Circular pumps manufactured by the Danish company Grundfos belong to the classical equipment, the design of which has undergone significant adjustments over the past 100 years. The technical characteristics of many models have changed, and the scope of their application has also expanded. The circulation pump for heating Grundfos is the main and unchanging component of modern heating systems in industrial and residential buildings.
Grundfos circulation pump device
According to their design, Grundfos heating circulation pumps are divided into two types: with a wet rotor and a dry rotor. The first of the structures historically appeared before the second version. Its basis is a body made of cast iron, steel, bronze or aluminum, inside of which a movable rotor is located in an aqueous medium. An impeller is mounted on the shaft, which drives the working fluid.
Pumps with a “dry” rotor began to be produced a little later, the engine and the liquid in them are separated from each other. Due to liquid lubrication, first-class pumps are highly reliable. But at the same time, the efficiency of such devices is very small (does not exceed 50 percent).
For units with a “dry” rotor, the efficiency is slightly higher (it reaches 70%). These models are most often used for industrial purposes, where operating conditions involve pumping large volumes of water. For domestic needs, wet pumps are typically used.
Specifications
The main technical indicators that are paid attention to when choosing a suitable model of equipment are:
- a graph of the pressure of the liquid on the value of its supply to the system
- power consumed by the engine of the unit from the network;
- heat transfer performance;
- permissible temperature of the pumped medium;
- dimensions and weight of the device.
The first of the characteristics allows us to understand what volumes of water are pumped by the pump depending on the pressure developed in the system. The higher this indicator, the lesser amount of water resource must be passed through the unit to obtain the desired pressure. In order to correctly select a sample of equipment, the operating point should be located under the curve of the graph. When choosing this indicator, it is desirable to ensure a supply margin of at least 20%. Another parameter is directly related to it - pump performance.
The power taken from the network is determined by the magnitude of the current in the load and the supply voltage (220 or 380 Volts). This parameter is taken into account when selecting power supply circuit protection devices for current and when calculating the cross-section of wires included in power supply lines. The productivity of pumping equipment, which increases with its increase, depends on the indicated value.
The dimensions of the purchased sample and its mass are also taken into account when choosing the right model. This also applies to the operating conditions of the pump - the minimum and maximum permissible temperature of the pumped medium. The reliability and durability of the purchased sample depend on the correct selection of this indicator.
Advantages and disadvantages
The advantages of pumps from a Danish manufacturer include:
- high work efficiency;
- reliability of all components and parts;
- low level of intrinsic noise;
- universality of application.
Grundfos pumps are used as part of heating systems and are in demand for organizing hot water circuits (DHW). In addition, they are allowed to be installed in “underfloor heating” systems or in climatic equipment.
The versatility of Grundfos units is also manifested in the fact that after their purchase the user will be able to work with the following types of coolants:
- water heated to a certain temperature;
- solid-free antifreeze;
- coolant with the addition of ethylene glycol in the amount of not more than 40 percent.
The advantages of samples of equipment of this class include the work of the rotor in direct contact with the coolant, a metal glass from stainless steel separates it from the rest of the nodes. In addition, in these models, the inlet and outlet pipes are located at the same level, which makes the entire unit quiet. Significant advantages of products from a Danish manufacturer include:
- the optimal ratio of the declared price and quality;
- high rates of energy efficiency;
- a large selection of models that can satisfy the most demanding customer;
- long service life and developed technical support system.
The characteristic disadvantages of Grundfos pumps are the relatively high price per unit of goods (from 6500 rubles) and the lack of a cable to connect to the mains.
Features of choice
When choosing the right type of pumping equipment from Grundfos, much attention is paid to the diameter of the union nuts. It is selected depending on the size of the pipe, prepared for installation in the heating system:
- if a polypropylene pipe with sizes 20, 25 mm is used - nuts 25 mm in diameter are suitable for installation;
- when using pipes of larger diameter (or steel billets from 25 mm and above), it makes sense to purchase equipment designed for the use of union nuts with an inner diameter of 32 mm.
If you comply with the above requirements, there will be no serious problems during the installation of the equipment if you follow the instructions.
Pump energy efficiency
Well-known European manufacturers of pumping equipment have made great strides in optimizing energy consumption indicators by introducing several wet rotor models on the market. This was achieved through the use of modern DC motors controlled by a controller. Such models belong to class “A” equipment, which is considered the most effective in terms of minimizing energy losses - their consumption does not exceed 0.09-1.3 kW).
Grundfos specialists have developed a series of energy-saving pumps under the names ALPHA2 and MAGNA3. The former are distinguished by simple functionality and are intended for use in heating systems and hot water supply of private houses. Models of the second type have the AUTOAdapt function, which allows you to automatically set the optimal mode of energy consumption. Their capabilities correspond to modern requirements for indicators of efficiency and productivity of equipment of this class. They are designed for operation in heating systems of private houses and industrial enterprises.
Operating modes
Modern recirculation pump for heating refers to multifunctional devices. Various samples of this equipment are able to work in the modes indicated in the passport, including “fixed speed”. All of them are equipped with a synchronous motor, the operation of which is controlled by an integrated processor. The control unit during operation of the unit registers the following main parameters:
- current strength;
- rotor speed;
- temperature in the work area and others.
Its presence allows you to adapt to a specific heating network with an optimal energy consumption mode.
DIY pump disassembly
Any user who has a good knowledge of the design can disassemble the purchased sample of pumping equipment if desired. The need for this often arises when it is necessary to repair or overhaul it with the replacement of worn parts. After complete disassembly, the main working parts of the mechanism are inspected, and then checked for wear.
The main attention is paid to the examination of the condition of the “wet” rotor. Remove it and replace it with a new part in the presence of a repair technician who can control this difficult operation.
Rating of popular models
The rating of pumps is based on a comparison of technical indicators and operational capabilities of the three models. In the first place is the product Grundfos UPS 25-60 (N) 180, representing a circulating unit with a cast iron housing (this option is used only for heating). Its modification for hot water supply has a stainless steel case. All samples are equipped with a single-phase asynchronous motor, a speed switch and a special sleeve that separates the rotor and stator.
The advantages include:
- permissibility of use in all types of circuits (in closed and open);
- wear resistance and profitability (consumption no more than 60 W);
- low noise level (up to 43 dB);
- compactness, light weight and the presence of protection against overheating;
- ease of installation and maintenance;
- long service life.
The disadvantages of these products are the obsolescence of individual models and their high cost.
The second position is occupied by the brand pump Grundfos ALPHA2 25-40 180equipped with a built-in permanent magnet motor. The power consumed by this device from the network is 0.022 kW, and the capacity is 2.4 m3 / h. At a working temperature of the coolant from +2 to +110 ° С, the pressure created by the circuits is 4.0 meters.
This product has a purely cast-iron housing and is equipped with an efficient wet rotor motor and an ALPHA plug. Vertical or horizontal installation of the unit is allowed, which after start-up is controlled by built-in electronics. All information about the possible modes of operation of the device, its power consumption and characteristic breakdowns is displayed on the display located on the front panel.
The positive aspects of this model include:
- Low power consumption (only 22 watts).
- Small size (10 × 15 × 18 cm) and light weight (2.1 kg).
- Low noise level during operation (no more than 43 dB).
- Protection against corrosion (the body is made of stainless steel).
- The presence of the AUTOADAPT function, as well as the ability to select night or summer mode.
- Low heat loss (the housing is insulated with a protective cover).
- Ability to set fixed operating modes.
- Long-term warranty (up to 5 years).
The disadvantages of this product are the frequent malfunctions of the electronics, as well as the lack of special protection against dry running.
The third place is confidently occupied by the product. Grundfos UPA 15-90 (N) - A modern unit of a monoblock type, having characteristics slightly worse than the previous model.
