home · On a note · Types of heating devices for heating systems. Heating devices: purpose, types, requirements, design, main brands, design features. So what is more profitable financially?

Types of heating devices for heating systems. Heating devices: purpose, types, requirements, design, main brands, design features. So what is more profitable financially?

A heating device is a device for transferring heat from the primary coolant to a directly heated medium, which can be air, water, a technological or household product, etc. In heating systems, such devices are called heating devices, and in centralized hot water supply systems - heated towel rails (registers ) or design radiators, water heaters.

Through the walls of the heating device, heat exchange occurs between the coolant (heated water, water vapor) and the air in the room. All heating devices must meet certain thermal, sanitary and hygienic requirements.

Heating devices made from steel, cast iron, non-ferrous and stainless metals(copper, aluminum), polymer and other materials. The first heating systems used cast iron finned heating devices and pipes connected at flanges.

When choosing a heating device, the following are usually taken into account:

  • architectural planning and construction solutions, pre-determining the height, depth and length of the device;
  • calculated thermal power of one device;
  • category of production in premises according to fire hazard;
  • customer requirements for the appearance of the device;
  • the price of the device per 1 kW of heat flow;
  • the quality of the coolant and the adopted heat supply scheme for the building (from the heating network of a centralized heat supply source or an autonomous source);
  • operating pressure in the heating network, heating system.

Currently, the most common types of heating devices are steel and cast iron radiators, convectors and air heaters.

Structurally, they are made in the form of separate sections and, depending on the number of vertical channels in each section, they can be one-, two-, three- and multi-column, multi-row with a varied cross-section of channels.

Cast iron two-column sectional radiators are the main type of heating devices. Manufacturing plants produce them assembled in blocks of 4; 5; 7; 12 sections, with a surface primed for painting. By height (between the denters of the nipple holes) radiators are divided into: high - 1000 mm, medium - 500 mm and low - 300 mm. Factories complete each of them with two blind plugs and two plugs with threaded holes with 1/2" or 3/4" threads according to customer specifications. The sections are assembled into the radiator using threaded nipples (with right and left threads) and sealing gaskets (picture below).

The gaskets at the plugs and nipples are made of materials that, when well-fitted, provide reliable tightness at operating temperatures of hot water entering the radiators. When the coolant temperature is less than 100 °C, gaskets made of cardboard impregnated in boiling water are used for seals. natural drying oil. At a coolant temperature of up to 140 °C, in systems with organic coolants, heat-resistant and gasoline-resistant rubber is used, and at a coolant temperature above 140 °C, gaskets made of paronite, klingerite (rubber-asbestos sealant) are used.

Assembling radiator sections

1 - radiator key; 2 - section; 3 - nipple; 4 - gasket

The heating surface area of ​​one section of M-140-AO-500 is 0.3 m2.

Before installation and additional painting, domestic radiators require mandatory broaching of intersection threaded connections. Although cast iron radiators are designed for a coolant operating pressure of 0.6 MPa, they do not withstand hydraulic shocks that occur in external supply networks. At the same time, they have high corrosion resistance, which is necessary in Russian operating conditions.

IN last years on the domestic market of heating and ventilation equipment, various designs of steel and aluminum radiators.

Panel steel radiators are available in several design solutions:

  • in the form of panels stamped from sheet steel (1.5 mm thick) with a number of channels from 8 to 20 and a heating surface area from 0.65 to 4 m 2 (type MN6, ZS1, ZS2, PC-10, PC -33, RSV1, RSVZ, RSV9, etc.);
  • in the form of sheet-tube coil type (mainly for steam heating systems);
  • in the form of convectors.

Stamped radiators are designed for a coolant operating pressure of up to 0.6 MPa and, without special protective internal coatings, quickly fail due to corrosion.

IN steel pipes chat radiators combine convective and radiant types of heat transfer (2 times more efficient than a conventional radiator), and the shape and design make it competitive in the global heating equipment market. Heat output, depending on the number of sections, ranges from 900 to 2520 W.

A convector is a heating device made of steel pipes with sheet steel ribs strung on them. The device received its name due to the predominant convective process (up to 90%) of heat transfer. Currently, this is the most common heating device. It is used in heating systems of residential, public, administrative and municipal buildings with a coolant temperature of up to 150 ° C and pressure of up to 0.6 MPa. The device is distinguished by its low price and trouble-free operation.

Convectors are produced following types: steel plinth gearboxes; built-in floor “Breeze”; steel low and high with a casing "Accord" and "Universal", convectors of OJSC "Santekhprom" (short depth with a rated heat flow of 0.4-2.0 kW) and "Santekhprom Avto-S" (medium depth with a rated heat flow flow 1.2-3.0 kW).

Skirting and built-in floor convectors, used for heating external walls with large glazing, when there is no room left for traditional heating devices (they occupy small spaces - no more than 10 cm in depth and 20-25 cm in height), create a reliable thermal curtain from streams of cold air falling from the walls. Their use is typical for heating systems Western Europe, North America and other countries with temperate climates.

Aluminum and bimetallic radiators, which first came to us about 15 years ago as imports from Italy, attracted attention due to their high heat transfer (mainly radiant heat transfer), clean, beautiful casting, and sectional designs. They are available in two versions:

  • cast aluminum radiators, where each section is manufactured as a single piece;
  • collapsible (extrusion) radiators, consisting of several sections, mechanically assembled into one using seals and glue.

The disadvantages of aluminum radiators are due to the amphoteric properties of aluminum, as a result of which they are very sensitive to the acid-base reaction of water pH, which in some cases causes the release of hydrogen gas and carbon dioxide into the water and “airing” of heating systems. This phenomenon does not exist in bimetallic radiators - the aluminum layer is moved to the top of the structure and replaced from the inside with steel.

Tubular heating devices made of cast iron and smooth steel pipes are installed mainly in buildings of industrial and agricultural enterprises in the form of registers and welded panels for heating external walls, roof lights, the soil of greenhouses and greenhouses, preparing hot water in capacitive heaters and etc.

In recent years for the device underfloor heating for indoor and outdoor heating, metal-polymer pipes began to be used as heating elements of the structure, as well as electrical cables(according to the DEVI cable heating system of the Danish company DEVI).

Heated towel rails for hot water supply systems. In hot water supply systems of residential and public buildings, heated towel rails, registers, and design radiators are installed to create comfortable conditions in bathrooms and dry clothes. In most cases, they are made of steel tubular elements with a nominal thermal current of 0.3-0.6 kW and are connected in a flow-sequential manner to the hot water supply system, and in some cases to the heating systems of buildings.

Heaters are widely used to heat the air passing through them in ventilation systems, air heating, air conditioning, drying installations, etc. The domestic industry produces heaters:

  • steel plate single-pass medium (KFS) and large (KFB) models with heating surface area from 10 to 70 m 2;
  • steel finned (spiral-wound) single-pass medium (KFSO) and large (KFBO) models with a heating surface area from 10 to 70 m 2;
  • steel plate multi-pass models for water (KMS, KMB);
  • steel plate single-pass models for steam (STD-3009V) and for water (STD-ZOYUV) with a heating surface area from 7 to 75 m 2.

Most Applications received air heaters the latest developments type KSkZ and KSk4 with bimetallic finned tubes, with a heating surface area from 10 to 136 m 2.

Infrared (IR) emitters are used in radiant heating systems for working areas of workshops, workshops, hangars, warehouses and other industrial premises large area. In the West, they have become widespread for heating public buildings and structures - sports, shopping, places of worship, airports, train stations, etc. The devices use electromagnetic waves in the range from 0.77 to 340 microns (with a range of 0. 77-15 microns is considered short-wave, from 15 to 100 microns - medium-wave, and from 100 to 340 microns - long-wave). IR emitters with a surface temperature from 700 to 2500 °C, having a wavelength of 1.55-2.55 microns (close to visible light), are called “light”, emitters with a lower surface temperature have a longer length waves, and they are called “dark”. Thermal power they can range from 3-4 kW (street gas lamps and lamps for cafes, snack bars, kiosks) to 200-300 kW (I-K emitters of the “dark” type for industrial buildings), efficiency 92%.

Imported industrial infrared installations include: a heat generator with a capacity of 50 to 300 kW with a gas burner and control unit; ribbon pipe radiator up to 140 m long, smoke exhauster with electric motor; emitter casing made of steel with thermal insulation coating and reflective film.

The domestic industry is represented by gas gas structures infrared emitters GII-5 - GII-31 of the Siberian enterprise "Sibshvank" (power from 5 to 31 kW in one device, with pipe distributors) and models from Moscow Stroyproektservis (power from 11 to 140 kW).

Based on their design, panel-radiant heating systems are divided into panel heating systems, through the tubes of which superheated water (steam) passes; tubular coils laid during manufacture building structures; gas-air; radiation hanging or wall mounted.

Metal panels are designed for heating large industrial premises that do not require enhanced ventilation (mechanical, tool, model shops, hangars, warehouses).

Radiant panels suspended in the upper zone of such rooms consist of a metal reflective screen with visors, to the lower surface of which heating pipes are attached, and the upper surface is covered with a layer of thermal insulation.

Suspended panels must be structurally such that the heat transfer by radiation downwards is at least 80% of the total heat transfer. Only then is air temperature uniformity achieved across the height of the premises and thermal energy is saved compared to conventional convective heating, especially air heating.

Concrete panels with embedded steel heating pipes are used in wall radiant heating systems in prefabricated mass-produced buildings, mainly for heating public and industrial buildings, mainly with enclosing structures made of wall panels.

IN Lately For the purpose of recycling the heat of heated air removed from the premises and extracting the heat of process gases and vapors, special heat exchangers have been developed, which are heat exchangers installed in ventilation and air conditioning systems and allowing the use of heat from the air removed from the premises. Heating devices of a new design - ejection closers - are air distribution devices for preparing an air mixture and supplying it to the room. Closers are used for round-the-clock air conditioning of industrial and civil buildings, having a centralized supply of primary air, coolant and coolant.

Part 2 HEATING DEVICES Classification Area of ​​application various designs Features of installation in premises Regulating heat transfer Determining the heating surface

REQUIREMENTS FOR HEATING DEVICES 1. Sanitary and hygienic: - n/a must have the lowest possible surface temperature to prevent dust sublimation; - have a minimum horizontal surface to reduce dust deposits; - the design must allow the surface of the device to be cleaned from dust. 2. Economic: - n/a should have the lowest reduced costs for their production, installation and operation; - have low metal consumption, providing increased thermal stress of the metal. The thermal stress indicator of metal n/p is defined as: where Qnp – thermal load n/a, W; Gm – mass of metal n/a, kg; , W/(kg K) Δt - temperature pressure n/a, ºС; The higher the thermal stress indicator, the more economical the device is in terms of metal consumption. The value of the M indicator for modern n/a is in the range: 0.2 ≤ M ≤ 0.6 3. Architectural and construction: The appearance of the n/a must correspond to the interior of the room, and the volume it occupies should be minimal. 4. Production and installation: - maximum mechanization of work during production and installation must be ensured; - n/a must have sufficient mechanical strength. 5. Operational: - n/a must ensure controllability of their heat transfer (depends on the thermal inertia of n/a); N/P must ensure temperature resistance and water resistance at the maximum permissible hydrostatic pressure inside the N/P under operating conditions. 6. Thermal engineering: - n/a must provide highest density specific heat flux per unit area, W/m2. To fulfill this requirement, the item must have an increased heat transfer coefficient.

Classification of heating devices By heat transfer according to the material used By height By depth By thermal inertia value Radiation metal high low low inertia convective-radiative non-metallic medium medium high inertia low large Convective baseboard

Shares of consumption of various types of heating devices per Russian market in 2011 29% - cast iron radiators Cast iron radiators 3% - steel tubular radiators 20% - steel panel radiators 27% - aluminum and bimetallic radiators 21% - convectors (including special ones) Steel tubular radiators Steel panel radiators Total consumption about 6 million kW/year

Cast iron radiator section: hm – installation height of the device, m; hп – construction height of the device, mm; a – depth of the device, mm; b – width of one section of the device, mm

Cast iron sectional radiators: high operational reliability in domestic conditions, can be used in dependent heating systems of buildings for various purposes; price domestic models on average 1500 rub. /To. W; the cost of design radiators is 4000 -6000 rubles. /To. W additional cost of regrouping, leak testing, installation and painting is 400 - 500 rubles. /To. W; the share of consumption in Russia is about 29%

Steel panel radiators: modern design; wide range; full construction readiness; high hygiene of models without fins; There are models with a built-in thermostat; all models strictly require compliance with operating rules; cost 1500 – 2000 rub. /To. W (without built-in thermostat); the share of consumption in Russia is 20%.

Basic requirements for the coolant of heating systems with aluminum heating devices Name of indicators and their dimensions Hydrogen indicator p. N Optimal values ​​Acceptable values ​​Indicator values ​​7 – 8.5 Dissolved oxygen content, mcg/dm 3, no more than 20 Iron compounds content, mg/dm 3, no more than 0.3 Total hardness, mEq/dm 3, no more 0, 7 Amount of suspended substances, mg/dm 3, no more than 5 The use of aluminum radiators is allowed only in independent and autonomous systems heating Direct connection of the heads of aluminum radiator sections with steel and copper heat pipes is prohibited. The use of galvanized plugs is prohibited; the use of aluminum and cadmium-plated plugs is recommended. The use of cadmium-plated nipples is recommended.

Comparison of aluminum and bimetallic radiators Parameter Aluminum Bimetal Design The radiator is completely aluminum. Radiators are made using two methods. The extrusion method produces cheap and lightweight products that are not very High Quality(This method is not used in Europe). Radiators made by casting will be more expensive, but more durable. Bimetallic radiators are made from two different metals. The body, equipped with ribs, is made of aluminum alloy. Inside this housing there is a core of pipes through which coolant flows (hot water from the heating system). These pipes are made either from steel or copper (and the latter are practically never found here). Their diameter is smaller than that of aluminum models, so they are more likely to clog. Heat dissipation Heat dissipation from one section depends on the model and manufacturer. It is slightly lower than that of the manufacturer. 1 section is capable of delivering 140 - 210 W. aluminum radiator, since the steel core helps reduce overall heat transfer. 1 section gives off Has minimal thermal inertia. 130 – 200 W. From 6 to 16 (some models up to 20) ati. From 20 to 40 ati ( this parameter is important if you choose radiators for an apartment with a centralized heating system. If you choose these radiators for a private home, then this parameter is not a minus for aluminum radiators, since there is no excess pressure in the local heating network.). Relation to coolant Aluminum undergoes various chemical reactions, which leads to corrosion of the walls of the device. And still in progress chemical reactions aluminum releases hydrogen, which is a fire hazard. Therefore, it requires the installation of a special valve in the upper radiator cap. Steel pipes in the middle of a bimetallic radiator are less demanding on the quality of the water flowing through them. A bimetallic radiator is more protected from coolant. Maximum temperature water Up to 110 0 C. Up to 130 0 C. Durability Up to 10 years. 15 – 20 years. Operating pressure

Radiators from aluminum alloys, bimetallic with aluminum collectors (sectional, columnar and block): modern design; wide range; full construction readiness; all models except completely bimetallic ones require strict adherence to installation and operation rules; bimetallic models are equivalent in performance to cast iron radiators; the cost of radiators made of aluminum alloys is ~ 1700 - 2200 rubles. /To. W; the cost of “semi-bimetallic” radiators is 2000 - 2800 rubles. /To. W; the cost of bimetallic radiators is 2800 - 4000 rubles. /To. W; the share of consumption in Russia is 27%, including 14% bimetallic and bimetallic with aluminum collectors.

Steel tubular radiators and design radiators (sectional, columnar, block and block-sectional): modern design and hygiene; full construction readiness; wide range; There are models with a built-in thermostat; require strict adherence to operating rules; There are models with increased anti-corrosion resistance; price: tubular radiators 3800 rub. /To. W; design radiators – 8000 rub. /To. W; the share of consumption in Russia is 3%.

convectors Without casing (adjustment of heat transfer through water) With casing: - adjustment of heat transfer through water; - adjustment of heat transfer through the air.

Sketches of convectors: a) “Comfort-20” with a casing; b) “Accord” without casing; 1 – plate (heating element; 2 – casing; 3 – air valve

Convectors (wall-mounted, floor-mounted, with a casing, without a casing, steel, using non-ferrous metals): high operational reliability in domestic conditions, can be used in dependent heating systems of buildings for various purposes; low inertia; wide range; full construction readiness; modern design; low temperature external elements of the convector structure, eliminating the risk of burns; There are models with a built-in thermostat; cost: steel ~ 1300 rub. /To. W; with copper-aluminum heating element ~ 3000 rub. /To. W; share of consumption in Russia (including special convectors) – 21%.

Cases of improper installation of wall convectors The gap between the device and the floor or window sill is small (less than 70% of the depth of the device). Reduction of heat flow by 5 -50% Installation of brackets on an unprepared surface (subsequent plaster) - it is impossible to hang the casing Air flow past the heating element. Reduction of heat flow by 5 -20% The heating element is not installed horizontally. Decrease in heat flow by 4-7% Incorrect marking of bracket installation locations - it is impossible to hang the casing Lagging of the casing, gap between the wall and the casing. Heat flow reduction by 3 -20%

6. Special heating devices - convectors built into the floor structure, fan convectors: complete construction readiness; modern design; low inertia; There are models with built-in fans and thermostats; designed for luxury buildings and cottages; fan convectors operating in heat pump mode are characterized by high energy efficiency; cost 4000 -10000 rub. /To. W; the share of consumption in Russia is about 4% (in the general group of convectors).

Basic requirements for the design of heating devices in accordance with GOST 31311 -2005 “Heating devices. Are common technical specifications" and STO NP "AVOK" 4. 2. 2 -2006 "Heating radiators and convectors" 1. Devices must withstand the static strength test: 1. 1. The destruction pressure must exceed the maximum operating excess pressure of the coolant declared by the manufacturer: - for cast devices – no less than 3 times; - for other devices - no less than 2.5 times. 1. 2. Test pressure (factory) must exceed the declared maximum operating excess pressure: - for cast devices - no less than 1.5 times or no less than 0.6 MPa; - for other devices - no less than 1.5 times. 2. The nominal heat flux of wall-mounted devices with a height of up to 600 mm inclusive and a thermal density of up to 2000 W/m should be no more than 400 W for the minimum standard size and no less than 2000 W for the maximum. 3. The average nomenclature step of the nominal heat flux of wall-mounted devices with a height of up to 600 mm inclusive and a thermal density of up to 2000 W/m in the range of values ​​from 400 to 1400 W should not exceed 200 W, and over 1400 W - no more than 400 W. 4. The thickness of the wall of the device in contact with water must be no less than: - for a cast iron radiator - 2.7 mm; - for steel panel radiator– 1.2 mm; - for a tubular steel pipe and bimetallic radiators– 1.25 mm; - for cast and extruded aluminum radiators – 1.5 mm.

Basic requirements for coolant according to the “Rules” technical operation power plants and networks Russian Federation» for heat supply systems made of steel heat pipelines Name of indicators and their dimensions Values ​​of indicators for open closed heat supply systems 8, 3 – 9, 0 8, 3 – 9, 5 8, 0 – 9, 5 Content of dissolved oxygen, µg/dm 3, not more than 20 20 Content of iron compounds, mg/dm 3, no more than 0.3 0.5 Total hardness, mEq/dm 3, no more than 0.7 5 5 Hydrogen index p. N: optimal values permissible values ​​Amount of suspended substances, mg/dm 3, no more

Schemes for installing heating devices with different coverage coefficients β 4: a) β 4 = 1, 2; b) β 4 = 1.05; c) β 4 = 1.05; d) β 4 = 0.9; e) β 4 = 1.25

Installation diagrams for heating devices under windows: a) installation of the heating device relative to the edge of the window; b) installation of radiators; c) installation of a convector with a casing; d) installation of a convector without a casing

Heat transfer coefficient n/a The intensity of heat transfer from the coolant through the heat transfer medium into the room is characterized by the heat transfer coefficient of the heating device - Knp. It expresses the heat flux density on the outer surface of the n/p wall with a temperature difference of 1 C: where Rnp – thermal resistance heat transfer of the heating device: where Rin is the thermal resistance to heat transfer from the heated liquid to inner surface walls n/a (heat exchange occurs due to convection + thermal conductivity); Rst – thermal resistance to heat transfer from the inner to the outer surfaces of the wall of the heating device (thermal conductivity); Rн – thermal resistance to heat transfer from the outer surface of the wall to the cold medium (liquid or gas) (heat exchange occurs due to convection + radiation). The main factors that determine the CHP: the type and design features of the CHP and the temperature difference. The heat transfer coefficient of the newly developed CHP is determined experimentally. The type of n/a allows you to judge in advance the possible meaning of the knp. The results of experiments to determine Knp showed that it can be described: - for water coolant: where: m, n, p – experimental coefficients that are determined for each type of n/p; - temperature pressure n/a; - air temperature in the heated room, ºС; - temperature of the coolant, respectively, at the inlet to the reservoir and at the outlet from it, ºС; G – relative water flow in n/a, kg/h, - the ratio of the actual flow rate through n/a to the nominal one, accepted during the thermal test of n/a. When testing samples of n/a, a flow rate of 360 kg/h was taken as such a flow rate (previously, tests of each type of n/a were carried out at different nominal water flow rates: for radiators 17.4 kg/h, for convectors 300 kg/h).

Schemes of water movement through the heating device: a) from top to bottom; b) from bottom to top; c) from below - down

Thermal calculation of heating devices (determination of the heating surface), W (kcal/h), where is the nominal conditional heat flow n/a, according to which the standard size of the device is selected using catalogs n/a or a reference book. – complex coefficient of adaptation to design conditions. - for water: - temperature pressure n/a (for coolant - water), ºС; - coolant flow through n/a, kg/h; b – accounting factor atmospheric pressure; - factor taking into account the direction of movement of the coolant in n/a; n, p, c – constant coefficients for this type of n/a.

Small circulation rings in single-pipe heating systems Small circulation rings in a single-pipe heating system are radiator units, which include closing sections, connections to heating devices and the heating device itself. The water flow through the heating device in a heating system with a three-way valve KRT is equal to the water flow through the riser, since the working design position of the KRT is “fully open”. The riser in this case turns out to be flow-regulated. The water flow through the heating device with the closing section and the KRP pass-through valve is determined by the coefficient of water flow into the heating device: where: Gnp is the flow rate of water passing through the heating device, kg/h; Gst - water consumption in the riser, kg/h; αнп = 0 – the heating device is closed; αнп = 1 – the heating device is fully open (at KRT).

In order to in the cold winter period provide in living quarters the necessary conditions for living, you need a system that would help maintain the desired temperature. The heating system is the most successful engineering solution to this problem. The heating system will help maintain the house comfortable conditions throughout the cold period, but you should know what heating systems are available in modern times.

Heating systems may vary depending on different criteria. There are such main types of heating systems as: air heating, electric heating, water heating, water heated floors, and others. Undoubtedly, an important issue is choosing the type of heating system for your home. The classification of heating systems includes many types. Let's look at the main ones, and also compare types of fuel for heating.

Water heating

Among the entire classification of heating systems, water heating is the most popular. Technical advantages Such heating were identified as a result of many years of practice.

Undoubtedly, when asked what types of heating there are, it is water heating that first comes to mind. Water heating has such advantages as:

  • Not very high surface temperature of various devices and pipes;
  • Provides the same temperature in all rooms;
  • Fuel is saved;
  • Increased service life;
  • Quiet operation;
  • Easy to maintain and repair.

The main component of a water heating system is the boiler. Such a device is necessary to heat water. Water is the coolant in this type of heating. It circulates through closed pipes, and then the heat is transferred to various heating components, and from them the entire room is heated.

The simplest option is natural circulation. This circulation is achieved due to the fact that different pressures are observed in the circuit. However, such circulation can also be of a forced nature. For such circulation, water heating options must be equipped with one or more pumps.

After the coolant passes through the entire heating circuit, it is completely cooled and returned back to the boiler. Here it heats up again and thus allows the heating devices to produce heat again.

Classification of water heating systems

Water heating type may vary according to criteria such as:

  • water circulation method;
  • location of distribution lines;
  • structural features of risers and the diagram according to which all heating devices are connected.

The most popular is the heating system, where water circulation occurs through a pump. Heating with natural water circulation has recently been used extremely rarely.

In the pump room heating system heating of the coolant can also take place thanks to a hot water boiler house, or thermal water that comes from a thermal power plant. In a heating system, water can even be heated by steam.

A direct-flow connection is used when the system allows water supply with very high temperature. Such a system will not cost as much, and the metal consumption will be somewhat less.

The disadvantage of direct-flow connection is the dependence thermal regime on the “impersonal” temperature of the coolant in the external type supply heat water.

Air heating

These types of heating of various premises are considered one of the oldest. For the first time such a system was used before our era. Today, such a heating system has become widespread - as in public spaces, and production.

Heated air is also popular for heating buildings. When recirculated, such air can be supplied to a room, where the process of mixing with indoor air occurs and, thus, the air is cooled to room temperature and heated again.

Air heating can be of a local nature if the building does not have central supply ventilation, or if the incoming amount of air is less than necessary.

In air heating systems, the air is heated by air heaters. The primary heater for such components is hot steam or water. In order to warm the air in the room, you can use other heating devices or any heat sources.

Local air heating

When asked what kind of heating there is, local heating is often equated only to production premises. Devices local heating are used for such premises that are used only during certain periods, in premises of an auxiliary nature, in premises that communicate with external air flows.

The main devices of the local heating system are a fan and a heating device. For air heating, devices and devices can be used such as: air heating devices, heat fans or heat guns. Such devices operate on the principle of air recirculation.

Central air heating is done in rooms of any type, if the building has a central ventilation system. These types of heating systems can be organized according to three different schemes: with direct-flow recirculation, with partial or complete recirculation. Full air recirculation can be used mainly during non-working hours for standby types of heating, or to heat the room before the start of the working day.

However, heating according to such a scheme can take place if it does not contradict any rules fire safety or basic hygiene requirements. For such heating circuit a supply ventilation system should be used, but the air will be taken not from the street, but from those rooms that are heated. The central air heating system uses the following: structural types heating devices such as radiators, fans, filters, air ducts and other devices.

Air curtains

Cold air can come in in large quantities from the street if the house is opened too often. entrance doors. If you don't do anything to limit the amount of cold air that enters the room or don't warm it up, it can negatively affect your health. temperature conditions, which must comply with the standard. To prevent this problem, possible in the open doorway create an air curtain.

At the entrances of residential or office buildings, you can install a low-rise air-thermal curtain.

Limiting the amount of cold air entering from outside the building takes place thanks to constructive change entrance to the room.

Compact air-thermal curtains have become increasingly popular lately. The most effective curtains are considered to be “shielding” type curtains. Such curtains create a jet air barrier that will protect the open doorway from the penetration of cold air flow. As a comparison of heating types shows, such a curtain can reduce heat loss by almost half.

Electric heating

Heating of the room occurs due to the distribution of air passing through dashboard without its front side heating up. This will completely protect against various burns and prevent any fire.

Electric convectors can heat any type of room, even if you only have one source of energy, such as electricity.

These types of building heating systems do not require large expenses for installation or repair, and they can provide maximum comfort. An electric convector can simply be placed in a certain place and connected to the mains power supply. When choosing a heating system, you can pay attention to this type - it is quite effective.

Operating principle

The cold air, which is at the bottom of the building, passes through the heating component of the convector. Then its volume increases and it goes up through the output grids. The heating effect also occurs due to additional heat radiation from the front side of the electric convector panel.

The level of comfort and efficiency of such a heating system is achieved due to the fact that electric convectors use electronic system, which helps maintain a certain temperature. You just need to install the necessary temperature indicator and the sensor, which is installed in the lower area of ​​the panel, will begin, after a specified period of time, to determine the temperature of the air that enters the room. The sensor will send a signal to the thermostat, which in turn will turn on or turn off the heating element. Through such a system to maintain certain temperature, which will make it possible to connect electric convectors in different rooms in order to heat the entire building.

Which system is better

Of course, the question of which heating system is better is inappropriate, since one or another system is effective under certain conditions. Comparisons of heating systems should be made taking into account all their pros and cons, focusing on installation conditions and your own capabilities.

Having considered what heating systems exist, you can draw certain conclusions for yourself. But in general, the best option will consult with professionals.

Heating devices systems central heating are called devices for transferring heat from a coolant to a heated room. Heating devices must best transfer heat from the coolant to the room, ensure a comfortable thermal environment in the room without deteriorating its interior, at the lowest cost of funds and materials.

The types and designs of heating devices can be very diverse. The devices are made of cast iron, steel, ceramics, glass, in the form of concrete panels with tubular heating elements embedded in them, etc.

The main types of heating devices are radiators, finned tubes, convectors and heating panels.

The simplest is heating device made of smoothof steel pipes. It is usually implemented in the form of a coil or a register. The device has a high heat transfer coefficient and can withstand high coolant pressure. However, devices from smooth pipes roads and take up a lot of space. They are used in rooms with significant dust emissions, for heating skylights in industrial buildings, etc.

The most widely used heating devices are radiators. Their Various types differ from each other in size and shape. Radiators are assembled from sections, which allows you to assemble devices different sizes. Typically, sections are cast from cast iron, but they can be steel, ceramic, porcelain, etc.

Quite widespread in heating systems received cast iron finned pipes. The ribs on the surface of the pipe increase the heat-transfer surface area, but reduce the hygienic qualities of the device (dust accumulates, which is difficult to remove) and give it a rough appearance.

Convectors They are steel pipes with sheet steel fins. The most advanced among convectors is a convector in a casing made of steel sheet. The device is equipped with a cap to regulate heat transfer. Intense air circulation occurs between the finned surfaces of the device and the casing under the influence of gravitational pressure. This increases heat removal from the finned surface by 20% or more. Convectors in a casing are compact and have a good appearance. In some designs, convectors are equipped with a special type of fan that provides intense air movement. Artificial stimulation of air movement significantly increases heat removal from the device. Some disadvantage of convectors is the need and difficulty of cleaning from dust.

Concrete heating panels They are slabs with coils of steel pipes embedded in them. Such panels are usually located in the structures of room fencing. Sometimes they are freely installed near walls.

Currently, for heating large industrial workshops, hanging pa-panels with reflective screens.

The use of panels for heating buildings satisfies the requirements of prefabricated construction and allows you to save metal spent on heating devices. The disadvantages of panel heating include: large thermal inertia, which complicates the regulation of heat transfer; impossibility of changing the heating surface; the danger of pipe clogging and the difficulty of eliminating it; complexity of system repair; the possibility of internal corrosion and, as a result, a violation of the hydraulic tightness of the pipes.

Yu. M. Solovey Fundamentals of construction. - M.: Stroyizdat, 1989. - 429s.

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: low surface temperature, small area horizontal surface, ease of cleaning 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 aluminum surface.
  2. 2. Long-term operation leads to the unsuitability of the cast structure and to rupture.

    3. 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 lot of variety cast iron radiators: single channel, double channel, triple channel, embossed, classic, enlarged and standard.

In our country economical option cast iron appliances are most widely used.

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 buildings. 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 the top goes up and the cold one 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.