A variety of modern heating systems - their design and control. Types and types of heating devices Types of heating devices of the heating system

The types of heating devices are determined by their design, which determines the method of heat transfer (convective or radiation heat transfer may predominate) from the external surface of the devices to the room. There are six main types of heating devices, radiators, panels, convectors, finned tubes, smooth tube devices and air heaters.

By the nature of the outer surface heating devices can be with a smooth (radiators, panels, smooth-tube appliances - Appendix 9, A) and ribbed surface (convectors, finned pipes, air heaters - Appendix 9, B).

Based on the material from which heating appliances are made, a distinction is made between metal, combined and non-metallic appliances.

Metal devices are made of cast iron (from gray cast iron) and steel (from sheet steel and steel pipes).

In combined appliances, a concrete or ceramic mass is used, in which steel or cast iron heating elements (heating panels) or finned ones are embedded. steel pipes, placed in a non-metallic (asbestos-cement) casing (convectors).

Non-metallic appliances are concrete panels with embedded glass or plastic pipes or with voids without pipes at all, as well as porcelain and ceramic radiators.

By height, all heating devices can be divided into high (over 600 mm in height), medium (400-600 mm) and low (<400 мм). Низкие приборы высотой менее 200 мм называются плинтусными.

Basically, the choice of the type of heating device depends on financial capabilities, on the required technical qualities of the heating device, and on the quality of the product. A significant role when choosing heating equipment is its type, installation method and the conditions in which it will need to function, as well as its appearance (Appendix 9, B).

Sectional cast-iron radiators - widely used heating devices - are cast from gray cast iron in the form of separate sections and can be assembled into devices of various sizes by connecting the sections on nipples with heat-resistant rubber gaskets. The main advantages of cast iron sectional radiators are that they transfer heat well and withstand relatively high pressure. The large bore diameter and low hydraulic resistance of most cast iron radiators allow them to be successfully used in systems with natural circulation. The disadvantages of cast iron radiators are labor-intensive installation, not the most attractive appearance and high thermal inertia.

The radiator releases about 25% of the total amount of heat transferred from the coolant into the room by radiation, and is called a radiator only by tradition. The panel is a convection-radiation type device of relatively shallow depth, without any gaps along the front. The panel transmits by radiation a slightly larger part of the heat flux than the radiator, but only the ceiling panel can be classified as a radiation-type device (emitting more than 50% of the total amount of heat by radiation). The heating panel may have a smooth, slightly ribbed or wavy surface, columnar or serpentine channels for the coolant.

Aluminum sectional radiators have very good heat transfer, low weight and attractive design. The disadvantages include the fact that they are susceptible to corrosion, which increases when there are galvanic pairs of aluminum with other metals in the heating system.

Bimetallic sectional radiators (having an aluminum body and a steel pipe through which the coolant moves) combine the advantages of aluminum radiators - high heat transfer, low weight, good appearance and, in addition, under certain conditions they have higher corrosion resistance and are usually designed for higher pressure in the heating system. Their main disadvantage is their high price. Due to the fact that these radiators can withstand high pressure, they can be used in city apartments.

Columnar radiators are two separately manufactured collectors (upper and lower), connected by vertical “columns”.

Convectors are a casing with a structure made of metal tubes, which have fins in the form of pressed or welded plates. Column and panel appliances, as well as convectors, are produced in a range of standard sizes, which allows you to choose a model with optimal (for a specific room) power characteristics.

Steel panel radiators are most often used for individual heating. Steel panel radiators have low thermal inertia, which means they make it easier to automatically regulate room temperature. They have become so widespread due to their relatively low cost and many options for height, length, depth and thermal power. In accordance with Russian SNiP, the pressure when testing heating devices must exceed the working pressure by 1.5 times, which happens before the start of each heating season during pressure testing of heating systems.

Modern heating devices intended for installation in bathrooms and hallways are the most numerous in terms of the number of models, sizes, colors and their combinations offered.

For rooms with special requirements for air purity, for example, hospital wards, radiators with the ability to easily clean them from dust are offered, which are parallel panels with free space between them. There are also devices whose fastenings and connection to the heating system allow you to tilt the existing radiator away from the wall to clean its rear wall of dust.

Heating device- this is an element of the heating system that serves to transfer heat from the coolant to the air of the heated room.

1. Registers made of smooth pipes They are a bundle of pipes located in two rows and connected on both sides by two pipes - manifolds, equipped with fittings for supplying and discharging coolant.

Registers made of smooth pipes are used in rooms where increased sanitary, technical and hygienic requirements are imposed, as well as in industrial buildings with a high degree of fire hazard, where a large accumulation of dust is unacceptable. The devices are hygienic and easy to clean from dust and dirt. But they are not economical, they consume metal. Calculated heating surface of 1 m of smooth pipe.

2. Cast iron radiators. A block of cast iron radiators consists of sections cast from cast iron connected to each other by nipples. They come in 1-2 and multi-channel types. In Russia, there are mainly 2-channel radiators. Based on the mounting height, radiators are divided into high 1000 mm, medium 500 mm and low 300 mm.

M-140-AO radiators have intercolumn fins, which increases their heat transfer, but reduces aesthetic and hygienic requirements.

Cast iron radiators have a number of advantages. This:

1. Corrosion resistance.

2. Well-established manufacturing technology.

3. Easy to change the power of the device by changing the number of sections.

The disadvantages of these types of heating devices are:

1. High metal consumption.

2. Labor-intensive manufacturing and installation.

3. Their production leads to environmental pollution.

3. Finned tubes. They are a pipe cast from cast iron with round ribs. The fins increase the surface area of ​​the device and reduce the surface temperature.

Finned pipes are used mainly in industrial enterprises.

Advantages:

1. Cheap heating devices.

2. Large heating surface.

Flaws:

Do not meet sanitary and hygienic requirements (difficult to clean from dust).

4. Stamped steel radiators. They consist of two putty steel parts connected to each other by resistance welding.

There are: column radiators RSV 1 and coil radiators RSG 2.

Columnar radiators: form a series of parallel channels connected to each other at the top and bottom by horizontal collectors.

Coil radiators form a series of horizontal channels for the passage of coolant.

Steel plate radiators are manufactured single-row and double-row. Double-row ones are manufactured in the same sizes as single-row ones, but consist of two plates.

Advantages:

1. Small weight of the device.

2. Cheaper than cast iron by 20-30%.

3. Lower transportation and installation costs.

4. Easy to install and meet sanitary and hygienic requirements.

Flaws:

1. Low heat dissipation.

2. Special treatment of heating water is required, since ordinary water corrodes metal. They are widely used in housing in public buildings. Due to the rise in metal prices, production is limited. High price.

5. Convectors. They are a series of steel pipes through which the coolant moves and steel fin plates mounted on them.

Convectors are available with or without a casing. They are manufactured in various types: For example: “Comfort” convectors. They are divided into 3 types: wall-mounted (hung on a wall h=210 m), island-mounted (installed on the floor) and staircase (built into a building structure).

Convectors are manufactured as end-type and through-type. Convectors are used for heating buildings for various purposes. Used mainly in central Russia.

Non-metallic heating devices

6. Ceramic and porcelain radiators. They are a panel cast from porcelain or ceramics with vertical or horizontal channels.

Such radiators are used in rooms that have increased sanitary and hygienic requirements for heating devices. Such devices are used very rarely. They are very expensive, the manufacturing process is labor-intensive, short-lived, and subject to mechanical stress. It is very difficult to connect these radiators to metal pipelines.

7. Concrete heating panels. They are concrete slabs with pipe coils embedded in them. Thickness 40-50 mm. They are: window sill and partition.

Heating panels can be attached or built into the structure of walls and partitions. Concrete panels meet the most stringent sanitary and hygienic requirements, architectural and construction requirements.

Disadvantages: difficulty of repair, large thermal inertia, which complicates the regulation of heat transfer, increased heat loss through additionally heated external structures of buildings. They are used mainly in medical institutions in operating rooms and in maternity hospitals in children's rooms.

Plumbing heating devices must satisfy thermal, sanitary, hygienic and aesthetic requirements.

Thermotechnical assessment heating devices is determined by its heat transfer coefficient.

Sanitary and hygienic assessment- characterized by a design solution of the device that makes it easier to keep it clean.

Temperature of the external surface of the heating device must meet sanitary and hygienic requirements. To avoid intense burning of dust, this temperature should not exceed 95 o C for residential and public buildings, and 85 o C for medical and children's institutions.

Aesthetic evaluation- the heating device should not spoil the interior appearance of the room and should not take up much space.

The heating system uses heating devices that serve to transfer heat to the room. Manufactured heating devices must meet the following requirements:

1. Economic: low cost of the device and low material consumption.
2. Architectural and construction: the device must be compact and match the interior of the room.
3. Production and installation: mechanical strength of the product and mechanization in the manufacture of the device.
4. Sanitary and hygienic: low surface temperature, small horizontal surface area, easy to clean surfaces.
5. Thermal engineering: maximum heat transfer into the room and heat transfer control.

Classification of devices

The following indicators are distinguished when classifying heating devices:

• — the magnitude of thermal inertia (large and small inertia);
• - material used in manufacturing (metallic, non-metallic and combined);
• — method of heat transfer (convective, convective-radiative and radiation).

Radiation devices include:

• ceiling radiators;
• sectional cast iron radiators;
• tubular radiators.

Convective-radiation devices include:

• floor heating panels;
• sectional and panel radiators;
• smooth-tube devices.

Convective devices include:

• panel radiators;
• finned tubes;
• plate convectors;
• tubular convectors.

Let's consider the most applicable types of heating devices.

Aluminum sectional radiators

Advantages

1. high efficiency;
2. light weight;
3. ease of installation of radiators;
4. efficient operation of the heating element.

Flaws

1. 1. not suitable for use in old heating systems, since heavy metal salts destroy the protective polymer film of the aluminum surface.
2. 2. Long-term operation leads to the unsuitability of the cast structure and to rupture.

Mainly used in central heating systems. Operating pressure of radiators from 6 to 16 bar. Note that radiators that were cast under pressure can withstand the greatest loads.

Bimetallic models

Advantages

1. light weight;
2. high efficiency;
3. possibility of quick installation;
4. heat large areas;
5. withstand pressure up to 25 bar.

Flaws

1. have a complex structure.

These radiators will last longer than others. Radiators are made of steel, copper and aluminum. Aluminum material conducts heat well.

Cast iron heating devices

Advantages

1. not subject to corrosion;
2. transfer heat well;
3. withstand high pressure;
4. it is possible to add sections;
5. The quality of the coolant does not matter.

Flaws

1. significant weight (one section weighs 5 kg);
2. fragility of thin cast iron.

The operating temperature of the coolant (water) reaches 130°C. Cast iron heating devices last quite a long time, about 40 years. Heat transfer rates are not affected by mineral deposits inside the sections.

There is a wide variety of cast iron radiators: single-channel, two-channel, three-channel, embossed, classic, enlarged and standard.

In our country, the economical version of cast iron appliances has received the greatest use.

Steel panel radiators

Advantages

1. increased heat transfer;
2. low pressure;
3. easy cleaning;
4. simple installation of radiators;
5. light weight compared to cast iron.

Flaws

1. high pressure;
2. metal corrosion, in the case of using ordinary steel.

Today, a steel radiator heats up better than a cast iron one.

Steel heating appliances have built-in thermostats that provide constant temperature control. The design of the device has thin walls and responds fairly quickly to the thermostat. Discreet brackets allow you to mount the radiator on the floor or wall.

The low pressure of steel panels (9 bar) does not allow them to be connected to a central heating system with frequent and significant overloads.

Steel tubular radiators

Advantages

1. high heat transfer;
2. mechanical strength;
3. aesthetic appearance for interiors.

Flaws

1. high price.

Tubular radiators are quite often used in room design because they add beauty to the room.

Due to corrosion, ordinary steel radiators are not currently produced. If you subject the steel to anti-corrosion treatment, this will significantly increase the cost of the device.

The radiator is made of galvanized steel and is not subject to corrosion. It has the ability to withstand pressure of 12 bar. This type of radiator is often installed in multi-storey residential buildings or organizations.

Heating devices of convector type

Advantages

1. low inertia;
2. small mass.

Flaws

1. low heat transfer;
2. high requirements for coolant.

Convector-type appliances heat the room quickly enough. They have several manufacturing options: in the form of a plinth, in the form of a wall block and in the form of a bench. There are also in-floor convectors.

This heating device uses a copper tube. The coolant moves along it. The tube is used as an air stimulator (hot air rises to the top, and cold air goes down). The air change process takes place in a metal box, which does not heat up.

Convector-type heating devices are suitable for rooms with low windows. Warm air from a convector installed near a window prevents cold air from entering.

Heating devices can be connected to a centralized system, as it is designed for a pressure of 10 bar.

Heated towel rails

Advantages

1. variety of shapes and colors;
2. high pressure levels (16 bar).

Flaws

1. may not perform its functions due to seasonal interruptions in water supply.

Steel, copper and brass are used as manufacturing materials.

Heated towel rails are available in electric, water and combined types. Electric ones are not as economical as water ones, but they allow buyers not to depend on the availability of water supply. Combined heated towel rails must not be used if there is no water in the system.

Radiator selection

When choosing a radiator, you need to pay attention to the practicality of the heating element. Next, you need to remember the following characteristics:

• overall dimensions of the device;
• power (per 10 m2 area 1 kW);
• operating pressure (from 6 bar - for closed systems, from 10 bar for central systems);
• acidic characteristics of water as a coolant (this coolant is not suitable for aluminum radiators).

After clarifying the basic parameters, you can proceed to the selection of heating devices based on aesthetic indicators and the possibility of its modernization.

How to choose the optimal radiators

Russia is located in a climate zone where heating systems are used for a long time. Sometimes the home is heated even for six months. Therefore, experts recommend a more careful approach to the choice of heating devices.

The modern market offers a huge number of models designed for different operating conditions. Often, it is the technical features that become the fundamental criteria that you should focus on when purchasing. But there are still a lot of additional nuances, which we will talk about.

Existing requirements

All heating systems have one purpose - they are designed to create comfortable living conditions in the winter season. The room temperature should be at least 18–20 degrees, but this is not the only condition that a heating device must meet. Let us outline other criteria and requirements on the basis of which one can judge the effectiveness of a heating device and the degree of its perfection.

Classification of criteria

All criteria are conditionally divided into several groups:

1. Sanitary and hygienic. There are standards that limit the maximum surface temperature. Devices should have the smallest horizontal area, which does not allow large amounts of dust to accumulate. The form of the installation should allow for easy cleaning, removing dust and other contaminants, as well as cleaning nearby surfaces.
2. Economic. Any installation must guarantee an optimal price-performance ratio, minimizing the costs of manufacturing, metal use and maintenance during operation.
3. Architectural and construction. Recently, much attention has been paid to the ergonomics and versatility of devices. They should fit well into existing stylistic concepts and occupy a small amount of space.
4. Assembly and production. Any unit must have sufficient strength and reliability. And its installation should not require the involvement of super-professional labor.
5. Operational. Modern heating installations must allow heat transfer to be regulated and ensure sufficient heat and water resistance when operating within the maximum permissible technical parameters.
6. Thermal engineering. It is important to maximize the heat flow given off by the coolant per unit area of ​​the room.

Finding a heating device that would meet all these requirements is almost impossible, since there are no ideal designs. Therefore, manufacturers are still experimenting in this direction, offering modified installations to potential buyers. This explains the wide range of similar products. Each type meets some of the listed requirements. Therefore, when choosing a unit, it is necessary to focus on priority criteria.

For example, the sanitary and hygienic component is important for medical institutions, and the architectural and construction component is important for designer interiors. And in the domestic sphere, most often they pay attention to installation, production and operational requirements, so other indicators may be slightly worse. To understand the priorities in more detail, it is necessary to study the classification of modern heating devices.

Types of Heat Transfer

All heating devices, taking into account the method of transferring heat flow, can be divided into two large groups:

1. Convective systems.
2. Radiant modes.

Convective devices transfer heat by moving air masses. From a school physics course we know that air, when heated, rises, there it cools and falls down. Convective systems consist of installations that heat the air in a room and create natural convection processes in it.

Radiant systems transfer heat using infrared radiation. They act similarly to a natural source of heat - the sun, which heats objects rather than air. Accumulating heat, they then release it to the surrounding space.

Technical features of the convective system

Types of electric convectors

The most striking example of the convective heating method is autonomous and central heating systems. They use various radiators as heating devices.

According to the material of manufacture and the shape of the structure, they are divided:

1. For sectional batteries.
2. Tubular.
3. Panel.
4. Plate models.

What are the advantages and disadvantages of each type?

Sectional

Sectional batteries are separate heating units consisting of a different number of sections, which determines the power of the heating device. Sectional radiators can be made of different materials. The most common- these are cast iron models, but analogue products made of steel, aluminum or bimetal have appeared relatively recently. For higher efficiency, they are made in the form of ribs and channels, have different heights and widths of the ribs, as well as manufacturing design.

Almost all of them require a large amount of coolant. Some have significant limitations for use, but they all have one thing in common - the convection mode of operation. To understand where and how a particular device can be used, it is worth paying attention to the technical features of each.

Cast iron sections

Cast iron heating device

Cast iron radiators are the oldest heating device, which today lives a second life. The design familiar from childhood has become outdated, so cast iron radiators have begun to fit poorly into modern interiors. Manufacturers have not yet been able to find a better alternative, so they have made certain concessions. ABOUT neither changed the shape of the front panel, rounded the corners, reduced the size of the sections, added automation and made a convex volumetric ornament for each section. As a result, the devices were transformed in appearance, so buyers turned their attention to them again.

Cast iron is the only metal that today is ideally suited to the conditions and operating characteristics of a central heating system. It is resistant to corrosion and unpretentious to the quality of the coolant. Cast iron, although it heats up slowly, gives off most of the heat by radiation, heating the room more evenly over its entire height.

Almost all products are designed for an internal system pressure of 9 atmospheres. But they have a large margin of safety, and many years of use of the devices have shown that they are able to function effectively even at an operating pressure of 15 atmospheres. Cast iron has minimal hydraulic resistance, so batteries made from it can be used where natural circulation is provided.

Despite the extensive modernization, manufacturers have not yet been able to eliminate one more drawback. Cast iron products are still heavy, with each section weighing an average of 8kg. Therefore, it is difficult to transport cast iron radiators and install them alone. Cast iron appliances remain difficult to clean, and many people don't like their rough surface.

Aluminum sections

The very first receiver of cast iron products were aluminum sectional radiators. New appliances do not have the disadvantages of cast iron products, but they have completely different disadvantages that are also worth mentioning. But first, the good stuff.

Aluminum radiator

Aluminum installations have improved technical indicators:

1. High level of heat transfer and ideal surface plane.
2. Improved convection transmission method.
3. The light weight of each section is up to one and a half kilograms versus eight.
4. Reduced volume of coolant used - 0.25 liters of water are consumed to fill one section.
5. Fast heating of the room.
6. Possibility of installing automatic units that regulate the operating mode of each section.
7. Wide operating pressure range.

Taking into account such technical features, one could call aluminum batteries ideal heating devices, if not for one BUT. The fragile metal is very sensitive to the pH value of the coolant. If it exceeds the permissible standards even a little, aluminum begins to deteriorate from the inside and becomes porous, like a sponge. Therefore, any water hammer will cause a leak.

When using parts made of other metals, electrochemical corrosion occurs, which can also lead to utility accidents. Therefore, it is permissible to use the described products only in autonomous systems, where it is possible to control the quality of the supplied water and use purification filters.

Bimetal sections

Bimetallic heating radiators

An alloy of two metals was supposed to be a compromise between reliability, ease of operation and efficiency. Manufacturers have managed to create a good alternative to cast iron products. Externally, bimetallic sections are similar to aluminum radiators. They have all their advantages and at the same time are devoid of many disadvantages.

Technologists have figured out how to eliminate contact of the coolant with fragile and capricious aluminum. In bimetallic radiators, water moves through steel pipes that are installed inside an aluminum casing. Steel is a durable material that can withstand operating pressures of up to 30–45 atmospheres. At the same time, the entire product does not weigh much more than aluminum models.

There are no restrictions on the use of bimetallic products today. The inside of steel parts is coated with special polymer compounds that prevent the development of corrosion phenomena. The only drawback of such radiators is their high price compared to other products. And it is precisely this circumstance that is currently hindering the growth of the popularity of bimetal.

Tubular devices

Radiators in the interior

Tubular batteries differ from sectional ones in design. They are made in the form of vertical curved tubes connected to each other at the bottom and top using manifolds. The efficiency of heat transfer is influenced by various factors - the size of the model, its height, width and diameter of the tubes.

Three types of tubular batteries can be found on sale:

1. Steel products.
2. Tubular convectors.
3. Heated towel rails.

They all differ from each other in a host of design features that are also worth highlighting.

Steel tubular radiators

The technical features of tubular steel instruments are well known. The height of the products can be 0.3 or 3 meters. The thickness of the pipe walls also varies. For example, for Russian manufacturers it is 2mm. The device is designed for a pressure of 10–12 atmospheres, but domestic manufacturers produce models that can withstand a working pressure of 15–22 atmospheres. The method of heat transfer is dominated by the radiation rather than the converter mechanism.

The smoothness of the bends and the absence of corners makes it easy to clean the device, so the tubular steel radiator is the most hygienic model of all existing ones. It has one drawback - low corrosion resistance. The fact is that steel is susceptible to oxygen oxidation, so the radiator needs to be filled with water all the time. It is extremely difficult to ensure this condition where a central heating system operates. After all, during the summer, utilities drain water from the common system. Therefore, tubular models cannot be used in apartment buildings.

Note! There are no tubular steel batteries that are absolutely resistant to corrosion. But Russian products are manufactured taking into account domestic operating conditions, and European models do not have large pipe wall thickness. Also, European manufacturers do not treat the internal parts of the parts with anything, while Russian tubular devices are coated on the inside with special polymer compounds that increase their service life.

Tubular convectors

Steel tubular convectors

Convector radiators are a new generation of heating devices. In cross section, the tubes of such models are similar to a donut. The pipe has double walls, between which the coolant flows. This design made it possible to double the heat transfer of the devices. At the same time, the efficiency of the process increases due to heat transfer from the walls of the device, as well as through the creation of a converter flow, which is formed between the inner walls of the pipes.

Ease of maintenance, beautiful appearance, completely new design - these are the main advantages of the described device.

Heated towel rails

It is worth mentioning separately another type of tubular heaters - heated towel rails. They perform two functions at once - they heat the bathroom and dry the towels.

You can connect heated towel rails to central heating by installing them in a heating cycle. In our country, this element is connected to the hot water system, so the device often fails. And all because the steel from which these devices are made is afraid of oxidation processes. When connected to the hot water supply, water enriched with calcium, iron and other impurities enters the radiator, which gradually leads to “overgrowing” of the pipes. As a result, heated towel rails quickly become unusable.

Note! This does not happen when connected to a heating cycle. Therefore, when choosing a model, you should pay attention to the features of its connection. There are models on sale made from different materials. The most common heated towel rails are made of black or stainless steel, chalk, aluminum or brass. Experts recommend purchasing stainless steel models.

Often non-ferrous metals require compatibility with the materials from which other elements of the system are made. For example, in order for copper heated towel rails to function well and for a long time, it is necessary to connect copper pipes and fittings to them, and this is a very expensive pleasure. If this rule is not followed, abrasive wear will not be prevented.

If the model is connected to a domestic hot water system, you should choose dual-circuit products. They have a longer service life. Hot water flows through one circuit and heats the other. In this case, the dryer tubes do not come into contact with the aggressive coolant environment, do not overheat and do not experience system pressure.

Panel batteries

The name itself speaks about the design of such devices. The rectangular shape acts as a heating source. In this case, the coolant circulates between steel sheets having vertical channels, which increases the usable area of ​​the installation.

In its finished form, such a unit may contain several panels welded together. They are placed parallel to each other and covered with special powder enamel, and the top and side parts are closed with decorative inserts.

The technical features of this model are:

• The installation is light in weight.
• There are products on sale that have different sizes and differ from each other in width and height.
• The device has slight inertia.
• 75% of the heat is transferred using the converter method.
• The operating pressure for each model is different, so it is necessary to select a device taking into account this value.

All of the above indicators can be considered positive. But such a choice also has disadvantages. The first is a little water pressure. The maximum value is 10 atmospheres, so panel radiators are very sensitive to water hammer. But this is not the main thing.

The inner surface of the panels is not protected by anything, so when exposed to oxygen, the steel quickly becomes rusty and “loses weight.” This means that panel devices can only be used for heating in autonomous systems that are constantly filled with water.

Plate batteries

Steel radiator

Plate radiators are convectors in their purest form, the main advantage of which is reliability. The design is always closed on top with an aluminum casing, so you cannot get burned on such batteries. Their heat transfer is 95%. Thermal inertia is negligible.

But the plate device has more disadvantages than advantages. This includes an unpresentable appearance, low heat transfer, and the need to maintain a high coolant temperature. In addition, due to the low intensity of thermal convection, the room is heated ineffectively.

But modern manufacturers are trying to improve such models, combating their negative aspects. Experts have achieved good success in this direction. Firstly, copper tubes are now used to make the base, onto which copper and aluminum plates are mounted. Secondly, modern models have an original design that fits perfectly into popular stylistic concepts. And this circumstance is very popular with those who dream of exclusive interiors.

Such a disadvantage as uneven heating of the room can easily turn into an advantage where the ceiling height exceeds the standard dimensions. Large front halls, lobbies, exhibition stained glass windows, indoor swimming pools, loggias and winter gardens - here today they use wall-mounted models, linear varieties, as well as devices built into the floor.

The working pressure in plate batteries is 16 atmospheres. There are exclusive specimens in which the operating pressure reaches 37 atmospheres.

So far, manufacturers have not been able to eliminate another drawback of the described option - poor compatibility with the current system, as well as difficulties in caring for the device.

Technical features of the radiant system

Heat movement in a radiant system

The radiative system differs radically from the convective system. There is no point in describing the technical features, since studying them is the domain of specialists. But let's take a closer look at the advantages of this heating method and outline the main types of devices.

Positive points

1. Radiant heating devices have an efficiency of 95%, which is explained by the direct conversion of electricity into heat. For comparison, for converter systems this figure is 50%. One cannot believe manufacturers’ claims that they were able to achieve 100% of the indicators in this regard. This is contrary to the laws of physics. The efficiency of any device mounted on the wall will drop by 30%. In addition, it “eats” useful space and warms up the air that is under the ceiling. And the person “uses” the already cooled air, which tends to the battery.
2. A radiant device warms up a room much faster. Even when it is turned off, the room takes a long time to cool down. And all this happens due to the fact that it is not the air that is heated, but objects that then give off heat themselves.
3. The absence of convection eliminates the movement of air masses, as well as temperature differences. As a result, no
4. Heating modes in radiant heating devices can be controlled, adjusting the temperature and creating more comfortable conditions.
5. The described installations always operate silently. In addition, any unit is easy to install, move to a convenient place, and also dismantle.
6. Modern models consume 30% less electricity.

Types of devices

There are two types of radiant devices:

1. Long wave models.
2. Infrared heaters.

They differ from each other in the different intensity of heating of the heating element. In infrared heaters, heating elements heat up to 800 degrees, while in long-wave heaters - only up to 250 degrees. But the second type is fireproof, does not burn oxygen, heats the room evenly and creates a very soft, comfortable heat.

Other varieties

Which heated floor is better

There are several other types of heating devices that cannot be classified as either converter models or radiant devices. This is a “warm floor” system and radiant films.

Warm floor

In terms of efficiency, heated floors occupy an intermediate level between convectors and radiant systems. This is currently the most expensive heating option, and also complex and time-consuming. To install heated floors, it is necessary to open the floor, make a screed, lay electric heating mats or a pipeline for hot water.

Therefore, in addition to the cost of the elements themselves, complex and labor-intensive finishing work will have to be included in the final price. Moreover, the described system is not mobile; dismantling and moving the main elements is impossible without further major repairs.

Emissive films

Emissive films are the latest know-how that is just beginning to appear in Russia. They can become a worthy alternative to heated floors, but so far the capacity of the products is extremely limited.

In addition, the efficiency of the devices is significantly lower than that of long-wave heaters. Therefore, emissive films are not very popular yet. But they are the future, and experts are sure of this.

Generalization on the topic

We have provided a detailed classification of existing heating devices, outlined their technical advantages, as well as the operating features of each. From this information it is clear that there are no perfect designs that could be called universal and effective.

But modern production is able to provide consumers with a huge range of products, giving them the opportunity to choose an installation taking into account individual requirements. Until recently, it was difficult to find a couple of alternative options. And today, only listing existing models can demonstrate the enormous capabilities of modern heating systems.

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 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 devices successfully withstand such tests, it means they will last a long time, as they are of 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 of the 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 horizontal surface area 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 the different types of 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, and fashionable 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.

The convective type heating device is a finned tube. The material for it is a 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.

Nevertheless, finned pipes find application - 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 release heat through convection, which accounts for 75% of the heat flow, 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 of air pockets 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 versions - single- and double-row, with a smooth or ribbed surface, with or without a 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 are panels that have concrete, plastic or glass channels that differ in their configuration, and heating elements of 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 is two vertical steel pipes (it should be noted that the diameter of the internal channels is quite small, which is a disadvantage), coated with an 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.

When heated, water heating risers can move, damaging the plaster, so during installation they must be passed through pipes of 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 pressure test is 37 atm (thanks to the latter, bimetallic radiators are preferable for systems with high pressure), the maximum coolant temperature is 120 ° C. In addition, they are suitable for installation in different heating systems, while the number of floors of the house varies does not have.
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 heating devices are offered by modern industry and the market, all that remains is to make the right choice. In this case, you must be guided by the following criteria:

1. type and design of the heating system;
2. open or hidden pipeline laying;
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. You need to carefully study the available material, consult with a specialist, find out from the seller or look for information about manufacturing companies, find out how long they have been working on the 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, usually heating devices take their place under the window near the outer wall, but even then a number of requirements must be met:

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.