Water heated floor contour length. Warm water floor - maximum pipeline length

We continue to disassemble design of heated floors, started in the previous article, and now we will consider the main design recommendations.

What should the surface temperature of the heated floor be?

Actually, I already wrote about this in a separate article, but it would be worth repeating. Listed below are maximum extreme temperatures floor surface for premises of 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, swimming pools: 33 degrees
• for rooms where active activity takes place: 17 degrees
• in premises with limited presence of people ( industrial premises) a maximum floor temperature of 37 degrees is allowed.

In the edge zones up to 35 degrees.

What is the temperature of the coolant in the water heated floor system?

The supply water temperature should be between 40 and 55 degrees. The maximum temperature of the coolant at the entrance to the water heated floor 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 coolant flow through the circuit, which leads to big losses pressure More than fifteen degrees is not recommended due to a noticeable difference in the temperature of the surface of the floor itself (in this case, under the windows we can have 27 degrees, at the end of the circuit 22 degrees, such a large difference is not comfortable). The optimal temperature drop is 10 degrees. Recommended temperatures at the inlet/outlet loops: 55/45 degrees, 50/40 degrees, 45/35 degrees, 40/30 degrees.

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

What should be the length of water heated floor pipes?

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;
• diameter 20 mm – 120 m.

The difference in lengths is explained by different hydraulic resistance and thermal load of the pipes different diameters. Well, it’s clear: the thicker the pipe, the lower its hydraulic resistance (resistance to fluid flow).

Typically one circuit heats one room. But if the area of ​​the room is large, the length of the circuit is longer than optimal, then it is better to make two circuits per room than to lay a pipe that is too long.

If during design and calculations you take one pipe diameter and then install another, then the hydraulics of the system will be different. So it is better and correctly to allow all experiments at the design and calculation stage, compare the results, choose the best one and follow it.

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

Of course, in practice, it is impossible to adjust 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, as is known, have different area. To lay the same number of meters of pipe in a smaller room as in a larger one, you need to do smaller step between turns.

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

At what step should the underfloor heating pipes be laid out?

The pitch (distance between adjacent turns of pipes) of pipe laying 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). Pipe laying pitches of 30, 35, 40, 45 cm are allowed 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 thermal load, type of room, circuit length, coating material, etc.:

• edge zones - 100...150 mm (standard number of rows in the edge zone - 6);
• central zones 200…300 mm;
• bathrooms, bathrooms, shower rooms, etc. are completely laid in increments of 100...150 mm. The same step may not be possible due to the need to bypass the plumbing and due to the cramped space 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! The 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 laid with a snake). Therefore, when laying with a snake, it is better and optimal to have a pitch of 150...200 mm. And in general, take note: despite any recommendations and clever justifications, make the pipe pitch in the edge zones 100 mm, and in the remaining 150 mm, and you will never go wrong.

A pitch of 300 mm will not provide uniform heating of the floor at all (again, when laying with a snake).

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

IN residential buildings or apartments with an area ranging from 50 m2 to infinity - a pipe with a diameter of 16 mm is used. No need for more!

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 meet all these conditions. In general, larger diameter pipes are not needed for a private home: they are optimal in terms of “ease of installation – price – coolant volume”.

Another pipe often used is 18 mm. However, you need to understand that a thicker pipe means extra costs, and not only for the pipe, but also for fittings and everything else.

Sometimes they lay 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 heating will require more energy. And it’s difficult to install such a pipe: bending it for installation with a snake and a step of 150 mm is unrealistic, and a larger step will not provide 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, with a large number of people present there at the same time. There will be a thick screed poured in there! For a 16 mm pipe, the thickness of the screed is sufficient 50 mm from the top of the pipe. Up to 80 mm is allowed.

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

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

Almost every underfloor heating collector has a 1-inch (25 mm) thread for connecting to the main line - it doesn’t matter whether it is internal or external.

There are manifolds with an inch and a quarter thread, but these are for large industrial or public institutions where a larger diameter pipe will be used, so you do NOT need to take such manifolds for a private home.

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

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

Other data for designing underfloor heating

It is not advisable to connect the concrete and deck systems to the same mixing unit (and manifold).

One circuit should be for one room (meaning, there is no need to get weird by laying out a loop, filling in 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 loop lengths is solved by installing flow meters on the manifold: with their help, the uniform flow of coolant through loops of different lengths is regulated.

If the circuits are 90 m long (or even more), then a maximum of nine circuits can be “attached” to one collector. With loop lengths of 60...80 m, up to 11 loops can be mounted on one collector.

There is no need to “press” two (or more) collectors with one pump. It is correct to install separate pumps for each manifold group.

Mixing modules (mixing units) are not all suitable for all pipe lengths of underfloor heating loops, so please check when purchasing.

For an accurate calculation, it is necessary to take into account not only heat loss, but also the possible heat influx into the premises - for example, from operating equipment, household equipment etc. (it hardly makes sense to fool around with this when calculating the heating of a private house), heat flow through the ceiling - if the upper room also has a heated floor. Calculation multi-storey buildings must be carried out starting from the premises of the upper floor to the lower ones. Because heat loss through the floor of the second floor is a useful heat gain for the premises of the first floor.

The thickness of the insulation on the first and ground floor not less than 50 mm (in reality, it depends on the climate zone: what is good for the south is not good at all in the north), on other floors - not less than 30 mm. A logical question: why insulate the ceiling between the first and second floors, even if the heat from the heated floor on the second floor also warms the first floor? Answer: if the floor is concrete, then insulation is installed so as not to heat the floor itself, because this is very expensive both in terms of money and time.

The maximum pressure loss in the circuit is 15 kPa (optimally 13 kPa). If the circuit has a pressure loss of more than 15 kPa, you need to reduce the coolant flow or divide the floor area in the room into several circuits. We’ll look at what this means in one of the following articles, when we perform calculations using a specific example.

Minimum consumption coolant in one circuit is at least 27-30 liters per hour. Otherwise, the contours need to be combined. Why such a restriction? At a lower flow rate, the coolant will not have time to pass through the entire circuit, but will have time to cool down - the floor will be cold! The minimum coolant flow on each circuit can be set on the control valve (flow meter) installed on the manifold.

The above requirements for design of heated floors will need to be taken into account when performing calculations for heated floors, when we do this in a special program. So, if these terms don’t mean anything to you yet, don’t worry, everything will fall into place in due time. However, I recommend making a note for yourself somewhere so that you can return to the information in this article when making calculations.

design of heated floors

In order to avoid unnecessary costs and technological errors, which can lead to partial or complete rework of the system with your own hands, the calculation of the water heated floor is made in advance, before installation begins. The following input data is required:

• Materials from which housing is built;
• Availability of other heating sources;
• Room area;
• Availability of external insulation and quality of glazing;
• Regional location of the house.

You also need to determine what maximum air temperature in the room is required for the comfort of the residents. On average, it is recommended to design the water floor contour based on 30-33 °C. However, such high performance may not be necessary during operation; a person feels most comfortable at temperatures up to 25 degrees.

In the case where additional heat sources are used in the house (air conditioning, central or heating system etc.), the calculation of heated floors can be based on average maximum values ​​of 25-28 °C.

Advice! It is strongly recommended not to connect warm water floors with your own hands directly through central system heating. It is advisable to use a heat exchanger. Perfect option– completely autonomous heating and connection of heated floors through a manifold to the boiler.

System efficiency directly depends on the material of the pipes through which the coolant will move. There are 3 varieties used:

• Copper;
• Polyethylene or cross-linked polypropylene;
• Metal-plastic.

U copper pipes maximum heat transfer, but quite high cost. Polyethylene and polypropylene pipes have low thermal conductivity, but are relatively cheap. The best option in terms of price and quality – metal-plastic pipes. They have low heat transfer consumption and a reasonable price.

Experienced specialists primarily take into account the following parameters:

1. Determining the desired t value in the room.
2. Correctly calculate heat loss at home. To do this, you can use calculator programs or invite a specialist, but it is also possible to make an approximate calculation of heat loss yourself. A simple way to calculate a warm water floor and heat loss in a room is the average value of heat loss in a room - 100 W per 1 sq. meter, taking into account a ceiling height of no more than 3 meters and the absence of adjacent unheated premises. For corner rooms and those that have two or more windows - heat loss is calculated based on a value of 150 W per 1 sq. meter.
3. Calculation of how much heat loss the circuit will have for each m2 of area heated by the water system.
4. Determination of heat consumption per m2 based on decorative material coatings (for example, ceramics have higher heat transfer than laminate).
5. Calculation of surface temperature taking into account heat loss, heat transfer, and desired temperature.

On average, the required power for every 10 m2 of laying area should be about 1.5 kW. In this case, you need to take into account point 4 in the above list. If the house is well insulated and the windows are made of high-quality profiles, then 20% of the power can be allocated to heat transfer.

Accordingly, with a room area of ​​20 m2, the calculation will take place according to the following formula: Q = q*x*S.

3kW*1.2=3.6kW, where

Q – required heating power,

q = 1.5 kW = 0.15 kW - this is a constant for every 10 m2,

x = 1.2 is the average heat loss coefficient,

S – area of ​​the room.

Before you begin installing the system yourself, it is recommended to draw up a plan diagram, accurately indicate the distance between the walls and the presence of other heat sources in the house. This will allow you to calculate the power of the water floor as accurately as possible. If the area of ​​the room does not allow the use of one circuit, then it is correct to plan the system taking into account the installation of the collector. In addition, you will need to install the cabinet for the device yourself and determine its location, distance to the walls, etc.

How many meters is the optimal contour length?

There is often information that the maximum length of one circuit is 120 m. This is not entirely true, since the parameter directly depends on the diameter of the pipe:

• 16 mm – max L 90 meter.
• 17 mm – max L 100 meter.
• 20 mm – max L 120 meter.

Accordingly, than larger diameter pipeline, the lower the hydraulic resistance and pressure. This means the contour is longer. However experienced craftsmen It is recommended not to “chase” the maximum length and choose pipes D 16 mm.

You also need to take into account that thick pipes D 20 mm are problematic to bend; accordingly, the laying loops will be larger than the recommended parameter. And this means a low level of system efficiency, because the distance between the turns will be large; in any case, you will have to make a square outline of the snail.

If one circuit is not enough for heating large room, then it is better to install a double-circuit floor with your own hands. In this case, it is strongly recommended to make the contours the same length so that the heating of the surface area is uniform. But if the difference in size cannot be avoided, an error of 10 meters is allowed. The distance between the contours is equal to the recommended step.

Hydraulic pitch between turns

The uniformity of surface heating depends on the pitch of the coil. Typically, two types of pipe laying are used: snake or snail.

It is preferable to make a snake in rooms with minimal heat loss and a small area. For example, in a bathroom or hallway (since they are located inside a private house or apartment without contact with the outside environment). The optimal loop pitch for a snake is 15-20 cm. With this type of installation, the pressure loss is approximately 2500 Pa.

Snail loops are used in spacious rooms. This method saves the length of the circuit and makes it possible to evenly heat the room, both in the middle and closer to the outer walls. The loop pitch is recommended within 15-30 cm. Experts say that the ideal step distance is 15 cm. Pressure loss in the cochlea is 1600 Pa. Accordingly, this do-it-yourself installation option is more profitable in terms of system power efficiency (you can cover less usable area). Conclusion: the cochlea is more efficient, there is less pressure drop in it, and, accordingly, higher efficiency.

The general rule for both schemes is that closer to the walls the step should be reduced to 10 cm. Accordingly, from the middle of the room the loops of the circuit are gradually compacted. Minimum laying distance to outer wall 10-15 cm.

Another important point- pipes cannot be laid on top of the seams concrete slabs. It is necessary to draw up the diagram in such a way that the same location of the loop is maintained between the joints of the slab on both sides. For installation with your own hands, you can first draw a diagram on a rough screed with chalk.

How many degrees are allowed when temperature changes

System design, in addition to heat and pressure losses, involves temperature changes. The maximum difference is 10 degrees. But it is recommended to focus on 5 °C for uniform operation of the system. If the specified comfortable floor surface temperature is 30 °C, then the direct pipeline should supply about 35 °C.

Pressure and temperature, as well as their losses, are checked during crimping (checking the system before the final filling of the finishing screed). If the design is done correctly, then the specified parameters will be accurate with an error of no more than 3-5%. The higher the t difference, the higher the floor power consumption.

The most common way to implement underfloor heating systems is monolithic concrete floors, made by the so-called “wet” method. The floor structure is “ layered cake” from various materials (Fig. 1).

Fig. 1 Laying underfloor heating loops with a single coil

Installation of a heated floor system begins with preparing the surface for installation of a heated floor. The surface must be level, unevenness in area should not exceed ±5 mm. Irregularities and protrusions of no more than 10 mm are allowed. If necessary, the surface is leveled with an additional screed. Failure to comply with this requirement may lead to air-filling of the pipes. If there is high humidity in the room below, it is advisable to install waterproofing (polyethylene film).

After leveling the surface, it is necessary to lay a damper tape at least 5 mm wide along the side walls to compensate for the thermal expansion of the heated floor monolith. It should be laid along all walls framing the room, racks, door frames, bends, etc. The tape should protrude above the planned height of the floor structure by at least 20 mm.

After which a layer of thermal insulation is laid to prevent heat leakage into the lower rooms. It is recommended to use foam materials (polystyrene, polyethylene, etc.) with a density of at least 25 kg/m 3 as thermal insulation. If it is impossible to lay thick layers of thermal insulation, then in this case foil-coated thermal insulation materials 5 or 10 mm thick. It is important that foil thermal insulation materials have protective film on aluminum. Otherwise, the alkaline environment of the concrete screed destroys the foil layer within 3–5 weeks.

The pipes are laid out with a certain step and in the desired configuration. It is recommended that the supply pipeline should be laid closer to the outer walls.

When laying a “single coil” (Fig. 2), the temperature distribution of the floor surface is not uniform.

Fig.2 Laying underfloor heating loops with a single coil

When laying spirally (Fig. 3), pipes with opposite flow directions alternate, with the hottest section of the pipe adjacent to the coldest. This leads to an even temperature distribution over the floor surface.

Fig.3 Laying heated floor loops in a spiral.

The pipe is laid according to the markings applied to the heat insulator, with anchor brackets every 0.3 - 0.5 m, or between special protrusions of the heat insulator. The laying step is calculated and ranges from 10 to 30 cm, but should not exceed 30 cm, otherwise uneven heating of the floor surface will occur with the appearance of warm and cold stripes. Areas near the outer walls of a building are called boundary zones. Here it is recommended to reduce the pipe laying step in order to compensate for heat loss through the walls. The length of one circuit (loop) of a heated floor should not exceed 100–120 m, the pressure loss per loop (including fittings) should not exceed 20 kPa; the minimum speed of water movement is 0.2 m/s (to avoid the formation of air pockets in the system).

After laying out the loops, immediately before pouring the screed, the system is pressure tested at a pressure of 1.5 of the working pressure, but not less than 0.3 MPa.

When pouring a cement-sand screed, the pipe should be under a water pressure of 0.3 MPa at room temperature. Minimum height the filling above the surface of the pipe must be at least 3 cm (maximum recommended height, according to European standards - 7 cm). Cement-sand mixture must be at least grade 400 with plasticizer. After pouring, it is recommended to “vibrate” the screed. If the length of a monolithic slab is more than 8 m or the area is more than 40 m2, it is necessary to provide seams between the slabs minimum thickness 5 mm, to compensate for the thermal expansion of the monolith. When pipes pass through seams, they must have a protective sheath of at least 1 m in length.

The system is started only after the concrete has completely dried (approximately 4 days per 1 cm of screed thickness). The water temperature when starting the system should be room temperature. After starting the system, increase the supply water temperature daily by 5°C to operating temperature.

Basic temperature requirements for underfloor heating systems

It is recommended to take the average temperature of the floor surface no higher (according to SNiP 41-01-2003, clause 6.5.12):
• 26°C for rooms with constant occupancy
• 31°C for rooms with temporary occupancy and bypass paths of swimming pools
• The temperature of the floor surface along the axis of the heating element in children's institutions, residential buildings and swimming pools should not exceed 35°C

According to SP 41-102-98, the temperature difference in certain areas of the floor should not exceed 10°C (optimally 5°C). The coolant temperature in the underfloor heating system should not exceed 55°C (SP 41-102-98 clause 3.5 a).

Set of water heated floors for 15 m 2

Heated floor kit for heating rooms with an area of ​​15-20 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted manually by turning the valve handle.

Set of water heated floors for 15 m2 (with reinforced thermal insulation, for unheated lower rooms)

Heated floor kit for heating rooms with an area of ​​15-20 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted manually by turning the valve handle. Reinforced thermal insulation allows you to install a heated floor system over unheated rooms.

When laying a heated floor loop in a spiral (screed thickness 3 cm with a floor covering made of ceramic tiles) with a step of 15-20 cm and a design coolant temperature of 30°C - floor surface temperature 24-26°C, coolant flow rate of about 0.2 m 3 /h, flow speed 0.2-0.5 m/s, pressure loss in the loop approximately 5 kPa (0.5 m).

Accurate calculation of thermal and hydraulic parameters can be carried out using free program calculations for underfloor heating Valtec Prog.

Set of water heated floors up to 30 m 2 - 1

Heated floor kit for heating rooms with an area of ​​30-40 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted manually by turning the valve handle. To ensure equal coolant flow in the heated floor loops, their length and laying pattern must be the same.

When laying a heated floor loop in a spiral (screed thickness 3 cm with a ceramic tile floor covering) in increments of 15-20 cm and an estimated coolant temperature of 30°C, the floor surface temperature is 24-26°C, coolant flow is about 0.2 m 3 / h, flow speed 0.2-0.5 m/s, pressure loss in the loop approximately 5 kPa (0.5 m).

Accurate calculations of thermal and hydraulic parameters can be carried out using the free underfloor heating calculation program Valtec Prog.

Set of water heated floors up to 30 m 2 - 2

Heated floor kit for heating rooms with an area of ​​30-40 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted manually by turning the valve handle. To facilitate air release, the system is supplemented with automatic air vents and drain valves. To ensure equal coolant flow in the heated floor loops, their length and laying pattern must be the same. Reinforced thermal insulation allows you to install a heated floor system over unheated rooms.

When laying a heated floor loop in a spiral (screed thickness 3 cm with a ceramic tile floor covering) in increments of 15-20 cm and an estimated coolant temperature of 30°C, the floor surface temperature is 24-26°C, coolant flow is about 0.2 m 3 / h, flow speed 0.2-0.5 m/s, pressure loss in the loop approximately 5 kPa (0.5 m).

Accurate calculations of thermal and hydraulic parameters can be carried out using the free underfloor heating calculation program Valtec Prog.

Set of water heated floors up to 60 m 2 - 1

Heated floor kit for heating rooms with an area of ​​60-80 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted manually by turning the valve handle. To facilitate air release, the system is supplemented with automatic air vents and drain valves. To ensure equal coolant flow in the underfloor heating loops (hydraulic balancing of the loops), manifolds with integrated shut-off and control valves are used. Reinforced thermal insulation allows you to install a heated floor system over unheated rooms.

When laying a heated floor loop in a spiral (screed thickness 3 cm with a ceramic tile floor covering) in increments of 15-20 cm and an estimated coolant temperature of 30°C, the floor surface temperature is 24-26°C, coolant flow is about 0.2 m 3 / h, flow speed 0.2-0.5 m/s, pressure loss in the loop approximately 5 kPa (0.5 m).

Accurate calculations of thermal and hydraulic parameters can be carried out using the free underfloor heating calculation program Valtec Prog.

Set of water heated floors up to 60 m 2 - 2. (automatic temperature control)

Heated floor kit for heating rooms with an area of ​​60-80 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted automatically by the valve servomotor, depending on the value of the coolant temperature set on the scale of the overhead thermostat. To facilitate air release, the system is supplemented with automatic air vents and drain valves. To ensure equal coolant flow in the underfloor heating loops (hydraulic balancing of the loops), manifolds with integrated shut-off and control valves are used. Reinforced thermal insulation allows you to install a heated floor system over unheated rooms.

When laying a heated floor loop in a spiral (screed thickness 3 cm with a ceramic tile floor covering) in increments of 15-20 cm and an estimated coolant temperature of 30°C, the floor surface temperature is 24-26°C, coolant flow is about 0.2 m 3 / h, flow speed 0.2-0.5 m/s, pressure loss in the loop approximately 5 kPa (0.5 m).

Accurate calculations of thermal and hydraulic parameters can be carried out using the free underfloor heating calculation program Valtec Prog.

Set of water heated floors up to 60 m 2 - 3. (automatic temperature control)

Heated floor kit for heating rooms with an area of ​​60-80 m2 with a mixing unit with manual adjustment of the coolant temperature based on the mixing and separating valve MIX 03. The operating temperature of the coolant is adjusted automatically by the valve servomotor, depending on the value of the coolant temperature set on the scale of the overhead thermostat. The system uses a manifold block with control valves with flow meters (optional) to ensure equal coolant flow in the underfloor heating loops (hydraulic balancing of the loops). The use of a manifold adjustable bypass allows you to redirect the coolant flow from the supply to the return manifold in the case when the flow through the manifold loops decreases below the value set on the bypass bypass valve. This allows maintaining hydraulic characteristics collector system regardless of the influence of the manifold loop controls (manual, thermostatic valves or servos).

When laying a heated floor loop in a spiral (screed thickness 3 cm with a ceramic tile floor covering) in increments of 15-20 cm and an estimated coolant temperature of 30°C, the floor surface temperature is 24-26°C, coolant flow is about 0.2 m 3 / h, flow speed 0.2-0.5 m/s, pressure loss in the loop approximately 5 kPa (0.5 m).

Accurate calculations of thermal and hydraulic parameters can be carried out using the free underfloor heating calculation program Valtec Prog.

** - optional

A set of water heated floors with an area of ​​more than 60 m2. (Combimix pumping and mixing unit)

Heated floor kit for heating rooms with an area of ​​more than 60 m 2 s pumping and mixing knot with automatic maintenance coolant temperature. The maximum power of the underfloor heating system is 20 kW. The system uses a manifold block with control valves with flow meters (optional) to ensure equal coolant flow in the underfloor heating loops (hydraulic balancing of the loops).

An accurate calculation of the thermal and hydraulic parameters of underfloor heating loops can be carried out using the free underfloor heating calculation program Valtec Prog.

Warm floor perfect solution to improve your home. The floor temperature directly depends on the length of the heated floor pipes hidden in the screed. The pipe in the floor is laid in loops. In fact, the total length of the pipe is determined by the number of loops and their length. It's clear what longer pipe in the same volume, the warmer the floor. In this article we will talk about restrictions on the length of one heated floor circuit.

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

Consequences of exceeding the length

Let's figure out what consequences an increase in the length of the heated floor pipe can lead to. One of the reasons is an increase in hydraulic resistance, which will create 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. The resistance calculation consists of many parameters. Conditions, installation parameters. The material of the pipes used. Here are the three main ones: loop length, number of bends and thermal load at her.

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

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

Therefore, it is necessary to fill the heated floor screed with pressed pipes. It is better to pressurize with air at a pressure of about 4 bar. This way, when you fill the system with water and start heating it, the pipe in the screed will have room to expand.

Optimal pipe length

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

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

One of the conditions for the implementation of high-quality and proper heating The purpose of a room using a heated 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 quantity heat for a heated room and floor covering.

Required data for calculation

To maintain a given 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 consists 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,
• 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 listed data, it is possible to correctly calculate the length of the heated floor circuit and thereby ensure a comfortable temperature regime in the room with minimal costs 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 be no more than those indicated in the table:

Pipe laying options used for heated floors

The laying pattern can be made 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 like a snake, and then the middle part - like a snail.

IN large rooms For complex configurations, it is better to lay them in a snail shape. Indoors small sizes and having a variety of complex configurations, snake laying is used.

Distance between pipes

The pipe laying pitch is determined by calculation and usually corresponds to 15, 20 and 25 cm, but no more. When laying pipes at intervals of more than 25 cm, a person’s foot will feel the temperature difference between and directly above them.

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

Allowable contour length

This 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 liquid that is supplied to them per unit time.

When installing a heated floor, situations often occur when the circulation of the coolant in a separate loop is disrupted, 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, you can adhere to the following recommended sizes:

1. Less than 100 m can be a loop made of metal-plastic pipe with a diameter of 16 mm. For reliability optimal size is 80 m.
2. No more than 120 m is the maximum length of the contour of an 18 mm pipe made of cross-linked polyethylene. Experts try to install a circuit 80-100 m long.
3. 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 length of the loop for a heated 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.

Application of multiple contours of different lengths

For example, it is necessary to install a heated floor system in several rooms, one of which, say a bathroom, has an area of ​​4 m2. This means that heating it will require 40 m of pipe. It is impractical to arrange 40 m loops in other rooms, whereas 80-100 m loops 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 loop lengths can be compensated by increasing or decreasing the diameter of the pipe and changing the pitch of its installation.

Possibility of connection to one unit 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 ​​the heated premises, the material of the enclosing structures and many other various indicators.

Such calculations must be entrusted to specialists who have knowledge and practical skills in carrying out such projects.

Loop size determination

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

To do this, you need 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.

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

In this room it is necessary to lay 61 m of pipe, forming a thermal circuit, 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 pipe length of several heating circuits for large quantities premises powered 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 the uninterrupted circulation of water depends, and therefore high-quality heating floor.

Optimal length heated floor contours
One of the conditions for high-quality and proper heating of a room using a heated floor is the optimal length of the heated floor circuit.

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

In practice, it is not easy to realize what has been repeatedly replayed in your 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 circuit is one of the first issues that needs to be dealt with.

Pipe location

The underfloor heating system includes a considerable list of elements. We are interested in tubes. It is their length that defines the concept of “maximum length of a warm water floor.” They must be laid taking into account the characteristics of the room.

From this we get four options, known as:

If you do correct styling, then each of the listed types will be effective for heating the room. The length of the pipe and the volume of water may (and most likely will) be different. 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 water heated floor circuit. Another parameter is diameter. Pipes with a diameter of 2 cm are mainly used.

We also take into account the distance from the pipes to the wall. Here they recommend laying 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 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:

1. Let’s say our room is 5 m long and 4 m wide.
2. Laying the pipeline of our system always starts from the smaller side, that is, from the width.
3. To create the base of the pipeline, we take 15 pipes.
4. A gap of 10 cm remains near the walls, which then increases by 5 cm on each side.
5. 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 = 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 heated floor circuit? What to do if the room requires, for example, 130 or 140-150 m of pipe? The solution is very simple: you will need to make more than one circuit.

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-heated floor circuit should not exceed this figure. 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 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 heated floor circuit

To determine this parameter we must consider:

• hydraulic resistance,
• pressure loss in a specific circuit.

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

In the installation of heated floors there is a concept - the so-called effect. locked loop. We are talking about a situation where circulation through the loop will be impossible, regardless of the power of the pump. This effect is inherent in a pressure loss situation of 0.2 bar (20 kPa).

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

1. A maximum contour of 100 m is used for pipes with a diameter of 16 mm made of metal-plastic or polyethylene. Ideal option – 80 m
2. A contour of 120 m is the limit for an 18 mm cross-linked polyethylene pipe. However, it is better to limit yourself to a range of 80-100 m
3. With a 20 mm plastic pipe you can make a contour 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 one is better to choose flooring for warm water floor:

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

Are two identical ones necessary/possible?

Naturally, the ideal situation would be when the loops are the same length. In this case, no adjustments or searches for balance will be needed. But this is mostly 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 heated floors in a facility 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, dividing it into tiny sections?

Since this is not advisable, we approach another question: how not to lose pressure. And for this purpose, elements such as balancing valves have been created, the use of which consists in equalizing pressure losses along the circuits.

Again, you can use calculations. But they are complex. From the practice of carrying out work on installing a warm water floor, we can safely say that the variation in the size of the contours is possible within 30-40%. In this case, we have every chance to get the maximum effect from using 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 more specific. 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 coolant passing through the unit per unit of time (calculation is in m3 per hour).

We need to look at the technical data sheet of the unit, where the maximum coefficient is indicated bandwidth. If we carry out the calculations, we get maximum rate, but you can't count on it.

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

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

We saw that installing a warm water floor is a very troublesome task. Especially in the part where we're talking about about the length of the contour. Therefore, it is better to contact specialists so as not to redo a not entirely successful installation, which will not bring the effectiveness that you expected.

Laying and calculating the maximum length of the water heated floor circuit
The article contains detailed information about the maximum length of the water heated floor circuit, the location of the pipes, optimal calculations, as well as the number of circuits with one pump and whether two identical ones are needed.

Laying heating pipes under the floor covering is considered one of 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, distribute heat evenly in the room, rather than creating separate “cold” and “hot” zones.

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

Laying options

Builders use four common pipe laying patterns, each of which is better suited for indoor use. various shapes. The maximum length of the heated floor contour largely depends on their “pattern”. This:

• "Snake". Sequential laying, where the hot and cold lines follow each other. Suitable for elongated rooms divided into zones of different temperatures.
• "Double Snake" Used in rectangular rooms, but without zoning. Provides uniform heating of the area.
• "Corner Snake". A sequential system for a room with equal length of walls and the presence of a low heating zone.
• "Snail". Double laying system, suitable for close to square shaped rooms 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 length of the underfloor heating pipe for each circuit is calculated separately. To get the required value you will 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” (distance between loops).
• K is the distance from the collector to the connection point with the circuits.

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

As an example of calculating the maximum length of a pipe for a heated 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, we get the following:

5% is added to the result, which is 4.94 m and the recommended length of the water heated floor circuit increases 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, the number of circuits in the room and the power of the pump, which is responsible for circulating the coolant.

In apartments and houses with medium-sized 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 a water heated floor 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 “locked loop” effect may occur when, regardless of the power of the pump, the movement of the coolant in the communication stops due to high fluid resistance.

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 for a small room or part of a large one; stretching the loop over several rooms is irrational.
• One pump per collector, even if the declared power is enough to provide two “combs”.
• With a maximum length of underfloor heating pipe of 16 mm per 100 m, the collector is installed on no more than 9 loops.

If the maximum length of the heated floor loop 16 pipes exceeds the recommended value, then the room is divided into separate circuits, which are connected into one heating network by a manifold. To provide uniform distribution coolant throughout the entire system, experts advise not to exceed the difference between individual loops of 15 m, otherwise the smaller circuit will heat up much more than the larger one.

But what to do if the length of the heated floor contour of a 16 mm pipe differs by a value that exceeds 15 m? Balancing fittings will help, changing 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 heated floor contours for pipe 16 affects the heating level. To maintain a comfortable indoor environment you need certain temperature. To do this, the water pumped through the system is heated to 55-60 °C. Exceeding this indicator may have a detrimental effect on 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 “input” and “output” of the mixing boiler should not exceed 5 °C, a different value indicates heat loss on the heating main.

Maximum length of the water heated floor circuit: installation and calculation optimal value
Laying heating pipes under the floor covering 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, and evenly distribute heat in the room rather than creating separate

One of the conditions for high-quality and proper heating of a room using a heated floor is maintaining 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 a given 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 consists of the following indicators and characteristics:

• temperature that should be above the floor covering;
• layout diagram of loops with 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 correctly calculate the length of the heated floor circuit and thereby ensure a comfortable temperature regime in the room with minimal costs 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 be no more than those indicated in the table:

Pipe laying options used for heated floors

Options for laying heated floors

The laying pattern can be made 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 like a snake, and then the middle part - like a snail.

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

The pipe laying pitch is determined by calculation and usually corresponds to 15, 20 and 25 cm, but no more. When laying pipes at intervals of more than 25 cm, a person’s foot will feel the temperature difference between and directly above them.

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

Allowable contour length

This 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 liquid that is supplied to them per unit time.

When installing a heated floor, situations often occur when the circulation of the coolant in a separate loop is disrupted, 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, you can adhere to the following recommended sizes:

1. Less than 100 m can be a loop made from a metal-plastic pipe with a diameter of 16 mm. For reliability, the optimal size is 80 m.
2. No more than 120 m is the maximum length of the contour of an 18 mm pipe made of cross-linked polyethylene. Experts try to install a circuit 80-100 m long.
3. 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.

To more accurately determine the size of the loop length for a heated floor in the room in question, in which there will be no problems with coolant circulation, it is necessary to perform calculations.

Application of multiple contours of different lengths

The design of the floor heating system involves the implementation of several circuits. Of course, the ideal option is when all the loops are the same length. In this case, there is no need to configure and balance the system, but it is almost impossible to implement such a pipe layout. Detailed video For information on calculating the length of the water circuit, see this video:

For example, it is necessary to install a heated floor system in several rooms, one of which, say a bathroom, has an area of ​​4 m2. This means that heating it will require 40 m of pipe. It is impractical to arrange 40 m loops in other rooms, whereas 80-100 m loops 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 loop lengths can be compensated by increasing or decreasing the diameter of the pipe and changing the pitch of its installation.

Possibility of connection to one unit 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 ​​the heated premises, the material of the enclosing structures and many other various indicators.

Such calculations must be entrusted to specialists who have knowledge and practical skills in carrying out such projects.

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

To do this, you need 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 you need to add the length of the pipeline that will need to be laid from the collector to warm floor and back. Watch the answer to key questions about organizing a heated floor in this video:

You can determine the length of the loop laid in increments of 20 cm in a room 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 it is necessary to lay 61 m of pipe, forming a thermal circuit, 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.

In order to correctly determine the pipe length of several heating circuits for a large number of rooms powered 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, and therefore high-quality floor heating, depends.