Heating system in the floor. Underfloor heating. About two-core and single-core electrical cable

The main argument in favor of the “warm floor” system is the increased comfort of a person’s stay in the room, when the entire surface of the floor acts as a heating device. The air in the room warms up from the bottom up, while at the surface of the floor it is slightly warmer than at a height of 2-2.5 m.

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

The disadvantages of underfloor heating systems include the relatively high cost of equipment compared to radiator systems, as well as increased requirements for the technical competence of installers and the quality of their work. Using quality materials and following the installation technology of a well-designed water underfloor heating system, no problems arise during its subsequent operation.

The heating boiler operates on radiators in 80/60 °C mode. How to properly connect a "warm floor"?

To obtain the design temperature (usually not higher than 55 °C) and the specified coolant flow rate in the “warm floor” circuit, pumping and mixing units are used. They form a separate low-temperature circulation circuit into which hot coolant from the primary circuit is mixed. The amount of coolant added can be set either manually (if the temperature and flow rate in the primary circuit are constant) or automatically using thermostats. All the benefits of a “warm floor” can be fully realized by pumping and mixing units with weather compensation, in which the temperature of the coolant supplied to the low-temperature circuit is adjusted depending on the outside air temperature.

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

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

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

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

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

Parquet, parquet boards and boards can also be used as a “warm floor” covering, but the surface temperature should not exceed 26 °C. In addition, the mixing unit must include a safety thermostat. Moisture content of floor covering materials natural wood should not exceed 9%. Work on laying parquet or plank flooring is permitted only when the room temperature is not lower than 18 ° C and 40-50 percent humidity.

What should be the temperature on the surface of the “warm floor”?

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

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

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

What should be the thickness of the thermal insulation layer under the "warm floor" pipes?

The thickness of the thermal insulation, which limits heat loss from the "warm floor" pipes in the "downward" direction, must be determined by calculation and largely depends on the air temperature in the design room and the temperature in the underlying room (or ground). In most Western calculation programs, downward heat loss is assumed to be 10% of the total heat flow. If the air temperature in the design and underlying rooms is the same, then this ratio is satisfied by a layer of polystyrene foam 25 mm thick with a thermal conductivity coefficient of 0.035 W/(mOK).

Which pipes are best used for installing a "warm floor" system?

Pipes for underfloor heating must have the following properties: flexibility, allowing the pipe to be bent with a minimum radius to ensure the required installation pitch; ability to maintain shape; low coefficient of resistance to coolant movement to reduce the power of pumping equipment; durability and corrosion resistance, since access to pipes during operation is difficult; oxygen-tight (like any heating system pipeline). In addition, the pipe should be easy to process simple tool and have a reasonable price.

The most widespread systems are “warm floors” made of polyethylene (PEX-EVOH-PEX), metal-plastic and copper pipes. Polyethylene pipes are less convenient to use because they do not retain their given shape, and when heated they tend to straighten out (“memory effect”). Copper pipes, when embedded in a screed, must have a coating polymer layer to avoid alkaline effects, and this material is also quite expensive. Metal-plastic pipes most fully satisfy the requirements.

Is it necessary to use a plasticizer when pouring a “warm floor”?

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

What is the point of using aluminum foil coated insulation?

In cases where "warm floor" pipes are installed in air gap(for example, in floors along joists), foiling the thermal insulation allows you to reflect most of the downward radiant heat flow, thereby increasing the efficiency of the system. The same role is played by foil when constructing porous (gas or foam concrete) screeds.

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

How to avoid cracking of underfloor heating screed?

The reasons for the appearance of cracks in the “warm floor” screed may be low strength of the insulation, poor compaction of the mixture during installation, lack of plasticizer in the mixture, or too thick screed (shrinkage cracks). The following rules should be adhered to: the density of the insulation (expanded polystyrene) under the screed must be at least 40 kg/m3; the screed solution must be workable (plastic), the use of a plasticizer is mandatory; to avoid the appearance of shrinkage cracks, polypropylene fiber must be added to the solution at the rate of 1-2 kg of fiber per 1 m3 of solution. For heavily loaded floors, steel fiber is used.

Is waterproofing required when installing underfloor heating?

If the architectural and construction part of the project does not provide for a vapor barrier device, then with the “wet method” of installing a “warm floor” system on the floors, it is recommended to lay a layer of glassine over the leveled floor. This will help prevent laitance from leaking through the ceiling while pouring the screed. If the project provides for an interfloor vapor barrier, then additional waterproofing is not necessary. Waterproofing in wet rooms (bathrooms, lavatories, showers) is installed in the usual manner on top of the “warm floor” screed.

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

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

What should be the step for laying the pipes of a “warm floor” loop?

The pitch of the loops is determined by calculation. It must be taken into account that a loop pitch of less than 80 mm is difficult to implement in practice due to the small bend radius of the pipe, and a pitch of more than 250 mm is not recommended, as it leads to noticeable uneven heating of the “warm floor”. To facilitate the task of choosing a loop pitch, you can use the table below.

Is it possible to install heating only using a “warm floor” system, without radiators?

To answer this question in each specific case, it is necessary to carry out a thermal engineering calculation. On the one hand, the maximum specific heat flux from a “warm floor” is about 70 W/m2 at a room temperature of 20 °C. This is enough to compensate for heat losses through enclosing structures made in accordance with thermal protection standards.

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

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

The screed must have time to acquire sufficient strength. After three days under natural hardening conditions (without heating), it gains 50% strength, after a week - 70%. Full strength gain to the design grade occurs after 28 days. Based on this, it is recommended to start the “warm floor” no earlier than three days after pouring. You also need to remember that the “warm floor” system is filled with solution when the floor pipelines are filled with water under a pressure of 3 bar.

It's no secret that room heating technologies are very widespread today, and engineers pay a lot of attention to this issue. great importance.. So, in this publication we will look at the advantages and disadvantages of underfloor heating, its types and installation and installation technology.

What you need to know about underfloor heating:

Underfloor heating systems

Underfloor heating is a type of heating in which the coolant circulation system is located under the floor.

As you know, the most common type of heating is wall heating, in particular using batteries. This type heating has a number of disadvantages, one of them is that the room is heated unevenly and not rationally. The fact is that heat tends upward, and it turns out that the warmest places in the room are the part near the radiator and the ceiling, and from these zones the heat spreads throughout the rest of the room. Many will say that, despite such irrationality, the apartment is already quite warm - we don’t deny it, but it could be even warmer, or more economical in terms of resource costs.

In turn, underfloor heating is more efficient, since heat transfer goes from the bottom up, spreading over the entire area of the room, besides, you have a warm floor on which you can walk barefoot, but there will be no radiator on which you can hang things to dry. The maximum heat area is just the height of a person, thereby creating the most comfortable conditions for the inhabitants, and does not heat the ceiling.

Underfloor heating has its pros and cons, some of which we have already discussed. Among the advantages it should be noted:

- Rational heat distribution;

- Economical;

- Warm floor;

- Aesthetic beauty, since communications pass under the floor.

As for the disadvantages of underfloor heating:

- The coldest area of the room – the window – will be without heating;

- It will not be possible to dry things on the radiator;

- The labor-intensive process of laying underground communications;

- Expensive type of heating.

Underfloor heating is an excellent option for those residents who do not like carpets and prefer to walk barefoot. In addition, underfloor heating is an excellent heating solution for an apartment located on the ground floor, above a damp and cold basement. If you do complete replacement heating to autonomous, then you can think about floor view heating.

Types of underfloor heating

We should also touch upon the types of underfloor heating. If there are a lot of types of heating, then there are only two types of underfloor heating: water and electric.

As the name implies, water heating is based on the circulation of water coolant inside floor communications. The essence of water underfloor heating is that a pipe is laid under the floor through which hot water is distributed, heated to the desired temperature by a gas or electric boiler. And one more nuance, underfloor heating is autonomous, that is, make a branch from centralized system heating for floor heating is illegal, and also impractical. In the next article you will find out.

The second type of underfloor heating is electric. This type of heating is known to many as “warm floors”. This heating system is based on special electric heating sections; they can be cable or. These methods are an excellent alternative to water heating.

Below we will briefly tell you how to properly install underfloor heating with your own hands.

Do-it-yourself underfloor heating installation

An integral part of solving the heating issue is thermal insulation and heat conservation. That is why these factors must be taken into account before installing underfloor heating.

First, you need to eliminate heat leakage, and the most common areas for heat leakage are windows and walls. First of all, you need to install plastic windows, it is important to pay attention to strict adherence to the installation technology, since its violation can lead to heat loss. No less important is the finishing of window slopes from the outside and inside, again to eliminate blowing. Also, if you insulate the walls, the increase in heat savings will be quite high.

Now let's touch on the floor installation procedure itself.

Installation of underfloor heating

First of all, when installing underfloor heating, you need to prepare the base. In accordance with the rules for laying underfloor heating, the base must be smooth, without bumps or other irregularities. First you need to check the floor level and, if necessary, level it. When the floor is dropped, we move on to laying the heat-insulating material, which is necessary so that the heat goes up and does not heat the floor slab. The next step will be choosing the location of the thermostat and the supply of communications - for electric underfloor heating, or where the pipes and taps will come from - for water heating. Further, the procedure for installing the heating system of these two types differs from each other, and we will consider each of them separately.

Installation of water underfloor heating

Let's first find out how best to install underfloor water heating. The installation of water heating begins with the organization of the coolant supply location. To do this, it is necessary to make appropriate holes in the wall to supply pipes and install taps on them. For this, we recommend making a special niche-cabinet that will cover all these so-called coolant supply mechanisms.

Then, on the leveled floor, on which the heat insulator is laid, a special mesh is laid, which will serve as the basis for attaching the pipe. The pipe itself is folded in half and laid on the floor, secured to the base with ties. It is important to note that the pipe must be folded in half and laid exactly this way, since it is necessary to ensure that the coolant water is removed from the system. The pipes are laid in a spiral; there should be no kinks, otherwise this will significantly reduce the permeability of the coolant.

When the water underfloor heating system is installed, it is necessary to ensure that it is correct installation, and then connect it to the supply and return taps. A test run of the system is done to check the permeability of the pipes and the presence of leaks. Then the temperature of the coolant increases and at the same time the intensity, that is, the pressure of the water supply in the system, increases. The final stage of installing underfloor heating is pouring it using a self-leveling floor, followed by laying the finishing floor material.

This is how you install underfloor water heating with your own hands, now let’s talk about electric underfloor heating.

Installation of electric underfloor heating

An electric floor is installed in principle using the same technology as a water floor, but has some nuances. The coolant is also laid on a leveled floor and on a laid thermal insulation material. The installation of coolant begins from the thermostat.

When laying electric underfloor heating, the rolls are rolled out from one wall to the other, and in order to save money, you can bypass those places where a wardrobe, bed and other furniture will be installed, under which heating is not needed. Having reached the wall, a few centimeters before it begins, you need to cut the coolant base without damaging the so-called contour (how to cut correctly will be clearly demonstrated in the instructions). After this, the insulation tape is laid parallel to the first, close to it.

When the coolant is laid, check the correct installation and connect it. Then do a test run - if everything works, then we will lay the finishing flooring.

Now, based on the information received, you can choose the most optimal view underfloor heating and install it correctly.

To be fair, it should be noted that not only radiators can fully heat a house. Warm floors cope with this task no worse. In Ukraine, this heating method is not yet very common. AND main reason lies not in the limited financial capabilities of compatriots, but in a basic reluctance to destroy stereotypes formed over decades. Not everyone is yet able to believe that a house can be heated without traditional radiators. But in vain, because heated floors are a modern and energy-efficient alternative, the advantages of which have long been recognized in Europe. In particular, in Norway, the birthplace of underfloor heating, up to 80% of buildings are equipped with underfloor heating.

So what are the advantages of these systems? The operating principle of central heating is as follows: heat from the radiators rises to the ceiling, and cooler air sinks to the floor. While the lower layers of air heat up, the upper layers cool down (and some of the heat is also given off to ventilation). Then the process is repeated. Convection currents create a rather contradictory atmosphere, corresponding to the saying “Keep your feet warm and your head cold” exactly the opposite. As a result, a constant draft at floor level causes discomfort and unexpected energy costs for heating. When heating with the " warm floor» air moves only in one direction - from bottom to top. The large area of the “heater” ensures uniform heating of the air in the room. In addition, the warmest air is always below, excluding drafts. With an underfloor heating system, energy consumption is reduced by approximately 20%. And also the system warm floor» is absolutely invisible, therefore does not affect the design of the room, and has a long warranty period indicating its quality and durability.

Today there are two types of heated floors: water and electric. Regardless of the type, the system includes heating cables (circuit), a thermostat with a temperature sensor, thermal insulation and fasteners. They are also mounted in the same way - in the floor screed. But there are also differences.

Water heated floors require an additional purchase of a boiler, which increases the cost of installing the system. But if you consider that they are more economical to use, the final amount is equal to the cost of electric models. In suburban construction, water systems have an undeniable advantage, because the problem of energy efficiency becomes relevant precisely in large areas. And in summer time they also help cool the room using cold water.

Electric heated floors are easy to install, do not require additional equipment and preventative work during the period of operation. But use electrical systems less beneficial in terms of savings. Therefore, they are usually installed in separate rooms of the house (in the hallway, bath or kitchen).

Many companies supply underfloor heating systems to the Ukrainian market, including Aquatherm, Rehau (Germany), Ceilhit (Spain), Devi (Denmark), Easy Heat (Canada), Ensto (Finland), Fenix (Czech Republic), KAN (Poland) , Nexans (Norway), ThermoTech, Wirsbo (Sweden), “Our Comfort”, “Teplolux” (Russia), NPP “Eleter” (Ukraine), etc.

How you lay the floor is how it will serve

Installation of the system " warm floor» requires special training and is therefore performed by qualified workers. But knowing the basic principles and pitfalls of installation will help you control this process and avoid correcting poor-quality work.

The system is laid on the subfloor before the screed is poured. There are two types of pipe laying: parallel (snake, double snake) and spiral. Parallel laying is suitable for small rooms, as well as sloped floors. At the same time, the most hot pipe(the place where the coolant enters the coil) is located in the coldest zone, for example, near the outer wall. Spiral laying is more suitable for large rooms, as well as for places where temperature differences are undesirable. The hottest section of the pipe is adjacent to the coldest, so the temperature remains constant over the entire floor area.

The electric heating cable is laid only on a surface free from stationary furniture and floor-standing household appliances, and water pipes can be laid over the entire area (they are not at risk of overheating under heavy objects). There should be no pipelines or electrical cables in the areas where heated floors are installed. The distance from the boundary of the heated area of the room to the heating cable or pipe is equal to half the laying pitch (the distance between the turns of the circuit). And in areas near the outer walls of the building - the so-called boundary zones - it is advisable to reduce the laying step in order to compensate for heat loss.

When laying the thermal circuit and pouring the screed, make sure that workers do not accidentally damage the system. It will be possible to check its functionality only after the screed has completely dried (after 3-4 weeks), and if the system is damaged, you will have to open the floor and reinstall it.

The reliability of water heated floors is influenced by another factor - the quality of the water in them. When filling the pipes for the first time, ensure that workers rinse them thoroughly and then run warm water with 1-2 percent cleaning agent.

Systems installed in accordance with these requirements generally do not require repairs or maintenance throughout their entire service life. True, there are several other factors that influence the serviceability, and most importantly, the efficiency of heated floors:

correctly selected power of the circulation pump (if the power is insufficient, the longest turn of the circuit will have insufficient water pressure);
basic adjustment of the distribution manifold (if this is not done, water circulates only in short circuits where there is less resistance);
a mixing unit adjusted to a given temperature (otherwise the temperature of the heated floors will be uncomfortable).

It is advisable to discuss all these nuances with specialists during system installation. This way you will protect yourself from unpleasant surprises in the future.

Thermostats for heated floors

The thermostat is the only element of the heated floor visible in the interior. The main task of the thermostat is to maintain the set temperature.

Only, unlike radiator thermostats, the object of its attention is the floor temperature. This helps avoid situations where the air in the room (for example, in the bathroom or kitchen) warms up very quickly, but the floor remains cold. But there are also more functional thermostats that have two sensors - air and floor. As a rule, such models are used in systems intended not only for floor heating, but also for heating the entire room (in the absence of other heat sources).

When choosing a thermostat for a heated floor, remember that its switching power must correspond to the power of the heating system itself. According to modern standards maximum power thermostats is 3 kW (approximately the same amount consumed by a washing machine). If power installed system above, you need to additionally use a power relay or use several thermostats.

Installation, configuration and maintenance

Radiator thermostats are suitable for any known heating system. Their installation is simple and does not require special qualifications (with the exception of the special-purpose series). Just follow the instructions included in the package. But if you have never had to do such work yourself, it is better to seek help from a specialist. Any plumber will install the thermostat without any problems, and you can set it up according to the same instructions.

In the case of heated floors, special attention must be paid to the installation of the thermostat. The device is placed on the wall (or built into it, depending on the type) in any convenient place, but no higher than 30 cm from the floor. First, holes are made in the wall and floor to install the thermostat. Power is supplied to the place of its installation. And only then they install warm floor. The reliability of underfloor heating systems is 99% determined by quality installation work, so it’s better to entrust this work to specialists (including the installation of thermostats).

Setting up a thermostat for heated floors takes no more than 20 minutes. The set parameters are saved in the installation memory and maintained even after a power failure - this is ensured by the emergency battery power supply of the thermostat. In addition to the programmed settings, there are additional control buttons that allow you to change the temperature or mode for a certain period of time. When you click the "Restore Settings" button, all parameters return to the original time and temperature settings.

The idea of heating a home by heating floors was successfully implemented several thousand years ago. In the ancient empires of Europe and Asia, ceilings were equipped with branched channels through which heated flue gases from furnaces passed. The concept of heated floors turned out to be so successful that it is still used in an improved form today. Moreover, the popularity of heated floors is steadily growing, as such systems become more compact, cheaper, more efficient and safer. Now, of course, there is no need to build stone tunnels for chimneys under your feet - the heat is transferred using a heating electric cable or using more economical water heating floors. The features of this water heating option are worth considering in more detail.

What is a water heated floor: principle of operation

A hydronic floor heating system is a network of pipelines that are located inside the building structure of the floor. A coolant (water or non-freezing liquid) circulates through the pipes, with a temperature during the heating period of about 40 ºС. Warm pipes heat the massive floor screed, in which the concrete is concreted, and the finishing floor covering. The source of thermal energy can be a centralized network or local heating with any type of heat generating device. The heated mass of the floor, essentially being, together with the pipelines, one large heating device, transfers heat to the room through convection of air masses and thermal radiation. Water floor heating can be used as an addition to radiators or as the main and only one.

Advantages and disadvantages of fluid circuits in floors

Advantages of water heating in the floor

A person better perceives the heat that radiates from below. According to numerous studies, the most comfortable mode is considered to be when the temperature at the feet is 3-5 degrees higher than at head level. For example, 23 and 19 degrees, respectively. Without compromising comfort, heated floors help maintain temperature regime in rooms it is 2-3 degrees lower than with radiator heating, where the air near the ceiling is warmer than near the floor.

The diagram clearly shows the difference in temperature distribution along the height of the room with radiator (left) and underfloor (right) heating

With a properly designed and adjusted underfloor heating system, heating of all zones of the room is uniform, and there are no stagnant or overheated areas.
Unlike systems that use wall-mounted radiators or registers, the convective movement of air masses has a much lower speed, its direction is vertical - there is no feeling of a draft and less dust flies in the air.
The coolant temperature required for the operation of heated floors best corresponds to the optimal operating mode of highly efficient gas condensing boilers and allows for maximum fuel savings.
Water heated floors, albeit not by much (1-1.5%), are more economical than radiator heating due to the fact that the room temperature is lower. And provided that it works in a low-temperature system with condensing boiler savings reach 18%. It should be noted that the operation of an electric heated floor is not cheap, because the use of electricity is an expensive form of heating.
The floor heating is entirely hidden in the building structures, which makes it look more aesthetically pleasing and makes cleaning the house easier.
Being a low-temperature heating device, heated floors do not overheat dust, unlike traditional radiators. This has a beneficial effect on the respiratory system.
Moisture on the floor dries quickly, which is very convenient in the bathroom, hallway, bathhouse, and swimming pool.
Electric heated floors can be used in periodically and partially heated buildings, winter gardens, they are not afraid of sub-zero temperatures.

Disadvantages of water heated floors

The cost of installing heated floors is higher than installing radiators.
To prevent heat from escaping into the floor, it is necessary effective insulation from below, this slightly reduces the ceiling height.
The type of heating (water, electric) determines the design of the floor and limits the choice of types of floor coverings. Materials with high thermal conductivity are best suited: ceramic and stone tiles, porcelain stoneware. Wooden floors, carpet covering, linoleum on an insulated base reduce the heating efficiency. Laminate - acceptable, but not the best option.
Warm floors, to a greater extent than radiators, help reduce air humidity, so it is advisable to have a humidifier or house plants or an aquarium in the house.
Warm floors can cause damage wooden furniture with a closed base, massive musical instruments, you need to know the exact location before installation kitchen furniture(this does not apply to tables and chairs) and grandma’s old chest of drawers, determine the place where the piano will stand and do not lay pipes there.

Design features of water heated floors

A warm floor from water heating is not only a working pipeline. Here it is necessary to consider the whole pie as a whole, starting with the load-bearing base for the insulation and ending with the finishing coating.

Heating of the room is provided by a massive screed and floor covering; insulation prevents energy leakage.

Base type

The water heating line can be laid in two ways:

in a concrete screed,
in dry structures (prefabricated screeds, frame floors).

Concrete acts as the best heat-distributing element, and the monolithic screed works completely. Its optimal thickness is determined by the balance of strength characteristics and the fastest possible heating, the recommended value is 5 cm. If rigid insulation (foam glass) is used, there is no need for reinforcement, there is a possibility of subsidence (foam plastic, EPS) - it should be laid metal mesh. To improve the characteristics of concrete and facilitate the laying process, a plasticizer should be added to the cement-sand mixture. To avoid the formation of cracks as a result of thermal expansion, the screed is divided with continuous expansion joints into sections with an area of no more than 40 m2 and with the length of one side not exceeding 8 m.

In prefabricated dry screeds, the pipes are located in the grooves of molded polystyrene foam or in upper layers bulk materials. In frame floors, they are laid on lathing or profiled metal plates between the joists. Then they close GVL sheets, OSB and finishing coating. It must be said that heated floors in wooden structures less effective than concrete screed.

To evenly distribute heat in prefabricated wooden structures, metal plates with a recess for pipe laying are often used

Pipeline characteristics

Flexible metal-plastic pipes and cross-linked polyethylene pipes are best suited for laying heated floor contours. They are produced in coils, which makes it possible to lay long sections without joints. The material is thermally stable, easy to install, durable and even tolerates freezing with water.

In order not to exceed a reasonable value of hydraulic resistance, underfloor heating pipes are divided into separate sections (circuits) of the same length as possible, not exceeding 80 m. The distance between the pipes is determined by thermal engineering calculations, the minimum is 50 mm, the maximum is not limited. The optimal pitch is considered to be 100-250 mm. Installation is carried out with a distance of 100-300 mm. The configuration of heating pipes in the floor usually falls into one of four types:

Coil (snake, zigzag), in the figure below, type A. One side heats up more, it must be placed near the window.
Double coil, type B in the picture below. The floor is heated evenly.
Spiral (snail), type C. Two sides heat up more strongly; this layout is used in rooms with two external walls.
Double spiral, type D, uniform heating.

Note! The distance between the pipes is not always uniform; in areas vulnerable to cold it may be smaller - for example, near the external walls of a cottage

Depending on the type of structure, the pipeline is secured in several ways:

staples to the base,
screw clips,
splints for fixation,
free laying of profiled insulation boards in the grooves.

Manifold and control devices

Pipe switching is carried out through distribution manifolds. If you need to connect several rooms to heating, then the corresponding cabinet is located in the center of the house. It also contains:

regulators for setting flow - devices that allow you to balance all circuits with each other;
valves with a drive necessary to set the set temperature at the command of thermal sensors,
mixing units - a combination of a circulation pump and a valve that feeds the heated floor in a given volume hot water from the general system.

In the cabinet the circuits are connected to the main heating lines

Thermal insulation

Insulation materials necessary for the heat flow to be directed upward into the room. Suitable slabs made of foamed polymers and foam glass, in frame floors and mineral wool. IN concrete floors insulation, in addition to high thermal resistance, must have sufficient load-bearing capacity and absorb noise. As a rule, substrates with a density of 30-40 kg/m 3 are used, often with a rigid outer layer. If there is a heated room below, then the thickness of the insulating sheet can be at least 20 mm (preferably 50 mm), the cold floor or soil needs to be better insulated, for middle zone For Russia this is at least 100 mm, better - more.

Note! More practical (and expensive) are insulation boards with relief for laying pipes.

Separating layers

Damper tape made of foamed polyethylene is glued around the perimeter of the room and on any stationary structures. It allows the screed to expand freely when heated. The thickness of this tape should be more than 6 mm, the height should be no less than the height of the entire floor pie. The same tape fits into expansion joints.

In floors on the ground and on other potentially damp substrates arrange waterproofing.

How are the necessary system indicators calculated?

A water-heated floor, operating as the main heating, should fully compensate for heat loss in the room. To do this, you should evaluate the insulation characteristics of enclosing structures: walls, ceilings, windows and doors, determine the heat loss of the building by separate rooms. Are taken into account seasonal variations temperatures for a specific climate zone.

layout of pipes in rooms and zones (division into contours, diagram, step);
type of pipeline (material, diameter);
features of the collector and regulators;
floor design, including characteristics and insulation material, finishing floor covering).

Installation of underfloor heating pipes with water heating according to finished project A careful non-specialist with basic technical knowledge can also produce it, but in order to efficiently assemble a collector panel and make connections, you must have professional skills and have expensive specialized tools at your disposal. We also recommend not to engage in independent design similar systems, since the cost of an error will be too high.

Video: laying water heated floors with your own hands

Today, heated floor technology is not much inferior in efficiency to radiator heating systems, but has many advantages. We propose to consider the main advantages of hidden heating systems, installation and connection features.

Advantages of hidden heating

One aspect of the attractiveness of underfloor heating systems is the concealment engineering communications. Neither radiators, nor heating pipelines, nor shut-off and control valves will disturb the harmony of the interior. However, this is not the only advantage of the secrecy of the heating system.

If in living rooms pipes do not pass through the wall ceilings and along them, this will greatly facilitate the finishing work. For leveling and application decorative materials The entire plane of the walls is accessible; in addition, there are no difficulties with cutting the floor covering; there is no need to hide the passage of pipes during installation suspended ceilings. The absence of visible communications is especially beneficial when changing layouts.

In addition to aesthetic advantages, there are also technical ones: uniform heating of the floor creates an optimal distribution pattern warm air. Since the main emphasis is not on convection heat transfer, but on its direct radiation, there is no need to warm up the upper uninhabited zone. This ensures a reduction in heating costs of about 10-15%. What’s most interesting is that savings here do not come at the expense of comfort: the temperature in the leg area is about 20-22 ºС, in the head area it is 3-4 ºС lower.

The main disadvantages of water heated floors

The main disadvantage of a heated floor system is the complexity of its design. Laying process heating elements in the floor is quite technologically advanced and labor-intensive, but if we are talking about a water heating system, additional difficulties arise with organizing the piping and setting up the heating operation.

This is not at all a reason to refuse to use heated floors. If you use high-quality materials and installation systems, follow the technology of laying pipes in the floor and installing floor coverings, all your efforts will pay off handsomely. Underfloor heating is a truly effective, economical and durable heating system, but, we repeat, only if it is designed in compliance with a number of key requirements.

Among the difficulties of the device, it is worth mentioning separately the need to carefully select the material for the floor screed. In addition to strength qualities, it must meet standards for heat capacity and thermal conductivity, as well as the ability to emit heat in a certain spectrum - about 9-10 microns. In principle, when heated to 40 ºС, almost all cement-bound materials emit heat in this range. All that remains is to achieve the maximum possible coating density and uniform distribution of thermal energy in warm layer screeds. For this purpose, steel fiber can be used, liquid glass or special polymer additives for underfloor heating screed - plasticizers C-3, HLV-75, BV 3M and the like.

Materials for the device

As already mentioned, underfloor heating systems require extremely careful selection of materials. Just one and a half to two decades ago, everyone was content with laying a metal-plastic pipe in the floor, convincing themselves that, apart from corrosion, nothing threatened the heat exchanger in the floor. This approach has a number of disadvantages that become apparent during the first 3-5 years of operation.

In order not to repeat the mistakes of others, for heated floors you should use tubes that, if damaged, can restore the structure of the polymer over time and have the highest possible thermal conductivity. It is impossible to guarantee that when installing the tubes they will not be broken, but for metal-plastic this, without exaggeration, is a death sentence. Cross-linked polyethylene behaves best in this regard, the alternative to which is copper. In the latter case, there are a number of additional advantages: even higher thermal conductivity, a miniscule coefficient of thermal expansion and the ability to remember shape during deformation.

For open heating systems, the lack of excess pressure can lead to the ejection of gas molecules through the walls of the tubes; over time, gas particles can accumulate into fairly large plugs. To exclude such phenomena, modern pipes for heated floors they are made of composite materials with a built-in oxygen barrier.

When it comes to materials for installing heated floors, insulation cannot be ignored. Its choice is decisive for the durability of the heating system and the floor as a whole. The thermal barrier must be incompressible, retain its shape and, naturally, have high resistance to heat transfer. Of all the options, extruded polystyrene foam and polyurethane foam are most suitable for use as a thermal cutoff; polyisocyanurate boards are less commonly used.

Do you need a backup heating system?

You can often hear the opinion that water heated floor systems are unreliable, and therefore when using them as the main source of heating, there is an illusory risk that over time the house will be left without a single source of heat. This misconception is associated, first of all, with the experience of operating underfloor heating systems, which, in essence, are budget counterfeits of the original technology.

Judge for yourself: if low-quality pipes are used for the heat exchanger, the risk of their clogging, breakage and destruction of the screed due to thermal expansion increases significantly. Here it really makes sense to combine floor heating with the installation of radiators, although this version of the heating system is fraught with adjustment difficulties: you constantly have to adjust the flow, otherwise the temperature in the room increases to truly uncomfortable values.

However, if the warm floor is designed taking into account all technological requirements, it can work as the main heating system for many decades. Care and sensitivity during the installation of thermal insulation, pipes and when pouring screed eliminate the main risk factors for both the occurrence of leaks and damage to the floor covering or the base on which it is laid. In general, the costs of organizing a backup heating system and correct device water heated floors are approximately equal.

Preferred types of boilers

The main disadvantage of water floor heating systems is their extremely low resistance to overheating. This rule mainly applies to heat exchangers made of polyethylene - this material has one of the highest coefficients of linear thermal expansion. For copper pipes this figure is much lower.

Due to such restrictions, it is required right choice boiler unit and corresponding adjustment of its operating mode. Boilers running on natural gas and electricity are considered the most suitable. Their thermoregulation system eliminates the supply of too hot coolant to the underfloor heating system.

The least suitable for connecting a water floor heating system can be safely called solid fuel boilers. Their peak power is almost impossible to limit, especially when periodically changing the type of fuel. That is why such systems require the inclusion of special devices in the hydraulic circuit that maintain the water temperature in the heating circuit by mixing liquid from the return line.

Connection diagram

The final argument against underfloor heating systems is the complexity of organizing the coolant distribution scheme. If the system has more than one floor heating circuit, the installation of hydraulic manifolds with flow regulators is required.

House heating scheme with water warm floors. A - gas heating boiler; B - combined mixing unit and collector group; B - heated floor contour. 1 - boiler with built-in circulation pump; 2 - security group; 3 - expansion tank; 4 - three-way mixing valve; 5 - circulation pump; 6 - ball valve; 7 - needle valve or valve with a servo drive; 8 — pressure reducer; 9 - flow meter

On the one hand, installation and commissioning of such complex networks are comparable to additional costs. However, all the efforts to organize heating with underfloor heating are more than compensated by the comfort of its use: each room can easily adjust its own thermal regime, while the entire system can be easily and efficiently balanced even if there are several dozen “loops”.

Otherwise, the connection of the heated floor is carried out according to the classical organization scheme closed system heating with excess pressure. The only addition is the water preparation unit at the make-up inlet: since the heat exchanger consists of fairly narrow channels located at the lowest point of the system, it is necessary to remove from the water all mechanical impurities that can settle and eventually completely clog the tubes.