How many meters of pipe per circuit. Maximum length of the underfloor heating water circuit: installation and calculation of the optimal value. If the room is very large, do I need to create multiple paths

One of the conditions for the implementation of high-quality and correct 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 the required amount of heat for the heated room and floor covering.

Required data for calculation

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

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

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

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

Based on the listed data, you can correctly calculate the length of the underfloor heating contour and thus ensure a comfortable temperature regime in a room with minimal cost to pay for energy supply.

Floor temperature

The temperature on the surface of the floor, made with a hot water heating device underneath, depends on functional purpose premises. Its values should be no more than those indicated 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 installation options

The laying pattern can be done with a regular, double and angled 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.

V large rooms complex configuration is best done with a snail. In rooms of small size and having a variety of complex configurations, snake laying is used.

Distance between pipes

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

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

Permissible contour length

The length of the circuit must be matched to the pipe diameter

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 supplied to them per unit of 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 from metal plastic pipe with a diameter of 16 mm. For reliability optimal size is 80 m.
No more than 120 m is assumed to be a maximum loop length of 18 mm of XLPE pipe. Experts try to install a circuit with a length of 80-100 m.
No more than 120-125 m is considered an acceptable loop size 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 more precise definition the size of the loop length for the warm floor in the room in question, in which there will be no problems with the circulation of the coolant, it is necessary to perform calculations.

Applying multiple paths of different lengths

The device of the underfloor heating system provides for the implementation of several circuits. Of course, it is ideal when all the loops are the same length. In this case, adjustment and balancing of the system is not required, but it is almost impossible to implement such a pipe routing scheme. Detailed video for calculating the length of the water circuit, see this video:

For example, it is necessary to carry out a warm floor 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 impractical 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, you can apply a requirement 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 for by increasing or decreasing the diameter of the pipe and changing the pitch of its laying.

Possibility 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 heating circuits, the diameter and material of the pipes used, the area of the heated rooms, the material of the enclosing structures and on many other various indicators.

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

Determining the size of the buttonhole

The size of the loop depends on total area premises

Having collected all the initial data, having considered possible options creating a heated floor and determining 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 the 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, 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 with a step of 20 cm in a room with an area of 10 m2, located at a distance of 3 m from the collector, by following these steps:

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

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

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

To correctly determine the pipe length of several heating circuits for a large number premises supplied from 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 uninterrupted water circulation depends, and therefore high-quality floor heating.

It is pleasant to walk on a warm floor, there is no discomfort from the cold underfoot and stuffiness in the upper part of the room. A well-equipped system allows you to evenly warm up all zones of the rooms, creating coziness and saving money on heating. Installation of underfloor heating is relatively simple, but the efficiency of the heating circuit depends entirely on the correctness of the calculations during the preparation of the project.

In order for the warm floor to create the desired climate and not cause inconvenience or utility breakdowns, the room in which this heating circuit will be installed must meet the following requirements:

the height of the ceilings from the subfloor should be such that its decrease by 20 cm does not cause discomfort;
the doorway must be at least 2.1 m high;
the subfloor must be strong enough to withstand the cement screed, which will cover the thermal circuit;
if the subfloor is laid on the ground or there is an unheated one under the insulated room, it is necessary to lay an additional layer of insulation with a shielding coating;
the surface on which the installation of the heating circuit and all components of the “pie” of the warm floor is planned must be flat and clean.

If the above requirements are met, the “warm floor” system will be installed without problems. However, its effectiveness depends not only on the size of the room, but also on its other features, which will help to take into account the following recommendations:

Walls are the main source of heat loss, therefore, before calculation and installation heating system it is necessary to at least roughly calculate the amount of heat leaving for heating the street. If the resulting figure turns out to be higher than 100 W by square meter, it is advisable to insulate the walls so as not to overpay for heating;
The heating circuit should not fall under the place of installation of massive furniture and heavy stationary equipment. Constant high pressure on the floor will damage the pipes or cables of the heating system and render it unusable.
For uniform heating of the room, it is necessary that such unheated zones occupy no more than 30% of the floor area. Therefore, before carrying out the calculations, a drawing of the room is made to scale, and the places that should be left unheated are marked on this drawing. Then the total working area is calculated - it should be 70% or more of the total.
It is necessary to calculate the optimal shape, length and step of the heating circuit and its power, as well as make a drawing indicating the points of connection to the heating system, the direction of the flow of the coolant.

Methods for installing the "warm floor" system

For the correct functioning of this heating system, a clear sequence of layers of the so-called “cake” of the warm floor is important.

The thermal circuit is laid on a pre-heat and waterproof surface, and on top it is poured or covered with a cement screed, on top of which the finishing flooring... The above layers - the shell of the pie - are required in both cases. They protect the system from external influences and increase its efficiency.

The main argument in favor of the "warm floor" system is the increased comfort of a person's stay in the room, when the quality 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 most preferred.

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

The heating boiler operates on radiators at 80/60 ° C. How to connect the "warm floor" correctly?

To obtain the design temperature (as a rule, not higher than 55 ° C) and the specified flow rate of the coolant in the "warm floors" circuit, pumping and mixing units are used. They form a separate low-temperature circulation circuit, into which hot heating medium from the primary circuit is mixed. The amount of added heating agent can be set both manually (if the temperature and flow rate in the primary circuit are constant), and automatically using thermostats. Fully realizing all the advantages of a "warm floor" allows the 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 air temperature.

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

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

From a technical point of view, connecting a "warm floor" to a 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 heat point equipped with an elevator (jet pump), the use of plastic and metal-plastic pipes in heating systems is not allowed.

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

Best of all, the effect of "warm floor" is felt with floor coverings made of materials with a high thermal conductivity coefficient ( ceramic tile, concrete, self-leveling floors, baseless linoleum, laminate, etc.). If carpet is used, it must have a "suitability mark" for use on a warm substrate. Other synthetic coatings (linoleum, relin, laminated boards, plastic, PVC tiles, etc.) must have a "sign of absence" of toxic emissions at an elevated base temperature.

Parquet, parquet boards and boards can also be used as a "warm floor" covering, but the surface temperature should not exceed 26 ° C. In addition, a safety thermostat must be included in the mixing unit. The moisture content of natural wood flooring materials should not exceed 9%. Work on laying a parquet or plank floor is allowed only 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" (p. 6.5.12) in relation to 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 underfloor heating pipes be?

The length of one loop of the "warm floor" is dictated by the pump power. If we talk about polyethylene and metal-plastic pipes, it is economically expedient that the loop length of a pipe 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. At larger area collector systems are used, while it is desirable that the length of the loops connected 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 insulation, limiting the heat loss from the pipes "underfloor heating" in the "downward" 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 ground). In most Western design programs, heat losses "downward" are assumed to be 10% of the total heat flux. If the air temperature in the design and the underlying room is the same, then this ratio is satisfied by a layer of expanded polystyrene with a thickness of 25 mm with a thermal conductivity coefficient of 0.035 W / (moK).

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 bend with a minimum radius to ensure the required laying pitch; the ability to keep in 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 tightness (like any pipeline of the heating system). In addition, the pipe must be easy to handle simple tool and have a reasonable price.

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

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

The use of a plasticizer allows you 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-entraining plasticizers based on finely dispersed flaky particles are produced. mineral materials with a low coefficient of friction. As a rule, the consumption of the plasticizer is 3-5 l / m3 of mortar.

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

In cases where floor heating pipes are installed in air gap(for example, in floors on logs), foiling of 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, foiling of thermal insulation can be justified only as an additional waterproofing - the reflective properties of the foil cannot manifest themselves due to the absence of the "air - solid" boundary. It should be borne in mind that the layer aluminum foil flooded cement mortar must have protective covering from a polymer film. Otherwise, aluminum can collapse under the influence of a highly alkaline solution medium (pH = 12.4).

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

The reasons for the appearance of cracks in the underfloor heating 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, or too thick screed (shrinkage cracks). Should adhere to following rules: the density of the insulation (expanded polystyrene) under the screed must be at least 40 kg / m3; the mortar for the screed must be workable (plastic), the use of a plasticizer is mandatory; in order to avoid the appearance of shrinkage cracks, polypropylene fiber must be added to the solution at the rate of 1-2 kg of fiber per 1 m3 of solution. For power loaded floors, steel fiber is used.

Is waterproofing required for underfloor heating?

If a vapor barrier is not provided for in the architectural and construction part of the project, then with the "wet method" of installing the "warm floor" system along the ceilings, it is recommended to lay a layer of glassine on the leveled floor. This will help prevent the laitance from flowing through the overlap during the pouring of the screed. If the project provides for an interfloor vapor barrier, then it is not necessary to arrange additional waterproofing. Waterproofing in wet rooms(bathrooms, toilets, showers) is arranged in the usual manner on top of 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, a 5 mm seam is sufficient. For other premises, the seam is calculated according to the formula: b = 0.55 o L, where b is the seam thickness, mm; L is the length of the room, m.

What should be the step of laying the pipes for 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 step of the loops, 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 specific case, it is required to make a heat engineering calculation. On the one hand, the maximum specific heat flux 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 cost of heat 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, it is recommended to use edge zones with elevated surface temperatures along the outer walls, as well as the use of sections of "warm walls".

How long after pouring the screed can the "warm floor" system be started?

The screed must have time to acquire sufficient strength. After three days in natural conditions hardening (without heating), it gains 50% strength, after a week - 70%. A full set of strength 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. It should also be remembered that the "underfloor heating" system solution is filled with floor pipelines filled with water at a pressure of 3 bar.

The device of warm water floors in a private house has many nuances and others important points to consider. In this article I will show you how to make the right warm water floor. I will describe the main points that installation organizations and customers overlook.

Content

1.Thickness of the screed for warm water floors

Pipe manufacturers are misleading people by suggesting a screed height of 25, 30 or 35 mm above the pipe. Installers are confused about the readings. As a result, the warm floor does not work correctly.

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

Simply put, if we use the RAUTHERM S 17x2.0 pipeline with a height of 17 mm, then a screed should be 45 mm above the pipe. The minimum screed thickness for a warm floor 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 temperatures. With the height of the screed, we compensate for such temperature deformations. In practice, reducing the height of the screed leads to a feeling of temperature changes on the floor surface. One part of the floor is hotter, the other colder.

Some of my Customers want to be on the safe side and increase the maximum screed thickness 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 of at least M-300 (B-22.5).

2.Insulation for warm water floor

In the underfloor heating system, only 1 of 3 types of insulation is used: 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 foam is not suitable for underfloor heating. It is very brittle, has a lower density than expanded polystyrene. The use of polystyrene in the underfloor heating system will cause the screed to sag. It is prohibited to use polystyrene as insulation.

Foamed insulation 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 a warm floor. The option is working, but it significantly increases the load on the floors. Expanded clay is 12 times heavier than expanded polystyrene, and 5 times worse retains heat. Weight of 40 mm expanded clay backfill - 3.7 kg / m 2.

The task of the insulation in the underfloor heating system is not so much in thermal insulation as in compensating for the temperature expansion of 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. V interfloor ceilings apartments often mount a warm floor on a foil substrate - multi-foil without using a full layer of insulation.

3. Expansion 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, pipes are laid in a corrugated tube-sleeve 1 meter long. Division of the room expansion joints starts from the corners of the room, places of narrowing and columns.

4.Floor covering for underfloor heating

The floor covering has a direct effect on heat dissipation and system performance. You can make a mistake with the thickness of the insulation, the screed, the laying step, but the mistake in choosing the floor covering will be fatal.

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

For example: Ceramic tiles give off heat 7 times better than laminate and 20 times better than any textile flooring.

In most cases, the porcelain stoneware coating compensates for mistakes with the choice of the thickness of the insulation, the screed, the wrong pipe laying step and much more. Porcelain stoneware gives off heat 2.5 times better than ceramic tiles, 15 times better than polymer floor coverings and 17 times better than laminate.

When choosing a floor covering 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 cover is not selected correctly, The floor shrinks and smells.

5. Pipe for warm water floor

The warm floor does not allow joints and couplings. The underfloor heating loops are laid in a single piece of pipe. Therefore, the pipe is sold in coils of 60, 120 and 240 meters. Polypropylene pipes, pipes with threaded, coupled 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.

Maximum length underfloor heating contour 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 should be more than 15 meters, which corresponds to a floor area of 3 m 2. This requirement is very important 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 in jerks and quickly fails.

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

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 have to significantly narrow the pipe diameter so that the pressure loss in it is comparable to that of an 80-meter circuit. 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.Thermostat for a water heated floor

The room thermostat in the underfloor heating system can be controlled 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 servo drives of the manifold assembly and regulates the power supply, due to which the servo drive opens and closes, regulating the water flow in the underfloor heating circuit.

Warm floors are an excellent solution for the improvement of 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, the total length of the pipe is added. It is clear that the longer the pipe in the same volume, the warmer the floor. In this article, we will talk about the restrictions on the length of one contour of the 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.

The 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 the hydraulic pump, as a result of which it may fail or simply may not cope with the task assigned to it. Resistance calculation consists of many parameters. Conditions, styling parameters. The material of the pipes used. There are three main ones: loop length, number of bends and thermal load on it.

It is worth noting that the heat load increases with increasing 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 done, also increases. The hydraulic resistance of our system. There are also restrictions on it. 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 a blockage of the flow in the heating medium. For pipes made of different material, different expansion coefficient. For example, in polymer pipes the expansion coefficient is very high. All these parameters must be taken into account when installing a warm floor.

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

Optimum pipe length

Considering all of the above 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 the consequences can be if the circuit is longer. Everything in our article

One of the conditions for the implementation of high-quality and correct heating of a room using 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 floor covering.

Required data for calculation

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

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

the temperature that should be above the floor covering,
layout diagram of loops with a coolant,
distance between pipes,
maximum possible pipe length,
the ability to use 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 listed data, it is possible to perform the correct calculation of the length of the underfloor heating circuit and thereby ensure a comfortable temperature regime in the room with minimal energy costs.

Floor temperature

The temperature on the surface of the floor, made with a water heating device under it, depends on the functional purpose of the room. Its values should be no more than those indicated in the table:

Pipe laying options used for underfloor heating

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

Distance between pipes

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

Permissible contour length

Based on practical experience, the following recommended sizes can be adhered to:

Less than 100 m can be a loop made of 16 mm diameter reinforced plastic pipe. For reliability, the optimum size is 80 m.
No more than 120 m is assumed to be a maximum loop length of 18 mm of XLPE pipe. Experts try to install a circuit with a length of 80-100 m.
No more than 120-125 m is considered an acceptable loop size 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 a warm floor in the room under consideration, in which there will be no problems with the circulation of the coolant, it is necessary to perform calculations.

Applying multiple paths of different lengths

The difference in pipe lengths is determined by calculation. If it is impossible to perform calculations, you can apply a requirement 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 for by increasing or decreasing the diameter of the pipe and changing the pitch of its laying.

Possibility 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.

Determining the size of the buttonhole

Having collected all the initial data, having considered the 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 with a step of 20 cm in a room with an area of 10 m2, located at a distance of 3 m from the collector, by following these steps:

In this room, 61 m of pipes must be laid, forming a thermal 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 individual rooms.

To correctly determine the length of the pipe of several heating 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 uninterrupted water circulation depends, and therefore high-quality floor heating.

Optimal length of the underfloor heating contour
One of the conditions for the implementation of high-quality and correct heating of a room with a warm floor is the optimal length of the underfloor heating circuit.

The popular wisdom calls for measuring seven times. And you can't argue with that.

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

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

If we plan to install a water-heated floor, the length of the contour is one of the first issues that need to be dealt with.

Arrangement of pipes

The underfloor heating system includes a considerable list of elements. We are interested in pipes. It is their length that defines the concept of "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 you do correct styling, then each of the listed types will be effective for space heating. The length of the pipe and the volume of water can be (and most likely will be). This will determine the maximum length of the water floor heating circuit for a particular room.

Main calculations: water volume and pipeline length

There are no tricks here, on the contrary - everything is very simple. For example, we have chosen 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 diameter. Pipes with a diameter of 2 cm are predominantly used.

We also take into account the distance from the pipes to the wall. Here it is recommended to fit within 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 contour:

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

Our indicators now make it possible to calculate the length of the pipeline: 15x3.4 = 51 m. The entire contour 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 the 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.

The main thing in the operation of a water-heated floor system 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 water floor heating circuit 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 for the difference to be perceptible. Experts believe that the difference may well reach 15 m.

We have also prepared the following useful information for you:

Maximum length of a water-heated floor contour

To determine this parameter, we must take into account:

hydraulic resistance,
pressure loss in a specific 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 underfloor heating, there is a concept - the effect of the so-called. locked hinge. This is a situation where circulation in the loop will be impossible, regardless of the pump power. This effect inherent in a situation of pressure loss, calculated as 0.2 bar (20 kPA).

In order not to confuse you with long calculations, we will write several recommendations, proven by practice:

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

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

Read on our website about which is the best to choose a floor covering for a warm water floor:

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

Need / are two identical?

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

The fact is that it is often necessary to lay underfloor heating in an object consisting of several rooms. One of them is emphatically 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 areas?

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

Again, calculations can be used. But they are complicated. 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 of getting 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, in fact, needs to be concretized. 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 unit, where the maximum coefficient is indicated bandwidth... If we carry out the calculations, then we will get the maximum indicator, but we cannot count on it.

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

The maximum number of outputs in the collector does not exceed 12. However, there are exceptions.

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

Laying and calculating 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.

The laying of heating pipes under the floor is considered one of the best options heating a house or apartment. They consume less 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 contour is the most important parameter that must be determined before starting installation works... 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 layouts used by builders, each of which is better suited for indoor use. of various shapes... The maximum length of the underfloor heating contour largely depends on their "pattern". It:

"Snake". Sequential styling, where the hot and cold lines follow each other. Suitable for premises elongated shape 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". Double laying system, suitable for close to square room shapes without cold spots.

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

The values are indicated in meters and mean the following:

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

The length of the underfloor heating contour 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 to fittings.

As an example of calculating the maximum pipe length for a warm floor for 1 circuit, we 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:

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 is 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.

In apartments and houses with an average room size, pipes of 16, 18 or 20 mm are used. The first value is optimal for residential premises, it is balanced in terms of cost and performance. The maximum length of the water underfloor 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 "closed loop" effect can form, when, regardless of the pump power, the movement of the coolant in the communication stops due to the high resistance of the liquid.

To choose optimal 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 sufficient to provide two “combs”.
With a maximum length of a floor 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 pipes exceeds the recommended value, then the room is divided into separate circuits, which are connected into one heating network by a collector. To provide even distribution of the coolant throughout the system, experts advise not to exceed the difference between the 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 circuit of a 16 mm pipe 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 lengths can be almost two times.

Room temperature

Also, the length of the underfloor heating circuits for 16 pipes affects the heating level. To maintain a comfortable indoor environment, you need specific temperature... For this, the water pumped through the system is heated to 55-60 ° C. Exceeding this indicator can 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 walkways,
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.

Maximum length of the underfloor heating water contour: installation and calculation of the optimal value
Laying heating pipes under the flooring 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