Their absence would make the water heating system ineffective, since the walls of the pipeline are minimally suitable for this. The heat transfer capacity of a radiator depends on a number of factors:

1. the area of ​​its heating surface;
2. type of device;
3. location in the room;
4. diagram according to which it is connected to the pipeline.

One of the indicators characterizing heating devices, is the test pressure. When pressure testing a heating system, heating devices are subjected to hydraulic shocks (here it should be noted that in Russia, when testing, it is customary to raise the pressure testing pressure to 15 atm, which imported heating devices cannot withstand, since in the West the pressure is increased to 7-8 atm), and in during operation internal surfaces suffer from chemical and electrochemical corrosion. If the devices successfully withstand such tests, it means that they will last a long time, since they have high quality. In addition, heating appliances must comply
requirements of various types.

Among them are the following:

1. thermal engineering, i.e. heating devices must provide the maximum density of specific heat flux falling per unit area;
2. installation, which means minimal labor and time costs during installation and the necessary mechanical strength devices;
3. operational, i.e. heating devices must be heat-resistant; waterproof, even if during operation the hydrostatic pressure reaches the maximum permissible value; having the ability to regulate heat transfer;
4. economic. This means that the ratio of the cost of heating devices, their installation and operation should be optimal, and the consumption of materials in their manufacture should be minimal;
5. designer;
6. sanitary and hygienic, i.e. have a minimum area horizontal surface so as not to turn into a dust collector.

Classification of heating devices

Options	Type of devices	Varieties
Heat transfer method	Convective Radiation Convective-radiative	Convectors Finned tubes Ceiling radiators Sectional radiators Panel radiators Smooth tube heating devices
Heating surface type	With smooth surface With ribbed surface
Thermal inertia value	With low thermal inertia With high thermal inertia
Material	Metal Ceramic Plastic Combined
Height	Skirting	More than 65 cm From 40 to 65 cm From 20 to 40 cm

Let us briefly describe different types heating devices.

A convector is a finned heater equipped with a casing made of any material (cast iron, steel, asbestos cement, etc.) which increases its heat transfer. Convection of the heat flux of a convector with a casing is 90-95%. The functions of the casing can be performed by a finned heater. Such a heating device is called a convector without a casing.

The casing plays not only a decorative role - it is functional - it increases air circulation near the surface of the heater.

Despite the rather low heat transfer coefficient, lack of resistance to water hammer, and increased requirements for the quality of the coolant, convectors are widely used. The reasons for this are low metal consumption, light weight, ease of manufacture, installation and operation, fashion design. It would be unfair not to notice that convectors have another very unpleasant drawback - the convection air currents that arise during their operation lift and move dust and other small particles around the room.

Heating device convective type is a finned tube. The material for it is flanged cast iron pipe 1-2 m long, the outer surface of which consists of thin ribs cast during the pipe manufacturing process. Due to this, the outer surface area increases many times over, which distinguishes it favorably from a smooth pipe with the same diameter and length, which makes the device more compact. In addition, the device is quite simple to manufacture and quite economical, i.e., the cost of its production is low. A number of serious shortcomings:

1. low temperature observed on the surface of the fins, despite the circulation of high-temperature coolant;
2. heavy weight;
3. low mechanical strength;
4. unhygienic (fins are difficult to clean from dust);
5. outdated design.

However, finned tubes are used - usually in non-residential premises, such as warehouses, garages, etc. They are mounted horizontally in the form of a coil, connected with bolts, flanged cast iron double bends (practitioners call them rolls) and counter flanges.

A type of radiation heating device is a ceiling radiator, which, when heated, begins to give off heat, which, in turn, is first absorbed by the walls and objects in the room, then reflected by them, i.e., secondary radiation occurs. As a result, a radiant exchange occurs between heating devices, building enclosing structures, and objects, which makes a person’s stay in such a room very comfortable. If the temperature drops by 1-2 °C, a person’s convective heat transfer increases, which has a positive effect on his well-being. Hence, if with convective heating the optimal temperature is 19.3 °C, then with radiation heating it is 17.4 °C.

Ceiling radiators differ in the design of one element and come with a flat or wave-shaped screen.

The advantages of a ceiling radiator include: a favorable atmosphere in the room; an increase in the surface temperature of the room, which reduces human heat transfer; saving thermal energy used for heating. However, this type of heating devices also has disadvantages, including significant thermal inertia, heat loss through cold bridges that occur in those places in the enclosing structures in which heating elements are installed; the need to install fittings that regulate the heat transfer of concrete panels.

Heating the room can be solved by installing convective-radiation heating devices - radiators. Their distinctive feature is that they simultaneously give off heat through convection, which accounts for 75% of the heat flux, and radiation, which accounts for the remaining 25%.

Structurally, radiators are presented in two options:

1. sectional;
2. panel.

Sectional radiators differ in the material from which they are made.

First of all, it is cast iron. Radiators made from it have not lost their popularity since the beginning of the 20th century. And even now, when aluminum and steel radiators are quite accessible, cast iron ones are only strengthening their positions, especially since the former are less durable and therefore are less able to withstand the disasters of domestic heating networks.

Sectional aluminum (more precisely, an alloy of aluminum with silicon) radiators are pressed sections and collectors. They are cast and extruded. Firstly, each section is a single piece, secondly, it is three elements connected by bolts using sealing elements or glued on. Aluminum radiators have a number of positive qualities that distinguish them favorably from cast iron appliances. Firstly, they have high heat transfer due to the finned sections; secondly, they themselves and, accordingly, the air in the room heat up faster; thirdly, they allow you to regulate the air temperature; fourthly, they are light in weight, which facilitates both delivery and installation of the device; fifthly, they are aesthetically pleasing and modern in design. There are also very significant disadvantages: weak convection ability; increased gas formation, which contributes to the formation air jams in the system; risk of leaks; heat concentration on the ribs; demands on the coolant, primarily on the pH level, which should not exceed 7-8; incompatibility with elements in the heating system made of steel and copper (in such cases, galvanized adapters should be used to avoid electrochemical corrosion).

The fins of all radiators must be strictly vertical.

Steel panels are produced in different options- single- and double-row, with a smooth or ribbed surface, with or without decorative enamel coating. Heating devices of this type have certain advantages, in particular high heat transfer; slight thermal inertia; low weight; hygiene; aesthetics. The disadvantages include the small heating surface area (for this reason, they are often mounted in pairs - in 2 rows with a gap of 40 mm) and susceptibility to corrosion.

Concrete panel radiators- these are panels having concrete, plastic or glass channels, differing in their configuration, and heating elements different shapes- coil or register. Heating devices in the manufacture of which two metals are used (aluminum for fins and steel for conductive channels) are called bimetallic. A section of such a radiator consists of two vertical steel pipes(it should be noted that the diameter of the internal channels is quite small, which is a disadvantage), covered aluminum alloy(the process is carried out under pressure), connected through steel nipples. Gaskets made of heat-resistant rubber can withstand temperatures up to 200 °C and provide the necessary tightness.

Water heating risers can move when heated, damaging the plaster, so during installation they must be passed through pipes larger diameter or sleeves made of roofing steel.

Such models do not have the disadvantages characteristic of aluminum and steel radiators, but have an important advantage - thanks to the aluminum body they have high heat transfer. Aluminum's ability to heat up quickly allows you to control and regulate heat consumption.

The working pressure for bimetallic devices is 25 atm, the crimping pressure is 37 atm (thanks to the latter bimetallic radiators preferred for systems with high blood pressure), the maximum coolant temperature is 120 ° C. In addition, they are suitable for installation in different heating systems, and the number of storeys of the house does not matter.
As heating devices, steel pipes with a smooth surface can be used, which are given a coil or register shape and which are placed at intervals smaller than the diameter of the pipes (the latter is very important, since with an even greater decrease in the distance, mutual irradiation of the pipes begins, which leads to a reduction in heat transfer device). Heating devices of this design show the highest heat transfer coefficient, but due to their significant weight, large dimensions, and lack of aesthetics, they are installed, as a rule, in non-residential premises, for example, in greenhouses.

The place where the thermostat with a built-in air temperature sensor will be located should be in a heated room at a height of 150 cm from the floor, protected from drafts, UV radiation and not adjacent to other heat sources.

Thus, having an idea of ​​what kind of heating devices modern industry and market offers, all that remains is to do right choice. In this case, you must be guided by the following criteria:

1. type and structural device heating system;
2. open or hidden gasket pipeline;
3. quality of the coolant to be used;
4. the amount of operating pressure for which the heating system is designed;
5. type of heating devices;
6. house layout;
7. the thermal regime that is expected to be maintained in the premises, and the duration of the residents’ stay there.

In addition, we must remember that the operation of heating devices is associated with problems such as corrosion and water hammer. Need to study carefully available material, consult a specialist, find out from the seller or look for information about manufacturing companies, find out how long they have been working for domestic market, which heating devices are best adapted to the conditions of our reality. All this will help to avoid a rash purchase and will be the key to a successfully operating heating system.
After heating devices have been purchased, it becomes necessary to place them in the premises of the house. And here there are options (by the way, this should also be foreseen in advance in order to buy heating devices of the appropriate height).

So, metal heating devices are placed along the walls or in niches in 1 or 2 rows. They can be mounted behind screens or openly.

However, heating appliances usually take their place under the window near outer wall, but at the same time it is necessary to comply with a number of requirements:

1. The length of the device must be at least<50-75 % длины окна (об этом уже было сказано, но, следуя логике изложения, считаем возможным повторить). Это не относится к витражным окнам;
2. The vertical axes of the heater and the window must coincide. The error may be no more than 50 mm.

In some situations (subject to short and warm winters, short-term stay of people in the room), heating devices are placed near the internal walls, which has certain advantages, since the heat transfer of heating devices increases; the length of the pipeline decreases; the number of risers is reduced.

There are wishes regarding the height and length of heating devices.

With high ceilings in the house, it is preferable to install high and short radiators, with standard ones - long and low.

Description:

The master class consisted of three blocks. The first block was devoted to the problems of using heating devices in modern construction. Here the issues of classification of heating devices, their main characteristics, methods for determining these characteristics in Russia and abroad, problems of harmonization of testing methods for heating devices and requirements for them were considered.

Heating devices in modern construction

The ABOK master class “Heating appliances in modern construction” was conducted by Vitaly Ivanovich Sasin, Candidate of Technical Sciences, senior researcher, head of the department of heating appliances and heating systems of NIIsantekhniki OJSC, director of the scientific and technical company Vitaterm LLC, member of the Presidium of the Non-Profit Partnership “ ABOK."

The master class was attended by specialists from Moscow, Veliky Novgorod, Dmitrov, Zhukovsky, Ryazan, St. Petersburg, Ufa, Chelyabinsk, Elektrostal.

The master class consisted of three blocks. The first block was devoted to the problems of using heating devices in modern construction. Here the issues of classification of heating devices, their main characteristics, methods for determining these characteristics in Russia and abroad, problems of harmonization of testing methods for heating devices and requirements for them were considered. The second block examined new heating devices presented on the Russian market, their main technical characteristics, recommendations for use, installation and operation. The third block was devoted to thermostatic and shut-off valves used to regulate the heat flow of heating devices.

This article summarizes the issues discussed during the first and second blocks of the ABOK master class.

The classification of heating devices and the basic technical requirements for their designs, methods of control, installation and operation are given in the ABOK Standard “Heating radiators and convectors. General technical conditions" (STO NP "ABOK" 4.2.2–2006).

I would like to draw the attention of designers to the features of testing heating devices and the existing methods for these tests. In Russia, the testing methodology differs from the methods adopted in Europe and China. For example, in our country, when testing heating devices in a climate chamber, the walls must be cooled in order for the process to be stationary, but it is forbidden to cool the floor. As a result, devices tested using different methods produce different indicators. European figures are usually somewhat higher than domestic ones. Previously, with a temperature difference of 90/70 °C, this overestimation was about 8–14%; now, with the transition in European countries to a difference of 75/65 °C, the difference has decreased, but is still 3–8%.

On average, the thermal performance of heating devices, determined according to the European standard EN 442–2, exceeded domestic ones at the same temperature drop by 6–14% with the previously used design parameters of the coolant 90/70 °C and air temperature 20 °C and by 3 –8% with new parameters (75/65% and air temperature 20 °C). However, it should be noted that most of the calculated data in foreign catalogs and prospectuses are recalculated from the “old” standard temperature difference θ = 60 °C to the “new” θ = 50 °C, which are still determined with an error of up to 14%.

In addition, there are differences in the methods of conducting hydraulic tests. Foreign methods involve testing a new device, while domestic methods involve testing an already contaminated device, corresponding to approximately three years of operation. Hydraulic characteristics obtained using foreign methods on “clean” devices turn out to be 10–30% lower than those determined according to domestic requirements on devices with approximately a three-year service life.

The requirements of domestic and foreign standards for strength also differ. On the other hand, some domestic manufacturers, in order to save money, use the so-called “calculated” method for determining the heat transfer of heating devices, which is unjustifiably overestimated. As a result, instead of the calculated temperature of 18–22 °C, only 13–14 °C is provided in the premises.

And finally, domestic operating strength characteristics of heating devices are determined with a large margin compared to test ones with an overestimation of 1.5 times, and not 1.3 times, as abroad. Domestic devices are additionally subject to requirements regarding the ratio of the values ​​of the minimum pressures that destroy the device and their maximum permissible operating pressures.

A comparison of domestic and European (EN 442–2) methods for thermal testing of heating devices shows that the domestic method, to a greater extent than foreign ones, meets the actual operating conditions of heating devices and does not overestimate the thermal characteristics. Hydraulic and strength tests of heating devices, carried out in accordance with Russian requirements, also, to a greater extent than foreign ones, reflect the realities of operating heating devices in domestic construction.

Thus, we can conclude that domestic test methods more clearly than foreign ones determine the main technical characteristics of heating devices in relation to domestic operating conditions. The problem of using heating devices is determined to a large extent by the possibility of obtaining complete and reliable data on their thermal-hydraulic, strength and operational characteristics. Foreign methods, taking into account the test methods adopted in Europe, overestimate thermal (usually by 4–8%) and strength indicators (by 12%), and also underestimate hydraulic characteristics by 5–20%. Domestic manufacturers often use calculations and tests on non-accredited and non-certified stands to obtain basic technical data, overestimating, in particular, thermal indicators by 20–50%, and in some cases doubling.

The use of copper pipes in heating systems is possible if the content of dissolved oxygen in the water is no more than 36 μg/dm 3, i.e., in European conditions, copper pipes can be used with certain restrictions. In practice, they can be used everywhere, but the specified regulatory limitation does exist. In our country, the parameter under consideration does not limit the use of copper pipes in heating systems.

In domestic practice, the following classification of heating systems is accepted:

According to the method of connecting central heating systems to a source of thermal energy: according to an independent scheme (autonomous or heat supply system independent of the coolant), according to a dependent scheme with mixing hot water of the heating system with return (cooled) water of the heating system and according to a dependent direct-flow scheme.

According to the method of stimulating the movement of the coolant: with natural circulation (gravity) and with artificial circulation (pump or elevator).

According to the scheme for connecting heating devices to heat pipelines: two-pipe and single-pipe. In two-pipe systems, heating devices are connected in parallel to two independent heat pipes - a hot one, supplying water to the device, and a return one, taking it away from the devices; In single-pipe devices, they are connected in series to one common heat pipe.

According to the method of laying heat pipes (pipes): vertical and horizontal, open or hidden (in channels, grooves).

According to the location of the supply and return lines: with the top placement of the hot water line and the bottom return, or with the bottom placement of the supply line and the top return, as well as with the bottom or top placement of both the supply and return lines.

According to the direction of movement of the coolant in the distribution main heat pipelines and the layout of the latter: dead-end (with the opposite direction of movement of the coolant in the supply and return lines) and associated (with the movement of the coolant in both lines in the same direction).

According to the maximum temperature of hot water entering the heating system: low-grade (up to 65 °C), low-temperature (up to 105 °C) and high-temperature (over 105 °C).

One of the most successful options for a heating distribution scheme is a two-pipe system for distributing the main risers with connections through the manifold to the apartment distribution. Apartment wiring is carried out either according to a two-pipe perimeter or radial scheme. Pipes in the floor are laid either in a corrugated pipe or with thermal insulation with a thickness of at least 9 mm. The last option is preferable. In both options, pipe movement as a result of thermal expansion does not have any effect on the normal operation of the system.

Abroad, a single-pipe system of apartment-by-apartment plinth wiring with an H-shaped connection of heating devices has recently become increasingly widespread. One of the advantages of this scheme is the ease of laying highways along the walls of the serviced premises.

Vertical heating systems come with bottom supply lines and with top supply lines. Both systems have both advantages and disadvantages. For example, in order to implement a heating system with an upper supply line, it is necessary that the building has an attic or an upper technical floor. With lower wiring, the supply lines are located in the basement of the building or on the lower technical floor.

In this case, all shut-off and control valves are easily accessible, balancing, accident localization, etc. can be easily done.

Unfortunately, at present, in multi-storey residential buildings, especially municipal ones, the practice of replacing heating devices provided for by the project with devices of a completely different type is widespread. When replacing a heating device, it is necessary to drain the riser (there is a known case when, in order to replace a heating device, it was necessary to drain water from the heating system of three residential buildings connected to this central heating station at a central heating station). There are many known cases when residents made heated loggias with the transfer of heating devices. There was also a case when an open balcony was converted into a closed one, and five radiators connected to one riser were used to heat it, while the circulation of coolant throughout the entire floor practically stopped. Very often, with two-pipe heating systems with thermostats, residents remove these thermostats (not the thermostatic head, which is acceptable in extreme cases, but the thermostat itself), as a result of which water stops flowing to the upper floors. In this regard, single-pipe heating systems are more stable due to the presence of a closing section.

In one of the cities of the Moscow region, four fairly large residential 14-story buildings were equipped with panel radiators. The heating systems were connected according to an independent scheme through an ITP. Houses with a warm attic, the flow pattern of the coolant is “bottom-up”. A manual air valve is installed at the top of the system in the warm attic. An expansion tank of sufficiently large volume is provided for all four buildings. Three buildings were connected normally, but in the fourth building, due to an error by the maintenance service, the system was not connected to the common closing section (to the expansion tank). As a result, panel radiators in apartments on the upper floors turned into air collectors, and heating devices simply swelled under the influence of excess pressure.

If it is possible to equip a two-pipe system in the required way, and then operate it professionally, you can use such a scheme. If there are no such possibilities, then it is still safer to use a one-pipe system. In addition to reliability, such a system will also be cheaper.

If you do not carefully insulate the risers, then even with a two-pipe heating system, the temperature of the coolant in each heating device will vary. Thus, in a two-pipe heating system on the last two floors of a 16-story residential building, the coolant temperature is not 95/70 °C, but 80/65 °C, which causes complaints from residents.

Nowadays, a technical solution adopted in European countries is sometimes borrowed, when the circulation pump of the heating system is installed on a direct line (hot). Here you need to keep in mind that previously in these countries, with coolant parameters of 90/70 °C, pumps were installed, as a rule, on the return line. Then, when going to parameters 75/

65 °C, it has become possible to install the same pumps on a direct line, since they can fully withstand the specified temperature, and in the system, due to such an installation, additional pressure is provided at which the heating system operates more stably. But in high-rise buildings at the upper geometric point the pressure must be at least 10 m of water. Art. In this case, installing a pump on the return line has virtually no effect on the operation of the heating system, since the pressure itself is quite high there.

The transition in European countries to coolant parameters from 90/70 °C to 75/65 °C led to the fact that the coolant consumption immediately doubled, the surface area of ​​heating devices and the diameter of pipes increased, which led to an increase in the cost of heating equipment. However, such a reduction in parameters has its own certain advantages. Firstly, useless irrecoverable heat loss is reduced (all risers are well insulated). Secondly, in systems with autonomous heat supply sources, for example, electric boilers, these boilers work better at lower temperatures of heated water (or antifreeze).

Reversed circulation heating systems emerged in the 1960s when single-pipe heating systems became widely used. With this heating organization scheme, the coolant circulates “bottom-up”. This scheme was proposed to compensate for heat loss through infiltration.

Currently, when calculating a heating system, only the ventilation load is often taken into account. This value is constant for all floors of a multi-story residential building. Infiltration depends on height. On the lower floors, the load on the heating system from heat loss due to infiltration is higher than on the upper floors. But with inverted circulation, a coolant with a higher temperature is supplied to the heating devices of the lower floors, which makes it possible to compensate for a slightly higher heating load. Another advantage of this scheme is improved air removal. This scheme also has disadvantages. One of the disadvantages is a slight decrease in the wicking coefficient, as a result of which heating devices perform worse, and the wicking coefficient varies depending on the type of heating device.

The characteristics of heating devices according to our standards are determined at a barometric pressure of 760 mm Hg. Art. This is due to the fact that our domestic heating devices, even radiators, transferred a fairly large proportion of heat to the room through convective heat exchange. The convective component depends on how much air flows around the heating device. This volume depends on the density of the air, which in turn depends not only on temperature, but also on barometric pressure. Therefore, for example, when designing a heating system for a facility located in Krasnaya Polyana, where the barometric pressure is below 760 mm Hg. Art., it should be taken into account that the heat transfer of convectors will decrease by 9–12%, and that of radiators by 8–9%.

Traditional heating devices – cast iron radiators(mainly sectional) - are highly reliable when used in domestic conditions, can be used in dependent heating systems of buildings for various purposes, with the exception of heating systems with antifreeze. The fact is that due to the not very high quality of processing of the joints of radiator sections, rubber seals are used in these units instead of paronite gaskets. These rubber seals change their structural properties when exposed to antifreeze.

Currently, the market offers models of cast iron radiators designed for an operating pressure of not 9, but 12 atm. It should also be noted that, according to the ABOK Standard “Heating radiators and convectors. General technical conditions" (STO NP "AVOK" 4.2.2–2006), more stringent requirements are imposed on the strength characteristics of heating devices: the test pressure of cast heating devices (including cast iron and aluminum radiators) must exceed the working pressure by 6 atm. or 1.5 times, and the burst pressure should exceed the working pressure by at least 3 times. It follows from this that radiators that are tested at 9 atm can operate at a pressure of 3 atm, and not 6, which is often declared by the manufacturer. Also, radiators tested at a pressure of 15 atm are designed for an operating pressure of 9, not 10 atm. This point must always be kept in mind, since there are cases where imported cast iron radiators were destroyed due to high pressure.

To a large extent, the high share of cast iron radiators (the share of consumption in Russia is 46–48%) is determined by the realities of our operation, since the coolant (water) often does not meet the requirements for it. The only document that formulates water requirements is the “Rules for the technical operation of power plants and networks of the Russian Federation” (previously this document had the number RD 34.20.501–95). Clause 4.8 of this document is called “Water treatment and water-chemical regime of thermal power plants and heating networks,” and this clause sets requirements for water used in heat supply systems and, accordingly, in heating systems, especially if the heating system is connected via a dependent scheme. It is necessary to note several important points from these technical operating rules that are relevant from the point of view of the use of heating devices. So, according to this document, the oxygen content in water should not exceed 20 μg/dm 3.

In Europe, this requirement is less stringent - the amount of dissolved oxygen in water should not exceed 100 μg/dm 3, and this norm is almost always observed. Proposals have been made to harmonize domestic standards with European ones in this regard. However, experience in operating domestic heating systems has shown that these standards are often not observed, sometimes being overestimated by 10–100 times. If we adopt a less stringent European standard and increase it by the same amount, the consequences can be very serious.

It is also necessary to keep in mind that cast iron sectional radiators should be remounted, tested before installation, and painted after installation. All these operations cause additional costs, which can be estimated at about $20 per 1 kW. This additional cost must be included in the estimate. There are known cases when only the cost of the radiators themselves were included in the estimate, and then, to compensate for unaccounted additional costs, the thermostatic and balancing valves provided for in the project were replaced with cheaper ball valves. A number of manufacturers offer their radiators already fully painted and prepared for installation; accordingly, the cost of such radiators is slightly higher. Regarding the cost of cast iron radiators, it can be noted that the indicated cost is subject to quite noticeable sharp fluctuations. In particular, some time ago there was a sharp increase in the cost of such devices, although by now the situation has stabilized.

The cost of domestic models of cast iron radiators is currently 1,400–1,500 rubles/kW. The additional cost of regrouping, leak testing, installation and painting is 400–500 rubles/kW.

With cast iron radiators, a fairly large proportion of heat, about 35%, is transferred to the room through radiant heat exchange. However, there are cases when unqualified maintenance service, during the renovation of premises, painted such radiators with paint based on aluminum powder (“silver”), thereby immediately reducing the heat transfer of heating devices by approximately 10–15%.

Steel tubular radiators and design radiators(sectional, columnar, block and block-sectional) are distinguished by a wide range and good appearance. These devices are supplied fully ready for construction. The thickness of the steel for the radiator head is usually 1.5 mm, and the thickness of the walls of the vertical pipes is 1.25 mm, although devices with pipe walls 1.5 mm thick are sometimes supplied. A number of manufacturers have models of devices with a special coating of internal walls, designed for the use of low-quality water as a coolant.

In addition to modern design, the advantages of these devices include hygiene and safety. Models with a built-in thermostat are presented. However, devices of this type require strict adherence to operating rules. Panel and tubular radiators often fail not because of oxygen dissolved in the water, but because of sludge corrosion due to dirt deposition.

The cost of steel tubular radiators is 2,500–3,000 rubles/kW. The share of consumption in Russia is 1.5–2%.

Radiators made of aluminum alloys(aluminum radiators), as a rule, have very good design solutions. Among their advantages, in addition to modern design, are a wide range of products and delivery of complete construction readiness.

For the manufacture of aluminum radiators, silumin (an alloy based on aluminum and 4–22% silicon) is usually used. This material does not interact very well with a coolant that has a lot of dissolved oxygen or a high pH (it can be recalled that a neutral environment has a pH value of 7, an acidic environment is below 7, and an alkaline environment is above 7). Aluminum and its alloys are not very susceptible to acidic environments. Manufacturers of such devices usually state among the requirements for the coolant a pH value of 7–8. However, according to the requirements of the above-mentioned “Rules for the technical operation of power plants and networks of the Russian Federation”, the pH value for open heat supply systems is 8.3–9.0, closed – 8.3–9.5, and the upper limit is allowed only when deep softening of water, and for closed heat supply systems, the upper limit of the pH value is allowed to be no more than 10.5 while simultaneously reducing the carbonate index value; the lower limit can be adjusted depending on corrosion phenomena in the equipment and pipelines of heat supply systems. In real operating conditions, the pH of the coolant is, as a rule, from 8 to 9. It follows that formally, aluminum radiators cannot be used in our conditions, with the exception of cottages. In cottages, the coolant circulates in a closed circuit, as a result of which a chemical equilibrium is established in the system after some time; in addition, in the heating systems of such objects the pressure is relatively low.

Recently, some dealers have specified an expanded pH value from 5 to 11 among the coolant requirements. However, experience in testing and actual operation shows that at a pH value of 10, intensive thread destruction occurs in aluminum heating devices. Thus, during hydraulic tests, due to the destruction of the threads, plugs flew out of such radiators. To prevent such situations, in recent years, manufacturers have begun to apply a special protective coating to the inner surface of such heating devices. In addition, aluminum alloys of a special composition, insensitive to high pH, ​​began to be used for the manufacture of heating devices. This is the so-called “marine” aluminum - an aluminum alloy characterized by high corrosion resistance and strength.

Sometimes the situation is aggravated by the fact that galvanized pipes are used in heating systems, as a result of which the speed of the electrochemical reaction increases sharply. To prevent this, you can use shut-off and control valves in a brass or bronze body for transitions.

Problems also arise in cases where in a heating system with aluminum heating devices, heat pipes made of copper are used in any area. For example, copper tubes can be used in heat exchangers installed in ITP. In this case, it is not aluminum radiators that are destroyed, but copper products.

In systems with aluminum radiators, as operating experience has shown, automatic air vents do not always operate reliably. It is better to use manual air vents, and in order to avoid ignition of an explosive mixture, it is strictly forbidden to use open fire when performing this operation.

As noted above, aluminum radiators can be used in cottages. Another possible area of ​​application for such heating devices is office buildings of large companies, which have their own highly qualified operation service, which does not allow the replacement of individual heating devices with devices with other characteristics, strictly maintains the specified operating conditions, etc.

As a rule, it is not recommended to use aluminum radiators in multi-storey residential buildings. In general, all models of aluminum radiators require strict adherence to installation and operation rules.

The cost of radiators made of aluminum alloys is 2,000–2,600 rubles/kW. The share of consumption in Russia is 16%, of which 6% is the share of bimetallic and bimetallic with aluminum collectors.

To prevent possible problems characteristic of aluminum radiators - gas emissions, electrochemical corrosion, etc. - bimetallic radiators were developed. These heating devices are approximately 20–25% more expensive than aluminum ones. Bimetallic radiators come in two types. Radiators of the first type (sectional, columnar and block) have an all-steel manifold. This steel manifold is then filled with aluminum alloy under high pressure. As a result, such radiators form well-developed external fins, like conventional aluminum ones. The sections are assembled on steel nipples. As a result, there is no contact between steel and aluminum on the coolant side. These devices are equivalent in performance to cast iron radiators. However, such devices are quite difficult to manufacture. For example, steel billets have a linear thermal expansion that is half that of aluminum fins. As a result of this, even a small mistake when pouring the aluminum alloy can lead to the fact that the mounting height of the section will differ from the nominal one, which makes the assembly of the heating device impossible in principle. There are other technological difficulties. Because of these difficulties, some manufacturers use only individual steel parts, and the manifolds themselves are made of aluminum. In devices of this type, gas formation as a result of electrochemical corrosion is not completely prevented, although it is significantly reduced.

The cost of bimetallic radiators of the first type is 2,500–3,000 rubles/kW, of the second type – 2,400–2,800 rubles/kW. The share in the Russian market is indicated above.

Abroad, the most common type of heating devices are steel panel radiators. Their advantages are modern design, wide range, complete construction readiness, high hygiene (models without fins). Models are available with a built-in thermostat.

Several versions of domestically produced devices of this type are made of 1.4 mm thick steel and are designed for a maximum operating excess coolant pressure of 10 atm. The minimum test pressure in this case is 15 atm. Here we take into account the fact that for panel radiators the minimum permissible normalized destruction pressure increases not by 3 times, compared with the maximum operating pressure of the coolant, as for cast heating devices, but by 2.5 times, since heating devices of this type lead to increased pressure. yourself a little differently. Already at 9–10 atm. their paint layer begins to crack. Then, after the pressure exceeds 15.5–16 atm. The panel radiator begins to swell. The destruction of the device usually occurs at a pressure of 25–30 atm. Thus, these devices meet all the stated parameters. Moreover, thanks to the spring properties of the structural material, these heating devices can dampen hydraulic shock to some extent.

All models of steel panel radiators require strict adherence to operating rules. Their cost is 800–1,300 rubles/kW, the share of consumption in Russia is 15%.

Convectors(wall-mounted, floor-mounted, with a casing, without a casing, steel, using non-ferrous metals) are highly reliable in operation in domestic conditions and can be used in dependent heating systems of buildings for various purposes. In addition, among their advantages are low inertia, a wide range, modern design, low temperature of the external elements of the convector structure, eliminating the risk of burns. The devices are supplied fully ready for construction; there are models with a built-in thermostat.

Among convectors, two types of structures can be distinguished. For convectors of the first type, the casing contributes to the formation of the “draft effect”. When removing the casing, the heat transfer of the heating device is reduced by 50%. For convectors of the second type, the casing performs a purely decorative function; removing it not only does not reduce heat transfer, but can even increase the efficiency of the device. In addition, removing the casing helps reduce contamination of the heating device and improves the conditions for its cleaning. However, in order to determine what type of convector is installed and whether the casing can be removed, apartment owners should consult with specialists.

The cost of steel convectors is 500–750 rubles/kW, convectors with a copper-aluminum heating element – ​​1,500–2,300 rubles/kW. The share of consumption in Russia is 16%.

Separately, we can highlight special heating devices - convectors built into the floor structure, fan convectors. These devices are intended mainly for “elite” class buildings and cottages. Their cost is 3,000–10,000 rubles/kW, the share of consumption in Russia is 0.5–1%.

From the experience of operating heating devices, there are cases when, due to the local entry of a stream of cold air from a window open in winter ventilation mode, heating devices locally froze and burst. Typically, cast iron and, to a lesser extent, aluminum radiators are susceptible to such freezing. In this case, convectors almost never freeze. Therefore, ventilating a window with a sash from the position of protecting heating devices from rupture when freezing is quite dangerous. It is preferable to use traditional windows for ventilation in our country.

To save thermal energy, heating devices can be equipped with thermostats. Here it is necessary to pay attention to the fact that a thermostat is not a shut-off valve, but only a control valve, therefore installing a thermostat in no way eliminates the need to install ball valves to turn off individual heating devices.

However, to save thermal energy in heating systems, simply installing thermostats is not enough. The thermostat allows you to regulate the heat load in accordance with the actual heat balance of the room; a particularly large effect of saving thermal energy is achieved during the transition period, when overheating is quite frequent in warm weather. However, in the absence of thermal energy metering, the installation of thermostats provides more comfortable conditions in the serviced room than energy savings, which are only about 5–8%. When connecting each individual apartment through collectors, it is possible to install an apartment-by-apartment heat meter. These heat meters are not intended for commercial accounting of heat energy, but allow mutual settlements with the owners of each apartment, taking into account the readings of the heat meter at the entrance to the building: by comparing the indicators of the general and apartment heat meters, it is established what share of the consumed heat energy is paid by each tenant. In general, in Moscow, a decision was made to install an ITP in every building, and in each ITP, in turn, a heat meter is installed.

The installation of heat meters is associated with many different problems. For example, it should be borne in mind that abroad the procedure for paying for consumed thermal energy according to heat meter readings is often established at the state level. This procedure is not legalized in our country. The heat meters themselves are quite expensive; in addition, they require periodic inspection, which also requires financial costs. As a result, for an individual resident, installing a meter may in some cases be inappropriate from an economic point of view, although installing a meter already forces people to save thermal energy.

Another problem that needs to be solved when installing a heat meter is the allocation of apartments in which installing meters is generally impractical. In one of the regions of Russia, an entire urban residential block was reconstructed, during which tachometer heat meters (“turntables”) were installed in all apartments. However, heat meters with a sensitivity of 36 kg/h were used. This sensitivity is comparable to the calculated coolant flow for a one-room apartment, and the meters in one-room apartments simply did not work. As a result, for one-room apartments, payment for thermal energy was introduced not according to meter readings, but in proportion to the area of ​​the apartment, but at the same time, all the savings that were achieved in 2-3-room apartments were included in the price.

According to a number of foreign data, experience in the operation of multi-apartment buildings in Europe has shown that when calculating the heating system for a difference of 90–70 °C, the installation of heat meters is justified only in apartments whose area exceeds 100 m2 (of course, in this case it is more correct to talk about the load apartments, but since here we are talking about apartments of the same type with good thermal insulation, sealed windows, etc., we can conditionally talk about the area). In some countries, at the level of regulatory documents, it is allowed not to install meters in apartments with an area of ​​less than 100 m2, and therefore relatively cheap municipal apartments are limited to this area.

If it is not possible to install a heat meter, the consumption of thermal energy can be metered using “thermal energy distributors”, more precisely, distributors of the cost of consumed heat. These devices are not meters that show the total amount of thermal energy consumed, but rather allow you to determine the cost of heat consumed by each individual apartment. However, the payment procedure must be clearly and unambiguously defined here. It should be legislated in what proportions the heating of an individual apartment and common areas is paid for. For example, in European countries, unlike Russia, it is legalized what share the apartment owner must pay for heating public areas - staircases, lobbies, rooms for strollers and bicycles, etc.

When installing distributors, certain difficulties arise in determining possible locations for their installation (for example, at what level they should be installed - one third of the height of the device, in the middle, etc.). European-made devices are designed mainly for installation on panel or tubular radiators. Installation of these devices on convectors requires recalculation of readings. In addition, these devices are not designed for use in heating systems in which the coolant moves according to the “bottom-up” scheme, since the distribution of the coolant in the heating device with such a scheme will differ from the distribution of the coolant in the device connected according to the “top-down” scheme " Obviously, to calculate the consumed thermal energy in the latter case, special design coefficients are required, with a different coefficient for each length of the heating device.

Distributors are of two types - with an electronic temperature sensor and evaporative type, cheaper. When using evaporative type meters, it is necessary that access to them be provided to the controlling organization. Since the meters are installed inside the apartment, access to them is often impossible. Electronic meters allow you to organize data transmission over a radio channel, so access to each apartment is not required to take readings.

Another problem associated with the installation of heat meters and calculations for actual heat consumption, as foreign experience has shown, a number of apartment owners turn off the heating, especially if they are not in the apartment, and the apartment is heated only by heat input from neighboring apartments. Of course, in this case, heating costs for the owners of these apartments increase. One of the possible solutions here is a payment procedure, when a certain share is paid in proportion to the area of ​​the apartment, part - for heating public areas and part - according to the readings of apartment heat meters or distributors.

Is it advisable to install an automatic thermostat on heating devices when the heating system is connected to heating networks in a dependent manner?

From the point of view of creating comfortable indoor conditions and saving energy, installing automatic thermostats is advisable in any case. However, it is necessary to determine whether the quality of the water circulating in the heating networks allows the use of this control valve. If the network water contains a large amount of contaminants, it is preferable to use manual thermostats.

It is impossible to imagine heating a room without heating devices, which are presented on the market in a fairly wide variety of types. In order to choose the most suitable option for yourself, you have to take into account a number of factors.

What are there

Classification of heating devices is carried out according to the following criteria:

• Coolant type. Can be liquid or gaseous.
• Material of manufacture.
• Technical specifications. This refers to dimensions, power, installation features and the presence of adjustable heating.

When choosing the best option, you need to take into account the characteristics of the home’s heating system and operating conditions. In this case, the entire list of requirements and standards relating to heating devices must be observed. Along with the power of the products, the specifics of their installation are of great importance. In the absence of a gas supply and the possibility of installing water heating, there is still an option with electric heaters.

Water heating system design

Water heating is the most common method of heating buildings. This explains the presence on sale of a significant variety of types of heating devices for water circuits. The reasons lie in the good level of efficiency of these products, as well as reasonable costs for purchase, installation and maintenance. The designs of these heating devices are very similar to each other. The core of each of them is a cavity: hot water circulates through it, heating the surface of the battery. Next, the convection process comes into play, transmitting heat to the entire room.

Radiators for water heating systems can be made from the following materials:

1. Cast iron.
2. Steel.
3. Aluminum.
4. Combinations of materials (so-called “bimetallic batteries”).

Each of these types of heating devices has its own specifics. In each specific case, it is necessary to take into account the area of ​​the heated room, installation features, quality and type of coolant used (for example, in some cases antifreeze is used). To regulate the battery power, it is possible to extend or detach sections. It is advisable that the length of one radiator does not exceed 1.5-2 meters.

Cast iron batteries

The cast iron type of heating devices is one of the most common options for completing domestic centralized systems. It was preferred to other varieties mainly because of its low cost. Subsequently, devices of this type began to be gradually replaced by devices with a higher heat transfer coefficient (for cast iron batteries it is only 40%). Currently, old-style systems are mainly equipped with cast iron radiators. As for modern interiors, you can find designer cast iron models in them.

The strengths of heating devices include a significant surface area through which energy is transferred from the coolant to the surrounding space. Another noticeable advantage is the durability of cast iron batteries: they can last 50 years or more without problems. There are also disadvantages, and there are many of them. Firstly, the coolant is used in very large volumes (up to 1.5 liters for each section). The cast iron heats up slowly, so you have to wait until, after turning on the boiler, heat begins to flow into the rooms. Repairing such batteries is not easy, and in order to minimize the likelihood of breakdowns, they have to be cleaned every 2-3 years. Installation work is complicated by the large weight of the radiators.

Aluminum batteries

Aluminum devices are characterized by very high heat transfer, which allows the power of one section to be increased to 200 W. This is quite enough to fully heat 1.5–2 m2 of living space. The advantages of aluminum batteries also include their low cost and low weight, which significantly simplifies installation work. In terms of service life, aluminum appliances are almost twice as long as their cast iron counterparts (they can last no more than 25 years).

Bimetallic batteries

The strength of bimetallic structures are special convection panels that increase the quality of air circulation. In addition, devices of this type can be equipped with special regulators, with the help of which you can increase or decrease the coolant flow. Installation work in its simplicity resembles the installation of aluminum radiators. Each section has a power of 180 W, providing heating of 1.5 m2 of area.

In some cases, the use of water-type heating devices encounters serious difficulties. For example, bimetallic radiators cannot be installed in systems where antifreeze is used as a coolant. These non-freezing liquids, which protect pipes from freezing, can have a destructive effect on the inside of batteries. You should also take into account the high cost of this heating option.

Electric types of heaters

In cases where problems arise with the organization of water heating, it is customary to use electric heaters. They are also available in several varieties, differing from each other in power and method of heat transfer. The most significant disadvantage of household heating devices of this kind is the high cost of electricity consumed. In this case, it is often necessary to lay new wiring designed for increased loads. If the total power of all electric heaters exceeds 12 kW, technical standards provide for the organization of a network with a voltage of 380 V.

Convection type heating devices

Convection-type electric heaters are characterized by the ability to heat rooms at high speed, which is facilitated by circulating flows of warm air. The lower part of the devices is equipped with special holes for sucking in air flows, for heating which heating elements are used (warm air exits through the upper notch). The power of modern heating devices of this type ranges from 0.25-2.5 kW.

Oil radiators

The principle of convection is also used in the operation of oil electric heaters. A special oil is poured inside the device to be heated by a heating element. To regulate heating, a thermostat is often used, turning off the power when the desired temperature is reached. Oil-based devices have high inertia. This manifests itself in the slow heating of the device and the same slow cooling after the power supply is cut off.

The surface temperature is usually heated to 110–150 degrees, which ensures compliance with safety regulations. Such a device must not be installed close to flammable surfaces. Oil radiators are equipped with convenient adjustment of heating intensity, designed for 2–4 operating modes. Keeping in mind the power of one section (150–250 kW), choosing the optimal model for heating a particular room is not at all difficult. The maximum power of such a device is limited to 4.5 kW.

Infrared heating

The choice of infrared heating devices brings the following dividends:

• Energy savings of up to 30% when compared with conventional electrical appliances.
• Oxygen in the air does not burn.
• The room heats up in a matter of minutes.

Infrared devices are classified according to the method of wave transmission. In new heating devices, radiation is transmitted into the surrounding space thanks to resistor conductors installed on a special film. The power of warm mats can reach 800 W/m2. Film heaters are convenient because they can be used to create heated floors.

As for carbon emitters, the waves are emitted in spirals from a sealed transparent bulb. The power of such devices is in the range of 0.7-4.0 kW. The power of carbon heaters is an order of magnitude higher, which requires more stringent fire safety measures.

Gas heating

To save money, you can use gas heaters. Their simplest variety is a gas convector, which is connected to a main gas pipeline or a liquefied propane cylinder. The burner of the device is completely protected from contact with the surrounding atmosphere: in this case, a special tube is used to supply oxygen, which is led outside through a hole in the wall. These devices are characterized by high power (at least 8 kW) and low cost of operation. Among the weaknesses of gas heaters are the mandatory registration with regulatory agencies, the need for effective ventilation and the need for regular cleaning of nozzles.

One of the main elements of water heating systems - a heating device - is designed to transfer heat from the coolant to the heated room.

To maintain the required room temperature, it is required that at each moment of time the heat loss of the room Qп is covered by the heat transfer of the heating device Qпp and pipes Qтp.

The heat transfer diagram of the heating device Qпp and pipes to compensate for the heat losses of the room Qп and Qadd during heat transfer Qт from the water coolant side is shown in Fig. 24.

Rice. 24. Heat transfer diagram of a heating device located near the external fence of the building

The heat Qt supplied by the coolant for heating a given room must be greater than the heat loss Qp by the amount of additional heat loss Qadd caused by increased heating of the building's building structures.

Qt=Qp + Qadd

A heating device is characterized by the heating surface area Fpp, m2, calculated to ensure the required heat transfer of the device.

Heating devices, according to the predominant method of heat transfer, are divided into radiation (ceiling radiators), convective-radiation (devices with a smooth outer surface) and convective (convectors with a ribbed surface).

When heating rooms with ceiling radiators (Fig. 25), heating is carried out mainly due to radiant heat exchange between heating radiators (heating panels) and the surface of the building structures of the room.

Rice. 25. Suspended metal heating panel: a - with a flat screen; b - with a wave-shaped screen; 1 - heating pipes; 2 - visor; 3 - flat screen; 4 - thermal insulation; 5 - wave-shaped screen

Radiation from a heated panel, hitting the surface of fences and objects, is partially absorbed and partially reflected. In this case, so-called secondary radiation occurs, which is also ultimately absorbed by objects and fences in the room.

Thanks to radiant heat exchange, the temperature of the internal surface of the enclosures increases compared to the temperature with convective heating, and the surface temperature of the internal enclosures in most cases exceeds the room air temperature.

With panel radiant heating, due to the increase in surface temperature in the room, an environment favorable for humans is created. It is known that a person’s well-being significantly improves with an increase in the share of convective heat transfer in the total heat transfer of his body and a decrease in radiation to cold surfaces (radiative cooling). This is exactly what is ensured with radiant heating, when heat transfer from a person by radiation decreases due to an increase in the surface temperature of the fences.

With panel radiant heating, it is possible to lower the air temperature in the room compared to the usual (normative for convective heating) (on average by 1-3° C), and therefore the convective heat transfer of a person increases even more. It also helps improve a person's well-being. It has been established that under normal conditions, people's well-being is ensured at an indoor air temperature of 17.4° C with wall heating panels and at 19.3° C with convective heating. This makes it possible to reduce the consumption of thermal energy for space heating.

Among the disadvantages of the panel radiant heating system, the following should be noted:

Some additional increases in heat loss through external fences in those places where heating elements are embedded in them;-

The need for special fittings for individual regulation of heat transfer of concrete panels;

Significant thermal inertia of these panels.

Devices with a smooth outer surface are sectional radiators, panel radiators, and smooth-tube devices.

Devices with a ribbed heating surface - convectors, finned pipes (Fig. 26).

Rice. 26. Diagrams of heating devices of various types (cross section): a - sectional radiator; b - steel panel radiator; c - smooth-tube device of three pipes; g - convector with casing; D - device made of two finned tubes: 1 - channel for coolant; 2 - plate; 3 - edge

Based on the material from which heating appliances are made, a distinction is made between metal, combined and non-metallic appliances. Metal appliances are made mainly of gray cast iron and steel (sheet steel and steel pipes). Copper pipes, sheet and cast aluminum and other metals are also used.

In combined appliances, a heat-conducting material (concrete, ceramics, etc.) is used, into which steel or cast iron heating elements (panel radiators) or finned metal pipes are placed and a non-metallic (for example, asbestos) casing (convectors).

Non-metallic devices include concrete panel radiators with embedded plastic or glass pipes, or with voids, as well as ceramic, plastic and other radiators.

By height, all heating devices are divided into high (over 650 mm in height), medium (over 400 to 650 mm), low (over 200 to 400 mm) and baseboard (up to 200 mm).

Based on the magnitude of thermal inertia, devices of low and high inertia can be distinguished. Low-inertia devices have a small mass and hold a small amount of water. Such devices, made on the basis of small-section metal pipes (for example, convectors), quickly change the heat transfer to the room when regulating the amount of coolant admitted into the device. Devices with high thermal inertia are massive, holding a significant amount of water (for example, concrete or sectional radiators), heat transfer changes slowly.

For heating devices, in addition to economic, architectural, construction, sanitary, hygienic and production and installation requirements, thermal technical requirements are also added. The device is required to transfer the greatest heat flow from the coolant through a unit area to the room. To fulfill this requirement, the device must have an increased value of the heat transfer coefficient Kpr, compared with the value of one of the types of sectional radiators, which is taken as the standard (cast iron radiator type N-136).

In table 20 shows thermal performance indicators and symbols indicate other indicators of devices. The “plus” sign indicates positive indicators of the devices, and the “minus” sign indicates negative indicators. Two pluses indicate indicators that determine the main advantage of any type of device.

Table 20

Design of heating devices

A sectional radiator is a convective-radiation type device consisting of individual columnar elements - sections with round or ellipse-shaped channels. Such a radiator releases about 25% of the total heat flux transferred from the coolant into the room by radiation (the remaining 75% by convection) and is called a “radiator” only by tradition.

Radiator sections are cast from gray cast iron and can be assembled into devices of various sizes. The sections are connected on nipples with gaskets made of cardboard, rubber or paronite.

Various designs of single-, double-, and multi-column sections of various heights are known, but the most common are double-column sections (Fig. 27) of medium-sized (installation height hm = 500 mm) radiators.

Rice. 27. Double-column radiator section: hp - full height; hm - installation height (construction); b - construction depth

The production of cast iron radiators is labor-intensive; installation is difficult due to the bulkiness and significant mass of the assembled devices. Radiators cannot be considered to meet sanitary and hygienic requirements, since cleaning the intersectional space from dust is difficult. These devices have significant thermal inertia. Finally, it should be noted that their appearance does not correspond to the interior of premises in buildings of modern architecture. These disadvantages of radiators make it necessary to replace them with lighter and less metal-intensive devices. Despite this, cast iron radiators are the most common heating device today.

Currently, the industry produces cast-iron sectional radiators with a construction depth of 90 mm and 140 mm (type “Moscow” - abbreviated as M, type IStandardI - MS and others). In Fig. 28 shows the designs of manufactured cast iron radiators.

Rice. 28. Cast iron radiators: a - M-140-AO (M-140-AO-300); b - M-140; c - RD-90

All cast iron radiators are designed for operating pressure up to 6 kgf/cm2. The heating surface of heating devices is measured by a physical indicator - a square meter of heating surface and a thermal indicator - an equivalent square meter (ecm2). An equivalent square meter is the area of ​​a heating device that releases 435 kcal of heat in 1 hour with a difference in the average temperature of the coolant and air of 64.5 ° C and a water flow rate in this device of 17.4 kg/hour according to the flow pattern of the coolant from top to bottom.

Technical characteristics of radiators are given in table. 21.
Heating surface of cast iron radiators and finned tubes
Table 21

Continuation of the table. 21

Steel panel radiators consist of two stamped sheets forming horizontal collectors connected by vertical columns (columnar form), or horizontal channels connected in parallel and in series (serpentine form). The coil can be made of a steel pipe and welded to one profiled steel sheet; such a device is called a sheet-tube device.

Rice. 29. Cast iron radiators

Rice. 30. Cast iron radiators

Rice. 31. Cast iron radiators

Rice. 32. Cast iron radiators

Rice. 33. Cast iron radiators

Rice. 34. Diagrams of channels for coolant in panel radiators: a - columnar; b - two-way coil, c - four-way coil

Steel panel radiators differ from cast iron in their lower mass and thermal inertia. With a weight reduction of approximately 2.5 times, the heat transfer rate is no worse than that of cast iron radiators. Their appearance meets architectural and construction requirements; steel panels are easy to clean from dust.

Steel panel radiators have a relatively small heating surface area, which is why it is sometimes necessary to install panel radiators in pairs (in two rows at a distance of 40 mm).

In table 22 shows the characteristics of manufactured stamped steel radiator panels.

Table 22

Continuation of the table. 22

Continuation of the table. 22

Concrete panel radiators (heating panels) (Fig. 35) can have concrete heating elements of a coil or register shape made of steel pipes with a diameter of 15-20 mm, as well as concrete, glass or plastic channels of various configurations.

Rice. 35. Concrete heating panel

Concrete panels have a heat transfer coefficient close to that of other devices with a smooth surface, as well as high thermal stress of the metal. Devices, especially combined types, meet strict sanitary, hygienic, architectural, construction and other requirements. The disadvantages of combined concrete panels include difficulties in repair, high thermal inertia, which complicates the regulation of heat supply to the premises. The disadvantages of attachment-type devices are the increased cost of manual labor during their manufacture and installation, and the reduction in the usable floor area of ​​the room. Heat loss through additionally heated external fences of buildings also increases.

A smooth-tube device is called a device made of several steel pipes connected together, forming channels for the coolant in a coil or register shape (Fig. 36).

Rice. 36. Forms of connecting steel pipes into smooth-tube heating devices: a - coil form; b - register form: 1 - thread; 2 - column

In the coil, the pipes are connected in series in the direction of movement of the coolant, which increases the speed of its movement and the hydraulic resistance of the device. When the pipes in the register are connected in parallel, the coolant flow is divided, its speed and the hydraulic resistance of the device are reduced.

The devices are welded from pipes DN = 32-100 mm, located from each other at a distance of 50 mm greater than their diameter, which reduces mutual radiation and accordingly increases heat transfer to the room. Smooth-tube devices have the highest heat transfer coefficient, their dust-collecting surface is small and they are easy to clean.

At the same time, smooth-tube devices are heavy and bulky, take up a lot of space, increase steel consumption in heating systems, and have an unattractive appearance. They are used in rare cases when other types of devices cannot be used (for example, for heating greenhouses).

The characteristics of smooth-tube registers are given in Table. 23.

Table 23

A convector is a convective type device consisting of two elements - a finned heater and a casing (Fig. 37).

Rice. 37. Schemes of convectors: a - with a casing; b - without casing: 1 - heating element; 2 - casing; 3 - air valve; 4 - pipe fins

The casing decorates the heater and helps increase heat transfer by increasing air mobility near the surface of the heater. A convector with a casing transfers up to 90-95% of the total heat flow into the room by convection (Table 24).

Table 24

A device in which the heater fins perform the functions of the casing is called a convector without a casing. The heater is made of steel, cast iron, aluminum and other metals, the casing is made of sheet materials (steel, asbestos cement, etc.)

Convectors have a relatively low heat transfer coefficient. Nevertheless, they are widely used. This is due to the ease of manufacture, installation and operation, as well as low metal consumption.

The main technical characteristics of convectors are given in table. 25.

Table 25

Continuation of the table. 25

Continuation of the table. 25

Note: 1. When installing multi-row KP baseboard convectors, a correction is introduced for the heating surface depending on the number of rows vertically and horizontally: for a two-row installation vertically 0.97, three-row - 0.94, four-row - 0.91; for two horizontal rows the correction is 0.97. 2. The performance of end and pass-through models of convectors are the same. Pass-through convectors have index A (for example Nn-5A, N-7A).

A finned pipe is a convective-type device, which is a flanged cast-iron pipe, the outer surface of which is covered with jointly cast thin ribs (Figure 33).

The outer surface area of ​​a finned pipe is many times greater than the surface area of ​​a smooth pipe of the same diameter and length. This makes the heating device particularly compact. In addition, the lower surface temperature of the fins when using a high-temperature coolant, the comparative ease of manufacture and low cost determine the use of this heavy device, which is ineffective in terms of heat engineering. The disadvantages of finned tubes also include their outdated appearance, low mechanical strength of the fins and difficulty in cleaning from dust. Finned pipes are usually used in auxiliary rooms (boiler rooms, warehouses, garages, etc.). The industry produces round ribbed cast iron pipes 1-2 m long. They are installed horizontally in several tiers and connected in a coil pattern with bolts using “rolls” - flanged cast iron double bends and counter flanges.

For comparative thermal characteristics of the main heating devices in table. Figure 25 shows the relative heat transfer of devices 1.0 m long under equal thermal-hydraulic conditions when using water as a coolant (the heat transfer of a cast-iron sectional radiator with a depth of 140 mm is taken as 100%).

As you can see, sectional radiators and convectors with a casing are distinguished by high heat transfer per 1.0 m length; Convectors without a casing and especially single smooth pipes have the lowest heat transfer.

Relative heat transfer of heating devices 1.0 m long Table 26

Selection and placement of heating devices

When choosing the type and type of heating device, the purpose, architectural layout and features of the thermal conditions of the room, the place and duration of stay of people, the type of heating system, the technical, economic and sanitary-hygienic indicators of the device are taken into account.

Rice. 38. Cast iron finned pipe with round fins: 1 - channel for coolant; 2 - ribs; 3 - flange

To create a favorable thermal regime, choose devices that provide uniform heating of the premises.

Metal heating devices are installed mainly under light openings, and under windows the length of the device is desirable to be at least 50-75% of the length of the opening; under shop windows and stained glass windows the devices are placed along their entire length. When placing devices under windows (Fig. 39a), the vertical axes of the device and the window opening must coincide (deviation of no more than 50 mm is allowed).

Devices located near external fences help to increase the temperature of the internal surface at the bottom of the outer wall and window, which reduces the radiation cooling of people. The rising currents of warm air created by the devices prevent (if there are no window sills blocking the devices) the entry of cooled air into the work area (Fig. 40a). In southern regions with short, warm winters, as well as during short-term stays of people, it is permissible to install heating devices near the internal walls of premises (Fig. 39b). At the same time, the number of risers and the length of heat pipes are reduced and the heat transfer of devices increases (by about 7-9%), but air movement with a reduced temperature near the floor of the room, which is unfavorable for human health, occurs (Fig. 40c).

Rice. 39. Placement of heating appliances in rooms (plans): a - under the windows; b - near the internal walls; n - heating device

Rice. 40. Air circulation patterns in rooms (sections) with different locations of heating devices: a-under windows without a window sill; b - under windows with a window sill; c - near the inner wall; n - heating device

Rice. 41. Location of the heating device under the window of the room: a - long and low (preferably); b - tall and short (undesirable)

Vertical heating devices are installed as close as possible to the floor of the premises. When the device is raised significantly above the floor level, the air near the floor surface may become supercooled, since the circulating flows of heated air, closing at the level of the device, do not capture and warm up the lower part of the room in this case.

The lower and longer the heating device (Fig. 41a), the more even the temperature of the room and the better the entire volume of air is heated. A tall and short device (Fig. 41b) causes an active rise of a stream of warm air, which leads to overheating of the upper zone of the room and the lowering of cooled air on both sides of such a device into the working area.

The ability of a tall heating device to cause an active upward flow of warm air can be used to heat rooms of increased height.

Vertical metal appliances are usually placed openly against the wall. However, it is possible to install them under window sills, in wall niches, with special fencing and decoration. In Fig. 42 shows several techniques for installing heating devices in rooms.

Rice. 42. Placement of heating devices - a - in a decorative cabinet; b - in a deep niche; c - in a special shelter; g - behind the shield; d - two tiers

Covering the device with a decorative cabinet having two slits up to 100 mm high (Fig. 42a) reduces the heat transfer of the device by 12% compared to installing it openly against a blank wall. To transfer a given heat flow into a room, the heating surface area of ​​such a device must be increased by 12%. Placing the device in a deep open niche (Fig. 42b) or one above the other in two tiers (Fig. 42d) reduces heat transfer by 5%. However, it is possible to install devices hidden, in which the heat transfer does not change (Fig. 42c) or even increases by 10% (Fig. 42d). In these cases, there is no need to increase the heating surface area of ​​the device or it can even be reduced.

Calculation of area, size and number of heating devices

The area of ​​the heat-transferring surface of the heating device is determined depending on the type of device adopted, its location in the room and the connection diagram to the pipes. In residential premises, the number of devices, and therefore the required heat transfer from each device, is usually determined by the number of window openings. In corner rooms, another device is added, placed in a blank end wall.

The task of the calculation is, first of all, to determine the area of ​​the external heating surface of the device, which, under the design conditions, provides the necessary heat flow from the coolant into the room. Then, from the catalog of devices, based on the estimated area, the nearest commercial size of the device is selected (number of sections or brand of radiator (length of the convector or finned pipe). The number of sections of cast iron radiators is determined by the formula: N=Fpb4/f1b3;

where f1 is the area of ​​one section, m2; the type of radiator accepted for installation indoors; b4 - correction factor taking into account the method of installing the radiator in the room; L3 is a correction factor that takes into account the number of sections in one radiator and is calculated by the formula: b3=0.97+0.06/Fp;

where Fp is the estimated area of ​​the heating device, m2.

In order for the long-awaited warmth to come to your home, it is not enough to simply burn fuel in the firebox and load the coolant with the resulting calories. It is necessary to transfer precious cargo to the premises that need it without undue loss. This is exactly the kind of work that heating appliances do.

The most important place among them is occupied by water heating devices. Water as a coolant has many advantages: it has high fluidity, is environmentally flawless, and is accessible.

Heating devices hydraulic heating systems are radiators, convectors and water (not to be confused with electric!) heated floors. There are also smooth and cast iron finned pipes, but they are used primarily for heating industrial buildings.

Radiator translated from Latin as “radiating”, it gives off up to 30% of the heat flux in the form of radiation, the rest in the form of convection. In a convector, the phenomenon of convection that gives it its name (from the Latin convectio - bringing, delivery) accounts for over 90% of the heat flow. In city apartments and modern suburban housing, heating devices are the main “acting heroes” of heating systems. In city apartments and modern suburban housing, heating devices are the main elements of heating systems. With rare exceptions, heating devices are always visible, and design is important for them. According to marketers, it is given priority by up to 50% of buyers. However, beauty that is difficult to standardize is an important, but not the only characteristic that the buyer pays attention to.

Selection of heating equipment

First of all, the buyer pays attention to the thermal power of the device. . Has improved noticeably in recent years thermal insulation of premises. The result is that significantly less thermal energy is spent on heating them than a decade ago. But during this same time, the number of household appliances in our apartments has visibly increased (computers, microwave ovens, audio systems, etc.), whose total impact on the air temperature in the room cannot be ignored.

nota bene SINGLE-PIPE AND DOUBLE-PIPE SYSTEMS

In a one-pipe system, heating devices are connected in series. As a result, each subsequent coolant arrives colder than the previous one. That is, the temperature depends on the distance of the radiator from the heat source. Such a system is difficult to regulate, and the heating devices used in it must have low hydraulic resistance. With a two-pipe heating system, the coolant is supplied through one pipe and discharged through the other, which allows parallel, independent connection of heating devices. Another advantage of the “two-pipe” is that it allows you to maintain low operating pressures in the system, thereby increasing the service life of communications and making it possible to use cheaper thin-walled radiators. Such schemes are most common in Western European countries. In Russia, especially in houses built in the 1950s–80s, single-pipe systems predominate.

Therefore, today the problem of maintaining optimal temperature and the possibility of adjusting it are relevant. The consumer needs controlled heat. Heat that can lead to a reasonable compromise between two opposing desires - not to feel discomfort and to pay less for thermal energy, which is becoming more expensive every year. This heat is brought into the house by easily controlled heating devices that adequately respond to changes in air temperature (it’s very good if they operate in automatic mode).

It is also an axiom that the consumer should receive absolutely safe heat. That is, completely eliminating even the minimal possibility of mechanical and thermal injuries. A modern heating device should be pleasant not only in appearance, but also to the touch. Despite the fact that the temperature of the water circulating in it may approach 90–95 °C, the temperature of the casing should not exceed an absolutely safe 40–45 °C. This is important both for furniture and for electrical appliances, which are undesirable to be placed next to heating systems. Modern radiators and convectors have reduced the previously quite extensive “exclusion zone” to zero. And now in the immediate vicinity of them you can place televisions, refrigerators and even expensive leather furniture without any fear.

For a modern city dweller, who spends almost twenty-four hours a day within four walls, it is very important that he is also warmed by healthy warmth. A lower external surface temperature than that of old conventional batteries and an increase in the proportion of convection are the two main factors that ensure a more uniform distribution of air temperature in the room, eliminating the causes of drafts, and also contributing to the natural normalization of humidity, preventing the formation of mold and fungi in the room and, as a result, improving the well-being of people who live in these premises.

Water heating systems tend to reduce their size, which, in principle, does not affect the heat supply.

The design of heating devices is not only expressive shapes or pleasing colors, but also small sizes. The evolution of heating devices towards reducing their mass and volume does not occur for aesthetic reasons alone. Small size is also economical. The smaller the heating device (that is, its own mass and the amount of coolant contained in it at a time), which means its thermal inertia is smaller, it reacts faster to temperature changes, adjusting to the desired mode. For example, a heating system with JAGA copper-aluminum radiators reaches full power in just 10 minutes.

The desire to minimize the volume occupied by a heating device, taken to the absolute, is expressed in the production of mini series, presented in the assortment of many manufacturers. These devices are so small (their height is only 8-10 cm) that they can simply be hidden under the floor, which, however, is not at all necessary - a radiator or convector can serve as an interior decoration no less than a stylish interior door, an original lamp or panel on the wall. But hiding communications (valves and connections) under the casing is quite reasonable for any size.

What are they made of?

Radiators and convectors made from various materials - steel, cast iron, aluminum, a combination of several metals (bimetallic radiators).

When choosing a radiator for your home, you need to pay attention to the following characteristics:

• working and test (or pressure testing) pressure; usually their ratio is in the range of 1.3–1.5;
• nominal heat flow (flow determined under standardized conditions: temperature difference – 70 °C, coolant flow rate – 0.1 kg/s when it moves in the device according to the “top to bottom” scheme, atmospheric pressure – 1013.3 GPa);
• dimensions (length, height, depth, center-to-center distance);
• mass and its derivative value - specific material consumption (measured in kg/kW);
• price.

Radiators

Cast iron radiators. Cast iron has high thermal conductivity. For these reasons, heating devices made from it can be used in systems with large pressure drops and poor water treatment (increased aggressiveness, contamination, pieces of scale). The single-pipe systems that predominate in multi-story construction have all these qualities.

Cast iron radiators have been produced for over 100 years. This is a kind of classic on which more than one generation of our fellow citizens was “raised”, who usually called this heating device a battery. Until the 1960s, almost the entire range of heating devices in our country was formed from batteries. And today, this heating device, which was prematurely written off by many, still holds up to 70% of the Russian market.

Modern heating radiators have a good design and high heat output.

In our country, cast iron radiators are most often used, consisting of two-channel sections connected to each other. The number of sections is determined by the calculated heating surface. Single-channel, and abroad multi-channel (up to 9 channels in one section) cast-iron radiators are also used.

Their disadvantages include heavy weight, a significant percentage of manufacturing defects - cracks and cavities formed as a result of poor-quality casting and shortening a potentially very long service life. According to the regulations, the warranty period for radiators is 2.5 years from the date of commissioning or sale within the warranty storage period, and manufacturers and sellers promise at least several decades of impeccable service for these devices. Sometimes cast iron radiators are reproached for the lack of an attractive appearance (remember: “accordion battery”). However, the use of modern design and powder coatings can add charm to these veterans.

Systems that use cast iron radiators are difficult to regulate due to their high thermal inertia. Although there is a way out of this situation, and in some models, by reducing the capacity of the sections, it is possible to effectively use thermostatic elements (such as, for example, thermostats RTD-G, RTD-N from Danfoss).

Domestic products predominate in this class of heating devices. Among the foreign ones, we can highlight cast iron sectional radiators from companies Roca(Spain), Viadrus(Czech Republic), Biasi(Italy), "Santekhlit"(Belarus), Turkish radiators Ridem.

Steel panel radiators are formed from two stamped sheets. In our country, their production began in the 1960s. They are distinguished from sectional cast iron ones by their lower weight (specific gravity per 1 kW is approximately three times lower) and thermal inertia. They are considered “sissies” because they are more sensitive to hydraulic shocks that occur when the system is stopped or started and are afraid of corrosion provoked by frequent drains or high oxygen content in the coolant. In systems where multiple pressure surges “above ordinary” occur, one cannot count on a long service life of steel panel radiators. Typically, the operating pressure of devices of this type does not exceed 9 atm.

expert opinion V.V. Kotkov
Commercial Director of the HitLine Group of Companies

It can be argued that the share of progressive (in relation to the still prevailing classic cast iron) radiator designs is increasing. Today in Europe up to 5 million sections of aluminum radiators are produced annually. To a large extent, the development of this production is stimulated by the Russian market, where demand for them increases annually by 5–10%. Therefore, leading Western companies are trying to adapt their products as much as possible to Russian conditions (the existing problems with water treatment in our country, high unstable pressure in central heating systems, etc.). Although, by tradition, many Russian construction companies give priority to cast iron radiators, the number of companies working with aluminum ones is steadily increasing. After all, an aluminum radiator is not just a private technical solution, but a solution to a whole range of problems related to efficiency, safety and design. It can fit into a modern interior; it does not need to be disguised, spending a lot of money on it.

Steel panel radiators are widely used in low-rise construction. They are especially appropriate for a two-pipe heating system, which is preferred in cottage construction. In multi-storey buildings, it is reasonable to install them if there is an individual heating point, i.e. a boiler room. Three quarters of steel panel radiator sales are to private developers, luxury housing and civil buildings. The most famous company models in our country are: VSZ(Slovakia), Dia Norm, Preussag, Kermi(Germany), Korado(Czech Republic), DeLonghi(Italy), Stelrad(Holland), Purmo(Poland), Roca(Spain), DemirDokum(Türkiye), Impulse West(England, but assembled in Italy), Dunaferr(Hungary).

Tubular and sectional The radiators are similar in appearance, although structurally different - in tubular sections there are no sections as such, and the tubes are connected by two monolithic collectors. Both have an attractive appearance and fit organically into almost any interior. The streamlined shape of the radiator eliminates the possibility of injury to a person. The small capacity of the sections contributes to effective thermoregulation. And if some of its elements are made of finned tubes, then it is possible, without changing the linear dimensions, to significantly increase the power of the radiator.

The working pressure of tubular steel radiators is higher than that of panel radiators - 10 atm or more.

In our market, this type of radiator is represented mainly by German brands Bemm, Arbonia, Kermi.

Aluminum are called radiators made from an alloy of aluminum and silicon (the content of aluminum itself is from 80 to 98%). Aluminum is a material that has high thermal conductivity, but places increased demands on the chemical composition of the coolant. The disadvantage of radiators made of aluminum-silicon alloy with a high silicon content is the generation of hydrogen upon contact with water. The excellent design of most radiators is somewhat spoiled by the automatic air bleed valve installed on each device, since during operation there is an active release of hydrogen.

A significant part of the Russian market of aluminum radiators is occupied by products of Italian companies: Rovall, Industrie Pasotti, Global, Alugas, Aural, Fondital, Giacomini, Nova Florida. Also presented are Spanish radiators Roca, Czech Radus, English Wester, etc.

Bimetallic radiators. Externally similar to aluminum. The sections consist of two thin-walled steel pipes (channels for the passage of coolant), pressed under pressure with a high-quality aluminum alloy. The logic of this symbiosis is based on the fact that aluminum has high thermal conductivity, and steel has strength, guaranteeing operation of the device at excess pressure. Italian companies are the actual monopolists in the production of bimetallic radiators. The most famous brand is Sira.

Bimetallic radiators are both durable and efficient.

Convectors. The basis of the convector design is a heating element enclosed in a casing. Flowing into it from below, cooled room air heats up and rises. Thanks to this, more than 90% of the heat is transferred by convection.

Most widespread convectors received in autonomous systems. They are especially effective at low coolant temperatures. So, they are able to warm up a room at a water temperature of only 40 °C. For user convenience, the convector is equipped with an air valve and a drain tube. The built-in thermostat and water pressure regulator make its operation economical.

The convector fits particularly harmoniously into a modern architectural environment that actively uses large windows, bay windows, winter gardens, etc.

Structurally, it can have four solutions. Radiator convectors are a combination of two devices, reflected in the name itself. They are installed near windows, on the floor or on small stands. Skirting convectors are located in the floor under large windows. The low height (90–100 mm) does not require niches, and weak convective flow can be enhanced by a slowly rotating fan. Convectors recessed into the floor are the best option for residential premises on the first floors. The device is placed in a kind of shaft, cold air passing along the window freely enters the convector, and the flow of warm air ensures natural circulation in the room. And finally, convectors covered with a decorative screen. Unlike radiators, a closed convector does not lose any heat transfer; on the contrary, the screen helps to increase traction.

Pipes for water heating

The operation of heating devices in hydraulic systems is impossible without pipes. The first polymer (polyvinyl chloride) pipes were manufactured in 1936 in Germany. The first pipeline of them was built there in 1939. But the active introduction of polymer pipes into water supply and heating systems began in the mid-1950s, and in our country since the early 1970s.

Both for systems using classic radiators and for heated floors, cross-linked polyethylene pipes are best suited. They are not afraid of a short-term increase in temperature up to +110 °C (their normal operating temperature is usually +95 °C). Despite all their advantages, they have one drawback - the high price.

Used in heating systems and propylene pipes. But the high coefficient of thermal expansion of the material should be taken into account. The service life of polymer pipes can reach 30 years or more. The gasket must be hidden: they are hidden in baseboards, shafts, channels or in the floor structure. If polymer pipes are used in heating systems, then in order to protect them from exceeding the coolant parameters, provision should be made for the installation of automatic control devices.

Metal-plastic pipes combine the advantages of plastic and metal pipes. They are combined with other materials, do not allow oxygen to pass through, and due to the smooth inner surface they have less resistance to leakage than steel, which in conditions of mass use allows saving a lot of energy. The guaranteed service life is at least 20 years, but, as a rule, in reality it reaches 30–50 years. For comparison, according to the State Construction Committee of the Russian Federation, galvanized steel pipes in internal systems last an average of 12–16 years, and “black” pipes last half as long.

Competing water heating systems

Heating device type Stamps Price per conventional unit of equipment with a capacity of 1 kW (in euros) Steel tubular radiator Arbonia Kermi "TERMO-RS", "BITERMO-RS" 100–160 80 Copper-aluminum radiator (Belgium, Russia) JAGA, "Isotherm" 100 Bimetallic radiator (Russia, Czech Republic) SIRA, Style, Bimex 85–95 Cast aluminum radiator (Italy) Elegance, Nova Florida, Calidor Super, Sahara Plus, Global MIX, Global VOX 64–75 Aluminum extrusion radiator (Italy, Russia) Opera RN (“Stupino radiator”) 63 50 Steel panel radiator Kermi, Korado, DeLongi, Stelrad 50 Convector (Russia) "TB Universal" 25 Cast iron radiator MS-140 Demir Dokum, Roca 25 65

Warm floors

From pipes it is logical to make a smooth transition to water heated floors. This heating system has many advantages. Firstly, low (40–55 °C) coolant temperature helps save energy. Secondly, due to the participation of the entire floor surface in heat emission, almost ideal horizontal and close to ideal vertical temperature distribution is ensured. So, if the floor surface temperature is 22–25 °C, then the air temperature at head level is 19-22 °C. People, according to research by hygienists, feel most comfortable if their head is a little colder than their feet. During the hot season, running water at a temperature of 10–12 °C through pipelines can effectively cool the room. Thirdly, water heated floors make it possible to rationally use the living space.

In new buildings with self-leveling concrete floors, the underfloor heating system consists of several layers: a concrete slab, hydro, sound and thermal insulation, film, pipes, concrete screed (the most common concrete of a grade not lower than M-300 is used), a cement layer for leveling the floor and coating. In old buildings, the dry laying method is used, when heating pipes are installed in the insulation of the load-bearing layer in special metal plates that ensure uniform heat distribution.

A water heated floor can also be installed under a wooden floor mounted on floor beams. To do this, a subfloor is made from boards, chipboard, moisture-resistant plywood or cement-bonded particleboard (cement particle board with a thickness of at least 20 mm).

The pipes are fastened in the circuits using reinforcing mesh and wire, fastening tape and mounting brackets.

In accordance with Russian standards, the average temperature of a heated floor should not exceed 26 °C. Therefore, before entrusting a water-heated floor with the role of the main heating system, it is necessary to carefully calculate whether the heat “removed” from it is enough for the room or whether a backup system is still needed.