Designing underfloor heating: general recommendations. What is the optimal length of the underfloor heating pipe? How many meters of pipe are required for underfloor heating per circuit

One of the conditions for the implementation of high-quality and proper heating premises with the help of a warm floor is to maintain the temperature of the coolant in accordance with the specified parameters.

These parameters are determined by the project, taking into account required amount heat for the heated room and flooring.

Required data for calculation

The efficiency of the heating system depends on a properly laid circuit.

To maintain the set temperature in the room, it is necessary to correctly calculate the length of the loops used to circulate the coolant.

First, you need to collect the initial data on the basis of which the calculation will be performed and which consist of the following indicators and characteristics:

the temperature that should be above the floor covering;
layout diagram of loops with coolant;
distance between pipes;
the maximum possible length of the pipe;
the possibility of using several contours of different lengths;
connection of several loops to one collector and to one pump and their possible number with such a connection.

Based on the above data, it is possible to correctly calculate the length of the underfloor heating circuit and thus ensure a comfortable temperature regime indoors with minimal cost to pay for energy supplies.

Floor temperature

The temperature on the surface of the floor, made with a water heating device underneath, depends on functional purpose premises. Its values should not exceed those specified in the table:

Compliance with the temperature regime in accordance with the above values will create a favorable environment for the work and rest of the people in them.

Pipe laying options used for underfloor heating

Underfloor heating options

The laying scheme can be performed with a regular, double and corner snake or snail. Also possible various combinations of these options, for example, along the edge of the room, you can lay out a pipe with a snake, and then the middle part with a snail.

AT large rooms complex configuration, it is better to lay with a snail. indoors small sizes and having a variety of complex configurations, snake laying is used.

The pipe laying step is determined by calculation and usually corresponds to 15, 20 and 25 cm, but no more. When laying out the pipes with a step of more than 25 cm, the human foot will feel the temperature difference between and directly above them.

At the edges of the room, the heating circuit pipe is laid in increments of 10 cm.

Permissible contour length

The length of the circuit must be selected according to the diameter of the pipe

It depends on the pressure in a particular closed loop and hydraulic resistance, the values of which determine the diameter of the pipes and the volume of fluid that is fed into them per unit time.

When installing a warm floor, situations often occur when the circulation of the coolant in a separate loop is disturbed, which cannot be restored by any pump, the water is locked in this circuit, as a result of which it cools down. This results in pressure losses of up to 0.2 bar.

Based practical experience, you can adhere to the following recommended sizes:

Less than 100 m can be a loop made of metal plastic pipe 16 mm in diameter. For reliability optimal size is 80 m.
Not more than 120 m take the maximum length of the circuit of 18 mm pipes made of cross-linked polyethylene. Experts are trying to install a circuit with a length of 80-100 m.
No more than 120-125 m is considered allowable size loops for metal-plastic with a diameter of 20 mm. In practice, they also try to reduce this length to ensure sufficient reliability of the system.

For a more accurate determination of the size of the loop length for the underfloor heating in the room under consideration, in which there will be no problems with the circulation of the coolant, it is necessary to perform calculations.

Application of several contours of different lengths

The device of the floor heating system provides for the implementation of several circuits. Of course, the ideal option is when all the loops have the same length. In this case, no adjustment and balancing of the system is required, but it is almost impossible to implement such a piping scheme. Detailed video about calculating the length of the water circuit, see this video:

For example, it is necessary to implement a floor heating system in several rooms, one of which, for example, a bathroom, has an area of 4 m2. This means that 40 m of pipe will be needed to heat it. It is not advisable to arrange contours of 40 m in other rooms, while loops of 80-100 m can be made.

The difference in pipe lengths is determined by calculation. If it is impossible to perform calculations, a requirement can be applied that allows a difference in the length of the contours of the order of 30-40%.

Also, the difference in the lengths of the loops can be compensated by increasing or decreasing the diameter of the pipe and changing the pitch of its laying.

Ability to connect to one node and pump

The number of loops that can be connected to one collector and one pump is determined depending on the power of the equipment used, the number of thermal circuits, the diameter and material of the pipes used, the area of heated premises, the material of the enclosing structures, and many other various indicators.

Such calculations must be entrusted to specialists with knowledge and practical skills in the implementation of such projects.

The size of the loop depends on the total area of \u200b\u200bthe room

Having collected all the initial data, considering possible options creating a heated floor and having determined the most optimal of them, you can proceed directly to calculating the length of the contour of a water heated floor.

To do this, it is necessary to divide the area of \u200b\u200bthe room in which the loops for water floor heating are laid by the distance between the pipes and multiply by a factor of 1.1, which takes into account 10% for turns and bends.

To the result you need to add the length of the pipeline, which will need to be laid from the collector to warm floor and back. The answer to the key questions of organizing a warm floor, see this video:

You can determine the length of the loop laid in 20 cm increments in a room of 10 m2, located at a distance of 3 m from the collector, by doing the following:

10/0.2*1.1+(3*2)=61 m.

In this room, 61 m of pipe must be laid, forming a heating circuit, in order to ensure the possibility of high-quality heating of the floor covering.

The presented calculation helps to create conditions for maintaining a comfortable air temperature in small separate rooms.

To correctly determine the pipe length of several thermal circuits for a large number premises powered from one collector, it is necessary to involve the design organization.

She will do this with the help of specialized programs that take into account many different factors on which the uninterrupted circulation of water depends, and hence the high-quality floor heating.

The laying of heating pipes under the floor covering is considered one of the the best options heating a house or apartment. They consume fewer resources to maintain the specified temperature in the room, exceed standard wall-mounted radiators in terms of reliability, evenly distribute heat in the room, and do not create separate “cold” and “hot” zones.

The length of the contour of the water floor heating - the most important parameter, which must be determined before installation work. The future power of the system, the level of heating, the choice of components and structural units depend on it.

Styling options

There are four common pipe laying patterns used by builders, all of which are better suited for indoor use. various shapes. From their "drawing" to a large extent depends on the maximum length of the contour of the warm floor. It:

"Snake". Sequential laying, where the hot and cold lines follow each other. Suitable for elongated rooms with division into zones of different temperatures.
"Double snake". Applied in rectangular rooms but no zoning. Provides uniform heating of the area.
"Corner snake". Sequential system for a room with equal wall lengths and a low heating zone.
"Snail". Dual routing system suitable for square-shaped rooms with no cold spots.

The chosen laying option affects the maximum length of the water floor, because the number of pipe loops and the bending radius change, which also “eats” a certain percentage of the material.

Length calculation

Maximum length underfloor heating pipes for each circuit is calculated separately. To get the required value, you need the following formula:

W*(L/Shu)+Shu*2*(L/3)+K*2

Values are in meters and mean the following:

W is the width of the room.
D is the length of the room.
Shu - “laying step” (distance between loops).
K is the distance from the collector to the connection point with the circuits.

The length of the contour of the warm floor obtained as a result of calculations is additionally increased by 5%, which includes a small margin for leveling errors, changing the bending radius of the pipe and connecting with fittings.

As an example of calculating the maximum pipe length for a warm floor for 1 circuit, let's take a room of 18 m2 with sides of 6 and 3 m. The distance to the collector is 4 m, and the laying step is 20 cm, the following is obtained:

3*(6/0,2)+0,2*2*(6/3)+4*2=98,8

5% is added to the result, which is 4.94 m and the recommended length of the water floor heating circuit is increased to 103.74 m, which are rounded up to 104 m.

Dependence on pipe diameter

The second most important characteristic is the diameter of the pipe used. It directly affects maximum value length, the number of circuits in the room and the power of the pump, which is responsible for the circulation of the coolant.

In apartments and houses with an average size of rooms, pipes of 16, 18 or 20 mm are used. The first value is optimal for residential premises, it is balanced in terms of costs and performance. The maximum length of the water floor heating circuit with 16 pipes is 90-100 m, depending on the choice of pipe material. It is not recommended to exceed this indicator, because the so-called “locked loop” effect may form, when, regardless of the pump power, the movement of the coolant in the communication stops due to high fluid resistance.

To choose the best solution and take into account all the nuances, it is better to contact our specialist for advice.

Number of circuits and power

The installation of the heating system must comply with the following recommendations:

One loop per room small area or part of a large one, it is irrational to stretch the contour over several rooms.
One pump per manifold, even if the declared capacity is enough to provide two "combs".
With a maximum length of the underfloor heating pipe of 16 mm in 100 m, the collector is installed on no more than 9 loops.

If the maximum length of the underfloor heating loop 16 of the pipe exceeds the recommended value, then the room is divided into separate circuits, which are connected into one heating network by a collector. To ensure an even distribution of the coolant throughout the system, experts advise not to exceed the difference between individual loops of 15 m, otherwise the smaller circuit will warm up much more than the larger one.

But what if the length of the underfloor heating contour of 16 mm pipes differs by a value that exceeds 15 m? Balancing fittings will help, which changes the amount of coolant circulating through each loop. With its help, the difference in length can be almost two times.

Temperature in the rooms

Also, the length of the underfloor heating circuits for 16 pipes affects the level of heating. To maintain a comfortable indoor environment, certain temperature. To do this, the water pumped in the system is heated to 55-60 °C. Exceeding this indicator may adversely affect the integrity of the material. engineering communications. Depending on the purpose of the room, on average, we get:

27-29 °C for living rooms;
34-35 °C in corridors, hallways and walk-through rooms;
32-33 °C in rooms with high humidity.

In accordance with the maximum length of the underfloor heating circuit of 16 mm in 90-100 m, the difference at the "inlet" and "outlet" of the mixing boiler should not exceed 5 ° C, a different value indicates heat loss on the heating main.

Warm floor perfect solution to improve your home. The floor temperature directly depends on the length of the underfloor heating pipes hidden in the screed. The pipe in the floor is laid in loops. In fact, from the number of loops and their length, it adds up total length pipes. It is clear that the longer the pipe in the same volume, the warmer the floor. In this article, we will talk about restrictions on the length of one contour of a warm floor.

Approximate design characteristics for pipes with a diameter of 16 and 20 mm are: 80-100 and 100-120 meters, respectively. These data are approximate for approximate calculations. Let's take a closer look at the process of installing and pouring underfloor heating.

Consequences of exceeding the length

Let's figure out what consequences an increase in the length of the underfloor heating pipe can lead to. One of the reasons is an increase in hydraulic resistance, which will create an additional load on hydraulic pump as a result of which he may fail or simply may not cope with the task assigned to him. The resistance calculation consists of many parameters. Conditions, styling parameters. The material of the pipes used. Here are the three main ones: loop length, number of bends and thermal load on her.

It is worth noting that the thermal load increases with the increase in the loop. The flow rate and hydraulic resistance also increase. There are restrictions on the flow rate. It should not exceed 0.5 m/s. If we exceed this value, various noise effects may occur in the piping system. The main parameter, for the sake of which this calculation is made, also increases. The hydraulic resistance of our system. It also has limitations. They are 30-40 kP per loop.

The next reason is that with an increase in the length of the underfloor heating pipe, the pressure on the pipe walls increases, causing this section to elongate when heated. The pipe in the screed has nowhere to go. And it will begin to narrow at the very weak point. The constriction can cause blockage of the flow in the coolant. For pipes made from different material, different expansion coefficient. For example, polymer pipes have a very high expansion coefficient. All these parameters must be taken into account when installing a warm floor.

Therefore, it is necessary to fill in the underfloor heating screed with pressed pipes. Pressurize better with air with a pressure of approximately 4 bar. Thus, when you fill the system with water and start heating it, the pipe in the screed will expand somewhere.

Optimum pipe length

Considering everything above listed reasons taking into account the corrections for the linear expansion of the pipe material, we take as a basis the maximum length of the underfloor heating pipes per circuit:

What is the optimal length of the underfloor heating pipe?
Let's find out the optimal length of the underfloor heating pipe and what could be the consequences if the circuit is longer. Everything in our article

One of the conditions for the implementation of high-quality and proper heating of a room with a warm floor is to maintain the temperature of the coolant in accordance with the specified parameters.

These parameters are determined by the project, taking into account the required amount of heat for the heated room and flooring.

Required data for calculation

To maintain the set temperature in the room, it is necessary to correctly calculate the length of the loops used to circulate the coolant.

First, you need to collect the initial data on the basis of which the calculation will be performed and which consist of the following indicators and characteristics:

the temperature that should be above the floor covering,
layout diagram of loops with coolant,
distance between pipes
maximum possible pipe length,
the possibility of using several contours of different lengths,
connection of several loops to one collector and to one pump and their possible number with such a connection.

Based on the above data, it is possible to correctly calculate the length of the underfloor heating circuit and, due to this, ensure a comfortable temperature regime in the room with minimal costs for paying for energy supply.

Floor temperature

The temperature on the surface of the floor, made with a water heating device underneath, depends on the functional purpose of the room. Its values should not exceed those specified in the table:

Pipe laying options used for underfloor heating

The laying scheme can be performed with a regular, double and corner snake or snail. Various combinations of these options are also possible, for example, along the edge of the room you can lay out a pipe with a snake, and then the middle part with a snail.

In large rooms of complex configuration, it is better to lay with a snail. In rooms of small size and with a variety of complex configurations, snake laying is used.

Distance between pipes

At the edges of the room, the heating circuit pipe is laid in increments of 10 cm.

Permissible contour length

It depends on the pressure in a particular closed loop and hydraulic resistance, the values of which determine the diameter of the pipes and the volume of fluid that is fed into them per unit time.

Based on practical experience, you can adhere to the following recommended sizes:

Less than 100 m can be a loop made of a metal-plastic pipe with a diameter of 16 mm. For reliability, the optimal size is 80 m.
Not more than 120 m take the maximum length of the circuit of 18 mm pipes made of cross-linked polyethylene. Experts are trying to install a circuit with a length of 80-100 m.
No more than 120-125 m, the size of the loop for metal-plastic with a diameter of 20 mm is considered acceptable. In practice, they also try to reduce this length to ensure sufficient reliability of the system.

For a more accurate determination of the size of the loop length for the underfloor heating in the room under consideration, in which there will be no problems with the circulation of the coolant, it is necessary to perform calculations.

Application of several contours of different lengths

The difference in pipe lengths is determined by calculation. If it is impossible to perform calculations, a requirement can be applied that allows a difference in the length of the contours of the order of 30-40%.

Also, the difference in the lengths of the loops can be compensated by increasing or decreasing the diameter of the pipe and changing the pitch of its laying.

Ability to connect to one node and pump

Such calculations must be entrusted to specialists with knowledge and practical skills in the implementation of such projects.

Loop size determination

Having collected all the initial data, having considered possible options for creating a heated floor and determining the most optimal of them, you can proceed directly to calculating the length of the water floor heating circuit.

You can determine the length of the loop laid in 20 cm increments in a room of 10 m2, located at a distance of 3 m from the collector, by doing the following:

In this room, 61 m of pipe must be laid, forming a heating circuit, in order to ensure the possibility of high-quality heating of the floor covering.

The presented calculation helps to create conditions for maintaining a comfortable air temperature in small separate rooms.

In order to correctly determine the length of the pipe of several thermal circuits for a large number of rooms powered by one collector, it is necessary to involve a design organization.

She will do this with the help of specialized programs that take into account many different factors on which the uninterrupted circulation of water depends, and hence the high-quality floor heating.

The optimal length of the contour of the warm floor
One of the conditions for the implementation of high-quality and proper heating of the room with the help of a warm floor is the optimal length of the contour of the warm floor.

Seven times to measure calls for folk wisdom. And you can't argue with that.

In practice, to embody what has repeatedly scrolled in the head is not easy.

In this article we will talk about the work related to the communications of a warm water floor, in particular, we will pay attention to the length of its contour.

If we are planning to install a water heated floor, the length of the circuit is one of the first issues that needs to be dealt with.

Pipe arrangement

The underfloor heating system includes a considerable list of elements. We are interested in tubes. It is their length that determines the concept of "the maximum length of a warm water floor." It is necessary to lay them taking into account the characteristics of the room.

Based on this, we get four options, known as:

If done correct styling, then each of the listed types will be effective for space heating. Different can be (and most likely will be) the footage of the pipe and the volume of water. The maximum length of the water-heated floor circuit for a particular room will depend on this.

Main calculations: water volume and pipeline length

There are no tricks here, on the contrary - everything is very simple. For example, we chose the snake option. We will use a number of indicators, among which is the length of the contour of a water-heated floor. Another parameter is the diameter. Mostly pipes with a diameter of 2 cm are used.

We also take into account the distance from the pipes to the wall. Here it is recommended to fit in the range of 20-30 cm, but it is better to place the pipes clearly at a distance of 20 cm.

The distance between the pipes themselves is 30 cm. The width of the pipe itself is 3 cm. In practice, we get a distance between them of 27 cm.
Now let's move on to the area of the room.

This indicator will be decisive for such a parameter of a warm water floor as the length of the circuit:

Let's say our room is 5 meters long and 4 meters wide.
The laying of the pipeline of our system always starts from the smaller side, that is, from the width.
To create the basis of the pipeline, we take 15 pipes.
A gap of 10 cm remains near the walls, which then increases on each side by 5 cm.
The section between the pipeline and the collector is 40 cm. This distance exceeds the 20 cm from the wall that we talked about above, since a water drainage channel will have to be installed in this section.

Our indicators now make it possible to calculate the length of the pipeline: 15x3.4 \u003d 51 m. The entire circuit will take 56 m, since we should also take into account the length of the so-called. collector section, which is 5 m.

Quantity

One of the following questions: what is the maximum length of a water floor heating circuit? What to do if the room requires, for example, 130, or 140-150 m of pipe? The way out is very simple: it will be necessary to make more than one contour.

In the operation of a water-heated floor system, the main thing is efficiency. If, according to calculations, we need 160 m of pipe, then we make two circuits of 80 m each. After all, the optimal length of the contour of a water-heated floor should not exceed this indicator. This is due to the ability of the equipment to create required pressure and circulation in the system.

It is not necessary to make the two pipelines absolutely equal, but it is also not desirable that the difference be noticeable. Experts believe that the difference may well reach 15 m.

We have also prepared the following useful information for you:

Maximum length of the water floor heating circuit

To determine this parameter, we must consider:

hydraulic resistance,
pressure loss in a particular circuit.

The listed parameters are determined, first of all, by the diameter of the pipes used for the warm water floor, the volume of the coolant (per unit of time).

In the installation of a warm floor, there is a concept - the effect of the so-called. locked loop. This is a situation where circulation through the loop will not be possible, regardless of the pump power. This effect is inherent in the situation of a pressure loss of 0.2 bar (20 kPa).

In order not to confuse you with long calculations, we will write a few recommendations that have been proven by practice:

The maximum contour of 100 m is used for pipes with a diameter of 16 mm made of metal-plastic or polyethylene. Perfect option– 80 m
A contour of 120 m is the limit for a 18 mm pipe made of cross-linked polyethylene. However, it is better to limit yourself to a range of 80-100 m
With 20 mm plastic pipe, you can make a circuit of 120-125 m

Thus, the maximum length of a pipe for a warm water floor depends on a number of parameters, the main of which is the diameter and material of the pipe.

Read on our website about which flooring is better to choose for a warm water floor:

And also learn more here about how to make a warm water floor with your own hands.

Are two identical needed/possible?

Naturally, the situation will look ideal when the loops have the same length. In this case, you will not need any settings, the search for balance. But it's in more in theory. If you look at practice, it turns out that it is not even advisable to achieve such a balance in a warm water floor.

The fact is that it is often necessary to lay a warm floor at an object consisting of several rooms. One of them is emphasized small, for example - a bathroom. Its area is 4-5 m2. In this case, a reasonable question arises - is it worth adjusting the entire area for a bathroom, splitting it into tiny sections?

Since this is not advisable, we come to a different question: how not to lose on pressure. And for this, elements such as balancing fittings have been created, the use of which consists in equalizing pressure losses along the contours.

Again, calculations can be used. But they are complex. From the practice of carrying out work on the installation of a warm water floor, we can safely say that the spread in the size of the contours is possible within 30-40%. In this case, we have every chance to get maximum effect from the operation of a warm water floor.

Quantity with one pump

Another frequently asked question: how many circuits can operate on one mixing unit and one pump?
The question really needs to be clarified. For example, to the level - how many loops can be connected to the collector? In this case, we take into account the diameter of the collector, the volume of the coolant passing through the node per unit of time (the calculation is in m3 per hour).

We need to look at the data sheet of the node, where it is indicated maximum ratio bandwidth. If we carry out calculations, then we will get the maximum indicator, but we cannot count on it.

One way or another, the maximum number of circuit connections is indicated on the device - as a rule, 12. Although, according to calculations, we can get both 15 and 17.

The maximum number of outlets in the collector does not exceed 12. Although there are exceptions.

We saw that installing a warm water floor is a very troublesome business. Especially in that part of it, where we are talking about the length of the contour. Therefore, it is better to turn to specialists so as not to redo later a not entirely successful styling that will not bring the efficiency that you expected.

Laying and calculation of the maximum length of the water floor heating circuit
The article has detailed information about the maximum length of the water floor heating circuit, the location of the pipes, optimal calculations, as well as the number of circuits with one pump and whether two are the same.

Laying heating pipes under the floor is considered one of the best options for heating a house or apartment. They consume fewer resources to maintain the specified temperature in the room, exceed standard wall-mounted radiators in terms of reliability, evenly distribute heat in the room, and do not create separate “cold” and “hot” zones.

The length of the water floor heating circuit is the most important parameter that must be determined before the start of installation work. The future power of the system, the level of heating, the choice of components and structural units depend on it.

Styling options

Four common pipe laying patterns are used by builders, each better suited for use in a different room shape. From their "drawing" to a large extent depends on the maximum length of the contour of the warm floor. It:

"Snake". Sequential laying, where the hot and cold lines follow each other. Suitable for elongated rooms with division into zones of different temperatures.
"Double snake". It is used in rectangular rooms, but without zoning. Provides uniform heating of the area.
"Corner snake". Sequential system for a room with equal wall lengths and a low heating zone.
"Snail". Dual routing system suitable for square-shaped rooms with no cold spots.

The chosen laying option affects the maximum length of the water floor, because the number of pipe loops and the bending radius change, which also “eats” a certain percentage of the material.

Length calculation

The maximum length of the underfloor heating pipe for each circuit is calculated separately. To get the required value, you need the following formula:

Values are in meters and mean the following:

W is the width of the room.
D is the length of the room.
Shu - “laying step” (distance between loops).
K is the distance from the collector to the connection point with the circuits.

5% is added to the result, which is 4.94 m and the recommended length of the water floor heating circuit is increased to 103.74 m, which are rounded up to 104 m.

Dependence on pipe diameter

The second most important characteristic is the diameter of the pipe used. It directly affects the maximum length value, the number of circuits in the room and the power of the pump, which is responsible for the circulation of the coolant.

To choose the best solution and take into account all the nuances, it is better to contact our specialist for advice.

Number of circuits and power

The installation of the heating system must comply with the following recommendations:

One loop per room of a small area or part of a large one; it is irrational to stretch the contour over several rooms.
One pump per manifold, even if the declared capacity is enough to provide two "combs".
With a maximum length of the underfloor heating pipe of 16 mm in 100 m, the collector is installed on no more than 9 loops.

Temperature in the rooms

Also, the length of the underfloor heating circuits for 16 pipes affects the level of heating. To maintain a comfortable indoor environment, a certain temperature is needed. To do this, the water pumped in the system is heated to 55-60 °C. Exceeding this indicator can adversely affect the integrity of the engineering communications material. Depending on the purpose of the room, on average, we get:

27-29 °C for living rooms,
34-35 °C in corridors, hallways and walk-through rooms,
32-33 °C in rooms with high humidity.

The maximum length of the contour of a water-heated floor: laying and calculating the optimal value
Laying heating pipes under the floor is considered one of the best options for heating a house or apartment. They consume fewer resources to maintain the specified temperature in the room, exceed standard wall-mounted radiators in terms of reliability, evenly distribute heat in the room, and do not create separate

The device of warm water floors in a private house has many nuances and others. important points that need to be taken into account. In this article I will tell you how to make the right warm water floor. I will describe the main points that are missed assembly organizations and Customers.

Content

1. The thickness of the screed for a warm water floor

Pipe manufacturers are misleading people by offering 25, 30 or 35 mm screed height over the pipe. Installers are confused in the testimony. As a result, the underfloor heating does not work correctly.

Remember: According to SP 29.13330.2011 clause 8.2 - optimum thickness cement screed must be at least 45 mm above the pipeline.

Simply put, if we use a RAUTHERM S 17x2.0 pipeline with a height of 17 mm, then 45 mm above the pipe should be a screed. Minimum Thickness screeds for underfloor heating above the insulation is 62 mm.

With a decrease in the thickness of the screed, the risk of cracks and chips increases. Underfloor heating pipes expand and contract under the influence of temperature. With the height of the screed, we compensate for such temperature deformations. In practice, reducing the height of the screed leads to a sensation of temperature differences on the floor surface. One section of the floor is hotter, the other is colder.

Some of my customers want to play it safe and increase the maximum thickness of the screed to 80 mm, thereby greatly increasing the inertia of the system and heat consumption. The warm floor reacts with a great delay to changes in the air temperature in the room and consumes more heat to warm up additional centimeters of the screed. By the way, for the underfloor heating system, I recommend using a concrete grade not lower than M-300 (B-22.5).

2. Insulation for a warm water floor

In a warm water floor system, it uses only 1 of 3 types of insulation: extruded polystyrene foam with a density of more than 35 kg / m 2. When purchasing, be sure to check the type and density of the insulation. It is important!

Regular polystyrene foam is not suitable for underfloor heating. It is very brittle, has a lower density than polystyrene foam. The use of foam in a warm water floor system will cause the screed to sag. The use of foam as a heater is prohibited.

Foamed heaters will not withstand the weight of the screed and will shrink from 10 cm to 1-2 cm. Sometimes installers advise expanded clay backfills instead of insulation for underfloor heating. The option is working, but significantly increases the load on the floors. Expanded clay is 12 times heavier than expanded polystyrene, and retains heat 5 times worse. The mass of 40 mm expanded clay backfill is 3.7 kg / m 2.

The task of the insulation in the underfloor heating system is not so much in thermal insulation as in compensation thermal expansion pipes. The pipe is pressed into the insulation under the influence of temperature and does not deform the screed.

The underfloor heating cake is determined by the thickness of the insulation. The height of the insulation must be at least 50 mm in private houses. AT floors apartments often mount a warm floor on a foil substrate - multifoil without using a full-fledged layer of insulation.

3. Deformation joint in the floor screed

The expansion joint in the floor screed is used in rooms with an area of more than 40 m 2 where one of the sides of the room is more than 8 m.

In such rooms, the distribution of the contours of the warm floor is carried out depending on the placement of expansion joints. The expansion joint must not cross the underfloor heating loops and can only pass through the supply pipes.

At the intersection of expansion joints, the pipes are laid in a corrugated pipe-sleeve 1 meter long. Room division expansion joints starts from the corners of the room, places of narrowing and columns.

4. Floor covering for underfloor heating

The floor covering directly affects the heat transfer and the operation of the system. You can make a mistake with the thickness of the insulation, screed, laying step, but a mistake in choosing a floor covering will be fatal.

In I have already given calculations why a warm floor cannot be used for heating. And the main reason is all kinds of shelters, carpets, sofas, furniture.

For example: Ceramic tiles are 7 times better at dissipating heat than laminate and 20 times better than any textile flooring.

Porcelain stoneware coating in most cases compensates for errors with the choice of thickness of insulation, screeds, incorrect pipe laying steps and much more. Porcelain stoneware gives off heat 2.5 times better than ceramic tile, 15 times better than resin flooring and 17 times better than laminate.

When choosing flooring for underfloor heating, ask for a certificate marked "underfloor heating". This means that the material is certified for use with a warm water floor. Otherwise, if the coverage is chosen incorrectly, The floor dries out, the smell is released.

5. Pipe for a warm water floor

The heat-insulated floor does not allow joints and couplings. Loops of a heat-insulated floor keep within an integral section of a pipe. Therefore, the pipe is sold in coils of 60, 120 and 240 meters. Polypropylene pipes, pipes with threaded, coupling connections in underfloor heating systems for installation in a screed are strictly prohibited!

I am often asked which pipe to choose for a warm water floor. Cross-linked polyethylene is used as a material for underfloor heating pipes. I recommend 3 brands of underfloor heating pipe manufacturers for installation: Uponor - pePEX pipe, Rehau - Rautherm S, STOUT - PE-Xa / EVOH

The PEX pipe for underfloor heating is more plastic than its counterpart for heating.

The calculation of pipes for a warm water floor is reduced to determining the length of the circuit, the diameter and the pitch of the pipe, depending on the hydraulic balancing of the circuits.

The maximum length of the underfloor heating circuit should not exceed 80 meters. This pipe length corresponds to the maximum area of one underfloor heating circuit - 9 m 2 with a step of 150 mm, 12 m 2 - with a step of 200 mm, or 15 m 2 with a laying step of 250 mm.

At the same time, the minimum length of the underfloor heating circuit must be more than 15 meters, which corresponds to a floor area of 3 m 2. This requirement very relevant for small bathrooms and bathrooms, where customers are trying to make a separate circuit, and then wonder why the warm floor is either hot or completely cold. The underfloor heating thermostat for such circuits works jerkily and quickly fails.

The diameter of the pipe for a warm water floor is determined comprehensively for each collector cabinet, based on the requirements for pressure drop in the circuit - no more than 12-15 kPa and surface temperature - no more than 29 ° C. If one underfloor heating circuit turns out to be significantly longer than the other, then we can balance such circuits by changing the pipe diameter.

For example, our warm floor consists of 5 circuits 80 meters long, and 1 circuit - only 15 meters. Therefore, in a 15-meter circuit, we must significantly narrow the pipe diameter so that the pressure loss in it is comparable to 80-meter circuits. As a result: we mount 5 circuits with a diameter of 20 mm, and a 12-meter circuit with a 14 mm pipe. To calculate the underfloor heating system, they usually contact me.

6.Temperature regulator for water floor heating

The room thermostat in the underfloor heating system can be regulated both “by air” in the room, and “by water” - with a floor sensor. There are combined thermostats on sale that provide increased control accuracy, but also have increased requirements for the installation site.

A room thermostat for underfloor heating can control from 1 to 4 circuits, depending on the characteristics of a particular model. The thermostat is connected to the servomotors of the manifold assembly and regulates the power supply, due to which the servomotor opens and closes, regulating the flow of water in the underfloor heating circuit.

The main argument in favor of the "warm floor" system is the increased comfort of a person's stay in the room, when, as heater the entire surface of the floor protrudes. The air in the room warms up from the bottom up, while at the floor surface it is somewhat warmer than at a height of 2-2.5 m.

In some cases (for example, when heating shopping malls, swimming pools, gyms, hospitals) underfloor heating is the most preferred.

To the disadvantages of systems floor heating are relatively high, in comparison with radiators, the cost of equipment, as well as increased requirements for the technical literacy of installers and the quality of their work. Using quality materials and compliance with the installation technology of a well-designed water floor heating system, there are no problems during its subsequent operation.

The heating copper works on radiators in the mode 80/60 °C. How to connect the "warm floor"?

To obtain the design temperature (as a rule, not higher than 55 ° C) and the specified coolant flow rate in the "warm floor" circuit, pumping and mixing units are used. They form a separate low-temperature circulation circuit, into which the hot coolant from the primary circuit is mixed. The amount of mixed coolant can be set either manually (if the temperature and flow in the primary circuit are constant) or automatically using temperature controllers. Fully realize all the advantages of the "warm floor" allow pumping and mixing units with weather compensation, in which the temperature of the coolant supplied to the low-temperature circuit is adjusted depending on the outside temperature.

Is it allowed to connect a "warm floor" to the central heating or hot water system of an apartment building?

It depends on local legislation. For example, in Moscow, the installation of underfloor heating from common house water supply and heating systems is excluded from the list of permitted types of re-equipment (Decree of the Government of Moscow No. 73-PP of February 8, 2005). In a number of regions, interdepartmental commissions decisive question approvals for the installation of the "warm floor" system require additional expertise and calculated confirmation that the "warm floor" installation will not lead to disruption in the operation of common house engineering systems(see "Rules and norms for the technical operation of the housing stock", clause 1.7.2).

From a technical point of view, the connection of a "warm floor" to the central heating system is possible provided that a separate pumping and mixing unit is installed with limited pressure returned to house system coolant. In addition, if there is an individual heating point in the house equipped with an elevator (jet pump), the use of plastic and metal-plastic pipes in heating systems is not allowed.

What material is better to use as a floor covering in the "warm floor" system? Can parquet floors be used?

Best of all, the effect of "warm floor" is felt when floor coverings from materials with a high coefficient of thermal conductivity (ceramic tiles, concrete, self-leveling floors, baseless linoleum, laminate, etc.). If carpet is used, it must have a "suitability mark" for use on a warm base. Other synthetic coatings(linoleum, relin, laminated boards, plastic compound, PVC tiles, etc.) must have a “no sign” of toxic emissions at elevated base temperatures.

Parquet, parquet boards and boards can also be used as floor heating, but the surface temperature should not exceed 26 °C. In addition, a safety thermostat must be included in the mixing unit. Moisture content of floor covering materials natural wood should not exceed 9%. Works on laying parquet or plank flooring may only be carried out at a room temperature of at least 18 ° C and 40-50% humidity.

What should be the temperature on the surface of the "warm floor"?

The requirements of SNiP 41-01-2003 "Heating, ventilation and air conditioning" (clause 6.5.12) regarding the surface temperature of the "warm floor" are given in the table. It should be noted that foreign regulations allow slightly higher surface temperatures. This must be taken into account when using calculation programs developed on their basis.

How long can the pipes of the "warm floor" circuit be?

The length of one loop of the "warm floor" is dictated by the power of the pump. When it comes to polyethylene and metal-plastic pipes, then it is economically feasible that the length of a pipe loop with an outer diameter of 16 mm does not exceed 100 m, and with a diameter of 20 mm - 120 m. It is also desirable that the hydraulic pressure loss in the loop does not exceed 20 kPa. The approximate area occupied by one loop, subject to these conditions, is about 15 m2. With a larger area, collector systems are used, while it is desirable that the length of the loops attached to one collector be approximately the same.

What should be the thickness of the heat-insulating layer under the pipes of the "warm floor"?

The thickness of the thermal insulation, which limits the heat loss from the "underfloor heating" pipes in the "down" direction, should be determined by calculation and largely depends on the air temperature in the design room and the temperature in the underlying room (or soil). In most Western calculation programs, heat losses "down" are assumed to be 10% of the total heat flow. If the air temperature in the calculation room and the underlying room is the same, then this ratio is satisfied by a 25 mm thick expanded polystyrene layer with a thermal conductivity coefficient of 0.035 W / (mK).

What pipes are better to use for the installation of the "warm floor" system?

Pipes for a "warm floor" device must have the following properties: flexibility, allowing the pipe to be bent with a minimum radius to ensure the required laying step; the ability to keep the shape; low coefficient of resistance to the movement of the coolant to reduce the power of pumping equipment; durability and corrosion resistance, since access to pipes during operation is difficult; oxygen impermeability (as well as any pipeline of the heating system). In addition, the pipe must be easy to process a simple tool and have a reasonable price.

The most widespread systems are "warm floor" made of polyethylene (PEX-EVOH-PEX), metal-plastic and copper pipes. Polyethylene pipes are less convenient in work, because they do not retain the given shape, and when heated, they tend to straighten up ("memory effect"). Copper pipes, when embedded in a screed, must have a polymer coating to avoid alkaline exposure, moreover, this material is quite expensive. Metal-plastic pipes most fully meet the requirements.

Do I need to use a plasticizer when pouring a "warm floor"?

The use of a plasticizer makes it possible to make the screed more dense, without air inclusions, which significantly reduces heat losses and increases the strength of the screed. However, not all plasticizers are suitable for this purpose: most of those used in construction are air-entraining, and their use, on the contrary, will lead to a decrease in the strength and thermal conductivity of the screed. For "warm floor" systems, special non-air-entraining plasticizers are produced, based on fine scaly particles. mineral materials with a low coefficient of friction. As a rule, the consumption of the plasticizer is 3-5 l/m3 of solution.

What is the point of using aluminum foil coated thermal insulation?

In cases where the pipes of the "warm floor" are installed in air gap(for example, in floors along logs), foiling thermal insulation allows you to reflect most of the downward radiant heat flux, thereby increasing the efficiency of the system. Foil plays the same role in the construction of porous (gas or foam concrete) screeds.

When the screed is made of dense cement-sand mixture, thermal insulation foiling can be justified only as an additional waterproofing - the reflective properties of the foil cannot manifest themselves due to the lack of an air-solid body boundary. It must be kept in mind that the layer aluminum foil, poured cement mortar, must have protective covering from a polymer film. Otherwise, aluminum can be destroyed under the influence of a highly alkaline environment of the solution (pH = 12.4).

How to avoid cracking of the "warm floor" screed?

The reasons for the appearance of cracks in the "warm floor" screed may be the low strength of the insulation, poor-quality compaction of the mixture during installation, the absence of a plasticizer in the mixture, too thick a screed (shrinkage cracks). The following rules should be followed: the density of the insulation (expanded polystyrene) under the screed must be at least 40 kg/m3; the screed mortar must be workable (plastic), the use of a plasticizer is mandatory; in order to avoid the appearance of shrinkage cracks, polypropylene fiber should be added to the solution at the rate of 1-2 kg of fiber per 1 m3 of solution. Steel fiber is used for load-bearing floors.

Is waterproofing required for underfloor heating?

If a vapor barrier device is not provided for in the architectural and construction part of the project, then with the "wet method" of installing the "warm floor" system on floors, it is recommended to lay a layer of glassine over the leveled floor. This will help prevent laitance from leaking through the overlap during pouring of the screed. If the project provides for interfloor vapor barrier, then it is not necessary to arrange additional waterproofing. Waterproofing in wet areas (bathrooms, lavatories, showers) is arranged in the usual way over the "warm floor" screed.

What should be the thickness of the damper tape installed around the perimeter of the room?

For rooms with a side length of less than 10 m, it is sufficient to use a seam with a thickness of 5 mm. For other rooms, the calculation of the seam is carried out according to the formula: b \u003d 0.55 o L, where b is the thickness of the seam, mm; L is the length of the room, m.

What should be the step of laying the pipes of the "warm floor" loop?

The step of the loops is determined by calculation. It should be borne in mind that a loop pitch of less than 80 mm is difficult to implement in practice due to the small bending radius of the pipe, and a pitch of more than 250 mm is not recommended, as it leads to a noticeable uneven heating of the "warm floor". To facilitate the task of choosing the loop pitch, you can use the table below.

Is it possible to install heating only on the basis of the "warm floor" system, without radiators?

To answer this question in each case, it is required to make a thermal calculation. On the one hand, the maximum specific heat flow from the "warm floor" is about 70 W/m2 at an air temperature in the room of 20 °C. This is sufficient to compensate for heat losses through enclosing structures made in accordance with thermal protection standards.

On the other hand, if we take into account the heat costs for heating the required sanitary standards outdoor air (3 m3 / h per 1 m2 of living space), then the capacity of the "warm floor" system may be insufficient. In such cases, the use of edge zones with elevated surface temperatures along the outer walls, as well as the use of sections of "warm walls" is recommended.

How soon after pouring the screed can I start the "warm floor" system?

The screed must have time to acquire sufficient strength. Three days later in vivo hardening (without heating), it gains 50% strength, after a week - 70%. Full curing to the design grade occurs after 28 days. Based on this, it is recommended to start the "warm floor" no earlier than three days after pouring. You also need to remember that the filling of the "warm floor" system with a solution is carried out with floor pipelines filled with water at a pressure of 3 bar.