Circulation pumps are an essential part of many technical systems, including heating, ventilation and air conditioning systems. What should you know before buying one?
The efficiency of the heating system depends on many factors. The most important are of course the quality of individual elements and their technical condition, as well as the selection of appropriate solutions for the specifics of a given installation. Sometimes, however, even meeting these requirements does not guarantee effective heating operation. Fortunately, such problems can be solved relatively easily.
In many cases, the right solution is to install a circulation pump , i.e. a device that induces the circulation of the working medium. Pumps of this type are usually used in central heating installations, but their use is not limited to this technology. In the new entry, we discuss their functionality and operating principle and explain how to choose the model that best suits our needs.
Check out the circulation pumps at the Onninen wholesaler
Choosing the right size circulation pump
As we mentioned a moment ago, the circulation pump can be an element of the central heating system or another. They are also used in underfloor heating or solar installations. Thanks to this solution, it is also possible to deliver water from the heater to the collection points in installations not connected to the public water infrastructure.
The correct selection of a circulation pump requires taking into account various factors. One of them is the size of the device. There are five types of circulation pumps on the market - with an installation length of 80, 130, 150, 180 and 220 millimeters. This parameter is especially important when replacing an old pump with a new one or when it is to be located in a small box. Due to the specifics of a given location, it is often impossible to install a larger device.
Check out the circulation pumps at the Onninen wholesaler
When buying a circulation pump, you should also pay attention to its quality. At Onninen Wholesale we offer a wide selection of circulation pumps from the best manufacturers – e.g. FERRO circulation pump (model 25-60-180 with a solid cast iron body and aluminum housing), ONNLINE circulation pump (EQC-M model) 25-6/180 with electronically commutated synchronous motor) or GRUNDFOS circulation pump (model ALPHA2 25-40 very low power with radio communication function).
Characteristics of constant pressure difference and type of circulation pump
Another issue to keep in mind when choosing a circulation pump is its type – specifically, its operating characteristics. In this respect, we distinguish three types:
pumps with constant pressure difference characteristics;
proportional characteristic pumps;
pumps of constant character.
The first ones are used where it is necessary to maintain a constant pressure difference between levels, and therefore a constant lifting height. This parameter should be maintained regardless of the amount of working medium in the installation. Achieving this effect requires automatic adjustment of the pressure and power of the device. The diagram of pumps with a constant pressure difference characteristic consists of straight sections that break in the final part of the field.
Circulation pump with proportional characteristic
The next type is pumps with proportional characteristics. Their operation is based on the increase in lifting efficiency with the increase in the flow of the working medium. The use of pumps with this characteristic includes primarily installations in which there are different flow resistances on individual sections. The efficiency increases until the lifting height reaches a maximum, and then begins to decrease significantly.
This situation occurs, for example, in central heating systems with thermostatic heads. Due to the different distances between individual receivers (radiators) and the heat source (boiler), the pump must proportionally adjust the operating parameters in each part depending on the opening or closing of the heads. The graph of the operation of pumps with proportional characteristics shows steep curves, rising to a maximum and then falling.
Circulation pump with constant characteristic
Constant characteristic was used primarily in older models of circulation pumps. Devices of this type raise the working medium to a height corresponding to the set speed. Changes in the installation do not affect this operating parameter. The use of pumps of this type is primarily limited to installations without control elements and requiring constant flow. The graph shows rounded curves.
The selection of a circulation pump should be consulted with a specialist. If you have any doubts as to which type and model will work best in a given installation, please contact us - our employees will provide the necessary support and help in selecting the right product.