Pipes for a warm water floor

The number of supporters of heating the house on the principle of "warm floor" is constantly increasing - it has proved its high efficiency and convenience. Indeed, a properly planned, well-assembled and well-functioning water heating system differs with the high efficiency of the , and therefore - with efficiency, the is the most optimal microclimate it creates - with the rising warm air and comfortable air temperature distribution in height. If we add to this the and the fact that with such heating the floor surface acts as a heat exchanger, but there is simply no bad fit in the interior of the radiators, then the growing popularity of this type of space heating gets a full logical explanation.

Accordingly, the number of house owners that seriously is also reflecting on the complete transition to water heated floors. However, it should be noted that this is quite a complex and very ambitious event. In addition to the difficulties in carrying out construction work, it is necessary to correctly calculate and select heating equipment, distribution fittings, special instruments and devices for monitoring, control and

providing security. And, finally , very important point are themselves, actually, the pipes for warm water floor. To these components of a similar heating system , should be given special attention, due to the fact that the main load - both thermal and mechanical - falls on them.

What should be the pipes for warm water floor?

Anyone who believes that for a warm floor, any pipes can be purchased, based on economics considerations, it will probably be very disappointing. The system of floor water heating is just the case when for its installation requires strictly certain materials, and the use of more cheap "analogs" is either not welcomed or strictly prohibited.

First of all, it is necessary to thoroughly understand the specific requirements that are imposed on the pipes in the systems of warm floors. They are predetermined by the very special conditions of their exploitation.

• Most of the existing schemes for the water " warm floor" involves the pouring of mounted pipe circuits with a monolithic concrete screed. This means that there will not be any possibility of periodic revision or preventive works in principle. It is clear that the coupler is always filled with calculation for many years forward - and the pipes should not lose their functionality and reliability during the entire supposed long life. In short, the durability of the pipe should be commensurate with the durability of the building structures!

This concerns many operational parameters, but first of all - protection against corrosion processes, from internal ingrown of its cavity, from the stability of the material of manufacture - it should not be decomposed under the influence of time, high temperatures and chemical composition of the coolant. Modern pipe samples are equipped with a special " antioxidant barrier", since diffusion processes with the penetration of the walls of this active gas through the material thickness lead to a rapid aging of the heating circuits.

• Existing norms and rules completely exclude the use of welded technology( no matter whether with longitudinal or spiral seams) as closed contours of the warm floor. Thus, all steel, galvanized and even stainless pipes that are widely used in the water supply or in conventional heating systems are immediately cut off. The maximum that they can come in handy is the transportation of the coolant from the boiler to the distribution cabinets( collectors).

Well, on the other hand, such HCV pipes - it will be very expensive, and, in addition, will create absolutely unnecessary load on the overlap - in fact the metal weighs a lot.

• It should be remembered that any pipe joint that will be filled with screed, practically always becomes a vulnerable place( with rare exception).Any accident on the pipeline is unpleasant in itself, but on an open site this is not difficult to eliminate. But even a small leak, which will arise in the circuit " warm floor", can cause literally catastrophic consequences. To note its at once is very difficult, and there is a high probability to pour the lower floors, to spoil the floors or even to disable the electric house at home.

In addition, any connection on a long section is an potential for the formation of a clog or overgrowth. Eliminate such a problem in the circuit " warm floor" will be extremely difficult!

So, in an ideal, the contour should not have of interlaced plots - it should be performed from a single piece of pipe. And it says, among other things, that the material should be flexible, resistant to breaks and, in addition, it is good to keep the curvilinear form given to it.

The fact that on the Internet there are photos of hot heated floors using welding or soldering, using bends or tees - this is by no means an example for imitation. On a large account, there are a lot of things posted on the network, which is not necessarily equal. ..

• It will be immediately appropriate to note that the purchased pipes, based on , should be of sufficient length. In principle, the form of production of most pipes used for the purposes of such heating, allows you to execute the contours in one piece. Usually for a pipe with a diameter of 16 m m m axial the length of the of one circuit is selected 50 ÷ 80 meters. The increase in diameter allows to extend the contour - so, when using pipes Ø 25 m m m the maximum length can reach even 100 ÷ 110 m .But it is impossible to get involved in any case - increasing the hydraulic resistance in case of excessive extension of the will cause the to not have enough power for the pumping equipment to make the coolant move through the pipes. This effect is called a "locked loop" and in order to avoid this, if necessary to heat a large area, two( or more) contours are laid.
• You can immediately mention and about the external diameter trd ub. Usually, three varieties are used - 16, 20 and, quite rarely, 25 mm.

It is important to remember that the excessive narrowing is a lower heat transfer and unnecessary load on the equipment. Too big diameter all When the draws a significant increase in the height of the floor and the weighting of the screed.

• The pipe must have high strength. Its walls must successfully withstand external loads, because heavy concrete screed will have a serious effect, and directed from the inside - the peak jumps of the coolant pressure in some heating systems can reach even 7 ÷ 10 bar.
• The pipe should be calculated by the on the operation in a high temperature environment. Although uses extremely high heating in systems of warm floors, does not use ultra-high heating, however, the pipe must be able to withstand temperatures up to 90 ÷ 95 ° C in order to ensure the safety of the contour in case of unforeseen circumstances.
• The pipes used for the contours of the warm floor must have a quality, practically perfectly smooth inner wall surface. This will ensure an acceptable value of the hydraulic resistance and to the maximum will reduce the possible noise flowing through the pipes of the liquid - such sounds are not all pleases.

Now that the basic requirements for pipes for " warm floor" are clear, you can see what materials these conditions meet.

What is better to use for " warm floor "

Polypropylene

Partly , on this subject already the conversation was going above. In addition to the cheapness of the material, nothing else positive, this option is not different. These pipes are produced straight and short( by the standards of the warm floor), it is simply impossible to bend them with a small radius. Installation with welding is a very troublesome and unreliable business. Yes, by the way, and such pipes do not differ with a good level of heat transfer - even if it is possible to assemble such a floor heating system, then it will not be possible to call its effective .

In a word, this approach does not even deserve serious consideration.

Metal pipes

With metal , and is more precise than , it has already been mentioned about hot water pipes - they are simply unacceptable. However, the metal-to-metal is different, and there are ts , which are ideally suited for heating on the principle of " warm floor".

Copper pipe

This material - a full "bouquet" of all kinds of positive qualities. Copper pipes are excellent and transmit heat. This material has excellent plasticity along with high mechanical strength. Copper-metal is very durable, thanks to its chemical features, the is excellent in resisting corrosion. Moreover, in modern pipes copper wall is still and is closed with an additional high-strength polymer film - the operating time of such products is calculated for many decades.

The disadvantage is a rather complicated installation that requires special tools from and stable skills of working with it. This greatly limits the possibility of independent creation of such a heating system. But, probably , not even this main - the cost of such pipelines, especially in comparison with polymer, is extremely large, and is, alas, very few available.

Corrugated steel pipe

And this is probably the only one of pipe types that is not forbidden to splice along the length of the heating circuit - so reliable are considered their fitting connections.

Such stainless steel pipes are made, they easily bend and well retain the position given to them. Problems of corrosion resistance, high heat transfer of mechanical strength here do not even rise - such pipes meet these requirements in full. gives a special coating of high-quality high-density polyethylene.

Such pipelines, by the way, are actively used on technological lines in the chemical industry of many developed countries - and this speaks volumes. And yet they are not widely used in residential private construction. The main reasons are high prices and, possible, even lack of information from owners of homes about such materials.

The shape of the corrugated stainless pipes is ready-made lengths of various lengths of or as long as up to 30 or 50 meters.

Pipes on a polyethylene basis

Here it is necessary to make at once one important remark. If you read the variety of articles on water pipes used for heating circuits, you can see one common error. The authors divide the variety of flexible pipes into metal-plastic pipes and made of cross-linked polyethylene. The reader is often confused by this statement that some plastic polyethylene is used in metal plastic products, and in addition there is still and cross-linked. Nothing like this! All kinds of polyethylene used in modern production technologies have some degree of cross-linking. And the pipes will be distinguished better by other criteria - by the technology of polymer processing and by the structure of the pipe itself.

What is crosslinked PE polyethylene?

If you do not understand this immediately, you can just get confused in the future.

All known and so popular in the production of many household items polyethylene, with all its advantages, still does not differ stability. He has a pronounced linear molecular structure, these "chains" are not connected in any way, and even with a slight temperature effect, ordinary polyethylene begins to simply "swim".Use it in products that are subject to thermal loads, does not .

Otherwise, if the above molecular chains "sew" - , that is, create stable numerous cross-links, translate the linear structure into a three-dimensional one. The polymer does not lose its positive characteristics at this, and, in addition, it acquires stability. The more similar intermolecular "bridges", the higher the so-called degree of cross-linking( measured in percent), and the more qualitative and stronger the resulting material.

Moreover, cross-linked polyethylene has a very peculiar property of "memory".The products made of it, in the of a particular , deforming from mechanical, pressure or thermal loads, always tend to return to the original form once given to them after the exterminates completely or weakens. This is an extremely important feature of the for pipe production.

Crosslinked polyethylene has the accepted designation PEH.The cross-linking, that is, the creation of transverse intermolecular bonds, is technologically carried out in different ways.

• REX - with this technology, the formation of new bonds is caused by the chemical treatment of the raw material with peroxide. From all the existing methods, it is that gives the maximum degree of crosslinking( about 85%), polyethylene does not lose its elasticity at all, it turns out to be high-strength and with a pronounced "memory".The lack of technology is quite high its complexity and high cost. However, the process is completely controlled, which makes it possible to obtain a material with strictly specified qualities.
• REX-b -, this technology appeared later and was initially considered as a simpler and cheap alternative to REX.It would seem that a win-win and cheap, with the use of water vapors, such a technique of cross-linking still did not justify the hopes fully placed on by her .The material is not so elastic, that is, there will certainly be restrictions on the radius of its bending. And the degree of cross-linking is only about 65%.In the during the manufacturing process, the process is extremely difficult, so often such pipes do not fully comply with the declared characteristics. In a number of European countries, pipes REX-b are not allowed for use in heat distribution networks. There is still one interesting feature - sluggish process with with shiva in polymer REX-b never stops. That is, over time, the material significantly changes its characteristics, the becomes tougher , shrinks, so often the pipes from the REX-b require regular tightening of the joints, and the metal-plastic pipes can be laminated.
• REX with - in the this case of the process with with shiva is caused by directional emission of electrons. The production of pipes from such plastic is characterized by a low cost, but the material, I must say, is much inferior in terms of the qualitative characteristics of the same REX. Nevertheless, , such a polymer is still used, for example, in the manufacture of inexpensive metal-plastic pipes.
• REX-d - is a technology that has almost completely disappeared from production use, in which intermolecular bonds were obtained for the account for processing of raw materials by special nitrogen compounds.

PEX pipes made of cross-linked PEH

Special cross-linked, cross-linked polyethylene is very widely used for the production of various types of pipes, some of which are quite suitable for creating a water heating system for floors, and some are even specifically designed for this purpose.

• Already for a long time REX-AL-REX metal pipes have been actively used for circuits of warm floors by masters. It would seem that such material is suitable for such purposes, like no other. It combines the advantages of both polymer and metal, easily bends into the desired curvilinear shape( with the observance of certain technologies) and retains the configuration given to it, perfectly conducts heat.

Here needs to pay special attention to the specific type of polymer used to produce the of this pipe. As already mentioned, the optimal solution for is from REX, although they are, of course, much more expensive.

With plastic pipes there is yet one important nuance - too much in the market of building materials of counterfeit, obvious and substandard counterfeits, absolutely unknown manufacturers who do not accompany their production with any documents and warranty obligations. Therefore , with at finding of a metal plate should never be shy - it is necessary to show perseverance and demand to show on production certificates of quality and conformity to the available standards.

But even for quality pipes REX-AL-REX all has significant disadvantages. Thus, the heterogeneity of the wall material, and means and the coefficient of linear expansion of layers of , eventually leads to their delamination. The question is only in time - but this process is inevitable. The internal layer of PEH - is forcedly narrowed( to about 0.8 mm), and does not always cope with peak loads( any experienced plumber can tell about the rupture of metal-plastic pipes).In this case, a thin layer of foil( from 0.2 to 0.4 mm), even with the ideal of its welding, can not become a barrier to critical pressure.

Therefore, such pipes are not particularly recommended for use in the screed " warm floor".Probably safer for these purposes and is more reliable will use single-layer, pure polymer pipes made of cross-linked polyethylene.

For their manufacture, PEH-a or REX-b are used. The wall of the pipe can have a completely monolithic structure , or be provided with a special layer of EVON¸ which serves as an oxygen barrier.

These pipes are very convenient in the layout for the installation of circuits warm floor ».They have good plasticity, which makes it possible to produce a stack with a minimum step between adjacent loops.

All leading manufacturers necessarily equip their products with reliable connecting fittings, which turns the installation into a fairly simple and understandable occupation.

fittings. When choosing any polymer pipes, you need at least a little understanding of the system of their classification and marking. It may differ slightly depending on the manufacturer, but still the basic principles of are retained. You can consider a specific example.

1- the first place is usually indicated by a specific pipe model, its is a trademark.

2 - the outer diameter of the tri is decreasing and the total thickness of the is its wall.

3 - special European standards, which speak of the possibility of using pipes. In the case under consideration, an indication that the pipe is suitable even for drinking water.

4 - is the technology used by to control the quality of finished products.

5 - polyethylene crosslinking technology( in accordance with the classification according to Engel , which was discussed above).

6 - compliance of the pipe parameters with operating temperature and pressure to European standards DIN 16892/16893.Specific values ​​of operating parameters and service life can be specified in the accompanying documentation as a plate:

Operating temperature, ° C	Lifetime, years	Permissible operating pressure, bar
20	50	20
70	50	11,2
90	5	8,6

It happens sothat these values ​​are applied directly to the body of the pipe - for example "DIN 16892 PB 12 / 60 ° C PB 11 / 70 ° C PB 9 / 90 ° C "

7 -information on the date and time of release, line or machine numberand , the .

In addition, usually followed by a mark of the length of the pipe - through each meter. This simplifies both the implementation of the pipes, and working with them directly during the stacking.

Video: useful information about pipes made of cross-linked polyethylene

Polyethylene pipes RE- RT

Technological breakthrough is probably the appearance in the production of pipes of a completely new type of polyethylene - PE-RT ( abbreviated from Polyethylene оf Rаised Tempеrature resistаnce » - polyethylene with increased heat resistance).On a large account, , it is not a crosslinking product, and even the original raw , granulate , already possesses the necessary qualities - numerous and stable intermolecular bonds.

This became possible with the development of technologies for controlled processes of spatial formation of macromolecules. Such polymers offer the widest opportunities - you can create materials with precisely defined characteristics, placing emphasis on one or another property.

The complex grid-like structure of the grill allows to dramatically increase the resistance of the material to external and internal loads, to cracking at bends. And in this case, unlike the PEX, the remains thermoplastic, that is, it can be connected not only with mechanical adapters( fittings), but also with welding, which significantly increases the reliability of the joints with as necessary.

Polyethylene PE-RT uses in all on a larger scale, and there is a steady trend that it eventually completely supplant its "sewn fellow" - REX.All this - thanks to a whole "bouquet" of their positive qualities:

• The production of PE-RT pipes is much simpler, the material does not require cross-linking, all intermolecular bonds are already laid in the semi-finished product. By the way, this polyethylene is easily amenable to and recycling without loss of quality.
• The service life of such pipes is about 50 years or more.
• Pipes PE-RT are not afraid of freezing - they are able to withstand several cycles of full freezing of water without loss of wall integrity.
• Unlike REX, such pipes are easily repairable.
• The contours of these pipes do not creak in the "warm floor" and the even is absolutely noiseless with a high water flow intensity.

Polyethylene PE-RT is used, as well as PEH, and for the manufacture of metal-plastic pipes, and for purely polymeric ones.

Both performance characteristics are significantly higher than using cross-linked analogs.

Parameter	PERT-Al-PERT	PERT-Al-PERT
Operating temperature, C	95,0	95,0
Peak temperature, With	110,0	124.7
Elasticity, MPa	1100	660
Connection method	Only mechanical fittings	Mechanical fittings and welded fittings

When manufacturing a polymer pipe without a metal insert, manufacturers often use their own proprietary designs to provide oxygen permeability walls. For example, it can be an airtight OXYDEX layer, or a special antidiffusion barrier EVON.

The main performance characteristics of such pipes are given in the following table for an example:

Indicator	16 × 2 mm	20 × 2 mm
Volume( l / m)	0.113	0.201
Weight( kg / linear meter)	0,071	0.127
Min.bending radius - 5d( mm)	60	100
Temperature( ° C)	20	20
Pressure( bar)	20	20
Service life( years)	over 50	over 50
Temperature( ° C)	75	75
Pressure( bar)	10	10
Service life( years)	over 50 years	over 50
Temperature( ° C)	95	95
Pressure( bar)	6	6
Service life( years)	more than 50	over 50
Limiting pressure( bar)	6	4.5
at temperature( ° C)	110	110
Limiting pressure( bar)	11	10
at temperature(° C)	90	90
Elongation coefficient max at t = 95 ° C( 1 / ° C)	1.8 1E-4	8.2 1E-5
The coefficient of heat(W / K m)	0.41
Internal surface roughness( μm)	0,125( Class 10)
Estimated strength of the material( MPa)	6.3

If we summarize, we can note that the pipes made of polyethylene PE-RT for today are, probably, the material that most meets the requirements of the system " warm floor", while remaining in the sector of reasonable price availability.

What will cost buying pipes?

This depends, is primarily , from to the length of the heating circuit contours. How correctly its calculate - you can find out by reading the corresponding publication of our portal.

With the , the calculations should not forget about the sections from the floor to the distribution manifold, with taking into account the connecting stock, at least 500 mm at each end.

The cost of pipes can depend on the and from the manufacturer, and from the specific model, and from the region where the material is purchased. The products of well-known European companies "Uponor" , "Rehau" , "Kermi" , "Henco" , "Oventrop" and others are of great importance and, accordingly, in demand. For example - in the table there are several models of pipes suitable for " warm floors". The prices are indicative, typical for the central regions of Russia:

Manufacturer, brand	Diameter, mm	Brief specifications	Length in bay	Price per 1 linearmeter
Uponor PEX evalPEX Q & E 16 x 2.0	16	Crosslinked polyethylene, wall 2 mm, t max - up to 95 degrees,( short-term heating up to 110)	50 - 240 m	90 rub
Uponor PEX evalPEX Q & E 20 x 2.0,	20	- // -	50 - 120 m	114
REHAU "Rautitan stabil"	16	MetalopAST, PE-Xc /AI/ PE wall 2,6 mm	100	105
REHAU "Rautitan stabil"	20	Metal, PE-Xa-AL-PE wall 2.9 mm	100	150
REHAU "Rautitan flex"	16	Cross-linked polyethylene RAU-PE-Xa, wall 2, 2 mm	100	105
Kermi MKV xnet 16 x 2.0	16	Metal-plastic, PE-Xs-AL-PE-Xs	100	55
REHAU "Rautitan Pink"	16	Cross-linked polyethylene RAU-PE-Xa, wall 2,2 mm, t max - up to 90 degrees	120	64
Wieland cuprotherm CTX	20	Copper tube in plastic sheath, wall 2 mm	50	240
FLEXSY-20	20	Corrugated annealed stainless steel pipe with polymer coating, wall 2 mm	up to 50	175
BioPipe PERT 16x2.0	16	Monolayer, t max - up to 100 degrees, pressure -up to 6 bar.	240 m	35
Thermotech MultiPipe PE-RT II, ​​16 * 2 mm	16	Five-layered with diffuse barrier	240 m	85

The table does not purport to specify the most inexpensive types of pipes, from unknown or highly questionable manufacturers. It is worthwhile to think carefully before buying cheap , not trustworthy products, as the system of water " warm floor", poured by a concrete screed, should not cause the owner of the house or apartment no reason for concern.

And finally - a video with the evaluation of pipes for the system " warm floor" from specialist.

Video: which pipes are better for " warm floors"?