Heating the flooring with water is fundamentally different from its electric heating, both methods have strengths and weaknesses. In order for a water-heated floor to be as effective as possible, you need not only to install all its components in a certain order, but also to correctly configure the system, choose a good boiler.
Even the floor screed and waterproofing are essential for the proper operation of such a system.
Features of the
In the overwhelming majority of cases, underfloor heating is preferable for owners of private housing, but not for apartment owners. It works well when you need to warm up the whole dwelling as a whole, but if you only need to warm the floor in a separate room, it is more correct to use electricity. It is easier to lay the cable in a small (up to 20 sq. M.) Space than to install pipes there, supplementing them with the necessary control equipment.
It is unacceptable to heat the floor by supplying water from the central heating system.so that neighbors' batteries are not cold. Even if you equip the system by tying it to a separate heating circuit, you will need to coordinate this with the building inspection. Compared with the use of radiator heating means, underfloor heating allows you to evenly heat the house, the air temperature distribution is physiologically comfortable.
In both heating systems, the air around the heater is primarily heated. But since radiators are local heat sources, the maximum temperature is reached near them, near windows and at the very ceilings. There it is from 25 to 40 degrees, and this is a necessary condition for the average heating in the room to be 20 degrees.
The contours of the underfloor heating are evenly distributed over all parts of the room that can and should be heated, so its use is much more economical. By reducing the temperature of the coolant by only 1 degree, they reduce the consumption of thermal energy by 8% on average, local overheating and heat escape through the walls are excluded.
The radiator heating device does not allow the use of automation that sets different temperatures in individual rooms, especially in their parts. But the use of a warm floor just allows you to set your own operating parameters for each circuit. The service life of water-heated floors (more precisely, polymer and metal-polymer pipes laid in their base) is over half a century.
Among the reasons why water underfloor heating can fail is illiterate installation, in this sense it is much more demanding than other designs.
Finally, due to the long length of the pipeline and its sometimes very complex shape, servos will certainly be used.
Advantages and disadvantages
The undoubted advantages of a water-heated floor are not only the uniformity of air heating, but also:
- Ecological cleanliness;
- Lack of noise;
- Maintaining a good microclimate;
- Maintaining a rational, physiologically grounded moisture content;
- Elimination of dust and dirt accumulation in the apartment;
- Unnecessity of bulky parts and elements.
But one cannot fail to mention the disadvantages of water-heated floors. It is quite difficult to mount them, consumables cost a lot of money, which will have to be invested right away. You will either need to install a condensing boiler, or use a stirring unit, which will reduce the temperature of the coolant. Note that technology has gone far ahead over the past few decades, and water underfloor heating is absolutely not susceptible to water hammer, corrosive processes. The likelihood of leakage has become much less.
But still, only such a design works well, which is selected, installed and configured in full accordance with the basic principles of heating technology. Sometimes very complex calculations are required, especially if the contours are complex in shape and have many turns. So in such cases, high-level specialists should design and create the system, while you can lay the electrical cable on your own.
Warm water floors do not increase the dampness in the room, but if the room is already characterized by low humidity, prolonged heating can dry out the air. In the bathroom, this is not relevant, it is even to some extent an advantage, but in other rooms it is necessary to ventilate more often, put indoor plants, aquariums or use humidifiers. remember, that underfloor heating is bad for natural wood furniture and musical instruments. Where such objects will stand, there is no place for heating circuits! In addition, you should not drill the floor in which the pipes with water are hidden; as a last resort, check each action with the layout of the communications.
The absence of electromagnetic radiation can also be considered an advantage of water heating. However, it should be taken into account that electromagnetic fields arise during the operation of control automation, pumps and some other components of the system.
Always ask whether these devices meet basic safety requirements and standards, whether they have the necessary certifications and licenses.
The installation process, even when a relatively simple semi-dry screed or panels is used, is rather laborious and time-consuming. The slightest mistake during installation can result in serious negative consequences, breakthroughs, so it should be dealt with carefully. Not all floors are able to withstand the load created by a water-heated floor, and this is another reason why it is not always wise to use it in an apartment.
Views
In most cases, the water supply to the underfloor heating is regulated automatically, the thermostat controls compliance with the required parameters. But there are systems in which it is not provided: then boilers are used that limit the heating of water to a certain temperature. If the developers of heating equipment have not provided for such a mode, you will have to use three-way valve, which just gives commands to the thermostat.
The distinction between water heat-insulated floors is also carried out according to the type of performance. Concrete screed requires careful calculations that take into account thermal expansion; the screed is designed to keep heat in the room and does not allow it to go through the ceilings. Then they use a damper tape, a steel mesh, and only on top of it concrete is poured.
The flat view of the water floor does not require a screed; for laying the flooring, aluminum plates are preliminarily used, as well as cardboard or a layer of polyethylene foam. Heating of this type is advisable where the height of the premises is low, or the floors (foundations) are frankly weak. A specific feature is the need for reinforced thermal insulation, covered with mats based on polystyrene. Aluminum plate structures are inserted into these mats, which serve as a support for individual contours of the warm floor. The front cover finishes the work.
In many panel buildings, a warm water floor is organized using wooden parts - modules or slats. Modules, or chipboards, are initially equipped with channels in which pipes are laid. The panels are attached to the rough base with self-tapping screws, the gap between which is 20 mm. Plates are not placed close to each other, gaps serve for stacking aluminum blocks, and cardboard or polyethylene helps to prevent contact between the panel and the heat-conducting plate.
The pipes are installed, then the chosen flooring is laid, and this is where the work ends.
The choice of a specific option is not as easy as it seems, and a number of features of each of them must be taken into account. In a wooden and panel house, it is unacceptable to use a concrete screed; you will have to use a floor floor. The disadvantage of this solution is the low thermal inertia, the decking cools down rapidly. Polystyrene water floor, with a capacity of up to 0.0045 kW per 1 sq. m, can effectively supplement the main heating system, but it is hardly suitable as the main heating method.
The undoubted advantage of the concrete variation (where it can be used) is the ability to use all existing types of front coverings, the technology has no limitations. True, not everyone is ready to wait 48 hours for the screed to dry. The general conclusion is that only after carefully analyzing the features of a particular dwelling, your needs and financial capabilities, other circumstances, you can choose the right type of water floor heating.
Always keep in mind that it is almost impossible to disassemble and assemble the structure again, therefore, you should carefully select the components, pay more attention to them.
In addition to purely mechanical components, its automation is of great practical importance in the operation of a warm floor. Mechanical devices are considered more reliable and simpler, but they are less and less common. Simply because manual adjustment and the need to constantly monitor the operation of the device are not too popular with people. If you often leave for a long time, or you simply do not want to feel uncomfortable in the house during sudden changes in temperature outside during the day or overnight, use automatic control.
It can be quite different in design: some models collect information about the actual weather and change the operating mode accordingly, others are guided by the readings of air temperature sensors or flooring. The most advanced (but also the most expensive) option is a programmable device.
With its help, you can flexibly adjust the operation of the underfloor heating, and it will heat up thoroughly by the time of your daily return, all the rest of the time saving hot water as much as possible.
Principle of operation
Water underfloor heating is considered to be quite difficult to perform, but it turns out to be easier to use it after installation is completed than electric. Technically, such advantages are achieved by circulating warm liquid under the decorative layer of the floor. It can be not only water, but also ethylene glycol, and antifreeze, and some other options. The owner of the house chooses the coolant himself, focusing on his needs and the capabilities of specific pipes. Nonetheless, water is traditionally used, due to its wide availability and ease of replenishment if necessary.
The total length of the pipes that make up the water floor is always tens of meters. Therefore, the natural circulation of the coolant is not enough for uniform and high-quality heating over the entire area. To keep the coolant hot enough, it is either heated using an electric boiler or taken from a central heating system. The second option is difficult in engineering terms, it can be very dangerous if it is poorly executed and requires numerous approvals.
In many cases, housing supervisors completely prohibit connecting to central heating, and therefore it is not possible to install a water-heated floor in all apartments.
But be that as it may, the incoming water is too hot: ordinary room radiators are quite effective only at a coolant temperature of 65 - 95 degrees. Underfloor heating requires a much less heated liquid, because the outer surface of the flooring should not be warmed up above 30 degrees. Exceptions are made only for the bathroom and areas directly above the pipes, and the difference in these cases is 3 - 5 degrees maximum.
To do everything right, you will have to install a mixing unit, in which the freshly heated water is diluted with the water that has already passed along the circuit. From this unit, the coolant flows back into the pipes and heats the floor surface, moving along them, already to safe values.
When choosing components, you should give preference condensing heaters … They develop a relatively low temperature, just the kind that is required for the normal operation of a warm floor. In addition to the listed devices, the high-end system also contains automatic controls or meteorological sensors, means for venting excess air from pipes and some other parts.
The height of the "pie" of the water floor is determined primarily by the type of screed; most of all it is when using concrete structures.
You will also have to take into account the thickness of the thermal protection, you already know how to calculate it. High-quality underfloor heating is unthinkable without a manifold, and the mounting height of this device is also very significant. The manifold cabinet is usually placed at the level of the floor covering to minimize height differences and related undesirable effects. Do not install the distributor below the pipes to which it supplies water, if only there is an opportunity to avoid it - use it.
But even the best collector, installed according to all the rules, will not help warm the home if the recommended pipe installation step is not followed. It is selected primarily taking into account the diameter of the pipeline; if coils of large pipes are brought together too close, overheating will appear, and excessive removal of thin structures will lead to the appearance of so-called thermal voids.
In an apartment building, a water heat-insulated floor is almost inapplicable due to the very principle of its operation - since it is impossible to take hot water from heating circuits and hot water supply systems.
Thermoregulation
Although the temperature of the water in a warm floor is limited by the collector, it must "know" how to limit it, when to decrease, and when it is possible to increase heating. This function is taken over by the thermostat (in catalogs of online stores and brochures of manufacturers, for simplicity, it is called a thermostat). When installed, thermostats are immediately connected to devices that measure the heating of the floor covering (or air in the room) and the coolant.
The indicators, which are equipped with any of the existing panels, display information about the current heating. The microcontroller located inside the thermostat constantly works with the readings of the sensors, on their basis, automatic control of the coolant temperature is organized. In simpler systems, a mechanical method of coordination is used, but still automation is considered the most practical and convenient option.
If no one is at home, she is able to adapt herself to changes in the weather and consume exactly as much water as is needed for optimal heating. When all the inputs of the manifold assembly have been fitted with separate thermostats, it is still worth installing a floor controller as a whole, since a strict temperature setting increases the comfort in the house.
If, nevertheless, a warm floor is installed in an apartment building, it is impossible to regulate its temperature so that the radiators on all floors of the building work stably.
The solution can be the equipment of an autonomous heating circuit, which is not associated with the central heating of the dwelling. But then you will have to carefully think over the consumption of gas or electricity for the boiler, find out whether it will be possible to ensure the necessary supply of them through the existing communications.
Pipes
Having found out the details of how the thermoregulation of a water-heated floor is organized, it is time to deal with another point - those pipes that will deliver the heated coolant to the right places. In underfloor heating, structures made of metal-plastic, polyethylene, stainless steel, polypropylene and copper can be used. Any of these types of plumbing works well both in screeds and when using flooring.
For your information: all bays must be laid without any connections, and when one of them does not allow to close a certain area, the structure is divided into a number of contours. Be sure to connect each of these circuits to a separate input of the comb.
When choosing polyethylene products, be sure to make sure that they have the necessary reinforcing layer.
In addition to the material, the diameter of the pipe is certainly taken into account: by reducing the width of the pipeline, it is possible to make its single segment shorter, but it is not recommended to use very long circuits. The point is not only that this increases the cost of purchasing components, but also in the senseless accumulation of a large amount of water. If there is too much of it in the circuit, the heating becomes inert and cannot react flexibly to changes in environmental conditions. Therefore, the typical composition of a warm floor includes only pipes not less than 1.6 and not more than 2 cm in diameter.
We must not forget what kind of floor covering will be laid on top of the heating installation. Copper systems are quite expensive and are only recommended for floors with a high heat-saving effect. Always read the instructions for use and accompanying documents. It should be clearly indicated there that a particular pipe is intended specifically to create warm floors.
Polypropylene is slightly worse than metal-plastic, its bending radius is at least 8 times the pipe diameter. That is, by choosing a design with a caliber of 2 cm, it will not be possible to bring the turns closer together by more than 320 mm.
Sewn polyethylene is devoid of such a drawback, but it must be fixed as tightly as possible, otherwise the assembly will straighten and will not be able to fully perform its tasks.
Calculation and design of the system
But a simple selection of material does not always give a good result, and even taking into account the properties of the topcoat is also not enough for ultimate success. Accurate calculation and drawing up of a competent project of underfloor heating is of great importance. Since it is unlikely that you have the necessary experience, it is better not to risk it, but immediately contact the professionals. Collect and provide designers with data on:
- The diameter of the pipeline and the material from which it will be made;
- Boiler peak power;
- Thermal protection properties (thickness, material, number of layers);
- The total and heated area of the room;
- Materials of walls, floors, their thickness, level of thermal insulation, geometry.
A special computer program will help to calculate the parameters that the water floor will have. In most cases, the heat loss coefficient is not less than 40 and not more than 300 W per 1 sq. m. If the figure is closer to the maximum value, you should not save on the pipeline - bring its pipes closer to 150 mm between each other, or better still reduce this distance. It's another matter if the room has thick and thoroughly insulated fences, if reliable windows are installed without a single gap. Then feel free to expand the installation step to 0.3 m, it will still be quite comfortable and warm in the room after the warm floor is put into operation.
The drafting of a warm floor project should be preceded by a design project. Or at least think for yourself where the heavy furniture and plumbing fixtures will be installed. The maximum length of continuous piping circuits cannot heat more than 40 sq. m, otherwise the heat load turns out to be excessive, and no prevention will help to avoid cracking of the screed or panels.
Collector selection
When choosing a collector, focus on the area that will need to be heated with a coolant, but take into account the pressure developed in the system. Most often, the mixing unit is made of brass; only occasionally is there a stainless steel and plastic (pre-hardened). If you want to purchase the most reliable and stable product, check whether the Mayevsky crane has been used, whether there is a sensor that determines the amount of coolant passing through the device.
In addition to them, in various versions, the mixer can have thermocouples (measuring the heating of the liquid), nozzles that release air to the outside, and valves that change the flow rate.
The device containing the flow meter is a high-grade complete equipment. But the thermostat should be installed even in the cheapest products, otherwise you have a frank marriage or even a fake. Thanks to the thermoregulation complex, the water floor heats equally well, temperature jumps are prevented, which not only makes the house more comfortable, but also increases the service life of the floor covering.
Manifolds manufactured in the last few years can be equipped with a five-point ICMA flowmeter. If you are looking for a cheaper product, you should opt for products with static valves. Plastic control units work well only in rooms of small size; in a larger room, metal structures are necessarily used.
When buying a central manifold, it is worth choosing ready-to-use kits. Check carefully to see if there are valves for each required outlet, both supply and return. This is important so that you can disconnect and start the circuits autonomously from each other, and not work with the entire system at once. Note that pipes can be connected to the manifold either with compressor fittings or with connecting assemblies (a combination of a clamping ring, nuts and strong bushings).
Which boiler is suitable?
But the manifold and all the previous components are far from all that will have to be considered. The next in turn is an equally important element of the heating system - a boiler, without which it is impossible to ensure a stable supply of hot water. It is not possible to unequivocally answer the question of which heater is the best, too many parameters need to be taken into account.
So, all single-circuit devices are categorically unacceptable if you want to supply hot water not only to the warm floor, but also to the tap. You can, of course, purchase boilers, mixers of a special sample and other technological devices, but it is easier to immediately buy a two-circuit system. Carefully calculate the power you need, and depending on it, make a choice in favor of a suspended (up to 35) or placed directly on the floor (up to 120 kW) modification. The optimal version, in the opinion of both consumers and specialists, is a wall-mounted one, since a record energy capacity in everyday life is not particularly needed.
These devices are easier to install and easier to handle.
The undoubted advantage of the overhead scheme is that a pump is installed by default in it, which means that you do not have to select it, spend additional funds and lose free space in the room. If there is also a boiler in the system, this is almost a miniature boiler room, capable of additionally supplying coolant to radiators. A useful thing for those who do not want or cannot limit themselves to floor heating.
With regard to the source of energy used in the boiler, any fuel can be selected, but its combustion must be automated. Basically, specialists install gas or electric heaters. Since electricity is steadily rising in price, it is still more profitable to use gas, but the system that burns it will have to be installed in a separate room, where impeccable ventilation will be created. All work must be entrusted only to representatives of the gas service, the project documentation is coordinated with it in advance.
Diesel vehicles are preferred in cottages. Their installation is relatively simple, there are no special operational requirements for them. But you will need to constantly monitor the condition of the boiler so that it works normally. Outside the city, a good alternative to all these options is solid fuel, burning it allows you to provide decent power and normal efficiency.
Whichever type of boiler you choose, select a site for it, find out which additional components will have to be used and which will be incompatible. Please note that any heater, other than a convection heater, requires the use of a manifold assembly to lower the temperature to acceptable values.
Electric boilers with heating elements are bad in that the heating elements quickly fail; to some extent this disadvantage is compensated by the moderate price and sophisticated technologies. The electrode version has a lower thermal inertia, but it can only be used in contact with very pure water.
Attention: when the system starts up, it is required to immediately fill in prepared liquids of a special sample or independently prepared water. The advantage of induction versions is space saving and ease of installation of the device, even a non-professional can mount it.
Solid fuel boilers are the least acceptable and should be discarded whenever possible.
Even with a capacious hopper, where pellets can be stored in large volumes and when using a heat accumulator, cycling cannot be completely eliminated. Additional devices complicate and increase the cost of work several times, moreover, the system starts up very slowly.
Installation
Work on installing a warm floor does not begin with the installation of thermal insulation. First of all, you should make sure that the rough base is sufficiently flat, it should have a maximum difference in height of 10 mm per 1 sq. m. The selection of heat-saving material is determined by the initial insulation, the presence of various rooms below. It is always recommended to create a slightly thicker thermal protection layer than the calculation suggests, because it allows you to compensate for possible errors. Above apartments, offices and heated office premises of organizations, a sufficient layer of thermal insulation is considered to be 2 - 3 cm.
In private houses, on the ground floor of an apartment building above unheated basements, regardless of the region of the Russian Federation, you need to provide a layer of thermal insulation of at least 5 cm. And if you live in the coldest areas, take care of a heat-saving base of 0.1 - 0.15 m Thicker thermal shields are unnecessary unless the home is in the Arctic.
When thermal insulation is provided, the perimeter of the room is covered with a damper tape or laid with another tape thermal insulation. In its capacity, strips of polystyrene, expanded polystyrene and other sheet insulation are widely used. The width of the strip should be 100 mm, and the thickness should be approximately 10 mm, the same requirements apply when laying mineral wool cardboard. Such elements are designed to prevent the occurrence of temperature cracks at the edges of the flooring and to drastically reduce heat transfer through the surface of the walls through the foundation.
Then comes the turn of laying pipes and fixing them. Often, a metal mesh is placed on top of the heat-insulating layer with a pitch of 50 or 100 mm, which is considered the most practical. In order for the pipes to be firmly held on the rods, they must be fixed; both plastic clamps and steel wire are perfect for this purpose. If the manufacturer took care of applying the markings on the heat-insulating substrates, exactly according to this marking, fasteners are hammered into the base of the floor, which then will begin to hold the inserted pipe.
It is even easier to use polystyrene boards; by securing them, you can clamp the parts of the pipeline between the protrusions provided for this purpose.
Underfloor heating with a concrete base requires the screed to be poured at least 30 mm above the level of the pipes. 40 - 50 mm of concrete is poured under the tiles, but if laminate, linoleum are placed on top, only 15 - 20 mm will be enough. But it will be necessary to supplement the "pie" with one more reinforcing mesh to make the structure as a whole more stable. The technology allows making concrete screed only after starting the heating system under pressure, only cement of a category not lower than M-300 can be used during work.
Concrete should be dried for at least 28 days, even under ideal conditions; it is unacceptable to artificially accelerate this process, because cracks may appear. Only after complete hardening does it make sense to proceed with the final finishing.
When installing the warm floor, the thermal valve is placed in the jumper preceding the circulation pump in the diagram. This valve can be made according to a two-way or three-way system; in both cases, opening it initiates mixing of the coolant, makes heating more intense.
On a wooden floor
Until recently, it was believed that installing a warm floor on a wood base does not make sense at all, because wood itself has a sufficient level of thermal insulation. There is no talk about the use of concrete screeds, a modification of the flooring method is used. The pipelines are located directly on top of the logs or lower boards in specially prepared channels; these channels collect and transfer heat further due to the presence of special plates with elongated recesses for pipes.
Along with holding parts of the pipeline, the plates increase the rigidity of the entire system, which means that there is no need to use a substrate.
It should not be forgotten that budget-class solutions imply the replacement of plates with aluminum foil 0.02 cm thick … When, nevertheless, there is a need to use a substrate - for example, if the laying of ceramic tiles, linoleum is being prepared, gypsum fiber or DSP slabs should be used. As thermal insulation, these materials have practically no value, their role is purely mechanical.
The difference when laying a warm floor on a wooden underlay is also due to the individual method of preparing the channels.
There are two of them, and each home owner must choose what suits him best. So, if there are wooden logs at the bottom, you can buy chipboard blocks, the holes in which are made by milling. The distances of the channels are determined for a strictly specified level of thermal conductivity of the entire structure. The advantage of the ready-made kit can be considered that you will immediately have a complete set of accessories for high-quality and fast installation.
But a serious drawback of modules for the formation of flooring is their price, which in many cases is comparable to the same volume of a natural log frame. Wanting to save money, many use rack and pinion structures; slats are made of planed edged boards or moisture-resistant plywood. Sometimes for their manufacture, the same two types of building boards are used, which were discussed above (the thickness is strictly from 2.1 to 2.8 cm).
The distance between the individual slats is most often kept equal to the thickness of each of them, so that the pipe can fit and not suffer from a change in the size of the tree under the influence of heat. As for the width of the coordinating rail, it should be equal to the design gap between the pipes.
Finally, let's talk about another relatively new, but gaining popularity, way to insulate a wooden floor. They take an edged board and take it out on one side ¼ with the dimensions of the groove. Further, at least 70 mm from the plane of the wall, using the milling method, they make a continuous strip with the same depth (this will help to bring the pipes to the next rows).
For work, a board is used that is thicker than the sample size, but in width exactly coincides with the laying steps. Attachment to the base (beam, log) will be provided with self-tapping screws, the subfloor is not created at all. Everything seems to be simple and practical, but you will have to thoroughly examine all the supporting structures, and even disassemble and sort out some of them. Weakly insulated lower floors to the bottom line are packed with bars and laid with thermal protection plates. It is covered with polyethylene by 0.2 mm, and 50 mm of damper tape should be kept on the wall around the perimeter.
Most often, in this case, the pipeline is laid according to the "snake" system, the pipe is preferably corrugated with an external size of 1.6 or 1.7 cm. Where the heating circuits will turn, it is advisable to round off the edges of the slats. The grooves are laid with aluminum foil with a thickness of at least 0.05 mm.
Some professionals believe that it is necessary to surround the pipes themselves with this material for greater efficiency.
Floor screed
It is necessary to pour the screed over the water-heated floor in a special order and using a mixture of ordinary cement mortar with additives that increase the heat passage. The minimum thickness of the product is 30 mm, which alone makes it possible to make the coating stable, calmly bearing mechanical stress. The exclusion of bands of heat and cold also depends on the thickness of the tightening layer.
All the time until the screed after pouring reaches the required strength, it is unacceptable to turn on underfloor heating. Therefore, it is necessary to test their work in advance, and it is better to undertake the overhaul of the floor itself in the warm season of the year, when frosts and cold snaps are guaranteed to be excluded. The pouring process itself is recommended to be carried out along the beacons, especially when the finishing flooring requires an extremely flat, neat roughing part. Thermal insulation around the perimeter is always made higher than the finished floor will rise, and after the screed has finally hardened, the excess is cut off with an ordinary sharp knife.
Never put aluminum foil and materials based on it in the shrinking mass., since not even three months will pass, as all this will become dust, and heat protection will be reduced to zero.
You can use a self-leveling floor instead of a screed, but keep in mind that polymer filling can only eliminate minor differences in height. If the rough base is uneven, you will have to use a classic mixture of cement and sand with the necessary additives. The advantage of self-leveling floors is considered to be a very small thickness (no more than 35 mm), the ability to withstand impressive mechanical loads, the lightness of the material itself and its visual variety. As a pressure distributor, the filling layer proved to be very good, and its thermal conductivity is much better than even that of a modified mortar.
But there are also several drawbacks: you will have to fill the pipes with a very large amount of mixture (not so cheap), and in several stages.
If done all at once, the coating can quickly crack.
What is better to connect to?
We have already figured out the boilers and collectors, now we will consider the heating elements themselves. In private homes, it is preferable to use the dry connection method when thermal distribution plates are used. In practice, for many years now they have shown themselves to be an excellent alternative to the traditional concrete screed, but they are inferior to it in weight and superior in heat transmission, which is exactly what the consumer needs. An important advantage is the fact that the minimum pitch of pipe installation when using plates from 150 mm is reduced to 125 mm, which means that even in very cold areas, the floor will be comfortable.
With self-assembly, you will not need to adjust the reinforcing meshes and attach the pipeline to them, this is a completely unnecessary procedure in this case. A big plus is that immediately after the installation of the finishing floor covering, it will be possible to immediately turn on the underfloor heating system. The plates heat up very quickly, while concrete still has a fairly large thermal inertia due to its significant mass. Metal heat exchangers absorb three times less room height than even the lightest concrete screeds.
However, you should also know the disadvantages of metal thermal distribution plates: they not only quickly heat up, but also lose heat even faster when the boiler is stopped. And the cost ultimately turns out to be higher than when using traditional mortar. To some extent, this difficulty is eliminated by making the plates yourself, but keep in mind that you will need to use a special machine.
Selection Tips
A set of underfloor heating for parquet and laminate must be laid on polystyrene boards, no intermediate layer between them and the topcoat is required. If there is a tile or linoleum on top, the base is created from chipboard or gypsum fiber coatings. Returning to polystyrene structures, one should emphasize its advantages in country and country houses with not too high ceilings. In the event that you want to achieve maximum environmental friendliness, you need to put the water floor on top of the modules or slats.
The width of the slab (module) should be either 13, 18, or 28 cm. Lay in the project a thickness of at least 2.2 cm, and the interval from one slab to another is 2 cm.
Modular decks are thicker than slatted decks and should be used primarily on ground floors.
In a frame house, you can lay a warm floor in any way, but the step is limited to 150 mm, therefore buy more pipes. It is quite possible to calculate the power according to approximate values - if the building is thoroughly insulated and double-glazed windows are installed, it should be about 40 W per 1 sq. m. If the house is a relatively old building and there is practically no thermal insulation, this figure is usually 70 or 80 W.
Very badly worn out and not repaired buildings for a long time have heat losses of more than 100 W per 1 sq. m, and they need to be compensated by heating means. But the situation is even worse in new cottages without wall insulation and with panoramic windows - there heat loss can be 0.3 kW per square.
It is quite possible to equip a water-heated floor on the balcony, and experts recommend in this case use the "snake" system, providing the most uniform heating. Given the intense heat loss, the gap between the pipes must not be larger than 100 mm, otherwise the coating will be cold. And plates of insulation material, on the contrary, it is advisable to use thicker, so that they more reliably save precious energy.
When choosing a distributor (collector), it is worth giving preference to the same company that produced the temperature sensor, then there will definitely not be any problems with the compatibility of components with each other. Ideally, all components should be of the same brand.
As for the coolant, the underfloor heating system can use the same substances as radiators. Up to a third of all warm floors are filled with antifreezes (mixtures of propylene glycol and ethylene glycol). Approach the choice of technical fluid as carefully as possible and pay attention to the complete list of its components, basic physical properties. To pump antifreeze, the total pump capacity must be 1/10 more than when using water, and the created pressure in the system generally increases by 60%. In this case, it will be necessary to increase either the diameter of the circuits or their total length, taking into account the reduced heat transfer of non-freezing liquids.
The advantage when using antifreeze is that the replacement of the coolant can occur 3 - 5 times less often than when pouring water into the pipes. You can improve its quality by distilling and adding softeners.
It is categorically unacceptable to pour automobile antifreeze into the heating circuit, only specially selected mixtures are intended for this!
Manufacturers
Among the manufacturers of underfloor heating is a joint Russian-Italian company Valtec has long attracted the attention of consumers and has earned a number of favorable assessments. The range of the concern includes, for example, pipes of the category Pex-Evoh with a diameter of 1.6 or 2.0 cm. To connect them, brass fittings are added to the delivery set. The necessary protection against the penetration of oxygen from the outside is provided by a polyvinylethylene coating.
Rehau - the company is no less famous, deservedly associated with traditional German quality. The company's engineers have a secret of how to make the most flexible pipes. You can bend them within a fairly wide range, without fear of damaging something or provoking a leak. Much attention was paid to the structure of the inner walls - now they do not accumulate pollution at all, which makes it possible to reduce the requirements for the preparation of water poured into warm floors.
Testimonials
General reviews about water heated floors are rather favorable. Even those who initially believe that this is just a waste of money, having tried the benefits of such products in practice, change their minds dramatically. The heat-distributing properties of the underfloor heating system are highly rated, especially often positive assessments are associated with the use of underfloor heating in bathrooms.
Reinforced-plastic pipes, judging by the reviews, can last at least 10 years without a single complaint. Please note that in large rooms with a minimum of furniture, experienced people often advise heating only the middle, so that it is not too stuffy.
It is also not recommended to use water heated floors in toilets and kitchens, otherwise the smells characteristic of these rooms may increase. Better take care that there is effective thermal insulation.
But systems with sensors and high-quality thermostats are always rated higher than usual, and are recognized as the most convenient and practical to use.
Successful examples and options
You can use a water heat-insulated floor almost anywhere; this heating method has no special restrictions. Now you know exactly how to choose accessories for it, how to lay and connect them, how to calculate the required power. Now let's see some of the most successful performances of it.
This is how the professionals work on pouring the heating system with a concrete screed (one corner, distant from the entrance, is already poured, the work is going counterclockwise).
And here, simply and gracefully, the installation of a warm floor in a frame house takes place.
An excellent modern collector for supplying water to the heating system.
For information on how to make a water-heated floor with your own hands, see the next video.
