When solving heating problems for a home, the total number of square meters must be taken into account. When the calculation of the area is carried out not in units but in hundreds, and in the building more than one floor, the system with natural circulation does not cope with its tasks. In such systems, the pressure in most cases is not higher than 0.6 MPa, for this reason a pump cannot be dispensed with. From the article below you can find out what are the circulation pumps for heating systems, the technical characteristics of these devices, the principle of operation, as well as how to choose them correctly.
Principle of operation
Structurally, this pumping equipment resembles a drainage installation: the housing is made of stainless metals, equipped with a rotor and shaft, equipped with a vane wheel.
Consider circulation pumps for heating systems. The principle of operation is based on the following:
- The electric motor is driven by a rotor. A similar system takes water on the one hand and pumps it into the pipeline on the other.
- By means of centrifugal force, the coolant moves through the heating system.
- The pump helps to overcome the resistance that invariably arises in certain sections of the pipeline.
Varieties
So, there are two main types of pumps: with a wet rotor and a dry rotor. What does this mean? Let us consider in more detail these circulation pumps for heating systems, the technical characteristics of these devices will also not be disregarded.
"Dry"
In this case, the rotor is in no way in contact with the coolant - its working part is separated from the engine by means of o-rings. The efficiency of pumping equipment of this design reaches about 80%. However, the operation of the "dry" rotor is accompanied by a noise effect.
"Wet"
Circulation pumps for heating systems (how to choose this equipment, we will consider below) with a “wet” rotor, on the contrary, are immersed together with the impeller in a coolant that cools the electric motor, playing the role of a lubricant. In this regard, the noise level that is created by the engine is significantly lower. This version of the engine does not require special maintenance for a long time. However, compared with the previous version, its work is not so effective - the efficiency is reduced to 50%. Silently working equipment of the "wet" type is traditionally used in domestic heating systems for circulating coolant.
Circulation pumps for heating systems: how to choose?
When choosing pumping equipment for a heating system, it is recommended to take into account certain parameters. Let's consider them in more detail.
Pipe diameter
Typical piping sizes at the point where the pump connects to your heating system can range from 25 to 32 mm. When choosing pumping equipment, you need to make sure that the complete set of union nuts is necessary for its quick installation and dismantling.
Performance
The productivity of pumping equipment is the main parameter, which is the volume of coolant that circulating pumps for heating systems pump. The technical characteristics of the pump in this case depend on the performance, which is determined as follows:
Q = N / (t 2 - t 1 ), where:
- Q - flow rate of pumping equipment.
- N is the power (indicator) of the heat source, which can be taken as a gas boiler or column.
- t 1 is the temperature of the fluid circulating in the return pipe. Typically, it ranges from + 60 ° C to + 70 ° C.
- t 2 is the temperature of the liquid in the supply pipe, that is, that which moves in the direction from the heat source. Typically, boilers maintain temperatures between + 90 ° C and + 95 ° C.
The calculation of the future heating system, the hydraulic calculation, as well as the calculation of its losses are carried out with the aim of the correct selection of the design parameters of the pump, which will subsequently overcome the resistance in the system.
System Lift Level
This is an indicator of the maximum possible pressure that the heating system is capable of. The level of rise in the system reflects the total indicator of hydraulic resistance in the system as a whole.
When calculating the hydraulic resistance, the number of storeys of a heated structure with a closed heating system is not decisive, on average it is about 2-4 m. Of water. pillar. For heating systems mounted in low-rise buildings traditionally, this parameter is identical.
The diameter of the connection and the maximum pressure are indicated in the marking of the pumping equipment. For example, consider circulation pumps for Grundfos heating systems. The characteristics of the Grundfos UPS 25-60 pump are as follows: the diameter of the connected pipeline must be 25 mm, and its pressure is 6 m. Of water. pillar.
There is also pumping equipment of this company with a lifting height of 3, 4 and 8 meters. In this case, their markings indicate the numbers 30, 40 and 80, respectively.
We also consider circulation pumps for Wilo heating systems (the selection instructions are similar to the previous version). For example, a Wilo Star-RS 30/6 pump can be connected to a 30 mm pipeline, and its head is 6 m. Of water. pillar.
Energy requirement
In addition, there is another parameter that must be taken into account, albeit indirectly. This is the building's need for heat. The value of this parameter is indicated in the building passport during the design process. If these data are not available, then it is easy to calculate them yourself.
For each country on 1 m 2 its own heat standards are adopted. According to European standards, for heating 1 m 2 of a single-family or semi-detached house, 100 W and 70 W for a multi-unit building will be required. Russian standards are established for each specific region in accordance with the requirements of SNiP.
Power consumption
Any pumping equipment has up to three positions for connecting to the electric network. On the device’s body there is a plate that contains information about the electric current consumed by it. Each switch position will correspond to the new equipment performance, namely, the amount of coolant per hour pumped by the pump through the heating system. The third position corresponds to the maximum possible pump capacity. The maximum consumption is indicated on the device case.
Commercially available circulation pumps for heating systems have averaged technical specifications. Therefore, it is important to consider the individuality of your heating system. What is the reason for the increased noise in the pipelines resulting from excessive pump power (this is noted in the user reviews) when the system is active?
Reviews of specialists
The modern market offers a lot of different pumps for heating. Specialists among foreign manufacturers distinguish Grundfos and Lowara circulation pumps . Also high-quality high-tech products are supplied by Italian manufacturers of circulation pumps Ebara and Speroni.
Circulation pumps for heating systems "Octopus" at relatively low capacities are characterized by high efficiency. If you plan to increase the operational life of the boiler, save energy, and also ensure optimal thermal conditions in the rooms, then this equipment will suit you perfectly.
Currently, there are many modifications and types of pumping equipment. In most cases, a range is presented with a different bore, performance and pressure. As a result, the consumer can choose the best option for his heating system.
The principle of operation of the pumps is organized in such a way that the required fluid pressure is ensured by means of special rotors. As mentioned above, rotary pumps are divided into “wet” and “dry”. The only difference is in the operating conditions of the equipment and its ability to interact with the coolant. If you decide to purchase "dry" or submersible equipment, then circulation pumps for Wilo heating systems will be an ideal option - consumer reviews about them are mostly positive. Wilo brand has long established itself as a manufacturer of durable and quality products.