Protection devices used in the combined heating system. Modern hot water heating devices

One after another, economic crises hit the planet, which, coupled with the rapidly decreasing amount of resources, creates a need for the development and use of energy-saving technologies. This trend has not spared heating systems, which strive to maintain or even increase their efficiency while consuming significantly less resources. Let's figure out what new heating technologies are for a private house, apartment and industrial premises, decomposing the heating system into four main components: a heat generator, a heater, a heating system and a control system.

A boiler heating system is the most productive, although the most expensive (after electric heaters) of all modern autonomous heating technologies. Although the boiler itself is an invention with ancient history, modern manufacturers have managed to modernize it, increasing the efficiency and adapting it to different types of fuel. So, there are three main (fuel-fired) types of boilers - solid fuel, gas, liquid fuel. Electric boilers that are somewhat out of this classification, as well as combined, or multi-fuel ones, combine the qualities of two or three varieties at once.

Solid fuel boilers

An interesting tendency is to return to the traditions of the past and to actively use solid fuels: from ordinary firewood and coal to special pellets (pellets pressed from wood by-products) and peat briquettes.

Solid fuel boilers are divided by type of fuel into:

Classic without any problems "accept" any kind of solid fuel, the most reliable and simple (in fact, this is the oldest heat generator in the history of mankind), cheap. Among the disadvantages: "capriciousness" in relation to wet fuel, low efficiency, the inability to adjust the temperature of the coolant.

A pellet boiler is a heating device that uses wood waste compressed into small pellets. They stand out for their high efficiency, long-term operation at one load, an extremely convenient system for loading pellets (they are filled up from a bag or bag), and the ability to configure the boiler. The only significant drawback is the rather expensive pellets for heating, the price of which ranges from 6900 to 7700 rubles per ton, depending on the ash content and calorific value.

The next type is pyrolysis heating boilers operating on pyrolysis gas extracted from wood. The fuel in such a boiler slowly smolders, and does not burn, due to which it gives off noticeably more heat. Advantages: high efficiency and reliability, regulation of heat transfer, up to half a day of work without reloading. The only drawback is the need for an electrical connection, which can leave the house without heat during power outages.

Standard boilers long burning loaded with any kind of solid fuel, with the exception of wood: coke, lignite and hard coal, peat briquettes, pellets. There is another variety, designed specifically for working with wood and a slightly different device. Advantages: work up to five days with oil products and up to two days when loaded with wood. Disadvantages: relatively low efficiency, the need for constant cleaning.

Gas boilers

Main gas is the most economical of all types of fuel, and boilers running on it are considered the most convenient to use and maintain. This is explained by their fully automated operation and absolute safety, for which many sensors and controllers are responsible. They have no drawbacks as such, although they need a gas pipeline or the constant delivery of new cylinders.

Oil fired boilers

This is not to say that such heating systems are innovative, but they have been consistently in demand for decades and therefore worthy of mention. The main types of liquid fuel: diesel fuel and liquefied propane-butane mixture. Advantages over solid fuel: almost complete automation of work. Disadvantages: extremely high cost of heating, second only to electricity.

Electric heating

Differs in the widest variety of heating systems and individual devices. These are electric convectors (which in turn are floor-standing, floor-standing and wall-mounted), and electric boilers, and fan heaters, and infrared heaters, and oil radiators, and heat guns, and the well-known warm floor. Their common and so far insurmountable drawback is the extremely high cost of heating. The most economical of them are infrared radiators and underfloor heating.

Heat pumps

These heating systems are modern in the full sense of the word, despite the fact that they appeared back in the 80s. Then they were available only to wealthy people, but now many have got used to collecting them by hand, thanks to which they are slowly but surely gaining popularity. In a very simplified way, the principle of their work is to extract heat from the air, water or earth outside the house and transfer it to the house, where the heat is transferred either directly to the air, or first to the coolant - water.

Solar systems

Another rapidly developing technology is solar heating systems, better known as solar panels.

Advantages:

Flaws:

Thermal panels

They are thin rectangular (usually) plates fixed to the wall. The back side of such a plate is covered with a heat-accumulating substance that can heat up to 90 degrees and receive heat from a heating element. Energy consumption is only 50 watts per square meter, in contrast to older electric fireplaces requiring at least 100 watts per square meter. Heating takes place due to the convection effect.

In addition to efficiency, thermal panels differ:

There is only one drawback - thermal panels become unprofitable in the spring and early autumn when the home needs only a little heating from evening to morning.

Monolithic quartz modules

Unique development of S. Sargsyan - candidate of technical sciences. Externally, the plates are very similar to thermal panels, however, their principle of operation is based on high heat capacity. quartz sand... The heating element transfers the sand thermal energy, after which it continues to heat the home, even when the device is disconnected from the network. The savings, as in the case of thermal panels, are 50% of the cost of standard electric heaters.

PLEN - radiant film electric heaters

This innovative heating system has a device that is as simple as it is ingenious: power cable, heating elements, dielectric foil and reflective screen. The heater is fixed to the ceiling and the infrared radiation it produces heats up the objects below. These, in turn, transfer heat to the air.

The main advantages of PLEN:

Thermal hydrodynamic pumps

These devices, also known as cavitation heat generators for heating systems, generate heat by heating the coolant according to the cavitation principle.

The coolant in such a pump rotates in a special activator.

At the sites of rupture of an integral mass of liquid, as a result of an instantaneous decrease in pressure, bubbles-cavities appear, almost instantly bursting. This causes a change in the physicochemical parameters of the coolant and the release of thermal energy.

Interestingly, even with the current level of scientific and technical development, the process of cavitation energy production is poorly understood. An intelligible explanation of why the increase in energy is greater than its costs has not yet been found.

Air conditioner as a heater

Almost all modern models air conditioners are equipped with a heating function. Oddly enough, the air conditioner has three times more efficiency than standard electric heaters: 3 kW of heat from 1 kW of electricity versus 0.98 kW of heat from 1 kW of electricity.

Thus, the air conditioner for heating in winter is capable of a short time replace the switched off heating or a broken-down electric fireplace. However, due to the fact that heating elements are not used in air conditioners, their efficiency decreases with each degree of temperature outside the window. Besides, severe frost overloads the device, and operation in this mode can lead to breakdown. The best option will use the air conditioner in the off-season.

Convectors

Since a convection heating system is an extremely broad concept, and almost every modern heating device uses a convection effect, we will make a reservation in advance that we are talking here only about individual water and electric convectors. They represent a finned heater placed in a metal case.

The air circulating between the ribs of the device heats up and rises upward, and in its place air masses are drawn in, which have already cooled down during this time.

This endless circulation is called convection. According to the heat source, convector heaters are divided into water and electric, and according to the location - into floor, floor and wall. Also, any of them can work on the principle of either natural convection, or forced (with a fan).

Although the types of convectors and the features of each of them are a topic for a separate article, one can single out general benefits using these heaters:

So what is more profitable financially?

As a result, for this section, let us compare the cost of heating by different types fuel: on wood, pellets, coal, diesel fuel, propane-butane mixture, regular gas and electricity. With average prices for each type of fuel and with an average heating season duration of 7 months, during this time you will have to spend:

The leader is obvious.

Heating devices

First of all, modern heating radiators are bimetallic and aluminum models. However, there is a stable demand for both steel and cast iron products, which is due to the new approach of manufacturers to the manufacture of outdated, seemingly heating appliances... Let's briefly describe the advantages and disadvantages of each type.

Aluminum

The most popular in the post-Soviet space for the price / quality ratio (cheaper than bimetallic, in many respects more reliable than steel and cast iron).

Advantages:

the best heat transfer among all analogues;
expensive models can withstand pressures up to 20 bar;
little weight;
simplest installation.

Disadvantages: poor resistance to corrosion, especially noticeable at the junction of aluminum with other metals;

Bimetallic

It is generally accepted best type radiators. The name was given due to the combination of steel (inner layer) and aluminum (casing) in its structure.

Advantages:

Disadvantages: high price.

Steel

They are poorly suited for multi-storey buildings and the centralized heating system in general, and they show all their best properties in private houses, they fit perfectly into the heating systems of industrial premises in factories and plants. Learn more about steel radiators heating can be read.

Advantages:

heat transfer is above average;
rapid onset of heat transfer;
low cost;
aesthetic appearance.

Flaws:

Cast iron

It should be understood that modern cast-iron heating radiators are no longer lumpy and heavy remnants of the past that “adorned” almost every house during the Soviet era. Modern manufacturers have significantly improved their appearance, making them almost indistinguishable from bimetallic or aluminum models. Moreover, there is a growing fashion for the so-called, the forms and patterns of which bring the atmosphere of the beginning of the 20th century into the house.
Advantages:

Disadvantages: huge weight and the resulting difficulties with installation (often special support legs are required).

Heating system

Most modern country houses a horizontal heating system is used, the main difference of which from vertical wiring is the partial (less often - complete) absence of vertical risers.

In Russia, this kind of horizontal system is especially popular as a single-wire heating system (or one-pipe).

She presupposes natural, without circulation pump movement of water. From the heating device, the coolant flows through the riser to the second floor of the building, where it is distributed along the radiators and transmitting risers.

Water circulation without a pump is made possible by changing the density of hot and cold water.

The one-pipe system has a number of advantages over the two-pipe system:

Control system

Additional advantages can be provided by a heating system controller - a miniature computer device capable of:

The types of heating devices are determined by their design, which determines the method of heat transfer (convective or radiative heat exchange may predominate) from the outer surface of the devices into the room.

There are six main types of heating appliances, radiators, panels, convectors, finned tubes, smooth tube appliances and air heaters.

By the nature of the external surface, heating devices can be smooth (radiators, panels, smooth-tube devices) and ribbed surfaces (convectors, finned tubes, air heaters).

According to the material from which heating devices are made, they distinguish metal, combined and not metal appliances.

Heating device circuits

a - radiator, b - panels, c - convector, e - finned pipe, e - smooth pipe device.

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

Combined appliances use a concrete or ceramic array, in which steel or cast iron heating elements (heating panels) are embedded, or ribbed steel pipes placed in a non-metallic (for example, asbestos-cement) casing (convectors).

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

In terms of height, all heating devices can be divided into high (more than 600 mm high), medium (400-600 mm) and low (<400 мм). Низкие приборы высотой менее 200 мм называются плинтусными.

Diagrams of five types of heating devices are shown in the figure. Air heater used primarily for heating air in ventilation systems.

It is customary to call a radiator a device of a convective-radiation type, consisting of separate columnar elements - sections with round or ellipse-shaped channels. The radiator gives off about 25% of the total amount of heat transmitted from the coolant to the room by radiation, and is called a radiator only by tradition.

The panel is a device of a convective-radiation type of relatively shallow depth, which has no gaps along the front. The panel transmits with radiation a part of the heat flux slightly larger than the radiator, but only the ceiling panel can be attributed to radiation-type devices (emitting more than 50% of the total amount of heat by radiation).

The heating panel can have a smooth, slightly ribbed or wavy surface, columnar or serpentine channels for the coolant.

A convector is a convective type device consisting of two elements - a finned heater and a casing. The convector transfers at least 75% of the total amount of heat into the room by convection. The casing decorates the heater and helps to increase the rate of natural air convection at the outer surface of the heater. Convectors also include skirting-board heaters without casing.

A finned tube is an openly installed convection-type heating device, in which the area of the external heat-transfer surface is at least 9 times the area of the internal heat-absorbing surface.

Double column radiator section

hп - total height, hм - assembly (construction) height, l - depth; b - width.

A smooth-tube device is a device consisting of several steel pipes connected together, forming channels of a columnar (register) or serpentine (coil) shape for the coolant.

Consider how the requirements for heating devices are met.

1. Ceramic and porcelain radiators are usually made in the form of blocks, have a pleasant appearance, and have a smooth surface that can be easily cleaned from dust. They have rather high heat engineering indicators: kp p = 9.5-10.5 W / (m 2 K); f e / f f> 1 and a lower surface temperature in comparison with metal devices. When using them, the consumption of metal in the heating system is reduced.

Ceramic and porcelain radiators have not received widespread due to insufficient strength, unreliable connection with pipes, difficulties in manufacturing and installation, the possibility of water vapor penetrating through the ceramic walls. They are used in low-rise construction, used as free-flow heating devices.

2. 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 the nipples with gaskets made of heat-resistant rubber. Various designs of single, double and multi-column radiators of various heights are known, but the most common are two-column medium and low radiators.

Radiators are designed for the maximum operational (usually the term is used) coolant pressure of 0.6 MPa (6 kgf / cm 2) and have relatively high thermal performance: k pr = 9.1-10.6 W / (m 2 K) and f e / f f ≤1.35.

However, the significant metal consumption of radiators [(M = 0.29-0.36 W / (kg K) or 0.25-0.31 kcal / (h kg ° C)] and other disadvantages cause their replacement with lighter and less metal-consuming devices It should be noted their unattractive appearance when installed openly in modern buildings.In sanitary and hygienic terms, radiators, except for single-column ones, cannot be considered satisfying the requirements, since cleaning the intersection space from dust is rather difficult.

The production of radiators is laborious, installation is difficult due to the cumbersomeness and significant mass of the assembled devices.

Corrosion resistance, durability, layout advantages with good thermal performance, production efficiency contribute to a high level of radiators production in our country. Currently, a two-column cast iron radiator of the M-140-AO type with a section depth of 140 mm and inclined intercolumnar fins is produced, as well as of the C-90 type with a section depth of 90 mm.

3. Steel panels differ from cast-iron radiators in lower weight and cost. Steel panels are designed for operating pressure up to 0.6 MPa (6 kgf / cm2) and have high thermal performance: k pr = 10.5-11.5 W / (m 2 K) and f e / f f ≤1.7.

The panels are manufactured in two designs: with horizontal collectors connected by vertical columns (columnar), and with horizontal channels connected in series (serpentine). The coil is sometimes made of steel pipe and welded to the panel; the device in this case is called sheet-tube.

The panels meet the architectural and construction requirements, especially in buildings made of large building elements, are easily cleaned of dust, and allow their production to be mechanized using automation. On the same production areas, it is possible to produce per year instead of 1.5 million m 2 enp of cast iron radiators up to 5 million m 2 enp of steel. Finally, when using steel panels, labor costs during installation are reduced due to a decrease in the metal mass to 10 kg / m2 enp. Reducing the mass increases the thermal stress of the metal to 0.55-0.8 W / (kg K). The proliferation of steel panels is limited by the need to use high quality cold rolled sheet steel with a thickness of 1.2-1.5 mm, resistant to corrosion. When made from conventional sheet steel, the service life of the panels is reduced due to intense internal corrosion. Steel panels, except for sheet-tube panels, are used in heating systems with deoxygenated water.

Steel stamped panels and radiators various designs are widely used abroad (in Finland, USA, Germany, etc.). In our country, medium and low steel panels with columnar and serpentine channels are produced for single and twin (in depth) installation.

4. Concrete heating panels are manufactured:

with concreted coil or columnar heating elements made of steel pipes with a diameter of 15 and 20 mm;
with concrete, glass or plastic channels of various configurations (metal-free panels).

These devices are placed in the enclosing structures of the premises (combined panels) or attached to them (attachment panels).

When using steel heating elements, concrete heating panels can be used at an operating pressure of the coolant up to 1 MPa (10 kgf / cm 2).

Concrete panels have thermal performance indicators close to those of other smooth devices: k pr = 7.5-11.5 W / (m 2 K) and f e / f f ≈1, as well as high thermal stress of the metal. Panels, especially combined ones, meet strict architectural, construction, sanitary and hygienic and other requirements.

However, concrete panels, despite their compliance with most of the requirements for heating devices, are not widely used due to operational shortcomings (combined panels) and installation difficulties (attachment panels).

5. Convectors have relatively low heat engineering indicators k pr = 4.7-6.5 W / (m 2 K) and f e / f f<1, для отдельных типов конвекторов до 0,6. Тем не менее их производство во многих странах растет (при сокращении производства чугунных отопительных приборов) из-за простоты изготовления, возможности механизации и автоматизации производства, удобства монтажа (масса всего 5-8 кг/м 2 энп). Малая металлоемкость способствует повышению теплового напряжения металла прибора. M=0,8-1,3 Вт/(кг К) . Приборы рассчитаны на рабочее давление теплоносителя до 1 МПа (10 кгс/см 2).

Convectors can be equipped with steel or cast iron heating elements. Currently, convectors with steel heaters are produced:

skirting convectors without casing (type 15 KP and 20 KP);
low convectors without casing (such as "Progress", "Akkord");
low convectors with a casing ("Comfort" type).

Plinth convector type 20 KP (15 KP) consists of a steel pipe with a diameter of dy = 20 mm (15 mm) and closed fins 90 (80) mm high with a pitch of 20 mm, made of 0.5 mm thick sheet steel, tightly fitted to the pipe ... Convectors 20 KP and 15 KP are produced in various lengths (every 0.25 m) and are assembled at the factory into units consisting of several convectors (in length and height), pipes connecting them and control valves.

It should be noted such an advantage of using skirting convectors, as an improvement in the thermal regime of rooms when placing them in the lower zone along the length of windows and outer walls; in addition, they take up little space in the room depth (construction depths are only 70 and 60 mm). Their disadvantages are: the expense of sheet steel, which is not used efficiently for heat transfer, and the difficulty of cleaning the fins from dust. Although their dust-collecting surface is small (less than that of radiators), they are still not recommended for heating rooms with increased sanitary and hygienic requirements (in medical buildings and children's institutions).

The low convector of the "Progress" type is a modification of the 20 KP convector, based on two pipes connected by a common rib of the same configuration, but with a greater height.

The low convector of the "Accord" type also consists of two parallel steel pipes d y = 20 mm, through which the coolant flows in series, and vertical finning elements (height 300 mm) made of sheet steel 1 mm thick, mounted on pipes with gaps of 20 mm. The ribbing elements forming the so-called front surface of the device are U-shaped in plan (rib 60 mm) and open to the wall.

The "Accord" type convector is manufactured in various lengths and is installed in one or two rows in height.

In a convector with a casing, air mobility increases, which increases the heat transfer of the device. The heat transfer of the convectors increases depending on the height of the casing.

Jacketed convectors are mainly used for heating premises in public buildings.

The low convector with a "Comfort" casing consists of a steel heating element, a collapsible casing made of steel panels, an air outlet grille and a valve for air regulation. In the heating element, rectangular fins are mounted on two pipes d y = 15 or 20 mm with a pitch of 5 to 10 mm. The total weight of the metal of the heater is 5.5-7 kg / m 2 enp.

The convector has a depth of 60-160 mm, is installed on the floor or on the wall and can be through the movement of the coolant through passage (for horizontal connection with another convector) and end (with a roll).

The presence of a valve for air regulation allows the convectors to be connected in series along the coolant without installing fittings to regulate its quantity. Convectors can also be with artificial convection when installed in a fan casing of a special design.

6. Finned tubes are made of gray cast iron and used at operating pressure up to 0.6 MPa (6 kgf / cm 2). The most widespread are flanged cast iron pipes, on the outer surface of which there are thin cast round ribs.

The outer surface of a finned tube is many times larger than the surface of a smooth tube of the same diameter (inner diameter of a finned tube 70 mm) and length due to the high coefficient of ribbing. The compactness of the device, the lowered temperature of the surface of the ribs when using a high-temperature coolant, the comparative ease of manufacture and low cost determine the use of this device, which is ineffective in terms of heat engineering: k pr = 4.7-5.8 W / (m 2 K); f e / f f = 0.55-0.69. Its disadvantages also include an unsatisfactory appearance, low mechanical strength of the ribs and the difficulty of cleaning from dust. Finned tubes also have a very low thermal stress of the metal: M = 0.25 W / (kg K).

They are used in industrial premises, in which there is no significant dust emission, and in auxiliary premises with temporary stay of people.

Currently, round finned tubes are produced in a limited range of lengths from 0.75 to 2 m for horizontal installation. Steel iron finned tubes are being developed, which include the PK type finned tube with rectangular fins 70 X 130 mm. This pipe is easy to manufacture and relatively light in weight. The base is a steel pipe d y = 20 mm, poured into cast-iron fins with a thickness of 3-4 mm. Two longitudinal plates are poured over the ribs to protect the main ribbing from mechanical damage. The device is designed for operating pressure up to 1 MPa (10 kgf / cm 2).

Convector diagram with casing

1 - heating element, 2 - casing, 3 - air valve.

For a comparative thermal performance of the main heating devices, the table shows the heat transfer of devices with a length of 1 m.

Heat transfer of heating devices 1 m long at Δt av = 64.5 ° and a water flow rate of 300 kg / h.

Heating devices	Depth of the device, mm	Heat transfer
Heating devices	Depth of the device, mm	W / m	kcal / (h m)
Radiators:
- type M-140-AO	140	1942	1670
- type C-90	90	1448	1245
Steel panels, type MZ-500:
- single	18	864	743
- paired	78	1465	1260
Convectors type 20 KP:
- single row	70	331	285
- three-row	70	900	774
Convectors:
- type "Comfort" N-9	123	1087	935
- type "Comfort-20"	160	1467	1262
Finned tube	175	865	744

As can be seen from the table, deeper heating devices are distinguished by high heat transfer per 1 m of length; the highest heat transfer is provided by the cast-iron radiator, the lowest - by the plinth convector.

7. Smooth pipe devices are made of steel pipes in the form of coils (pipes are connected in series by the movement of the coolant, which increases its speed and hydraulic resistance of the device) and columns or registers (parallel connection of pipes with a reduced hydraulic resistance of the device).

The devices are welded from pipes d y = 32-100 mm, located at a distance from one another not less than the selected pipe diameter to reduce mutual irradiation and, accordingly, increase heat transfer to the room. Smooth-tube devices are used at an operating pressure of up to 1 MPa (10 kgf / cm 2). They have high thermal performance: k pr = 10.5-14 W / (m 2 K) and f e / f f ≤1.8, and the highest values refer to smooth steel pipes with a diameter of 32 mm.

Indicators of heating devices of various types

ittelnye	pressure	Requirements for devices
		Technical				architecturally Construction		sanitary hygienic		production Mounting
											labor
Radiators:
Iichesky and	2-4		>1	-	++	+	-	+	++	-	-
- cast iron	6		Up to 1.35	-	-	-	+	-	-	-	-
Panels:
- steel	6		Up to 1.7	++	+	+	-	-	++	++	+
- concrete	10		~ 1	+	++	+	±	++	+	-	±

- without casing
- with casing	10		<1	±	+	±	±	+	-	++	+
	6			+	-	-	++	+	-	-	-
	10		Up to 1.8	-	-	-	-	-	++	-	-
	8		>1	-	+	-	++	+	-	+	-

Note: The + sign marks the fulfillment, the sign - non-fulfillment of the requirements for the devices; the ++ sign marks the indicators that determine the main advantage of this type of heater.

Smooth-tube devices meet sanitary and hygienic requirements - their dust-collecting surface is small and easy to clean.

The disadvantages of smooth-tube devices include their cumbersomeness due to the limited area of the outer surface, inconvenience of placement under windows, an increase in steel consumption in the heating system. Taking into account the indicated disadvantages and unfavorable appearance, these devices are used in industrial premises in which there is a significant emission of dust, as well as in those cases when other types of devices cannot be used. In industrial premises, they are often used to heat skylights.

8. Heaters are compact heating devices of a large area (from 10 to 70 m2) of the outer surface formed by several rows of finned tubes; use them for air heating premises in local and central systems... Directly in the premises, air heaters are used as part of air heating units of various types or for recirculation air heaters. The heaters are designed for the operating pressure of the coolant up to 0.8 MPa (8 kgf / cm 2); their heat transfer coefficient depends on the speed of movement of water and air, therefore it can vary over a wide range from 9 to 35 or more W / (m 2 K) [from 8 to 30 or more kcal / (h m 2 ˚C)].

The table shows the indicators of heating devices different types; conditionally marked the fulfillment or non-fulfillment of the requirements for the devices.

Heating a room cannot be imagined without heating devices on the market in a fairly wide species diversity... In order to choose the most suitable option, you have to take into account whole line factors.

What are

Heating devices are classified according to the following criteria:

Coolant type. It can be liquid or gaseous.
Manufacturing material.
Specifications. This refers to the size, power, installation features and the presence of controlled heating.

When choosing the best option it is necessary to build on the features of the heating system of the house and the operating conditions. In this case, the entire list of requirements and standards regarding heating devices must be observed. Along with the power of the products, the specificity of their installation is of great importance. In the absence of gas supply and the possibility of arranging water heating, there is still an option with electric heaters.

Water heating system device

Hot water heating is the most common way to heat buildings. This explains the availability on the market of a significant variety of varieties of heating devices for water circuits. The reasons lie in good level The efficiency of these products, as well as reasonable purchase, installation and maintenance costs. The designs of these heating devices are very similar to each other. The core of each of them is a cavity: hot water heating the surface of the battery. Further, the convection process comes into play, transmitting heat to the entire room.

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

Cast iron.
Become.
Aluminum.
Combinations of materials (so-called "bimetallic batteries").

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

Cast iron batteries

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

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

Aluminum batteries

Aluminum devices are distinguished by a very high heat transfer, which makes it possible to bring the power of one section up to 200 W. This is quite enough for full heating of 1.5–2 m 2 of living space. The advantages of aluminum batteries can also be attributed to their low cost and low weight, which greatly simplifies installation work. In terms of the duration of operation, aluminum devices are almost two times inferior to their cast-iron counterparts (they can last no more than 25 years).

Bimetallic batteries

The strong point of bimetallic structures is special convection panels, which help to increase the quality of air circulation. In addition, devices of this type can be equipped with special regulators, with the help of which you can increase or decrease the flow rate of the coolant. Installation work in its simplicity resembles installation aluminum radiators... Each of the sections has a power of 180 W, providing heating of 1.5 m 2 of the area.

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

Electric types of heaters

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

Convection type heaters

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

Oil radiators

The principle of convection is also used in the operation of oil electric heaters. Special oil is poured into the apparatus for heating with a heating element. To regulate heating, a thermostat is often used, which turns off the power when the desired temperature mark is reached. Oil-powered devices are characterized by high inertia. This is manifested in a slow warming up of the device and in the same slow cooling down after a power outage.

The surface temperature usually heats up to 110-150 degrees, which provides for the observance of safety rules. Such a device must not be installed close to flammable surfaces. Oil radiators equipped with a convenient regulation of the heating intensity, designed for 2-4 operating modes. Keeping in mind the power of one section (150–250 kW), it is not at all difficult to choose the optimal model for heating a particular room. The maximum power of such a device is limited to 4.5 kW.

Infrared heating

The choice of heating devices infrared type brings the following dividends:

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

Infrared devices are classified according to the method of wave transmission. In new heaters, radiation is transmitted to the surrounding space thanks to resistor conductors installed on special film... The power of warm mats can reach 800 W / m 2. Film heaters are convenient because they can be used to organize warm floors.

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

Gas heating

In order to save money, you can use gas heaters. Their simplest variety is gas convector which commutes to main gas pipeline or a LPG bottle. The burner of the device is completely protected from contact with the surrounding atmosphere: in this case, a special tube is used to supply oxygen, which is led out into the street through a hole in the wall. These devices are characterized by high power (at least 8 kW) and low cost of operation. Among weaknesses gas heaters it is possible to highlight the obligation to register with regulatory agencies, the need for effective ventilation and the need for regular cleaning of the nozzles.

One of the main elements of water heating systems - a heater - is designed for heat transfer from heat carriers to a heated room.

To maintain the required room temperature, it is required that at each moment of time the heat loss of the room Qп is covered by the heat transfer of the heater Qпр and pipes Qтр.

The scheme of heat transfer of the heater Qпр and pipes for compensating for the heat losses of the room Qп and Qadd with heat transfer Qт from the side of the water coolant is shown in Fig. 24.

Rice. 24. Scheme of heat transfer of a heating device located at the outer fence of the building

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

Qt = Qp + Qadd

The heater is characterized by the area of the heating surface Fпp, m2, calculated to ensure the required heat transfer from the device.

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

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

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

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

Due to radiant heat exchange, the temperature of the inner surface of the fences increases compared to the temperature with convective heating, and the surface temperature of the inner fences in most cases exceeds the temperature of the room air.

Radiant panel heating creates a human-friendly environment by increasing the surface temperature in the room. It is known that a person's well-being is significantly improved with an increase in the share of convective heat transfer in the total heat transfer of his body and a decrease in radiation to cold surfaces (radiation cooling). This is exactly what is ensured with radiant heating, when a person's heat transfer by radiation decreases due to an increase in the temperature of the surface of the fences.

With radiant panel heating, it is possible to lower the air temperature in the room against the usual (standard for convective heating) air temperature (on average by 1-3 ° C), in connection with which the convective heat transfer of a person increases even more. It also contributes to the improvement of a person's well-being. It was found that under normal conditions well-being people are provided at an air temperature in the room of 17.4 ° C with wall heating panels and at 19.3 ° C with convective heating. Hence, it is possible to reduce the consumption of thermal energy for space heating.

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

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

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

Significant thermal inertia of these panels.

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

Appliances with a finned heating surface - convectors, finned tubes (fig. 26).

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

According to the material from which heating devices are made, there are metal, combined and non-metallic devices. Metal appliances are made mainly of gray cast iron and steel (sheet steel and steel pipes). Copper pipes, sheet and cast aluminum and other metals are also used.

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

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

In terms of height, all heating devices are divided into high (more than 650 mm high), medium (more than 400 to 650 mm), low (more than 200 to 400 mm) and baseboards (up to 200 mm).

By the magnitude of thermal inertia, devices of small and large inertia can be distinguished. Low-inertia devices are lightweight and hold a small amount of water. Such devices based on metal pipes small cross-section (for example convectors) quickly change the heat transfer to the room when adjusting the amount of coolant injected into the device. Devices with a large thermal inertia are massive, containing a significant amount of water (for example, concrete or sectional radiators); they change heat transfer slowly.

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

Table 20 shows the thermal performance and conventional signs other indicators of the devices are noted. The plus sign marks the positive indicators of the devices, the minus sign - the negative ones. Two pluses indicate indicators that determine the main advantage of any type of device.

Table 20

Heating device design

A sectional radiator is a device of a convective-radiation type, consisting of separate columnar elements - sections with round or ellipse-shaped channels. Such a radiator gives off about 25% of the total heat flux transmitted from the coolant to the room by radiation (the remaining 75% - by convection) and is called a "radiator" only by tradition.

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

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

Rice. 27. Two-column radiator section: hп - full height; hм - mounting height (construction); b - construction depth

The production of cast iron radiators is laborious, installation is difficult due to the bulkiness and considerable mass of the assembled devices. Radiators cannot be considered as satisfying sanitary and hygienic requirements, since cleaning of dust from the intersection space is difficult. These devices have significant thermal inertia. Finally, it should be noted that their appearance does not match the interior of the premises in buildings of modern architecture. The indicated disadvantages of radiators necessitate their replacement with lighter and less metal-consuming devices. Despite this, cast-iron radiators are currently the most common heating device.

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

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

All cast iron radiators are designed for operating pressures up to 6 kgf / cm2. The measurement of the heating surface of heating devices is a physical indicator - a square meter of a heating surface and a heat engineering indicator - an equivalent square meter (ecm2). Equivalent square meter is called the area of the heating device, which gives off 435 kcal of heat in 1 hour with a difference average temperature coolant and air 64.5 ° C and a water flow rate in this device 17.4 kg / h according to the flow pattern of the coolant from top to bottom.

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

Continuation of table. 21

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

Rice. 29. Cast iron radiators

Rice. 30. Cast iron radiators

Rice. 31. Cast iron radiators

Rice. 32. Cast iron radiators

Rice. 33. Cast iron radiators

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

Steel panel radiators differ from cast iron radiators in lower mass and thermal inertia. With a decrease in weight by about 2.5 times, the heat transfer rate is not worse than that of cast-iron radiators. Their appearance meets architectural and construction requirements, steel panels can be easily cleaned from dust.

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

Table 22 shows the characteristics of the manufactured stamped steel radiator panels.

Table 22

Continuation of table. 22

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

Rice. 35. Concrete heating panel

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

A smooth-tube device is a device made of several steel pipes connected together, forming channels for a heat-transfer agent of a coil or register form (Fig. 36).

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

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

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

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

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

Table 23

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

Rice. 37. Convector diagrams: a - with a casing; b - without casing: 1 - heating element; 2 - casing; 3 - air valve; 4 - pipe finning

The casing decorates the heater and enhances heat transfer by increasing air mobility at the heater surface. A convector with a jacket transfers to the room by convection up to 90-95% of the total heat flux (Table 24).

Table 24

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

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

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

Table 25

Continuation of table. 25

Note: 1. When installing KP skirting convectors in multiple rows, a correction is made to the heating surface depending on the number of rows vertically and horizontally: with two-row installation 0.97 vertically, three-row - 0.94, four-row - 0.91; for two rows horizontally, the correction is 0.97. 2. Indicators of end and straight-through convector models are the same. Pass-through convectors are indexed A (for example, Hn-5A, H-7A).

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

The outer surface area of a finned tube is many times greater than the surface area of a smooth tube of the same diameter and length. This makes the heater particularly compact. In addition, the low temperature of the surface of the fins when using a high-temperature coolant, the comparative ease of manufacture and low cost determine the use of this ineffective heat-engineering, heavy device. The disadvantages of finned tubes also include an outdated appearance, small mechanical strength ribs and the difficulty of cleaning from dust. Finned pipes are usually used in auxiliary rooms (boiler rooms, storage rooms, garages, etc.). The industry produces round finned cast iron pipes with a length of 1-2m. They are installed horizontally in several tiers and connected according to a serpentine scheme on bolts with the help of "rolls" - flanged cast-iron double bends and counterflanges.

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

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

Relative heat transfer from heaters 1.0 m long Table 26

Selection and placement of heating devices

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

Rice. 38. Cast iron finned tube with round fins: 1 - channel for the heat carrier; 2 - ribs; 3 - flange

To create a favorable thermal regime, devices are chosen that ensure uniform heating of the premises.

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

Devices located at the outer rails increase the temperature of the inner surface at the bottom of the outer wall and window, which reduces the radiation cooling of people. The ascending currents of warm air created by the devices prevent (if there are no window sills overlapping the devices), the ingress of cooled air into working area(fig.40a). In southern regions with short warm winters, as well as with short-term stay of people, heating devices can be installed near the inner walls of the premises (Fig. 39b). At the same time, the number of risers and the length of heat pipelines are reduced and the heat transfer of devices increases (by about 7-9%), but there is an unfavorable air movement with a low temperature near the floor of the room, which is unfavorable for human health (Fig.40c).

Rice. 39. Placement of heating devices in the premises (plans): a - under the windows; b - at the inner walls; p - heater

Rice. 40. Schemes of air circulation in rooms (sections) at different location heating devices: a - under windows without a window sill; b - under windows with a window sill; c - near the inner wall; n - heater

Rice. 41. Location under the window of the room of the heater: a - long and low (desirable); b - high and short (undesirable)

Vertical heating devices are installed as close to the floor of the premises as possible. With a significant rise of the device above the floor level, the air near the floor surface can be overcooled, since the circulating flows of heated air, closing at the level of the device, do not capture and do not warm up in this case lower part premises.

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

The ability of a tall heater to generate an active ascending flow of warm air can be used to heat rooms with increased heights.

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

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

Covering the device with a decorative cabinet with two slots up to 100 mm high (Fig. 42a) reduces the heat transfer of the device by 12% compared to its open installation near a blank wall. To transfer a given heat flow into the room, the heating surface area of such a device must be increased by 12%. Placing the device in a deep open niche (Fig. 42b) or one above the other in two tiers (Fig. 42e) reduces heat transfer by 5%. However, a hidden installation of devices is possible, in which the heat transfer does not change (Fig. 42c) or even increases by 10% (Fig. 42d). In these cases, it is not required to increase the area of the heating surface of the device, or it can even be reduced.

Calculation of the area, size and number of heating devices

The area of the heat-transfer surface of the heater is determined depending on accepted form the device, its location in the room and the connection diagram to the pipes. In residential premises, the number of devices, and, consequently, the required heat transfer of each device, is usually set according to the number of window openings. In corner rooms, another device is added, placed in a blank end wall.

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

where f1 is the area of one section, m2; the type of radiator adopted for installation in the room; B4 is a correction factor that takes into account the way the radiator is installed in the room; B3 is a correction factor that takes into account the number of sections in one radiator and is calculated by the formula: b3 = 0.97 + 0.06 / Fp;

where Fp is the estimated area of the heater, m2.

Heating devices can be safely called the crown of any heating system. Without them, any water heating loses all practical meaning. In this article we will talk about how the most common types of heating devices are classified and what are the advantages. So, let's begin!

The first type of classification is according to the method of heat transfer.

There are 3 ways of transferring heat from the heater to the environment:

radiation (radiation),
convection (direct air heating)
radiation-convective (combined) method.

Heat transfer by means of radiation. Also called radiant heat transfer. Any heated body emits infrared (radiation) rays, which, moving perpendicular to the radiation surface, increase the temperature of the bodies on which they fall, without increasing the air temperature. Further, the bodies that receive radiation radiation themselves become warmer and begin to produce infrared rays, heating the surrounding objects. And so it happens in a circle. At the same time, the temperature at different points in the room remains the same. An interesting fact is that radiation (infrared) radiation is perceived by our body as heat and does not harm our body at all, exerting, according to doctors, even positive effects on it. Radiation heating devices (radiators) agreed to consider those devices that transfer more than 50% of the heat into the environment in a radiant way. Such devices include various infrared heaters, "warm floors", sectional cast iron and tubular radiators, individual models of panel radiators and wall panels.

Heat transfer by convection. Convective heat transfer looks completely different. The air heats up from contact with hotter surfaces of convection heaters (convectors). The heated volume of air rises to the ceiling of the room due to the fact that it becomes lighter than colder air masses. The next volume of air rises to the ceiling after the first, and so on. Thus, we have a constant circular circulation of air masses "from the radiator to the ceiling" and "from the floor to the radiator". As a result, there is a feeling familiar to the inhabitants of premises heated by a convector - at head level the air can be warm, and a feeling of cold is felt in the legs. It is customary to call convective appliances heating appliances that carry out convection of at least 75% of the total heat. Convectors include tubular and plate convectors, finned tubes and steel panel heaters. Radiation-convective method of heat transfer.

Radiative-convective or combined heat transfer includes both types of heat transfer described above. They are possessed by devices that release heat into the environment in a convective way for 50-75% of the total amount of heat transfer carried out. Radiation-convective heating devices include panel and sectional radiators, floor panels, smooth-tube devices.

The second type of classification is according to the material from which the heating devices are made.

Here we are dealing with 3 groups of materials:

metals,
non-metals,
combined.

Metal heaters include heaters made of steel, cast iron, aluminum or copper, as well as possible combinations of two of the listed metals ( bimetallic devices heating).

Non-metallic heating devices are a rare occurrence in the market for household heating products. Glass is almost always used in the manufacture of such devices.

The class of combined heating devices usually includes panel radiators (they consist of an outer concrete or ceramic insulating layer and an inner metal - steel or cast iron heating elements) and convectors (metal pipes with fins, located in an additional metal casing).

The third way to divide heating devices is according to the degree of thermal inertia.

In this case, thermal inertia is the residual heat transfer to the room after the heater is turned off. Thermal inertia can be small or large (depending on the diameter of the pipes and specific types of heating devices).

The last way to classify heating devices is by its linear dimensions (meaning height and depth).

As dimensions often depend on the specific model and local space heating requirements, describe this way classification is meaningless.

Conclusion

This article has covered some of the concepts that describe how heat transfer works. In addition, standard methods of classification of the main types of heating devices present on the domestic market were given. heating equipment... We hope you found something interesting in this article. Glad to be helpful!

If you want to learn more about the characteristics of the main types of heating devices, we strongly recommend that you read the series of articles "The main thing about heating devices" on our website!