How to choose a circulating pump for underfloor heating?

Warm floors for many of us today have ceased to be something distant and unattainable. Due to the mass of information literature, practical use has been made possible to equip these heating systems with their own hands. Especially the sphere of use of heating floors expanded significantly. Not only private houses and cottages are equipped with heated floors. Even with all their design flaws city apartments can now be equipped with heating floors. Most importantly, how to carry out installation and how to pick up the necessary equipment and supplies.

For floor heating is crucial presence of additional hardware, with which the heating heating circuit operates as intended. A key element in the design of any auxiliary heating a circulating pump, to warm the floor - is the "heart of the heating system." The significance of this device is difficult to overestimate, especially if a detailed examination of the scheme of operation of underfloor heating.

The principle of operation of the circulation pump in the heating system "warm floors"

The name of the device, circulating pump, speaks for itself. Due to the operation of the rotor to the impeller, and rotating a movable part of the device, the heat transfer fluid is circulated in the pipe. It is appropriate to recall that, for the central heating or hot water supply line, the presence of the circulation unit is not required. Through a centralized filing, the system creates the necessary operating pressure, ensuring a sufficiently intense flow of coolant in the pipes.

On a note: Circulating pumps for central heating systems are not one but several units (pump stations) using which hot coolant is first distributed to the heated objects, and only then, diverges directly to consumers.

Pumps used for heating systems, can work with both the boiler water and other liquid media, which are used as a coolant. However, the device which is a pump, designed for water floor heatingOnly works on the water. It should be remembered.

Mounted assembly just behind the three-way valve which performs mix with cool water to the system. For underfloor heating is required the pump selection, which will be in charge of all the relevant parameters of independent heating. The unit installed in the system must pull the resultant mix with a liquid for subsequent delivery to the manifold. Due to the fact that the impeller is equipped with blades, during rotation of the rotor inside the processing chamber creates a low pressure zone. As a result, rotation of the rotor to the impeller, a part of the device body fluid under the laws of physics, continues further intensively only has an increased rate.

Together with a safety valve, a bypass pump and the expansion unit comprises a single set of equipment - pumping and mixing unit. As a result of the pumping group in loops water circuits creates optimal working pressure, through which water flows in each heating water circuit with a desired speed and intensity.

Features of the device structure

By design, the pump looks like a snail. A small sealed enclosure has two pipes - the input and output. The sealed housing an electric motor which rotates a rotor with impeller. Pump works from a home electrical outlet 220V.

Structurally, all units used in the operation of hydraulic systems are divided into two types:

  • type of equipment with dry rotor;
  • equipment wet type.

Before attempting to install floor heating and the selection of appropriate equipment should understand the nuances of both types of pumping equipment.

The first type of "dry rotor" - is a device whose main job is performed dry rotor without direct contact with the aqueous medium. In this type of rotor is in an airtight state and protected from liquid penetration sealing ring (gland). The main feature of this type of pumps - high efficiency. Some models have an efficiency of up to 85%. However, for dry model is characterized by a large noise during operation.

On a note: equipment with dry rotor have a considerable size, in comparison with the models of the wet type. Such devices are increasingly being used for the operation of heating systems in apartment buildings, or in the workplace.


Equipment for the wet-type feature is the location of the rotor. The rotating part of the pump in direct contact with an aqueous medium. The isolation is only the motor stator.

Here I must say that when in contact with a liquid is a natural lubrication of all rotating parts of the group. As a result, minimized noise, engine running, significantly increases the life of the instrument.

The efficiency of pumps in wet inferior counterparts with dry rotor. Some models have efficiencies of up to 65-70%, and the bulk of mechanisms for underfloor have even lower efficiency. But in this case, the devices have their advantages. Small size, low noise threshold. This pump is suitable for underfloor heating, ideal for home use, especially since the wet aggregates do not need maintenance.

What to look for when choosing equipment

In order that would have underfloor heating to be effective, it is necessary to make certain calculations warm before installation. Require accurate data and parameters of almost all the heating elements. Not be discounted and the circulation pump. By the choice of the model and the type of this unit should be treated with all seriousness.

On a note: equip a warm floor without a pump as possible if you plan to heat a small room in this way. For example, a bathroom or nursery room where the heated area is small, it is accepted to be connected to the hot water system or a central heating batteries. One water circuit a small length is quite up to the task, the more so that the pressure in a sufficient system that would be the coolant flow rate of the water loop.

In all other cases, do without the pump. How to choose a pump, if you have a large amount of water heating tubes, long length water circuits. All this imposes on the heating system an additional burden. Without forced circulation, without unit mix with such heating will be unusable.

  • The circulation pump should correspond to the technical parameters of the system;
  • You must be accurately known area of ​​heated space;
  • The likelihood of heat loss in the heating circuit.

Performance

Select the pump will help you correct picture of its performance - one of the most important characteristics. It is necessary to calculate the maximum performance of the unit, which will be required to create sufficient pressure and constant circulation of water in the system. This parameter is determined in m3 per hour pump. According to the rules of thermodynamics pump must average drive itself through the water volume of 3 times the amount of coolant filled in the heating system.

Accordingly, the more heating circuits, the greater must be the capacity of the unit. Therefore, when choosing the unit pattern should focus on a technique having a power supply 10-20%. Due to the existing gap in power, you save the equipment, ensuring it long-term operation.

Important! In winter, for the normal operation of the heating system "warm floor" require more pressure coolant in the system. high power pump will solve the problem painlessly

The area of ​​heated space also taken into account when choosing equipment. The larger the house, the more power you need to put a circulator. As a rule, in homes where a lot of heated rooms, do not put one, but several pumping and mixing stations.

pressure

Another parameter on which to look for when buying a pump - it's head. Each unit has its own capacity, and, consequently, a certain pressure value. In order to overcome all the normal coolant loops and bends water circuits, it requires a fairly strong pressure. The magnitude of the pressure depends on the flow rate of coolant in the system. Good and powerful pump will ensure the normal circulation of water in the heating circuit, reaching the most remote areas of the heated space, without losing its design characteristics.

Calculation of the circulating pump performance for underfloor

In the calculations it is important to get the minimum power, which is sufficient for the heating system. We use the formula for calculations:

G = Q x 0,86 / Δt, wherein

G - system capacity in l / h;

Q - thermal energy systems (W).

0.86 - conversion coefficient Kcal / hr;

Δt - parameters of temperature difference of water in the bundle feed-tank line (° C).

Typically underfloor taken pumps models that have a capacity of 2.5 m3/ H with a head of 6 m. This is for the average of floor heating, which has a standard amount of water circuits (2-4 contour). However, if you plan to heating of an apartment house in full, a power pump for underfloor heating It will not be enough, for the reason that the water flow will be considerable and will require more head. For this purpose, determined actual operating pressure loss in the piping of heating floors, made of thermal and hydraulic calculation.

Similar calculations can try to do it yourself or seek to perform such work to specialist services. The latter option is preferable as the errors in the calculations may turn out to have trouble.

Output

For use in the home for equipment underfloor pumping and mixing station, better focus on the regulated pump models. With this device you can easily manage the pressure of the coolant in virtually any heating system with different amounts of water heated circuits.

We should not discount the dimensions of the device and methods of installation. Compact size pumps are easy to use, easy to install. The pumps are mounted together with other mixing devices, providing a single pumping and mixing module.