Contents
- №1.Requirements for pipes
- №2.Metal pipes for floor heating
- № 3.
- No. 4 cross-linked polyethylene pipes. Copper pipes for heated floors
- №5.Corrugated stainless pipes
- №6.Polypropylene pipes
- №7.How many pipes are needed?
Water floor heating - the solution to the problem of arranging the most comfortable home. It allows you to efficiently distribute heat in the house, and, unlike the electrical counterpart, requires low operating costs. It is no wonder that systems of water heat-insulated floors use the increasing popularity and quite often become an independent source of heat in the house. The quality of such a system and its durability are equally dependent on the chosen materials and professional installation. Let's take a closer look at the features of the choice of pipes for a warm water floor, and it is better to entrust their installation for your peace of mind to specialists. The link provides comprehensive information and examples of the work of a leading company engaged in the installation of underfloor heating in Moscow and the region. It remains only to get the right pipes.
№1.Requirements for pipes
The advantages of the water system of underfloor heating are more than enough. These are cost-effectiveness, uniform heating, and durability, and the ability to regulate temperature, and the absence of heating radiators, which often only make it difficult to organize the interior of a dream. The easiest way is to organize heating with a water heated floor in a private house - in a high-rise building, the task is much more complicated. It will be necessary to reconstruct the existing heating system or install its own electric boiler in order not to disturb the heating system of the whole house and not to take heat from its neighbors. 
Reliability and durability of a heated floor depend in many respects precisely on pipes, which will have to be under a screed for decades, maintaining integrity and tightness. These include the requirements :
- durability and ability to withstand pressure drops and temperatures .Pipes designed for hot water are not suitable. Pay attention to the products of well-known and reputable manufacturers who give a guarantee on pipes of 50 years or more ;
- reliable insulation and tightness , because the heating system must be protected from oxidation;
- Elasticity and Flexural Strength .During the installation process, the pipes are bent to achieve uniform heating of the floor; therefore, during their installation and further operation, they should not break and crack, thereby violating the tightness of the system;
- The optimal is the diameter of pipes - 16 or 18 mm, while the floor height increases slightly, and the need for additional equipment that ensures normal hydraulics of the system is eliminated;
- coefficient of expansion should be 0.25 mm / mK, thermal conductivity - 0.43 W / mK.
Metal-plastic and polyethylene pipes are used in floor heating systems, less commonly copper, polypropylene and corrugated steel pipes. Norms prohibited the use of cast iron pipes. 
№2.Metal pipes for floor heating
Metal pipes are almost the most widespread. Durability and excellent performance are explained by the multi-layer structure of the material. The inner layer is an extruded polyethylene material that is responsible for the performance of the pipe. Next comes a layer of aluminum, which is attached to the polyethylene with a special adhesive. Aluminum foil protects oxygen from penetrating the tube and inhibits linear expansion and contraction. The thickness of this layer is 0.2-0.25 mm, depending on the diameter. Foil butt-weld or overlap is welded, an airtight layer is obtained. On top of the foil is another adhesive layer that holds it to the outer protective layer of polyethylene. 
This structure allows us to talk about the numerous advantages of metal-plastic pipes :
- excellent flexibility and ability to keep shape well after bending;
- thermal conductivity, which is provided by a layer of aluminum, and resistance to damage and overgrowth through the use of polymer;
- the installation of such pipes does not require the use of specific equipment, so it will be inexpensive;
- high durability;
- ability to withstand temperatures up to 1100C without changing the basic performance characteristics;
- resistance to corrosion and corrosive environments;
- light weight;
- good sound insulation. The sound of the coolant movement in the system will be inaudible.
Among the deficiencies of the , the twisting of pipes and bending about the axis are unacceptable, which must be remembered during installation. It is also important to take into account the property of the aluminum layer to be damaged during repeated bending. 
№3.
cross-linked polyethylene pipes The main competitor of metal-plastic pipes is cross-linked polyethylene pipes. The main indicator of product quality is the quality of the weld, which can be judged by the crosslinking density . The recommended value is 60-85%, processing can occur in different ways:
- achieves a density of 75% when crosslinked with peroxide, this is the most preferred method. Such pipes are marked as PE-Xa;
- with crosslinking with silane, 65% density is obtained;
- when irradiated with a stream of electrons in a magnetic field, the crosslinking density reaches 60%.
The can be specified in the abbreviation as the linking density range of the : HDPE is the pipe with the highest density, MDPE - with medium density, LDPE - low. 
The advantages of :
- the ability to withstand the temperature of the coolant to 1200C;
- resistance to temperature and pressure drops;
- low weight, sufficient internal section with a relatively small diameter;
- strength;
- sufficient flexibility. The minimum bending radius for such pipes is 5 diameters, and this is quite enough for the installation of an effective floor heating system;
- relative ease of installation;
- low price.
Disadvantages :
- the need to rigidly fix the pipe when laying, otherwise it may straighten. For fixing use reinforcement or a special substrate, you need a large number of fasteners to fix the pipe in the desired shape;
- when installing is easy to damage the pipe, so you need to work with some caution.
Pipes of cross-linked polyethylene are produced with a diameter of 10 to 110 mm, length reaches 200 m. 
No. 4.Copper pipes for underfloor heating
In terms of performance, copper is an ideal material for arranging underfloor heating. No wonder that in a number of European countries today it is mainly this material that is used.
Pros :
- high strength without comparing with polymer analogues. The strength of copper pipes can even be called excessive in the context of warm floors;
- durability. The minimum lifetime is 50 years;
- excellent heat transfer performance, because it is metal;
- is the minimum bending radius among all pipes, therefore the heating is uniform;
- ability to withstand temperatures up to 3000 ° C and system pressure up to 400 atm;
- full impermeability of pipes for gases, resistance to corrosion, liming and rodents.
The widespread use of copper pipes in domestic spaces is constrained by some of their minuses :
- high price;
- need to use special equipment during installation, with which you need to be able to handle. The connection is made only with brass fittings, which also raises the cost of installation.
№5.
Corrugated Stainless Pipe Stainless steel pipes are used even less often than copper, even despite the significant advantages of .Such products have a high service life, have high thermal conductivity, bend well, are durable and are not susceptible to corrosion, but can not boast of low cost. The biggest lack of is the limited service life of the sealing rubber( only 30 years old), which negates the durability of the pipes. 
№6.Polypropylene pipes
Polypropylene pipes will cost several times cheaper than copper, steel and even metal-plastic, but still not widespread. For the system of heated floors use products with marking PN25, which are reinforced with perforated aluminum foil. Outer diameter from 21 to 78 mm, wall thickness 4-13 mm.
Benefits of the :
- low price;
- the ability to withstand the temperature of the coolant to 950C at optimal 550C in the system of water heated floor;
- high strength, service life of at least 25 years.
Disadvantages :
- small bending radius, which is why it is often impossible to equip the heating system with the necessary efficiency. The minimum bending radius of a polypropylene pipe is 8 diameters, which means that pipes with a diameter of, for example, 23 mm can be positioned at a distance of 368 mm from each other, which may not be sufficient for uniform heating. If the heated floor will be used as an additional source of heat, the use of polypropylene pipes is justified;
- polypropylene pipe installation conditions. Installation is carried out at temperatures above + 10. .. + 150C, which is not always possible.
№7.How many pipes are needed?
In order to more or less accurately calculate the required number of pipes, you can use software tools or arm yourself with graph paper on which the floor plan is drawn on a scale. All large pieces of furniture that will stand motionless must be indicated on the diagram - there is no need to lay pipes under them: it is unprofitable and harmful for the furniture itself.
A pipe layout is put on the plan. Laying is usually carried out in one of the following ways:
- "snake". This is a simpler version of the installation, but has a significant drawback - uneven heating of the room, which is well understood from the figure. In the first case, one part of the room will warm up significantly less, because the coolant enters it already cooled, in the second - the distance between the sections with still not cooled water is too large, therefore the floor will warm unevenly, which will be felt when moving;
- “spiral” is more complicated, requires a more professional approach to the calculation and installation, but the heat across the floor will be evenly distributed as the zones with warm and cold water alternate. In addition, the rotation angles are smaller here, which affects the speed of movement of the coolant in the pipes;
- combined system.
When creating a plan, keep in mind that the pipes are laid at a distance of 15-20 cm from the walls, the step between them should be 20 cm, or at most, not more than 35 cm. If the floor heating is the only source of heat energy, then the step should be minimal, herewhy in houses where the warm floor plays only an auxiliary role, it is allowed to use polypropylene pipes with a large bend radius.
A pipe with a diameter of 16 mm is able to heat 10-15 cm of the surface to either side. For exterior walls, it is advisable to take a smaller step to provide a reliable barrier to cold. The approximate number of pipes can be calculated using the created scheme, but it is better to take the material with a margin or to ask the experts who will carry out the installation.
The recommended length of one coolant circuit is no more than 60 m, otherwise the water will cool too much and you will not build an effective heating system. If this is not enough for heating one room, then it is better to equip several heating circuits. The data are given so that you can calculate the approximate amount of necessary materials and the cost of them - the design of the system of heated floors, as well as their installation, it is better to entrust professionals.
pipes
