Circulators are electric devices that ensure the circulation of liquid in heating systems. Circulators can sometimes be also used for recirculation of hot water as well as coolant in air conditioning systems. They are also used in solar or geothermal systems.
Suitable for application not only in family houses, but also in office buildings. If you combine the selected heat distribution system and the right pump, correctly, perfect functionality and at the same time high efficiency can be achieved.
They are suitable for one-pipe and two-pipe heating systems, also for houses with the combination of underfloor heating and radiators. In this case, the pumps must be set to a constant flow and a variable differential pressure on the radiators.
Variable differential pressure (Δp-v): It is used in two-pipe heating systems with radiators to reduce noise on thermostatic valves. As the flow in the pipeline decreases, the pump lowers the head in half. By reducing the required pumping capacity, electricity is saved. As you open and close the radiators your pump changes the head, ie the pressure, resulting in energy savings.
Constant differential pressure (Δp-c): A constant head is maintained regardless of the pumping capacity. This is used for underfloor heating and all applications without variable characteristics (eg storage tanks) and for one-pipe heating systems with radiators. (Keeps the same pressure and changes flow according to open floor circuits = savings)
Constant speed (I, II, III): The pump runs unregulated in three preset fixed speeds. Such a setting is suitable for applications with constant device resistance. Thus, for example, pumping tanks or radiator systems that are never closed.
First you need to determine its purpose - whether it will be used only for heating or water recirculation as well. Other important parameters are the diameter of the pipe and the thread used, flow, the method of power regulation and the requirement for the maximum head of the pump. The head for circulating pumps is given in a closed system, so there is a different method of calculation than for garden pumps, where only the vertical height is monitored. In this case, the calculation is based on the pressure losses of the individual elements of the heating system.
The type translates into key technical parameters. As an example, let's analyze the Grundfos ALPHA 1L 25-40 180 pump. In this case, it is a pump of the ALPHA L series in light version, ie without Autoadapt, number 25 is the Nominal diameter (DN) of suction and discharge ports [mm] (15 = 1", 20 = 1 1/4", 25 = 1 1/2", 32 = 2"). A value of 40 determines the head (dm). In this case, it is 4 meters high at atmospheric pressure. The last value 180 indicates the construction length of the pump in mm (Port-to-port length [mm]).
All our sold pumps comply with requirements of the EuP directive. Modern products so-called "EuP ready", have up to ten times lower power consumption compared to older solutions with a fixed capacity - today normally up to 4 W. In the EU around 14 million circulators is sold every year, with 23 billion kWh of electricity saved by 2020, thanks to the introduction of the new standard.
Although the change in the standard meant a certain increase in the price of new types of electronic circulators, they represent an investment with a quick return due to significantly lower operating costs and minimal failure rates. In addition, a quality circulation pump can be replaced very simply and quickly.
Due to the quality and durability of the products, we only sell circulators from proven manufacturers: Grundfos is a traditional Danish manufacturer, while Wilo is a German specialist making most of their products in heir own factories. In our experience, the complaints for both manufacturers fall below 1 percent of the pieces sold.
Due to the introduction of a new generation of more energy-efficient pumps today, in many cases we are not able to provide the same pump that you have used so far. For both of our brands, however, we offer quality but significantly more energy-saving replacements:
If you are looking for a replacement for an older or electronic pump, or a pump from a different brand, you can find the matching products on the Grundfos website.