How to install a pump on a warm floor. Underfloor heating pump - selection and installation. Efficient underfloor heating: calculation of system power

Today it is very convenient and comfortable to have a floor heating system in a house or apartment. It allows you to avoid situations when the upper part of the room warms up well, and chills go down your legs. Thanks to warm floor the temperature can be adjusted in each individual room.

There are two ways to heat the floor: with electric or water. In this article, we will focus on the water floor heating system.

1 What is the principle of operation of a water heated floor?

Installing a floor with water heating is a rather laborious and expensive process. But when it comes to saving energy, it has no equal. At the same time, heat spreads evenly from bottom to top, and there are no poorly heated zones and areas in the room, which the owners of radiator heating systems cannot boast of.

The principle of installation is that pipes are mounted under the floor covering. They are characterized by a length of up to 120m and a small diameter (16-20mm). Pipes are laid in such a way that they have many bends and turns. Therefore, for the normal functioning of the system, forced circulation of the liquid is necessary, which will be provided by circulation pumps. The coolant can be water, antifreeze, ethylene glycol and other substances. It depends on the desire of the owner and the characteristics of the pipes.

2 How to choose a pump for a water heated floor?

The circulation of the coolant through the pipes of the water-heated floor system will be ensured by a properly selected circulation pump. The circulation pump for underfloor heating with water heating is no different from the pump used in radiator heating systems. One difference is that a pump for a warm floor can be bought already with a three-way valve (which will be called a mixing unit when assembled). The latter can be assembled independently by first purchasing a pump and a three-way valve.

So, how to choose a pump for underfloor heating? Consider some of the features that are recommended to consider when buying such a mechanism.

2.1 Availability of speeds

When choosing a pump, it is better to pay attention to one that has several speeds. Speed ​​control can be manual or automatic. If you have a desire to adjust the temperature in the room, you will need to change the speed of the coolant. Therefore, a circulation pump with several speeds is the best solution.

2.2 Rotor type

Depending on the type of rotor, pumps can be "wet" or "dry". "Wet" is a pump whose rotor is located directly in the pumped liquid. This liquid also performs the function of cooling and lubricating the mechanism.

Features of the "wet" type of motor:

• high reliability;
• no noise during operation;
• economical consumption of electricity;
• relatively low power (efficiency does not exceed 50%).

In a "dry" pump, the rotor does not come into contact with water or other liquid. It is in a separate sealed container. Such a pump requires periodic cleaning and lubrication. It also makes a lot of noise during operation. Among the advantages are a long service life and high efficiency, reaching more than 80%.

On the territory of private households, "dry" pumps can only be used when installing fountains, given the rumble during their operation. "Wet" pumps, despite the fact that their performance is lower, are quite capable of ensuring the operation of a warm water floor system up to 400 sq.m.

2.3 Housing material

Considering that the pipeline system is closed and contains a very small percentage of oxygen, it is allowed to install a pump from any material. But if oxygen permeability has not been taken into account and this oxidizing agent is present in the system, then the pump housing must be made of stainless steel or polymer. Cast iron cases in this case are contraindicated.

2.4 Capacity and head

Perhaps the main characteristics that affect the choice of pumping equipment in this case, are performance and pressure.

Productivity is understood as the volume of liquid pumped by the pump per unit of time. For normal operation of the system, it is necessary that the volume of the pumped liquid per hour is equal to three volumes of the entire pipeline liquid.

Head is the ability of a fluid to circulate freely through pipes. Long pipes with many bends are characterized by considerable hydraulic resistance. Therefore, to ensure uninterrupted and high-quality operation of the system, the pressure in the underfloor heating pipeline must be powerful enough.

These values ​​are mainly calculated by the company that installs the underfloor heating system. But if you do it yourself, it will not be difficult for you to calculate such parameters yourself.

We use the following formula:

Q \u003d 0.86 X PH / (tPR - tOBR),

• Q is the volume of the coolant (cubic meters per hour);
• 0.86 - conversion factor;
• PH - heating circuit power (kW);
• tpr-tobr - the difference in the temperature of the incoming and outgoing water through the return pipes.

The formula for calculating the pump head:

H= (P X L + ΣK) /(1000),

• H - pressure;
• P - hydraulic resistance of a linear meter of the pipe;
• L is the length of the pipes of the longest circuit;
• K is the power reserve factor.

When calculating the passport hydraulic resistance of a pipe meter, it is multiplied by the length of the circuit. The resulting value will be indicated in kilopascals (kPa). Since head is measured in atmospheres, convert this value to atmospheres, keeping in mind that 100kPa = 0.1atm. The resulting value, depending on the presence of fittings and valves, is multiplied by the appropriate coefficients.

2.5 Manufacturer

When buying a floor heating pump, it is better not to save money and purchase such a unit manufactured by well-known and reliable companies. Among the manufacturing companies, the German companies Wilo and Grundfos have excellent characteristics. It is better to choose products from the catalog, since both the characteristics of the pump and the features of its installation and operation are indicated there.

2.6 Choosing a model for underfloor heating (video)

3 Some causes of malfunction and their elimination

With the advent of the heating period, when you turn on the pump, which was idle in the summer, you may notice that the pump does not pump. It hums, but no fluid is being pumped. With what it can be connected?

If water is the coolant in your underfloor heating system, then often salts are deposited on the impeller. This happens when the temperature of the liquid exceeds 55 ° C. To prevent such a nuisance, a thermostat is used, which is equipped with some models of pumps. This is the shutdown mechanism of the unit: it does not turn on until the liquid temperature drops to the desired level.

So, how to help a rotor that is coked and does not rotate? It is necessary to turn the impeller several times with a screwdriver or other tool. If the rotor can be moved and rotated, consider that the breakdown has been fixed. You can start the pump.

The house must be warm! Best of all, a “warm floor” maintains a comfortable temperature in the room. A coolant pump drives a multi-meter circuit of thin tubes for. Properly selected and installed in the system, it will create a condition under which the entire heating chain will work efficiently and for a long time.

A complex scheme for heating a room is hidden under the floor covering, so every little detail is important in it. It will be a shame to open expensive parquet or break tiles to correct flaws. The contours of the tubes through which the coolant circulates are walled up in the floor. They constantly contain liquid heated to a temperature of 30-60 degrees Celsius.

Pumps in the circuit are installed for forced supply to the coolant circuits. As a heat carrier, a special antifreeze with improving additives, distilled water is used. But most often, in 68% of cases, tap water is used. This is a budget option, but not the best option for equipment and fittings.

The choice of coolant is made in advance, as it affects a lot. Including, on the parameters by which the selection of the pump is made, and.

Not all materials are compatible with antifreeze. The performance of the pump during its use decreases five times, which is explained by the low heat transfer of antifreeze. Harmful, even deadly poisonous components for humans are often added to the liquid. In the event of a leak or evaporation of antifreeze with additives, 10% of the ethylene glycol content in the air is enough to be fatal.

In addition to supplying the coolant to the pipes, the functions of the pump include coarse temperature control in the system by reducing or increasing the coolant supply rate. A circulation pump for underfloor heating is usually used, which has three modes of operation. As the hot water circulation rate increases, the floor temperature also rises. As it decreases, it decreases accordingly. This property is successfully used in a pump with three pumping speeds.

Calculation of the parameters of the circulation pump

Two main characteristics of the pump: performance and pressure. The formulas and the principle of calculation when using coolants are the same. Only the heat transfer constants change, and hence the performance. When using antifreeze, the final result is multiplied by 1.2. Let's make a calculation of a pump for a warm floor, through the pipes of which tap water circulates.

Calculation of pump performance

To adjust the speed of the run through the coolant pipes, we use a three-speed circular pump. Before purchasing, you need to calculate the performance using the formula:
Q \u003d 0.86 * Pn / (t pr.t. - t rev.t.),
where Рн is the power of the heating circuit required to cover the heat losses in kW, t pr.t. is the supply water temperature, and t re.t. - return temperature.

In rooms with an area of ​​​​more than 50 m2, up to ten circuits are made for, connecting them in parallel. In this case, the heat consumption (productivity) of each circuit is calculated separately, then added and inserted into the formula. As a result, the power of the pump serving the circuits is obtained.

Decades of work of builders and heat engineers in this area made it possible to bring the calculated data into a table. It reflects the dependence of pump performance on the area of ​​the heated room. The calculations and figures in the table are relative, since in this case the energy costs of the materials used are not taken into account:

• Area 80-120 m2 productivity 1.5 m3/hour
• Area 120-160 m2 productivity 2.0 m3/hour
• Area 160-200 m2 productivity 2.5 m3/hour
• Area 200-240 m2 productivity 3.0 m3/hour
• Area 240-280 m2 productivity 4.0 m3/hour

Pump head calculation

Another criterion that must be taken into account when choosing a pump for a water floor is the pressure it creates. It directly depends on the hydraulic resistance index of the pipes, the value of which is indicated in the documents accompanying the sale, and on the length of the circuit or all circuits, if there are several.

The head H is calculated by the formula:
H \u003d (P * L + ΣK) / (1000),
where P is the coefficient of hydraulic resistance of a linear meter of the pipe;
L is the length of the contour,
K - the level of power reserve, which is the sum of the resistance of fittings 1.2, valves 1.7, etc.

Which underfloor heating pump to choose

The technical characteristics are indicated in the passport of each pump. These are the two parameters on which you should make a choice. But how to choose it according to two indicators from the catalog offered by the industry.

Consider models acceptable for use in everyday life:

• The pump with a wet rotor, differs in reliability and quietness of work. It also has the advantage of low power consumption. This pump has low power, so it is designed for an area of ​​​​less than 400 m2.
• A dry rotor pump has more power than a wet rotor pump. But there are significant drawbacks: the need to regularly clean and lubricate it.

As a rule, the area of ​​action of a pump for a warm floor rarely exceeds 400 m2, so you can safely choose the first option. With the same performance, the preference for selection belongs to a pumping unit with a special exhaust valve to bleed air from the system.

Practice has shown that before hot water is supplied to the underfloor heating system, it has to be diluted with an already cooled return. To do this, you need to install a mixer in front of the pump or create a pump with an additional function. The designers picked up the idea, and the manufacturers launched the pumping and mixing unit for sale. In addition to pumping the coolant, it controls and regulates its temperature. When choosing such a pump group, proceed from the above calculations.

Marking and body material

The name of the manufacturer's company is applied on the pump housing, and below it are numbers, designations:

• connection dimensions DN (mm);
• liquid supply height;
• connection type (thread/flange, flange);
• nominal pressure PN (bar);
• maximum power P (kW);
• voltage U (V)
• degree of protection IP;
• permissible coolant temperature Т (0С);
• insulation class H;
• case material.

The first two parameters are indicated immediately below the label.

It is important to know how to choose a pump, given the quality of the material from which it is made. If the coolant is a neutral liquid (distilled water), choose a pump with a housing made of steel, cast iron, polymers, bronze, etc. The presence of an oxidizing agent limits the choice.

Features of pump installation

Heat engineers have developed rules that must be followed when installing pumps in a floor heating system:

• When installing a circular pump in the circuit, the rotor is placed horizontally. Compared to a vertical arrangement, this scheme saves 30% of engine power.
• More often, the pump is installed in the supply pipeline, but after the mixer. Although, other options are not excluded.
• Half of the pumps are equipped with an outlet valve. It is located on the front panel. It is a slotted disk. After the coolant is filled, but before the pump is turned on, the disk is turned with a screwdriver and air is released from the housing. If this is not done, the pump will fail, or the air lock will not allow the coolant to circulate freely through the pipeline.

Pump malfunctions and how to fix them

If a properly selected pump pumps the coolant - tap water, then layers of salt are deposited on the impellers. This problem occurs after a stop while the owners are away or during the summer. When plugged in, the pump makes a strained buzzing sound, but does not pump water. This means that the settled salts "coked" the rotor and do not allow it to move.
You can fix the situation yourself, without turning to professionals. It is necessary, taking a screwdriver and turn the impeller a couple of times.

Failure happens due to airing. With the help of a valve, air is released to a steady stream of water. Start the pump, and repeat the procedure after a minute.

Results

Before installing such a popular “warm floor” system in the house today, you need to carefully calculate the elements. The quality of the structure is affected by the correct choice of a circular pump. The right choice will be ensured by the correct calculations of the required power and pressure. This is difficult task. Therefore, it must be taken seriously. If an independent solution of the problem is beyond their strength, they turn to professionals.

The question of whether a pump is needed for a warm water floor is decided at the design stage. The desire to reduce the cost of the installed system by eliminating this equipment significantly reduces the efficiency of the water circuit, even if the need to install pipes with a design slope is taken into account.

Typical pump for water floor heating

This is due to the rather large total length of the pipeline being installed, as well as the frequent occurrence air locks. For this reason, experts recommend equipping a water heating system with a pump.

Functional purpose

The main functional role of the pump is to create the optimal pressure in the heating system, which contributes to the unhindered circulation of the coolant. This eliminates the risk of malfunctions in the functioning of the water floor due to air in the system.

Scheme of the pump of a warm water floor

Such a solution is of particular relevance if the length of the pipes being laid is significant, and when they are laid, a large number of turns are formed that slow down the movement of the fluid. Equipping the water floor system with a pump with several speeds increases the heating efficiency, as it becomes possible to maintain a stable design temperature in the system.

Type of equipment

An underfloor heating circulation pump will provide efficient heating, supplying liquid at a constant predetermined rate without the formation of destructive overpressure. It belongs to the centrifugal type. The working bodies are an electric motor, as well as a shaft equipped with an impeller.

How to choose a circulation pump

On the body, made of cast iron, stainless steel or durable, non-corrosive polymers, there are two branch pipes that serve to connect the return and supply. Some models are equipped with an air outlet, and in its absence, a special nut performs the function of bleeding air, which you just need to unscrew.

There are two types of circulation pumps.

• With a wet rotor, which comes into direct contact with water during operation. The shaft draws in the liquid during rotation, and then pushes it further under pressure. In such pumps, water additionally acts as a lubricant. These devices do not differ in high power, being used in small areas (≤ 400 m 2) rooms. They are reliable, economical with low power consumption. Among the advantages can be noted their almost silent operation.

Glandless pump

Dry rotor pump

Determination of performance, power

Scheme for selecting a pump for a heating system

where Q is the required power of the water circuit, W;

1.16 – specific heat capacity of water, Wh/kg °С;

t p. - supply water temperature, °С;

t arr. – return temperature, °C.

The required heat output is approximately 100 W times the area to be heated.

To determine the performance of the selected pump in m 3 / h (which is often indicated in the passport), you need to divide the result in kg / h by the density of water, determined from the reference tables at the desired coolant temperature. For example, for 80 ° C, the density will be 971.8 kg / m 3.

Pump installation diagram for a warm water floor

If it is planned to lay several water circuits, then the calculation is carried out for each separately, and the results are summarized. Usually, to avoid problems, the calculated performance indicator is increased by 15-20% so that the system can provide a home with heat when extreme cold sets in.

Another indicator to be calculated is the magnitude of the pressure created by the pump (N, m), which ensures the normatively established circulation of heated water in the system. The following formula is used to determine:

H \u003d (R L + Z) / p g,

Classification of pumps for underfloor heating

where R is the hydraulic resistance indicated in the technical documentation of the water circuit, the straight section of the pipe (depending on the size of the section and material), Pa / m;

L is the length of the laid pipeline, m;

Z is the resistance of various factors that interfere with water movement (bends, turns, fittings, valves, etc.), Pa;

p is the density of water at the temperature required for the calculation, kg / m 3;

g is the free fall acceleration, ≈ 9.8 m/s 2 .

For country houses, using the graphical characteristics that can be found in the reference literature, pump models are usually selected with an average head of up to 6 m (0.6 atm.).

Criterias of choice

In order for the circulation pump to ensure the uninterrupted and efficient operation of a water-heated floor, when choosing it, in addition to performance and pressure, pay attention to a few more indicators.

Average energy consumption of a floor heating pump

• Having multiple speeds. Usually three are enough, allowing you to quickly adjust the degree of heating of the coolant.
• Electricity consumption. The most economical are advanced models of pumps, equipped with a module for automatic control of the intensity of work, depending on the degree of heating of the coolant.
• Noise background. For residential premises, this indicator is important. Small-sized varieties of pumps with a wet rotor are practically not a concern.

An important criterion is the manufacturer. Among the large companies that have the image of reliable partners producing high-quality pumps, the following well-known brands can be noted:

Selection of a pump for underfloor heating

• Grundfos (Denmark);
• Ebara (Japan);
• DAB (Italy);
• Halm (Germany);
• Lowara (Italy);
• AlfaStar (Poland);
• Pedrollo (Italy);
• Wilo (Germany).

Circulation pumps of the Wester brand (China) are in demand, which, at a relatively low cost, are of good quality.

When installing the pump, it is advisable to position it so that the rotor is oriented horizontally. In this case, the arrow depicted on the body must coincide with the direction of movement of the coolant. After the installation is completed, water is opened into the pump, then the screw is opened to remove air. In the vertical direction, the performance does not decrease, but there is a risk of power loss up to 30%.

The circulation pump is mounted depending on the calculated connection diagram in the following positions:

• on the supply pipe. In this case, the pump is located after the mixing unit.
• On the return pipe. Among the recommendations of experts, the opinion prevails that the performance of the pump is higher if it is mounted on the return line. This point is of particular relevance if a solid fuel pump is installed for heating water, capable of bringing the coolant to a vapor state, in which the pump simply cannot function.

What is required for the installation of a warm water floor

If the area to be heated is less than 200 m2, then the temperature difference between the supply and return water temperatures is small. Therefore, the pump can be located in any place convenient for the user. When installing a water heating circuit in mansions with several floors, it is recommended to equip each with a separate pump so that the system is easily controlled.

Trouble-shooting

The main factor that negatively affects the functioning of the pump is the quality of the water entering the water heating circuit. If the pump is running continuously, then salt deposits reduce its performance to a lesser extent than during periods of shutdown.

Scheme of connecting the circulation pump to the mains

Sometimes, after turning off the underfloor heating for the summer period, the pump stops pumping water when it is turned on again due to the fact that the rotor does not turn. It is necessary to carefully rotate the impeller several times with the help of improvised means. If the pump does not start to function, specialist assistance will be required.

Pump for a warm water floor: how to calculate, choose, do you need it

Why do we need a pump for underfloor heating - functional purpose, type of equipment, determination of performance, power, pressure, selection criteria, installation, troubleshooting.

How to choose a pump for a warm water floor - differences in details

Systems of water heating of a floor differ in the profitability in use. But their installation is expensive and time-consuming. The design consists of a large number of components and components, one of which is a pump for a warm water floor.

Underfloor heating is a complex system. All its elements must function in concert and fulfill their purpose. The efficiency of heating the floor surface depends, among other things, on the correct operation of the pump.

Depending on the size and purpose of the premises, the entire length of the pipelines reaches 100 meters or more. In this case, the diameter of the pipes is about 20 millimeters. The pipeline is made with a large number of turns. Thus, conditions are created for the coolant under which the fluid flow receives a large resistance. To overcome it, it is necessary to use high-performance devices with sufficient power. That is why there is no doubt whether a pump is needed for a warm water floor.

In addition, depending on the temperature of the coolant, the speed at which the liquid moves through the pipeline changes. The pressure values ​​​​should change smoothly so that water hammer does not occur. The pump needs to respond instantly to the changing conditions under which the underfloor heating system is operated.

In order to be able to maintain comfortable living conditions in the room, they use the automation to which the unit is connected - it must be able to operate at several speeds.

Pump selection according to technical specifications

Usually, circulation pumps are used for floor heating construction, such as in the photo. The characteristics of these units correspond to the requirements imposed on them as much as possible.

Calculations are made according to the formula:

Q \u003d 0.86 × Pn / (t ° pr.t - t ° rev.t), where

Q is the flow rate in cubic meters per hour;

Pn is the maximum power of the circuit (kW);

t°pr. t is the value of the water temperature in the supply pipe;

t°arr. t is the temperature of the liquid at the outlet.

If, when laying the structure, the installation of several circuits is planned, then it is required to find out the total value, taking into account each of them.

According to experts, for a separate room it is better to equip autonomous system heating the floor surface, as a result of which it becomes possible to economically consume thermal energy. It will be possible to regulate the state of the microclimate depending on the purpose of a particular room, and make the operation of the structure more reliable.

The difference between the water temperature in the heating circuit at its inlet and outlet depends on a number of parameters:

1. Pipeline length. The longer the circuit, the larger the area it should heat. This means a significant consumption of thermal energy, and the temperature at the inlet and outlet will be very different;
2. The quality of the thermal insulation. If the technology was violated during the creation of the system, then heat losses during the operation of the warm floor will reach high numbers. This is especially true for premises located on the lower floor, since improperly made thermal insulation will contribute to the consumption of a significant amount of energy for heating the ground. Excessive heat loss leads to an increase in the load on the circulation pump for underfloor heating.
3. The climate in the area where the house is located. The further north the region, the greater the power reserve should be for the heating system and the circulation unit. Manufacturers advise choosing them with an indicator equal to 20-25%.

Another important value for determining how to choose a circulation pump for underfloor heating is the pressure of the coolant flow. It should be enough to overcome the hydraulic resistance of water in the system. The hydraulic resistance index depends on the length of the circuit, the cross-section of pipes for water, and the speed of movement of the liquid.

When purchasing a pump, you should pay attention to the fact that the above-mentioned parameters are indicated in the accompanying documents for it.

With an independent arrangement of the system, the formula is used to calculate the pressure of the coolant:

H= (П×L + ΣК) /(1000), where

H is the desired value;

P - hydraulic resistance on one meter of the circuit;

L is the length of the longest of the circuits, together with control systems;

After all the data become known, they proceed to the selection of the optimal pump model.

Types of circulation units

The design features of circular pumps designed for water floors depend on the power parameter.

Residential consumers can use the following models of units:

Pumps equipped with a wet rotor

The external dimensions of such devices are minimized due to the location of the impeller close to the pump rotor, sometimes it is located in the same housing with it. To prevent liquid from entering the electric motor, a reliable oil seal made of wear-resistant and heavy-duty rubber is installed on the drive shaft.

For the operation of devices with a "wet" rotor, a single-phase 220 V network is required. The units are characterized by low noise, high performance, and minimal power consumption. The completely sealed pump housing is light in weight.

All of the above characteristics make it possible to mount circulation units directly on the pipeline. In this case, their additional fastening on the bearing surfaces is not required. To eliminate the possibility of electric shock, elements such as the housing, wiring and winding are provided with increased protection. To prevent overheating of the rotor and starter windings as a result of prolonged operation of the unit at critical power indicators, a thermal relay is installed.

Pumps equipped with a "dry" rotor

In such devices, all elements are in a separate case. Sufficiently powerful hydraulic units are able to serve large apartments or several at the same time. To accommodate devices with a "dry" rotor, it is necessary to allocate a technological room. They are installed on a separate frame.

Such pumps have significant weight, and high noise levels do not allow them to be placed in living rooms. Rarely used for private households. Water pumps with a "dry" rotor are used for large areas - industrial and commercial.

They are driven by a three-phase motor. The pumps are equipped with a complete protective kit for electrical components.

Information on the pump body

The standard marking applied to the body must contain all the technical parameters of the unit. The first number from the top indicates the mounting diameter of the pipes for the coolant, the second - about the pressure (meaning the maximum rise of the liquid to a height), the third of the numbers - about the length of the pump in working condition.

The following indicators mean the voltage and frequency of oscillations in the network. Then comes information on the magnitude of the phase shift coefficient. On the body there may be data on the height of the rise of the liquid, depending on the section of the pipes.

Some of the units are equipped with two engines. This design feature allows you to overcome peak loads, preventing overheating of the windings. The work includes the second of them, which is also able to replace the failed first engine. As a result, the possibility of freezing of the structure in severe frosts is excluded.

Mounting options for electric pumps

Circulation units are allowed to be installed both at the inlet and at the outlet of the liquid from the pipeline. The place of installation is usually chosen based on the characteristics of the circuit.

At the outlet of the water, its temperature is much lower than at the inlet, which is preferable for pumps. But installation at the end of the circuit is not mandatory, since all units are manufactured with a certain margin of safety relative to the maximum operating temperature.

Choosing a pump for a water floor system

Many owners of private households planning to install a floor heating system are interested in the question: “How to choose a circulation pump for underfloor heating?”.

Experts advise buying pumps at the same time as the structural elements of the "warm" floor. Attempts to independently purchase the unit may result in a decrease in the efficiency of the system or its rapid failure. As for the repair of the "warm" floor, it will cost a significant amount.

Before buying, you should pay attention to certain parameters:

1. Productivity in cubic meters or in the number of liters of liquid that is pumped per unit of time. To ensure sufficient space heating, the unit must pass three times the volume of coolant that can be in the heating circuit per hour.
2. The maximum possible pressure. It is selected, taking into account the diameter, length and material of manufacture of pipes for the circuit.
3. Dimensions. The smaller the unit, the easier it is to find a mounting location for it. But small pumps are not able to work with high performance.
4. Phase current. For residential buildings, there will be enough pumps with a single-phase motor. For large buildings, for example, for industrial use, units driven by a three-phase motor should be purchased.

Knowing how to choose the right floor heating pump will help you purchase a model that will provide the desired system efficiency, reliability and long term operation.

To extend the life of the pump, you must not forget the following rules:

1. The unit must be installed in a place where, if necessary, it will be possible to carry out repairs or warranty service without problems.
2. Despite the fact that imported pumps are of high quality, before the start of the heating season, it is necessary to check their technical condition due to low water quality and operating conditions. Particular attention should be paid to the condition of the stuffing box, which provides waterproofing of the shaft of the device from the rotor.

On the eve of the start-up of the floor heating system, it is necessary to remove the air plugs in it. For this purpose, the water is changed several times in it and a special valve is installed. The presence of air pockets will become an obstacle to the movement of the liquid, and the automation will constantly turn on the circulation.

Pump for a warm water floor: how to choose a circulation pump, how to calculate power and choose whether you need it, photo and video

Pump for a warm water floor: how to choose a circulation pump, how to calculate power and choose whether you need it, photo and video

Underfloor heating pump: how to calculate, select and install

Keep your feet warm is the popular saying. The underfloor heating system helps us to implement such simple worldly wisdom. But what is a system or an organism without a heart? So in our system, the heart is a pump for a warm floor.

Such heating is not new in use. In ancient Rome, floor heating was used with warm water. Innovative technologies have brought a new outlook and possibilities to our lives. There is not a single reason for refusing the coziness and comfort obtained during the operation of such heating. In addition, using a heating system without radiators, there is additional space, which is modern and convenient. There is another advantage that cannot be ignored. The concept of "warm floor" is low-temperature, unlike radiator heating, where heating up to 90 ° C is used, and this is much more economical, with correctly made calculations and calculations.

Application in household system

The pump for a warm water floor is the heart of the system

The key difference between underfloor heating and heating with radiators is the single-level location and length of the water circuit. For the productive operation of a warm floor, a circulating type of device is used to ensure the movement of the coolant in the system. If this is a two-story house, then a two-level circuit requires the installation of two units. In this case, a mixing unit is used together with a three-way valve. They come in two types - for small and large areas. Therefore, when choosing them, this parameter must also be taken into account.

Types of pumps

All devices used in heating systems are centrifugal in their action. Their structural basis is an impeller or a rotor mounted on the main shaft, during the rotation of the blades of which a vacuum is created. Under its influence, the coolant enters the working chamber, from where it is ejected by centrifugal force into the main line. The following centrifugal devices are widely known

• Dry rotor pumps. These are high efficiency units. Their use is effective with a sufficiently large heating area. In addition, increased noise during the operation of devices requires the equipment of a separate room for their installation, which can really be arranged in a private house.

Structurally, these devices are a two-block system, one of the elements of which is an electric motor, and the other is a housing with a rotor that does not come into contact with water. There are also monoblock options.

Glandless pumps

• Wet rotor motor. The rotation of the impeller occurs directly in the coolant, which is also a lubricant for it. Such a unit has a lower efficiency than its counterpart, but the energy consumption is much lower. Low operating noise during operation of the device, allows its installation in any place.
• Single and multi-speed pumps. According to these parameters, the functionality of each is determined using a simple calculation. For a warm floor, the use of three-speed units is typical, then with the deterioration of external climatic conditions, an enhanced operation mode of the device becomes possible.

Calculation of performance and power

For arranging a "warm floor", the main characteristics of the device and the possibility of its use will be pressure and performance. These parameters determine the power of the circulation device.

To calculate the required characteristics of the pump, you can use the existing tables and expressions for determining the consumption of the coolant.

Q \u003d 0.86 * P circuit / (T supply - Tobr)

• Pcontour- heating circuit power, kW.
• Tobr- the temperature of the heat carrier in the return pipeline.
• Tsupply- temperature in the supply pipeline.

The next step is to calculate the hydraulic resistance of the water circuit. The performance determined by the formula must be greater than the loop resistance.

If there are any doubts in the calculation, then entrust them to professionals

Choice and its features

Mounting Features

1. Horizontal installation. When installing the circulation unit for the "warm floor", its horizontal installation is always used. Vertical mounting results in the loss of almost a third of the power of the unit and increases the risk of air in the system, which can lead to unnecessary trouble.
2. The pump is installed on the coolant return pipe. The temperature here is always lower, and this precaution will increase the guaranteed operation of the device. In addition, the device is separated from the system by ball valves so that it can always be accessed without draining the water from the circuit. This is necessary for preventive maintenance and possible emergency breakdowns.
3. Mounting connections and nuts are included with the purchase of the device. and facilitating its connection to the system.

Schematic illustration of installation

Possible malfunctions during operation

The main breakdowns of the pump occur due to the frequency of its use. In winter, the unit is constantly in operation, and in summer it is turned off. The coolant used is usually water, in the absence of circulation, precipitation occurs in the form of salt, which can cause the device to fail. In this case, it is necessary to gain access to the impeller-rotor of the apparatus by removing the cover and trying to manually turn it. If this succeeds, then you can start the engine. In exceptional cases, it will be necessary to subject the unit to a full range of preventive maintenance.

In conclusion, it should be noted that it is not always possible to use the "warm floor" system autonomously. Even with appropriate calculations, it can be said that the efficiency of using a double scheme "radiators plus floor" gives better results with large heated areas of the premises. In this case, the installation of the device will be somewhat different. The problem of matching the circuits with each other is solved by choosing a more powerful pump.

Underfloor heating pump: calculation, selection, installation

How to choose a pump for underfloor heating - types and installation rules. Circulation pump for underfloor heating: all the most important thing about pumps.

Reading 7 min.

Nowadays, underfloor heating systems are gaining more and more popularity. They are used both for heating the premises as a whole, and for heating its individual segments. Installation of underfloor heating systems is carried out in apartments and individual housing construction. After all, it is always pleasant, and even useful, to slap bare feet on a warm surface.

According to their design, underfloor heating systems are electric and water. It is for the second option that a circulation pump is needed, which is the heart of the entire system.

Water floor heating system: how is it arranged?

The system includes the following mandatory components:

• heat source (boiler, central heating riser);
• coolant (water, antifreeze, oil, etc.);
• heating pipes;
• insulation;
• control and distribution device;
• circulation pump.

The coolant circulates through an extensive network of pipelines located on the floor under the coating. The heat source is usually a gas boiler.

The use of water floors in apartments with a heat source supplied centrally through the riser is allowed in houses with apartment-by-apartment horizontal heating distribution.

For the purpose of equal heating of the floors, the pipes are placed at a small distance between them (100-200 mm). At the walls, the distance between the pipes is left less than in the center of the room. Pipe laying is carried out according to two schemes:

• snake - associated with the slalom or zigzag track;
• snail - resembles a spiral.

The coolant heated to a temperature of 35-45 degrees, passing through the pipeline, loses temperature. The optimal length of the pipeline (loop) is up to 120 m. This is enough to cover a room up to 20 m2. For large rooms, several pipelines are mounted. They are connected to the heat source in parallel through a collector, which is located in a special cabinet. It also installs shut-off and control equipment (pressure gauges, thermostats, drain taps, flow sensors, air valves), as well as pumps.

Standard circulation pump for water floor heating and its device

The device provides a uniform redistribution of the coolant in a closed circuit, maintains a constant pressure in the system. The use of the device significantly increases the efficiency of the underfloor heating system, eliminating the stagnation of the coolant in long pipeline circuits.

The standard device, in fact, is a conventional circulation pump, consisting of the following basic elements:

1. The case is the main element of the device, which is made of high-strength materials. Typically, cases are made from various metals: stainless steel, bronze, cast iron. In some modern devices, plastic cases are used.
2. Branch pipes or flanges are located on the body and provide connection with inlet and outlet pipes.
3. The impeller provides the movement of the coolant due to its rotation. They are made of metals, plastics and modern technopolymer material, which hardly wears out.
4. The electric motor is usually located on the side of the housing and drives the impeller.

Circulation pumps should be fixed so that the rotor is in a horizontal position. If the shaft is placed vertically, the power loss will be up to 40%.

Main characteristics of circulation pumps

The determining criteria when choosing a unit for a water-heated floor are indicators of its performance and pressure.

The performance of the unit is calculated in cubic meters (liters) per hour. In normal mode, the unit in 1 hour must pump a coolant that is 3 times the volume of the entire warm water floor system. The performance of the unit should be the higher, the larger the laying area of ​​​​the underfloor heating pipeline. The performance margin should be 15-20%. This will increase the life of the unit and prevent problems associated with poor heating during the cold season.

The pressure given out by the unit is the second important indicator. It must be sufficient to overcome all the bottlenecks and bends of the pipeline in order to deliver the coolant to the most remote points of the room. The calculated performance should remain unchanged. For domestic use, it is usually sufficient to use a unit with a head of up to 6 m of water column.

How to choose a unit according to the estimated pressure?

Since the pressure overcomes the hydraulic resistance of all elements of the system, these indicators must be taken into account personally:

• the material and diameter of the pipe affect the resistance, are contained in the instructions for the unit;
• coefficient of increase in resistance on the valve - 1.7;
• coefficient of resistance on fittings and fittings - 1.2;
• resistance coefficient at the mixing unit - 1.3.

The formula for calculating the pressure is as follows: H \u003d (PxL + EK) / 1000 where:

• H-head of the unit;
• P - resistance of 1 m running pipe;
• Pa / m, L - the length of the longest contour, m;
• K is the power reserve factor.

The length of the circuit is multiplied by the hydraulic resistance index of 1 m of pipe. The value obtained in kilo pascals (kPa) is converted into atmospheres of 100 kPa = 0.1 atm. The result is multiplied by the resistance coefficients of all elements of the system. The result will be the operating point of the unit.

Then, according to the catalog or passport of models, this characteristic is found, performed graphically. For a correctly selected unit model, the operating point should be located in the middle third of the graph. When installing a 3-speed unit, the pump is selected according to the 2nd speed, which will make it possible to operate the pump in the optimal mode.

How to choose a pump by calculating the volume of coolant?

Usually, the selection of the required unit is carried out by installation specialists, but this can also be done individually by making some calculations. We perform them according to the formula Q \u003d 0.86xPn / (T p -Tob), where

• Q is the volume of the coolant, in cubic meters per hour;
• 0.86 - conversion factor;
• Pn is the power of the underfloor heating circuit required to compensate for heat losses;
• (Tp-Tob) - the difference between the temperatures of the coolant entering the pipeline system and exiting through the return pipes.

The initial data on heat losses and temperatures are taken from construction guides. Thus, the volume of coolant flow in a certain circuit is recognized. Having information about the flow rate of the coolant and the resistance of the system and applying the parameters from the manufacturer's instructions, we will be able to select the appropriate unit.

What type of pump to choose?

Having calculated the technical indicators of the unit, necessary for the circulation in the system to be correct, you need to decide on the type of pump. For domestic use, two types of units are used:

• with a wet rotor;
• dry rotor.

Wet rotor units do not have very high power, but it is quite enough to ensure the performance of a warm water floor system that does not exceed 400 m2 in area. The rotor is called wet because it is located directly in the coolant. It provides lubrication and cooling of the motor. Such devices have advantages due to:

• silent operation;
• low energy consumption;
• reliability (have a supply of motor resources);
• ease of operation (do not require additional maintenance).

Dry rotor units have a lot of power. The rotor is located in an individual sealed housing. During operation, periodic maintenance (lubrication, cleaning) is required. In operation, the unit with a dry rotor behaves quite noisily.

In individual private construction, for arranging a water-heated floor system, they almost always stop at the wet rotor pump option.

Housing material and marking

When choosing a circulation pump for underfloor heating, you need to pay attention to the body material and markings. Usually the body material does not matter, since with the right choice of pipes and a closed system of oxygen, little oxygen is released. However, in order to be safe from oxidative processes, it is better to give preference to a case made of stainless steel or polymeric materials.

The marking on the pump housing consists of 2-3 digits, for example 25/60-130 or 32/80. The first indicator is the diameters of the inlet / outlet holes in millimeters, for example 25mm and 32mm. The second indicator is the lifting height provided by this unit. In our case, 6 m, 8 m. When translating meters into atmospheres, we get 0.6 and 0.8 atm. The third indicator is the size of the device, its installation length. In the example, this figure is 130 mm.

The nuances of installing a circulation pump

The most popular installation scheme for the unit when installing a warm water floor is its location on the supply pipeline, after the mixing unit. Sometimes the pump is put on the return line or in the mix bypass. For two-level buildings, it is recommended to use two autonomously operating units. This makes it easier to control the pressure of each branch.

The selected unit, no matter where it is installed, must be positioned so that its rotor is in a horizontal position. With a vertical rotor, the power loss is up to 30%.

Installation of a warm floor: circulation pump and collector installation (video)

Many owners of country houses, having read and heard a lot about the advantages that water "thermal floors" provide, are seriously thinking about creating such a space heating system on their own. It should be said right away: this task is an extremely difficult, large-scale one, requiring the mobilization of all one's skills and abilities both in general construction issues and in plumbing installation. It is necessary to pay special attention to the selection of all components, which, in turn, must meet a number of important requirements.

Apart from the boiler, the pump-mixing unit acts as the main unit that provides the required temperature level in the circuits and stable circulation. It is purchased ready-made, that is, factory assembled, or mounted independently. But be that as it may, in any case, it must be able to ensure the circulation of the amount of coolant necessary for the actually emitted system. How to evaluate this ability? This can help the calculator for calculating the performance of the pumping and mixing unit "warm floor"

Underfloor heating prices

Enter the requested values ​​and click the button "Calculate required minimum capacity"

AREA OF PREMISES CONNECTED TO THE HEATED FLOOR MIXING UNIT

The area of ​​premises in which underfloor heating is the main source of heating, m²

Area of ​​premises where underfloor heating plays an auxiliary role, m²

TEMPERATURE IN THE SUPPLY AND RETURN MANIFOLD OF HEATED FLOOR

Temperature in the supply manifold, ºС

Temperature in the return manifold, ºС

The following is used as a heat carrier:

Heat capacity of antifreeze, W×h/(kg×°С)

Density of antifreeze, g/cm³

Explanations on the principle and procedure for the calculation

First of all, what is performance? Everything is very simple - this is the ability of a device or a node (that is, each of its elements) to pass a certain amount of coolant through itself per unit of time. In the case under consideration, this primarily concerns the pump, which ensures the proper level of circulation through all the laid contours of the "warm floor". The throughput is also important for a two- or three-way thermal valve, which provides a metered mixing of hot and cold streams to obtain the required temperature.

It is clear that the pump acts as an “active link”, that is, it must be able to pump the required volume, and the valve only has the ability to pass it through itself. Despite this fundamental difference, the performance value must match the parameters of both devices.

• Naturally, in the initial data, the key parameter is the area of ​​\u200b\u200bthe premises in which the contours of the "warm floor" are located, connected to this mixing unit. The planned principle of operation of such a system is also important - whether it will act as the only source of heat in winter, or whether its operation is necessary only to increase the overall level of comfort in the rooms, and the main load will still fall on the radiators. It is clear that the required thermal power for these two cases will differ.

For rooms such as baths, bathrooms, hallways, kitchens, it is advisable to take into account the condition that the "warm floor" is the only source of heating.

• Further, the calculation is based on the heat capacity of the coolant, that is, its ability to accumulate thermal energy in the boiler room and release it to the premises. The more liquid of a certain temperature is pumped, the higher the heat transfer. This parameter is already included in the calculation program.
• The temperature difference between the flow and return manifolds is calculated by simply subtracting the values. For water heated floors, with their proper balancing and good quality thermal insulation of the room, the optimal difference is 5 ºС. Maybe a little more, but it is impossible to go beyond 8 ÷ 10 ºС. And for a comfortable perception of the very surface of the “warm floor”, 25-27 is enough, less often - 30 ºС.
• By default, the calculator will calculate for an underfloor heating system filled with water. If a different coolant is used, then an amendment can be made for this circumstance. The fact is that not a single antifreeze can be compared with water in terms of specific heat, differing at the same time in a higher density. These data can be indicated on the original packaging of the coolant, or they can be easily found on the Internet specifically for the planned type of antifreeze liquid of one or another concentration.

The result will be shown in several units of measurement - these are cubic meters per hour, liters per minute and per second. This is so that the user does not have to independently translate from one to another - various manufacturers of components often practice a different approach in indicating the performance of their devices.