What is the maximum length of the underfloor heating of 16. What is the optimal length of the underfloor heating pipe? How is the calculation of the length of the coolants

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 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 a given temperature regime in the room, it is necessary to correctly calculate the length of the loops used to circulate 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, it is possible to perform the correct calculation of the length of the underfloor heating circuit and thereby 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. Indoors 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 on practical experience, the following recommended sizes can be adhered to:

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 the total area of the room

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 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.

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 the 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. Minimum thickness screeds for a warm floor above the insulation are 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 the main reason is 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 tile, 15 times better than polymer flooring 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, couplings 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 maximum area one contour of underfloor heating - 9 m 2 with a step of 150 mm, 12 m 2 - with a step of 200 mm, or 15 m 2 with a 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.

We continue to disassemble underfloor heating design started in the previous article and will now go over some basic design guidelines.

What should be the temperature of the underfloor heating surface?

Actually, I already wrote about this in a separate article, but it will not be superfluous to repeat it. Listed below maximum limiting temperatures of the floor surface for premises for various purposes:

for living quarters and work rooms in which people mainly stand: 21 ... 27 degrees;
for living rooms and offices: 29 degrees;
for lobbies, hallways and corridors: 30 degrees;
for baths, pools: 33 degrees
for premises in which active activity takes place: 17 degrees
in rooms with limited stay of people (industrial premises), a maximum floor temperature of 37 degrees is allowed.

In the marginal areas up to 35 degrees.

What is the temperature of the coolant in the water underfloor heating system?

The supply water temperature should be between 40 and 55 degrees. The maximum temperature of the coolant at the entrance to the water floor heating system should not exceed +60 degrees.

The temperature difference of the coolant between the supply and return pipelines is optimal 5 ... 15 degrees. Less than five degrees is not recommended due to the greatly increasing flow rate of the coolant through the circuit, which leads to large head losses. More than fifteen degrees is not recommended due to a noticeable temperature drop in the surface of the floor itself (under the windows we can have 27 degrees, at the end of the contour 22 degrees, such a large drop is not comfortable). The optimum temperature drop is 10 degrees. Recommended temperatures at the entrance / exit of the loops: 55/45 degrees, 50/40 degrees, 45/35 degrees, 40/30 degrees.

If a heat source is used as a heat source pumping unit(although this is a great rarity), it is advisable to take the temperature of the supply coolant into the heating circuit 40 degrees. In all other cases, any other supply temperature within the above range can be used.

How long should the pipes for a water-heated floor be?

The maximum length of one circuit (loop) depends on the diameter of the pipes used:

with a diameter of 16 mm - 70 ... 90 meters;
with a diameter of 17 mm - 90 ... 100 m;
with a diameter of 20 mm - 120 m.

The difference in lengths is due to the different hydraulic resistance and heat load of the pipes. different diameters... Well, it is clear: the thicker the pipe, the less hydraulic resistance (resistance to fluid flow) in it.

Usually one circuit heats one room. But if the area of the room is large, the length of the contour turns out to be more than optimal, then it is better to make two contours per room than to lay a pipe that is too long.

If, when designing and calculating, we take one pipe diameter and then mount another, then the hydraulics of the system will be different. So all experiments are better and correctly allowed at the design and calculation stage, compare the results, choose the best one and follow it.

If two or more circuits fit in a room, you need to strive to ensure that their lengths are the same (the entire pipe is considered to be the length of the circuit, starting from the collector, and not only that part of it that is directly in the heated room itself).

Of course, in practice, it is impossible to fit the length perfectly, but you need to strive for this and the difference should be no more than 10 m!

The premises in the house are known to have different area... In order to lay as many meters of pipe in a smaller room as in a larger one, you need to take a smaller step between the turns.

If the room is small and the heat loss from it is not large (toilet, hallway), then it is possible to combine the circuits, heat from the return pipe of the adjacent circuit.

With what step to lay out the pipes of the warm floor?

The step (distance between adjacent pipe turns) of laying the pipe is from 15 to 30 cm (15, 20, 25, 30 cm - that is, not 21; 22.4; 27, etc., but with a step of 5 cm in the specified range 15-30 cm). Allowed pipe laying step of 30, 35, 40, 45 cm in large rooms(gyms, etc.). And 10 cm near large windows, external walls (in the so-called edge zones).

The pipe layout step is selected depending on the heat load, the type of room, the length of the circuit, the coating material, etc.:

edge zones - 100 ... 150 mm (standard number of rows in the edge zone - 6);
central zones 200 ... 300 mm;
toilets, bathrooms, shower rooms, etc. are fully stacked with a step of 100 ... 150 mm. The same step may not work due to the need to bypass the plumbing and due to the tightness in the room;
in rooms where the floor will be covered with a material with good thermal conductivity ( tile, marble, porcelain stoneware) pipe laying pitch - 200 mm.

Attention! Above are the recommended numbers. In practice, it is often impossible to bend a metal-plastic pipe with a small radius without the danger of breaking it (when laying with a snake). Therefore, when laying with a snake, a pitch of 150… 200 mm is better and optimal. Anyway, take a note: regardless of any recommendations and clever justifications, make a pipe step in the edge zones of 100 mm, and in the remaining 150 mm you will never go wrong.

A step of 300 mm will not give even floor heating at all (again, when laying with a snake).

How to choose the diameter of pipes for underfloor heating systems?

V residential buildings or apartments with an area ranging from 50 m2 to infinity - a pipe with a diameter of 16 mm is used. Thicker is not necessary!

Even in well-insulated houses, it is desirable that the pipe pitch does not exceed 150, maximum, 200 mm - and the 16th pipe makes it possible to comply with all these conditions. In general, pipes of a larger diameter are not needed for a private house: they are optimal in terms of the ratio "ease of installation - price - volume of the coolant".

Another pipe often used is 18 mm. However, it must be understood that a thicker pipe is extra expenses, and not only on the pipe, but also on fittings and everything else.

Sometimes they put a pipe with a diameter of 20 mm, without taking into account the characteristics. And in such a pipe, the amount of water is already significantly greater, which is why more energy will be required for heating. Yes, and it is difficult to mount such a pipe: bending it for laying with a snake and a step of 150 mm is unrealistic, and a larger step will not give heat in the house, and the cost of the coolant will be indecently decent. Such a pipe can be laid in some public buildings, with high ceilings, while being there a large number of people. A thick screed will be filled in there! For a pipe of 16 mm, the thickness of the screed is sufficient 50 mm from the top of the pipe. Allowed up to 80 mm.

What should be the diameter of the pipes from the boiler to the collector?

The task is to connect one, two or more floor heating collectors.

Almost every underfloor heating collector has a 1 inch (25 mm) thread for connecting to the mains - it does not matter whether it is internal or external.

There are collectors with thread per inch and a quarter, but this is for large industrial or public institutions, where a pipe of a larger diameter will be used, so you do NOT need to take such collectors for a private house.

It makes no sense to initially narrow or "widen" the diameters of the main pipes (that is, supplying the coolant from the boiler), but it makes sense to take the same diameter as the collector inlet, that is, 1 inch. For polypropylene pipe this is 32 mm in diameter (this is the outer one, and the inner one is just 25 mm). For a metal-plastic pipe, this is a diameter of 26 mm. For copper - 28 mm. These are the standard pipe options. But if there are doubts about the number of circuits, then the diameter of the main pipes can be increased by one size (40, 32 and 32 mm for polypropylene, metal-plastic and copper pipe respectively; an adapter is required to go 1 inch).

Pipes made of cross-linked polyethylene (PEX) have the same dimensions as metal-plastic pipes in wall thickness and diameters.

Other data for the design of underfloor heating

It is not advisable to connect a concrete and floor system to the same mixing unit (and manifold).

One contour should be for one room (in the sense, you do not need to freak out by expanding the loop, filling the screed, and then dividing the room with a partition).

It is advisable to place the collector in the middle of the house. If this does not work, then the problem with the difference in the lengths of the loops is solved by installing flow meters on the manifold: with their help, a uniform flow of the coolant through loops of different lengths is regulated.

If the circuits have lengths of 90 m (or even more), then a maximum of nine circuits can be "hooked" to one collector. With loop lengths 60 ... 80 m, up to 11 circuits can be mounted on one collector.

It is not necessary to "press" with one pump on two (or more) collectors. Correctly place separate pumps for each manifold group.

Mixing modules (mixing units) are not all suitable for all lengths of pipes for underfloor heating loops, so check with your purchase.

For an accurate calculation, it is necessary to take into account not only heat loss, but also the possible influx of heat into the premises - for example, from operating equipment, household appliances, etc. underfloor heating is also arranged in the upper room. Payment multi-storey buildings it is necessary to lead, starting from the premises of the upper floor to the lower ones. Because the heat loss through the floor of the second floor is a useful inflow of heat for the premises of the first floor.

The thickness of the insulation on the first and basement floor not less than 50 mm (in reality, it depends on the climatic zone: what is good for the south, it does not roll at all in the north), on other floors - not less than 30 mm. A logical question: why insulate the floor between the first and second floors, let the heat from the warm floor on the second floor warm the first floor as well? Answer: if the floor is concrete, then the insulation is placed so as not to heat the floor itself, because it is very expensive both in terms of money and time.

The maximum head loss in the circuit is 15 kPa (optimally 13 kPa). If the circuit has a head loss of more than 15 kPa, it is necessary to reduce the flow rate of the coolant or divide the floor area in the room into several circuits. What this means, we will consider in one of the following articles, when we will perform calculations on a specific example.

The minimum flow rate of the heating agent in one circuit is at least 27-30 liters per hour. Otherwise, the contours need to be merged. Why is there such a limitation? At a lower flow rate, the coolant, not having time to go through the entire circuit, but has time to cool down - the floor will be cold! The minimum flow rate of the heating agent on each circuit can be set on the control valve (flow meter) installed on the manifold.

The above requirements for underfloor heating design will need to be taken into account when performing calculations for a warm floor, when we will do this in a special program. So, if these terms are nothing to you yet, do not worry, in due time everything will fall into place. However, I recommend that you make a note for yourself somewhere in order to return to the information in this article when calculating.

underfloor heating design

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, it is important clear sequence layers of the so-called "pie" of the warm floor.

The thermal circuit is laid on a pre-heat and waterproof surface, and poured or filled in from above cement screed, on top of which the finish is laid 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 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 contour of the water underfloor heating - the most important parameter to 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... To a large extent depends on their "drawing" maximum length underfloor heating contour. It:

"Snake". Sequential styling, 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 rooms 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:

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

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, 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 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 maximum value lengths, 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 figure, because the so-called "closed loop" effect can occur, 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, a certain temperature is required. 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.