Why "warm floor"?
| Availability The water underfloor heating system has quite high level adaptability to already existing autonomous heating systems. On the basis of the radiator heating system available in your house, it is possible to organize a "warm floor" both in the entire building and in separate rooms, for example, in a bathroom or a children's room. When using underfloor heating systems, you get the most correct distribution of heat in the room. Heat spreads from the bottom up and the saying "keep your head cold and your feet warm" takes on a practical embodiment. hygiene Using heating appliances(radiators, convectors, etc.) you will inevitably encounter convection movement of air mass within the room. This effect is due to the suspended state of dust in the air of the room. In the case of underfloor heating, the room is heated evenly, and dust does not circulate with the air mass. This is especially true when it comes to children or people with allergies or asthma. economy When using an underfloor heating system, heat is distributed throughout the room in such a way that the space under the ceiling remains unheated, and, in addition, the floor ceases to be a heat-absorbing surface. As a result, the level of energy savings is 10-15% in standard rooms, and in the case of rooms with high ceilings reaches 50%. |
Durability
The service life of a water underfloor heating system is determined by the mode of operation and the type of materials used. Given the fact that floor heating is low-temperature and operates at a coolant pressure of 2 atmospheres, all elements of the system operate in a gentle mode, unlike radiator heating systems, where high temperatures lead to increased linear expansion of materials and, as a result, faster wear of system components. An underfloor heating system made using polymer pipes based on cross-linked polyethylene (PEX) and installed in compliance with all norms and requirements will serve you for a period no less than the period between overhauls buildings, i.e. at least 40-50 years old. In the case of using copper pipes, such a system is able to operate smoothly for up to 200 years. For comparison, the service life of an electric underfloor heating is 15-20 years, systems based on steel or aluminum radiators- 20-25 years old.
Self-regulation
One of the main features of a water heated floor is the effect of maintaining the selected temperature in the room without the need for additional regulation. The essence of this physical phenomenon lies in the fact that the surface that radiates heat gives off the more heat, the lower the air temperature in the room, and at the same time cannot heat environment stronger than the heat itself. Accordingly, depending on the setting of the "warm floor" will be supported and temperature regime in room. This effect does not exclude temperature fluctuations, but each time it is exposed to the outside (airing the room, changing outdoor temperature etc.) the room temperature will tend to the originally set one.
Simplicity
No matter how strange it may seem, the design process is the most difficult thing in installing a water-heated floor. With the direct installation of components, laying out the pipe and preparing the screed, highly qualified personnel are not required. If desired, the entire installation process can be carried out on your own. The following instructions will help you understand the intricacies of preparing, designing, installing and operating underfloor water heating systems.
Application restrictions
outdoor water heating applied in autonomous systems heating of private buildings, as well as multi-apartment buildings, if this system was originally included in the project. According to the law, it is forbidden to organize water floor heating in apartments with direct selection of the coolant from the networks central heating or hot water supply. This is due to the fact that the temperature regime and pressure in the central heating networks are designed for radiator heating and, when used in water-heated floor systems, will create a danger to residents, structures and engineering networks buildings. The device of a water heated floor in urban multi-apartment buildings from centralized heating networks should be organized using a heat exchanger, and must be agreed with the operating organization. Before deciding whether or not you will have underfloor heating, you also need to decide on the type of flooring. The most acceptable solutions are tiles and laminate. You can use linoleum, but in this case it is necessary to pay attention to its quality, since cheap varieties often contain low-quality components that, when heated, will release bad smell. A number of such traditional solutions like parquet or carpet is not suitable for laying over underfloor heating systems due to the high thermal insulation capacity, which leads to insufficient heat transfer and, as a result, makes the "warm floor" system ineffective.
Component Selection
A direct engineering solution for organizing a water-heated floor consists of two main parts:
distribution node- consists of a collector group, a pump for circulating the coolant and mixing unit, providing the necessary temperature regime of the coolant when connected to the radiator heating system. The device of small-sized systems is possible with the help of hand mixers, and when organizing underfloor heating as the main or only source of heat, it is advisable to use ready-made pumping and mixing units.
Floor heating circuit- consists of pipes through which the coolant is pumped and thermal energy is transferred to the floor material and flooring.
Best Choice by the combination of such qualities as price, specifications and service life are polymer pipes based on cross-linked polyethylene PEX or heat resistant PERT- their service life coincides with the period between planned overhauls of the building and is 40-50 years. At the same time, they are distinguished by low weight, high flexibility and strength, have a single coefficient of linear thermal expansion throughout the entire wall thickness and leave you “the right to make a mistake” - unlike metal or metal-plastic pipes, you can afford to lay the circuit incorrectly, dismantling will not change the characteristics pipes. The cost of a cross-linked polyethylene pipe is close to the cost of medium-quality metal-plastic pipes. In its turn metal-plastic pipes and fittings for their wiring are very common, and the service life copper pipe in heating systems can reach 200 years, which justifies a 4-fold superiority in price over polymer counterparts.
It is also necessary to pay attention to the materials that will be used for thermal insulation of the floor and the device. concrete screed. For insulation, it is recommended to use polystyrene boards and polyethylene foam. To prevent cracking of the screed, it is necessary to use plasticizing additives and reinforce the screed with iron reinforcement. It is also desirable to add polypropylene fiber when preparing the solution to additional protection at shrinkage.
Heating system design
Initially, you need to decide how your home will be heated. In the case of underfloor heating, two options are possible: an underfloor heating system and a combined system, which in turn can use underfloor heating as the main or auxiliary heat source.
The main difference between a radiator system and an underfloor heating system
In the case of radiators, high-temperature heating circuits are formed, where the temperature of the coolant fluctuates between 60-90 ° C. In the case of a warm floor - low-temperature circuits with a coolant temperature of 30-40 ° C. Accordingly, systems with different layouts will require different boiler settings. When selecting a distribution unit, it is necessary to proceed from the heated area. On average, for heating 1 square meter of area, the consumption is 5 running meters pipes. Taking into account hydraulic resistance in pipes, the optimal area heated by one circuit is 10-15 square meters. The number of collector group inputs corresponds to the number of circuits on the floor.
Underfloor heating system
In this case, it is taken into account that the only source of heating in the house will be a water-heated floor system. The very essence of the engineering solution will differ little from conventional radiator heating systems, while the main differences will be the reconfiguration of the heating boiler for low-temperature operation and the source of heat transfer - pipes in the floor screed instead of radiators.
At the design stage, it must be taken into account that each floor of the building requires a separate collector unit connected to the main riser. Setting the boiler according to the temperature of the coolant supply to the main riser when heating only by means of a water heated floor is 40-50 ° C, depending on the heat loss within the room.
Modern gas boilers completed circulation pumps, but, as a rule, of low power, which allows organizing sufficient pressure in the main riser, formed at relatively short intervals from pipes of large diameters. To take water from the main riser and overcome the hydraulic resistance of the "warm floor" circuits, it is advisable to use an additional circulation pump with increased productivity. This makes it possible to reduce the temperature difference between the flow and return lines, thereby increasing the efficiency of the system, since the temperature in different parts heated room will tend to the average value, which in turn eliminates the formation of "cold islands".
Combined heating system
A system designed with both high and low temperature heating circuits. This usually happens in cases where a "warm floor" is being introduced into an already finished project, providing for radiator heating or water heating by means of a boiler indirect type or require it design features buildings. In such a situation, it is necessary to ensure a series connection of high- and low temperature systems heating by installing a mixing unit. The purpose of this device, mixing in a certain proportion the heat carrier from the high-temperature part of the system (70 ° C) with the cooled heat carrier (30 ° C) from the return manifold of the floor heating system, is to prepare the required heating level (40 ° C) in the supply manifold of the floor heating system.
When designing combined system, in which floor heating is assigned the role of the main source of heat, it is advisable to use ready-made balanced pump-mixing units. In this case, a device is installed, complete with all necessary fittings, fully compatible with ready-made manifold groups and standard circulation pumps. In the case where underfloor heating is auxiliary and total area, heated by a "water-heated floor" does not exceed 60m2, it is possible to use a manual mixing unit. To do this, you will need a three-way mixing valve.
The principle of operation of this device is identical to a conventional sanitary faucet and allows you to adjust the temperature of the coolant entering the floor heating system. For this process, a heated coolant is used, coming from the boiler or radiator heating circuit and cooled down from the return collector of the "warm floor" system. But in case of serious temperature fluctuations in the main riser, for example, with a temporary increase in consumption hot water from the boiler, it may be necessary to change the settings of the three-way mixer, which creates some inconvenience.
However, if necessary, such a mixing unit can be switched to automatic control by installing a thermostat on the flow manifold to the underfloor heating circuits and an electric actuator on the three-way mixer.
Pipe layout project
After the heating engineering project has been prepared, it is necessary to form pipe layout schemes in the premises. To do this, you need to decide on the step and layout scheme.
To determine the layout step, it is necessary to take into account the zones of active heat loss, namely: external walls, windows and doors. It is advisable to shorten the step in the immediate vicinity of these zones. In order to get the most comfortable heating, it is worth designing the underfloor heating supply in such a way that the circuit pipe coming from the supply manifold with heated water passes along the zones of active heat loss in the first place.
For heating the central part of the room, a 20-30 cm pipe pitch is used, and in zones of active heat loss 10-15 cm. This is done in order to increase the heat transfer of the floor surface without changing temperatures and to eliminate duplicate heating sources. However, make sure that in all rooms you lay the same step multiplicity, for example, for central zones 25 cm, and for zones of active heat loss 10 cm, in this case, the calculation of the dependence of heat transfer on the coolant temperature for the entire floor surface of the building will be the same.
For direct pipe laying, there are 2 main schemes: "snake" and "spiral". Depending on the room, the priority of using one or another scheme changes. To determine the step, you will have to decide how much power is needed to heat a particular room. In the case when it is necessary to organize the heating of a small room, it is advisable to lay the pipe with a "snake". In principle, this styling option is the simplest and most versatile, but it has several disadvantages. Firstly, the difference in floor surface temperature in different corners of the room will be most noticeable, and secondly, if necessary, lay the pipe with a small step (<15 см) существует вероятность столкнуться с проблемой сгибания - труба может не выдержать перегрузки и сломаться.
In this case, it is necessary to provide for the use of wide fold loops. If it is necessary to heat living rooms of medium size (12-16 m2), it is better to use the “spiral” laying method.
In this case, the temperature at different ends of the room will tend to the average value, since next to the pipe with the cooled coolant there is always a pipe on the supply side with the heated coolant. In addition, all bend angles are directed at 90°, which greatly facilitates the installation of a rigid pipe, especially if it is necessary to make laying in small steps (<15 см) по периметру внешних стен и под окнами. Минусом такой укладки является ограничение по минимальной площади помещения - в комнате меньше 10 м2 лучше применить «змейку». В случае, когда необходимо обеспечить отопление большого помещения (>18-20 m2) and it becomes necessary to lay two or more circuits, it is still advisable to use several "spirals".
Installation begins with the alignment of the capital screed. If the height difference in one circuit exceeds half the pipe cross section (~6 mm), then the probability of air pockets in the pipes increases sharply, which in turn will prevent the normal movement of the coolant and reduce the efficiency of the system.
Next, it is necessary to provide hydro, steam and thermal insulation of the floors. This can be done using a combination of special waterproofing mastics, polyethylene film, polyethylene foam insulation and expanded polystyrene.
To begin with, with the help of mastic or plastic film, it is necessary to provide vapor and waterproofing. Foamed polyethylene has high insulating properties with a relatively small layer thickness (3-5 mm). However, you should not lay a concrete screed directly on top of it. It is very soft and easily pressed through, so when shrinking there is a risk of cracking the screed. Perform laying in small steps (<15 см) по периметру внешних стен и под окнами. Минусом такой укладки является ограничение по минимальной площади помещения - в комнате меньше 10 м 2 лучше применить «змейку».
In the case when it is necessary to provide heating for a large room (> 18-20 m 2), and it becomes necessary to lay two or more circuits, it is still advisable to use several "spirals", but use it as additional insulation. To ensure the necessary rigidity and proper shrinkage of the screed, as well as the minimum level of heat loss through the plane of the floor slabs, it is recommended to use expanded polystyrene with a thickness of at least 20 mm. When installing thermal insulation on slabs laid on top of the ground or above unheated rooms, it is necessary to increase the thickness of the insulating layer to 80 mm.
If you plan to arrange a water-heated floor in a wooden or other structure without reinforced concrete floors, the screed must be formed in a pre-prepared box of waterproof plywood, which will prevent the solution from spreading over the structure and under the floors. In this case, it is necessary to take into account the bearing capacity of the beams based on the mass of the screed formed for the installation of a water-heated floor. In order to reduce the mass of the structure as much as possible, it is advisable to reduce the thickness of the screed to the minimum possible, but not less than 20 mm above the pipe. The pipe pitch should be uniform and not exceed 15 cm for the most uniform heating. The design temperature of the coolant should not exceed 40 ° C. In this case, the introduction of lightening particles (chips, expanded clay) into the screed is allowed, but the dosage of such additives must be carefully calculated so as not to reduce the heat transfer properties of the formed surface. For additional protection of the structure from the flow of the solution, it is recommended to sheathe the box from the inside and outside with plastic wrap.
Layout of the heating circuit pipe.
After you have decided on the step and layout of the pipe in each room and prepared the surface for laying the pipes, it is recommended to transfer the sketch of the scheme to the top layer of thermal insulation, on top of which the direct pipe layout is planned. This can be done with a regular marker if the surface allows. In the future, such a drawing will greatly facilitate and speed up the installation process, as well as identify errors made at the design stage, if any.
There are several ways to fix the pipe above the surface of the thermal insulation in the desired position. The most common way is the layout using a reinforcing mesh. A reinforcing mesh is laid out on the surface of the thermal insulation in increments of 5-15 cm, the pipe is fastened every 50-80 cm and at the bend points with plastic clamps or thin wire. In this case, you will immediately get a double effect: you will fix the pipe and prepare a reinforcing layer for the screed, which will positively affect its durability during shrinkage and operation. In this option, it is recommended, after the final layout of the pipe, before pouring the solution, to “raise” the mesh with the pipe by 5-10 mm above the surface with the help of wooden or plastic elements.
The second, no less common option for fastening the pipe of the water floor heating circuit is special polystyrene plates. A feature of such plates are special regular elevations on the upper surface, arranged in a checkerboard pattern ("bosses"). Around the "bosses" and the pipe is laid out.
In this option, in addition to the pipe fixing element, a 20-mm heat-insulating layer is provided, but in the future it will be necessary to reinforce the screed in one form or another.
In addition to the traditional ready-made layout methods, you can also prepare the mounting base for the layout yourself. To do this, you will need long boards 15-25 mm thick and 50-80 mm wide. Using a jigsaw, you can form a frame for pipe layout with any pitch and type of layout. To do this, you will need to cut recesses in the boards along the outer diameter of the pipe with the required interval, then fix the boards in such a way that the contours of the future layout contour are formed, while the insulation should be laid out in such a way that the lower edge of the recesses is flush with the upper plane of the insulation layer . Next, a pipe is laid in the recesses in order to repeat the previously designed layout and layout step.
To decompose the pipe of the "snake" contour, it is necessary to form a rectangular frame.
Depending on the size of the room, 2-3 blanks will be required along the length corresponding to the length of the room, as well as 2-3 boards to fix the frame in width. In the case of laying the pipe in a “spiral”, it will be necessary to fix the boards diagonally or with two triangles. At the same time, it is rather difficult to calculate the places of recesses “on paper”. It is advisable to first assemble the frame and lay out the insulation, transfer the sketch of the design scheme to the surface and mark the places for cuts. After that, carefully remove the frame, cut out the notches and return the frame to its place. In this case, you can guarantee a complete match between the pattern and the frame. In addition, when laying out the pipe in a “spiral”, it will not be possible to achieve the correct geometry of the circuit. It is worth noting that this layout option is the least expensive in terms of acquiring materials, but in terms of additional work, it is certainly more lengthy and complicated.
System testing
After all the pipes of the underfloor heating circuits have been laid out and connected to the distribution nodes, the system must be checked for leaks. First of all, you should be interested in the tightness of the joints and pipe sections that will be in the screed. In addition, you need to make sure that all connections are made correctly and will withstand the planned pressure.
All these actions must be performed before the screed is poured. First you need to fill the system with water or a special solution - antifreeze. It is recommended to fill the contours one by one. To do this, leave one circuit open and start the water supply. As soon as the circuit is completely filled and the air is removed, turn off the taps and open the next circuit. In the same way, you need to fill in all the circuits connected to this distribution node. When the entire system on the floor is completely filled, open all circuits and raise the pressure to 4-5 bar, which will correspond to 1.5 times the maximum working pressure. The pressure will gradually drop, but if the system is tight, it will stabilize after a while, which will mean the functionality of the system. In order to additionally check the connections for tightness, it is necessary to once again bring the pressure to 4-5 bar and leave for 2 hours, then release the pressure and leave for 2 hours. The cycle is recommended to be repeated 3-4 times.
After the test is completed, it is advisable to set the operating pressure to 1.5-3 bar and leave the system for a day - the pressure should not fall anymore. In the event of a pressure drop, check all connections and circuits. As a rule, taking into account some degree of dustiness in the repaired premises, it is not difficult to detect fresh streaks. If antifreeze is poured into the system, then a specific smell will also let you know about a leak. After completing the filling and testing of the underfloor heating circuits, the flow circuits and the boiler can be filled and pressure tested. Open the distribution manifold and fill the main riser, supply lines and boiler. Carry out hydraulic tests in accordance with the regulations prescribed in the operating instructions for your boiler. After hydraulic testing, you can proceed to thermal testing of the system. Shut off all the contours of the "warm floor" at the distribution nodes. Set the operating pressure, turn on the circulation pumps to the design stage and bring the temperature in the main riser to the design one. Open the underfloor heating circuit farthest from the boiler and wait for it to warm up completely.
After the temperature difference between the supply and return manifold reaches 5-10 ° C, open the next circuit. Thus sequentially start the entire system. After the entire system has warmed up and reached its design capacity, increase the temperature in the circuits to the maximum temperature provided for in the project. If the underfloor heating system is the only heating source for the building, then check the boiler settings.
If the system is combined, then set the required values on the mixing units or thermostats. The maximum temperature of the heat carrier in the floor heating system must not exceed 55 ° C. The system must operate in peak mode for at least 6 hours. Record pressure and temperature at peak heat load at various points in the system. In the future, in case of activation of the emergency protection of the boiler or detection of incorrect operation of the system, you can use this data for diagnosing and troubleshooting. After thermal testing, recheck the system for air and leaks.
Screed device
After you make sure that the heating system is tight and working, you can proceed to the installation of a concrete screed. To do this, check the insulation again and prepare the solution. Don't forget to add plasticizer and fiberglass. To prevent the destruction of the screed due to linear thermal expansion, it is necessary to lay a damper tape around the perimeter of the room. Only the supply and return pipelines are allowed to pass through the damper tape - it is advisable to lay them in the corrugation for additional protection against accidental damage during operation. Start the system. Set an average design pressure of 1.5-2 bar. Do not heat up the coolant. The maximum temperature in the circuit for pouring the screed should not exceed 25 ° C until the final hardening of the concrete (17-28 days). After this period, the system can be run at design capacity. The thickness of the screed directly above the pipe should be 30-50 mm. The thinner the thickness of the screed, the faster it will warm up, while the effect of a “thermal zebra” may appear, when the place where the pipe with the coolant passes is clearly felt. Accordingly, the greater the pitch between the pipes, the proportionally greater thickness the screed should have for uniform heating of the floor surface. After pouring the screed, it is recommended to vibrate the surface to remove air bubbles and more tightly fit the concrete to the pipe. This will greatly increase the efficiency of your heating system. After the final curing of the screed, the floor covering can be laid.
When planning the arrangement of the heating system, the owners of private houses are increasingly deciding to install a heating water circuit. The option is economical and versatile - it can be used to heat the entire home or as a secondary heat source.
It is used as the main, backup or additional source of heating. It is easy to use, efficient, does not take up useful space in the interior.
To achieve maximum reliability and efficiency, it is necessary to correctly select pipes for a water-heated floor, comparing the characteristics of each option.
In our material, we will consider in detail the requirements for arranging a warm floor, and also talk about how to choose pipes and calculate their required number.
Heating floors are a type of heating system. Therefore, design, calculation and installation is carried out in accordance with standard regulatory documents. There is no single regulation for water floors - they are guided by the rules that apply to a specific technological process.
The heating circuit is operated in rather harsh conditions. The circulating coolant constantly presses on the pipes from the inside, and from the outside the coil is subjected to impressive loads: the weight of the screed, flooring, furniture and the residents themselves. Do not forget about the thermal effect.
Water heated floor is in great demand. It perfectly replaces alternative electrical equipment that consumes a lot of electricity and places a serious additional load on the wiring.
Not all materials are suitable for such specific service conditions.
Most water systems involve pouring cement or concrete mortar, which eliminates the possibility of revision of the heating branch and repairs. Any leakage is a reason for the complete dismantling of the floor and its replacement.
The basic requirements are set out in the documents: SNIP 2.03.13-88 "Floors", SP 41-109-2005 / SP 41-102-98 on the design of heating systems using polyethylene and metal-polymer pipes, respectively. According to the situation, it is allowed to follow the rules established by the manufacturer of pipe fittings
The quality of the laid pipes should not be in doubt, because the system is equipped with the expectation of long-term operation. Products that meet the set of basic requirements are suitable for use.
The material must respond painlessly to constant contact with the liquid heat carrier - the development of corrosive processes and the deposition of growths on the inner walls of the line are unacceptable.
The service life of the circuit depends on this nuance. High-quality materials easily tolerate high temperatures and have a smooth inner coating that does not accumulate lime deposits.
Underfloor heating works at a relatively low liquid temperature (up to 55 degrees). Despite this, it fully and evenly heats the area, saving about 30% of energy resources.
This requirement also includes the following features:
The separating layer prevents the flow of oxygen into the line, slowing down the diffusion destructive processes in the heating circuit.
The circuit must maintain integrity even with unexpected and jumps in the system.
High pressure acts on the pipes: the coolant presses on the inside, and the screed on the outside. In case of possible critical drops, they should be designed for 10 bar.
The "pie" of the warm floor, taking into account the concrete screed, exerts a significant load on the structural floors of the room. In order not to aggravate the situation, it is better to refuse heavy metal rolling.
In hidden heating circuits, it is forbidden to use pipe fittings made by welding, regardless of the type of seam - longitudinal or spiral
When the temperature rises, the materials tend to increase in volume, which is fraught with damage to the screed and decorative coating. Permissible value of thermal expansion of pipes is up to 0.25 mm/mK.
A high heat transfer capability is welcomed. The higher the coefficient of thermal conductivity, the higher the efficiency of the heating floor.
Ideally, the heating loop should be solid - without spliced sections. Welds on elbows and tees are potential hotspots for ruptures and leaks. This means that the pipe must have the appropriate length for laying an inextricable coil.
The photo shows an unsuccessful example of creating a water circuit from polypropylene pipes. Such a "virtuoso" performance is unacceptable when arranging a warm floor
The heating line must be smooth on the inside so as not to provoke pressure loss. In addition to maintaining hydraulic resistance, a smooth coating reduces the noise effect from the transportation of the coolant.
In addition to all of the above, you should not lose sight of a number of factors that allow you to check whether the device meets the standard technical requirements:
The most common diameters are 16, 18 and 20 mm. When choosing pipes for arranging a warm water floor, one point should be taken into account: a smaller diameter will increase fluid resistance and, accordingly, reduce heat transfer efficiency.
By increasing the indicator, you will have to increase the thickness of the screed. Such manipulation will increase the load on the ceiling and raise the level of the floor, which is not acceptable for every room.
Regardless of the layout of the coil, laying the water circuit implies the presence of bends. The pipe must be elastic, maintain strength along the entire length of the pipeline and maintain a given shape
The diameter of the product affects the maximum length of the contour.
When buying a pipe, the diameter is selected taking into account the maximum possible length of the system in a particular case. Approximate average values are as follows: 16 mm - 60-70 m; 20 mm - 80-90 m; 26 mm - 100-120 m
Referring to the listed requirements, we will conduct a comparative analysis of the most popular products for arranging a heating water circuit.
Manufacturers make pipes from many different materials. Among them there are budget and expensive models. All of them have their advantages, disadvantages and limitations. It depends on the material chosen how often it will be necessary to open the floor for repairs.
A warm floor is equipped with metal-plastic in every 2-3 cases. This is due to its affordable price and good technical characteristics. The composite material is made from a thin aluminum strip welded by ultrasonic butt or overlap.
Thanks to the combination of two materials, it was possible to achieve high technical characteristics. Composite pipes have a complex five-layer structure, where each element is responsible for a separate task.
The outer coating is a durable polymer material that protects the circuit from damage. Plastic reduces thermal conductivity, thereby reducing the intensity of condensation.
The aluminum shell located in the middle increases the rigidity of the product, compensates for the thermal expansion of the polymer, and prevents the penetration of air from the environment. The internal polyethylene layer provides smoothness and protection against corrosion.
Polyethylene layers are fixed inside and out with special adhesives. The adhesive composition is responsible for the reliable fixation of all layers, forming a single structure. The durability of the product largely depends on the quality of the adhesive.
To make sure that the pipe is properly made, it must be heated to 90 ° C and look at the cut. The delamination of the edge of the metal-plastic cut is a sign of poor-quality glue
Metal-plastic products are able to withstand up to 110 degrees when heated, without changing the original appearance.
Due to the bending radius of the pipes, it is possible to lay coils more often during installation, thereby achieving greater heat transfer from the system.
The maximum bending radius of metal-plastic products is equal to the outer diameter multiplied by 8. They are very light in weight, quickly and easily bent to the desired angle, suitable for any type of installation - double helix, volute, snake
The aluminum layer provides good thermal conductivity, the polymer part increases resistance to damage and overgrowing with deposits from substances contained in water, the influence of an aggressive environment. The walls of the material are qualitatively insulated, so the sound of the movement of the coolant does not reach the room.
Composite pipes are great for underfloor heating, as they meet a number of basic requirements.
Main advantages:
Among the shortcomings, the detrimental consequences of sudden temperature changes for the inner surface of the pipes should be noted. As for bending, then you need to be especially careful. With repeated bending and unacceptable twisting, there is a possibility of damage to the aluminum layers.
The table shows the general characteristics for various modifications of metal-plastic products. Composite pipes are suitable for the water circuit, where heat-resistant or cross-linked polyethylene is used as a polymer
A metal-plastic coil will perfectly cope with the assigned task. The main thing is not to try to save money on buying pipe fittings of dubious quality. It is better to play it safe and choose products from reliable manufacturers: Rehau, Henco, Valtec.
To organize underfloor heating, a water circuit is often made of polyethylene pipes.
Two categories of polymer products are used in the work:
Both options have good physical and chemical properties and are direct competitors of the metal-layer in terms of the price / quality ratio. Let us examine in detail the distinctive features of each material.
Pipes made of advanced high-pressure polyethylene have an increased density compared to conventional material. Thanks to the innovative technologies used in production, hydrocarbon molecules are interconnected in them, which gives PEX products unique properties.
The material is not afraid of temperature surges, is not damaged over time and is resistant to external influences. In many ways, its quality and durability is determined by the degree and method of stitching.
The optimal indicator for a warm floor is 65-80 percent of the crosslink density. The higher this value, the higher the price of the product. Insufficient degree is negatively reflected in performance.
The properties of a polymer are a consequence of its structural content. In ordinary polyethylene, the molecular filaments are in free "swimming". The absence of bonds explains the vulnerability of the material to thermal effects - it begins to melt.
In the cross-linked modification, the longitudinal links are supplemented with transverse bridges. The three-dimensional structure increases the molecular density, greatly improving the strength and stability of polyethylene
Cross-linking technology endowed the polymer with a number of distinctive characteristics:
In addition, the material has high boundary marks for melting (150 degrees) and combustion (400 degrees). Despite the recommended operating range of 0-95, XLPE pipes can maintain strength from -50 to +150 degrees. However, it should be borne in mind that with regular increased loads, the service life of products is reduced.
PEX-polyethylene has good flexibility - the smallest loop radius is 5 diameters. This is sufficient for any contour laying scheme.
XLPE pipes bend well in any direction. The curved material is able to restore its original shape after exposure to high temperatures, so it is recommended to carefully attach it to a substrate or specialized fittings
Suppliers produce pipes in voluminous coils containing up to 600 meters. This is very convenient for installation: they can be easily laid in a single circuit without using soldering.
Due to the special elasticity of the device, it should be fixed with additional fasteners that will help to avoid unwinding.
Cross-linked polyethylene easily restores shape. So that the coil does not unbend, it must be fixed with brackets or laid on a substrate with bosses
Weaknesses of PEX polymers: instability to UV rays and the destructive effect of oxygen that has penetrated into the structure of polyethylene. To solve the latter problem, some manufacturers produce multilayer pipes with an anti-diffusion barrier.
The method of creating a molecular network determines the density of side bonds, and hence the strength of the finished product.
Depending on the crosslinking technology, four groups of pipe fittings are distinguished, which are divided according to the method of connecting molecules:
The most reliable, but also the most expensive option is PEX-a marked models. PEX-b products will be a little simpler and more affordable. But let's look at all these 4 types separately.
PEX-a. The chemical method of bond formation is fixation due to organic peroxides. The reaction takes place at high temperature in molten polyethylene.
After choosing the optimal type of pipeline, do not rush to buy. The first step is to calculate how much material is required in order to equip a high-quality warm floor.
In the “spiral” type of laying, heat is distributed evenly over the entire surface due to the rational arrangement of the turns. There are practically no sharp kinks in the circuit, which removes the restriction on the use of pipes with a large bend radius
The laying scheme drawn on millimeter paper will help to make accurate calculations. A room plan is transferred to it on a scale, where the available household appliances and large-sized furniture are displayed. The heating circuit is drawn in a free space.
There are two main laying schemes:
If the room is too large, it is advisable to divide it into separate sectors. The boundary gap between adjacent lines for uniform heating is no more than 35 centimeters - the interval should decrease in places of large heat loss. You should also take into account the 15-20 cm indent from the walls.
If you are unsure of your capabilities, it is wiser to turn to professionals in order to draw up a competent engineering project, select and install equipment. Although this involves additional costs, it more than pays off after a short time.
When the drawing is ready, you can start the calculations. Everything is extremely simple: first, the total length of the contours is measured, then the resulting value is multiplied by the scale. It is better to add a few spare meters to the final figure.
In order not to make a mistake in choosing and understand which pipe for a thermal water floor is better, in addition to assessing the physical properties of materials, you should also pay attention to the name of the manufacturer.
Many companies offer a complete package for organizing underfloor heating, including a pumping and mixing unit, pipe fittings and auxiliary elements - a power supply, temperature sensors, a thermostat, etc.
It is better to dwell on brands that have already managed to positively establish themselves in the construction market. The purchase of proven products will guarantee the correct and efficient operation of the equipment.
Today, buyers distinguish the following pipe manufacturers:
The leaders in the production of polymer and composite pipes rightfully include: Henco Industries(Belgium), Oventrop(Germany), Kermi(Germany), Purmo(Finland), Termotech(Sweden), Neptune(Russia).
Among the manufacturers of rolled copper, it should be noted Hydrosta(South Korea) and KME(Germany), corrugated stainless pipes - Kofulso
The efficiency of the service of a water heated floor will depend on the quality of materials and components. The right choice will allow you to equip the most economical, comfortable and aesthetic heating system in the house.
We hope our material helped you decide on the choice of pipes for underfloor heating. If you have any questions, you can ask them in the box below.
A warm floor brings comfort and coziness to the house, allows you to forget about drafts and frequent colds. Such a closed hermetic system can be an additional or main type of space heating. But in order for the warm floor to last for a long time, it is necessary to take into account all the nuances during installation. An important factor is the choice of pipes.
Mounting types
Pipes are laid in three ways:
Since the installation of a warm floor is not the easiest process, heating pipes (in no case should pipes be used for hot or cold water supply) must be durable, that is, not to be destroyed by a pressure or temperature drop, arising chemical or bacteriological loads. Subject to all operating and installation standards, the service life of polymer and metal-polymer pipes is more than fifty years.
In addition, pipes must have a reliable insulation and tightness that protects the entire heating system from oxidation.
Underfloor heating pipes must be elastic(bend by hand) resistant to bending(a prerequisite for high-quality installation and calculation of the distance between pipes), do not break or crack.
Such requirements are met by metal-plastic (metal-polymer) pipes, copper pipes, pipes made of polyethylene, polybutane, and also steel.
It is forbidden to use cast iron pipes in accordance with the regulations.
Metal-polymer pipes are made from polyethylene and aluminum. They are able to withstand heat up to one hundred and ten degrees without destruction (optimal water heating for an underfloor heating system is not higher than 55 ° C), bend to the required angle (the maximum bending radius is equal to the outer diameter of the pipe multiplied by 8) and are very reliable. In addition, metal-polymer pipes are environmentally friendly, resistant to corrosion and chemically active environments, have low weight and high sound insulation properties of the coolant (the sound of the coolant movement is absolutely imperceptible).
There are some disadvantages: a change in the temperature of the coolant adversely affects the walls of the pipes; repeated bending of the pipe may damage the aluminum layer; Twisting of pipes or bending about their axis is unacceptable.
Metal-plastic pipes are made from a thin aluminum tape (thickness 200-400 microns), which is “overlapped” or “butt-jointed” using ultrasound. After that, a layer of polyethylene is fixed to the outer and inner parts of the pipe with a special glue.
The most commonly used products with a diameter of 16 and 20 mm. The wall thickness is 2 and 2.25 mm, respectively. In this case, the weight of 1 linear meter is 115 and 170 grams.
Marking: on the pipes indicate the manufacturer's company, certificate, production date, wall diameter and thickness (in millimeters, less often in inches), nominal pressure, batch serial number, PE brand (PP-R - polypropylene, PE-R - PE, PE-X - cross-linked PE).
Installation of polypropylene pipes is carried out only at an air temperature of at least +10 degrees. Their main advantage, along with low cost, is that after thermal welding, the pipes become monolithic. Such pipes are very durable, their service life is at least 25 years. The maximum water temperature is 95 degrees. However, such pipes are rarely used for underfloor heating due to their small bending radius (which, accordingly, reduces the level of space heating). During installation, special trimmers or welding nozzles are required.
For heating, pipes marked PN25 (reinforced with perforated aluminum foil) are used. They are produced with outer wall diameter from 21.2 to 77.9 mm and wall thickness from 4 to 13.3 mm.
These pipes are preferable to the previous ones, but polyethylene is easily damaged during installation. The smallest bend radius is 5 outer pipe diameters (for polypropylene pipes - 8). PE pipes for mounting the underfloor heating system can withstand a water temperature of 120 ° C as much as possible. For the installation of PE pipes, a large number of fasteners are required, since the pipes do not hold their shape after bending.
Marking: HDPE - pipes with the highest density, MDPE - with medium density, LDPE - with low density.
Are cross-linked polyethylene (PE-X) pipes more durable and resistant to deformation? temperature and pressure changes, such pipes are more flexible, light, environmentally friendly. They are produced with an outer diameter of 10 to 110 mm, wound in coils of 200 meters, which reduces the number of seams and simplifies installation. During installation, fittings for metal-plastic and axial technique are used.
Polyethylene is crosslinked by means of peroxide, silane gas or electrons in an electromagnetic field. The processing method affects the strength of the product. The highest quality pipes are cross-linked with peroxide (PE-Xa marking).
Quite expensive pipes, but the most durable and meeting all installation requirements.
Such pipes are characterized by the smallest bending radius without the occurrence of defects, which makes them leaders in the installation of underfloor heating. The minimum service life is 50 years. They can withstand an increase in the temperature of the water in the system up to three hundred degrees, and pressure up to 400 atm. Copper and stainless pipes are not afraid of liming, corrosion, rodents will not spoil them, the pipes are impervious to gases, and have a high heat transfer.
However, it should be remembered that it is impossible to connect copper pipes with any fittings other than brass.
Thus, summing up, it should be noted that the best pipes for underfloor heating are copper. But the cost of the pipes themselves and the work on their installation, as well as the laboriousness of the process, deters most consumers who do not have enough budget for this.
Metal-plastic pipes are more common due to their low cost and ease of installation (connection with fittings without welding). Abroad, for a warm floor system, plastic pipes that do not have an aluminum layer are more often used. They are quite cheap, but inferior in quality to metal-plastic and copper pipes. By the way, we wrote about it on our website.
