the flow rate, the pump can reduce the pressure, as well as, for additional functions, such as an on-off timer. Anyway, this feature makes life easier for the user, eliminating the need to perform certain operations manually and adding new features to the pump; but the specific set of these features depends on the model.

— Display. Various additional information can be displayed on the display: operating mode, performance settings, water temperature, set timers, error messages and much more. It makes management more convenient and intuitive. Pumps usually use the simplest form of black and white LCD screens, but this is quite sufficient for the purposes mentioned.

— Control panel. In this case, the control panel means a panel that has a switch with a choice of operating modes between automatic (see above) and manual. Accordingly, the presence of several modes almost necessarily means the presence of a control panel. But the speed switches themselves are not considered for this function.

The electrical power consumed by the pump during normal operation and maximum performance.

This indicator directly depends on performance — after all, for pumping large volumes of water, an appropriate amount of energy is needed. And the power depends on two main parameters — electricity consumption and the load on the power grid, which determines the connection rules. For example, pumps with a power of more than 5 kW cannot be connected to ordinary household sockets; more detailed rules can be found in special sources.

Operating voltage for which the pump is designed.

— 230 V. Standard voltage of household networks. Most of these pumps can be powered from a regular outlet, which makes them very convenient to connect. At the same time, this option is not well suited for creating high-performance units — already with a power consumption of more than 5 kW, certain tricks in connection will be required, and in general, 230 V provide less power than 400 V. Therefore, the such power supply is typical mainly for models elementary and intermediate levels.

— 400 V. This option implies power supply from three-phase networks with a voltage of 400 V. Such networks are rarely found in everyday life, but they are widely used in the professional field, including at industrial facilities — they are convenient for powering high-power equipment. Therefore, three-phase power is usually provided in professional high-performance pumps.

Arrangement of the motor shaft in the normal operating position of the pump.

First of all, the general layout of the unit and its suitability for certain conditions depend on this parameter. So, with the most popular coaxial arrangement of holes (see below), the motor shaft, usually, is located perpendicular to the direction of water movement. This means that only a pump with a horizontal shaft is suitable for tapping into a vertical pipe. But for a horizontal line, the choice is related to which direction it is more convenient to turn the pump housing — up (when installed in a narrow, elongated niche) or sideways (when other objects above the pipe interfere with the vertical installation of the unit).

Note that there are universal models that allow both placement options.