Central heating is a heating method in which heat is transported from a thermal power plant heat source through a pipeline system (in some cases through air ducts) to connected houses. The coolant in this case is water, air, steam.

Pipe materials and types

The main role in central heating, as in any other piping system, is played by pipes. Moreover, the material from which they are made is no less important for their reliability and resistance to mechanical shock and chemical corrosion. For example, if central heating is based on class “A” steel and types 20-35, then such a system will have a service life of 10 years.

Pipe marking

Main types and technical characteristics of heating devices (pipes):

• pn 10 - used in cold pipelines that require special strength. Such a pipe does not tolerate high temperatures: the maximum possible is + 20°C (under normal conditions), and the minimum should not be lower than -45°C;
• pn-16 is the optimal option for most pipeline systems; it can withstand up to +60°C heat. The usual pressure of this design is 1.6 MPa, which not all types of pipes can withstand;
• pn-20 is a pipe unique in its technical characteristics, which can withstand up to 90°C and is the best option for hot water supply. Typically used in central piping heating systems. Operating optimal pressure - 2.0 MPa;
• pn-25 is a reinforced pipe, similar to PN-20, and similar to it not only in technical characteristics, but also in pipeline systems. Withstands up to 95°C; optimal pressure is 2.5 MPa.

Nuances

The layout of each of the listed types of pipelines in the central heating system is similar to the most ordinary heating system. By and large, the user will not notice the difference between PN-20 or PN-10, since they differ only in technical characteristics.

However, the pipeline heating system in a private house and the pipeline in an apartment have their differences. In an apartment building, class A steel pipe and its connections are usually used.

Refusal from central heating center

If the central heating does not sufficiently heat a private home, or requires repairs, the user has the right to refuse the services of the supplier: this clause is specified in the contract.

You must obtain official permission from the city executive committee - a document that will allow you to refuse centralized heating. If you have any problems with issuing a permit, you must contact the administration.

To refuse, a list of all heating devices is compiled, for which housing department specialists are called, and then these devices are removed. It is clear that this can only be done during the inter-heating season, since shutting down would require unbalancing the entire system.

If you refuse central heating, it will be necessary to remove the existing elements of the heating system.

After abandoning the central heating system, the user's account remains obligated to pay for heating sewer pipes, water supply and other systems that pass through basement drains. Of course, the amount will be several times less, but you cannot completely refuse the service.

Composition of central heating systems for apartments

Central heating can be considered highly reliable, in which some types of pipes from the Borealis manufacturer are used as heating devices - in particular, Borealis RA-E130. Technical characteristics of the E130 are distinguished by high grade steel and powerful construction. The heating system in an apartment building using a pipe of this type will last more than 35 years.

Pipes marked PN-10.

The previously presented pipe options - from PN-10 to PN-25 - differ strikingly in the quality of steel and its alloy. The service life of pipes depends on the pressure, manufacturer and material of manufacture. Modern centralized heating systems are assembled either on Pn-10 - Pn-25 pipes, or on Borealis pipes. The latter option is more expensive, but also more reliable.

Disadvantages of CO

The main disadvantages are all the factors that negatively affect heating devices:

• high activity in the pipeline;
• a sharp increase in pressure;
• climatic instability leading to the destruction of pipes;
• loss of up to 10% of thermal energy during transportation;
• errors in heat use (applies to individual consumers).

Advantages

The central heating system has the following advantages:
the ability to use a source of cheap heat;

• reliability;
• environmental friendliness;
• convenience and practicality.

From an economic point of view, using centralized heating is very profitable: the costs will be several times lower compared to other options. Therefore, when abandoning central heating, it is necessary to make accurate calculations, weigh the costs - in any case, do not rush to switch off.

To understand what central heating is (the term “centralized” is more often used to define it), we need to understand how it all works together. The fact is that the method of supplying coolant to radiators can be very different from each other.

Therefore, in such cases, your approach to the installation or replacement of heating devices will also change. We will figure out how single-circuit systems differ from double-circuit systems, find out which radiators are better to use, and watch a video clip that reinforces the topic.

Centralized systems

Note. The main difference that defines central heating systems is their operation from a general boiler house or CHP, while autonomous heating is carried out using a home boiler house. For the average user, this, in fact, does not matter, but if it comes to routine or major repairs, then you have to pay attention to this.

Independent and dependent system

• If the system is independent, then powerful central heating boilers supply coolant not directly to the circuits of residential or non-residential premises, but first to heating points, where redistribution occurs. That is, hot water from a thermal power plant or a powerful boiler house enters such transformer stations through large-diameter pipes, then, depending on the needs of a group of buildings, a house or an entrance, it is distributed according to the power of the coolant pressure. At such TPs, circulation pumps are installed, which, if necessary, can increase the flow power (for example, for a nine-story building).

• In cases where the project is made according to a dependent scheme, the central heating system supplies hot water directly to the radiator circuits of each residential or non-residential premises, without prior distribution of flow power. It should be noted that the circulation pump, during its operation, does not in any way affect the temperature of the coolant - with its help, additional pressure is created, which is necessary for the upper floors of high-rise buildings.

Single-circuit system

This scheme is used quite often, but there are significant disadvantages of central heating (single-pipe) due to large heat losses during liquid transportation. Usually they are compensated for by increased pressure in the system, but, nevertheless, one can very often hear complaints from residents living in such houses.

The essence of the functioning of such a scheme is as follows: hot liquid is supplied through a pipe, to which radiators for central heating are connected using inlet and outlet pipes. That is, heated water, while circulating along the ribs of the device, cools down and again enters the central distribution pipe.

This means that the temperature of the liquid for the next battery will already be lower, and so on. Usually no more than three or four, maybe five devices can function without losses.

But in apartment buildings, problems arise even with so many radiators per supply pipe, and the reason most often lies in poor thermal insulation of the premises. Residents, instead of insulating windows and doors, and possibly walls, begin to increase the number of sections on radiators with their own hands - in some cases their number exceeds 20 pieces!

Now - simple arithmetic - if in the riser of a five-story building there used to be 5 batteries of 10 sections, for which the design capacity was calculated, now there are twice as many of them - here usually only the first two floors receive enough heat (upper or lower - depending on where the feed starts).

In order to reduce heat loss in such systems, bypasses are often installed in front of the radiators, as you can see in the photo above, but taps are usually not provided for them. It turns out that part of the hot flow can circulate with minimal heat loss if it does not completely enter the battery sections.

But a tap embedded there (into the bypass) in the closed position allows water to be redirected through the radiator, that is, with maximum temperature loss.

Double-circuit circuit

A double-circuit heating system of an open or closed type allows the supply of liquid in a continuous temperature regime for all floors, although the price of materials and installation here is slightly higher than that of a single-circuit one. The funds are spent on pipes for central heating.

In a double-circuit system, central heating radiators are independent of each other, since they return the cooled liquid to the return pipe and this coolant flows back to the heating point (CHP or boiler room), without affecting the temperature of other batteries. Hot water is also supplied through one pipe.

Note. Considering the fact that centralized systems have high pressure, the design provides for cast iron radiators. But if you want to improve your interior design, then the instructions allow you to replace them with steel or ones, which also hold pressure well.

Conclusion

So, in the direct (generally accepted) understanding, centralized or central heating is a system that operates from a thermal power plant or from a common boiler house. But it can also be considered as such if we consider it from each room, since they are all powered from a common point.

To make it comfortable to live in various buildings in big cities, special enterprises are built that produce electricity and heat - thermal power plants, on the basis of which central heating is created. Thus, thanks to such stations, there is no need to build many boiler houses, which will only pollute the atmosphere - and this has a positive effect on human health and the surrounding nature of the region.

In addition, a large supply of good quality fuel is not required, so the country's fuel reserves are preserved. Control panels are easier to maintain, but they still have disadvantages. The main one is that pipelines interact with oxygen, resulting in pipe breaks and fistulas.

The centralized heating system is designed to provide heat and hot water to residents of residential buildings and owners of industrial premises.

For the system to be effective, it is installed near buildings, divided into levels, each of which is assigned specific functions. And the more levels there are, the less load there will be on the previous level.

Central heating allows you to reduce the cost of purchasing fuel of the highest quality, since a low grade is also suitable for normal operation. In addition, central heating improves sanitary standards for all residential areas and areas.

Central heating structure

The central heating system includes several elements:

• Source of heat carrier. This is a thermal power plant that produces heat and electricity.
• The source of heat transportation is heating networks.
• Source of heat consumption. These are heating devices located in homes, offices, warehouses and other premises of various types.

If we compare the volume of heat loads, then heating systems can be seasonal in the type of heat transfer and constant in the type of hot water transferred to the end consumer. All this depends on what the end consumer’s needs for the heat carrier are, as well as on the economic component of the feasibility of supplying it to the supplier’s enterprise. The last parameter depends on how far the heating plant is from the end consumers.

Types of heat supply systems

The classification of heat supply systems will directly depend on what type of heat carrier enters the heating network - water, steam or air. Accordingly, when the system supplies water to consumers, it is water heating, steam is steam, and air is air.

Also, systems providing centralized heating are divided depending on the method of connecting the hot water source to the heating network. Thus, there are closed systems, when the heat carrier - water, is taken from the water supply and heated in the central network heat exchanger, and open systems, where water is taken directly from the heating network. Also, depending on the method used to connect the system to the central heating system, there are dependent and independent heating systems.

Each type of system has different characteristics. Steam central heating in an apartment is a more economical option compared to others, as it requires less operating costs, and the steam lines are made from smaller pipes, so the final cost will be lower. Note that the steam system is perfect for those buildings in which people are not present all the time, but periodically, and the coolant is supplied according to a schedule, as a result of which freezing and rupture of pipes is prevented.

If you take an air system, then it is capable of not only heating the room, but also ventilating it. But the cost of equipment for such a system is quite high, so it is rarely used.

A water central heating system for an apartment building is the most common option. And this is not without reason, since such systems are characterized by excellent sanitary and hygienic qualities.

The water temperature in central heating reaches 60 degrees Celsius; when transporting to end consumers, less energy flow is spent than with steam, here the density is greater, and it can be used over long distances.

For 1 kilometer of travel, the temperature of the coolant decreases by 1 degree Celsius. Note that the temperature supplied by water central heating in an apartment building can be controlled at a centralized level, and the system is easy to operate, since there are no condensation pumps, condensate pumping pipes and drains.

Advantages and disadvantages of connecting to central heating

Of course, in modern times, consumers are provided with a huge selection of heating systems, which use not only the heat sources that are familiar to us, but also alternative, sometimes the most unexpected ones. However, central heating in a private house, and even in an apartment building, is still a common phenomenon today. Therefore, it is worth considering the advantages and disadvantages of connecting to a central heating line, especially if you are faced with choosing a heating system in your new home or are thinking about switching to an individual system in your apartment.

So, the central heating scheme for an apartment building provides the following advantages to those who choose it:

• First of all, it is an opportunity to use cheap fuel. After all, even if a thermal power plant is not installed in your region, boiler houses usually use fairly cheap options and their analogues. In any case, gas is the cheapest heating.
• The next factor is reliability. After all, the city authorities undertake to monitor the condition of the equipment and pipes for central heating, and to repair the heating system in a timely manner.
• Boilers that use central heating are environmentally friendly in most cases.
• Another important point is ease of operation. In this case, you do not have to monitor the equipment, since the radiators will always give you a stable temperature (provided there are no changes).

However, central heating also has a number of disadvantages:

• The first and most important thing is to turn the heating on and off according to a schedule. If you are still cold or already hot, no one will care.
• The heating in each room is the same and cannot be adjusted.
• The pressure in the central heating system is not always ideal.
• You will have to spend a lot of money on the purchase and installation of equipment.
• During energy transport, large heat losses can occur.

Thus, even though in modern times there are many ways to heat your home individually, central heating is still popular. And the point here is not even the habit of citizens, but the fact that sometimes such a system is an excellent solution.

1.
2.
3.
4.

Most of those who live in apartment buildings, as a rule, have centralized heating - this is the option that runs from a common network. The functioning of such a system has a number of features and differs in many ways from the autonomous heating system usually used in private homes.

Many argue that centralized heating is a very ineffective way to heat a home. Therefore, you should consider in more detail the technical characteristics of this heating option, as well as understand how the connection to central heating should take place and how you can save your money.

The principle of operation of a centralized heating system

This option for heating a room in an apartment has a lot of features that should definitely be mentioned.

Firstly, central heating in a private house (this option is also found) and in an apartment involves generating heat in a completely different room from where the heating occurs. The place where heat energy is obtained is usually either a local boiler house or a thermal power plant. It is from there that the coolant, heated to the required temperature, enters the apartments through a pipeline.

There are two categories of centralized heating systems - water and steam, which explains the presence of steam and water boilers in boilers. The energy source is different types of fuel (coal, gas, wood waste, etc.).

After the temperature of the water in the central heating reaches the desired value, it enters the pipes, from where it is subsequently transferred to the heating radiators. In these devices, the water gradually cools down and then returns back to the heating point.

Many boiler houses, immediately before supplying water to apartments, pre-clean it with a special chemical composition. In this case, first of all, the hardness of the coolant is reduced, in addition, excess oxygen and carbon dioxide are removed from it. The purpose of this treatment is to prevent the appearance of scale and corrosion formations inside the pipe system.

Advantages and disadvantages of centralized heating

Despite the fact that many consider a centralized heating system to be ineffective, this option still has some obvious advantages, which include the following:

• This option for heating a living space is much cheaper than an autonomous one. In addition, there is absolutely no need to purchase expensive heat-generating devices, or to carry out installation work yourself;
• devices that heat the coolant before supplying it to homes are quite capable of operating on inexpensive fuel, which invariably increases the efficiency of the system;
• Moreover, it should be noted that most boiler houses are equipped with special devices that can operate on almost any type of fuel, which cannot but have a positive effect on the reliability of this heating option;
• Before abandoning central heating, do not forget that this heating method is completely environmentally friendly, since no harmful combustion products penetrate into the apartments, which cannot be said about some autonomous systems. Read also: "".

However, such heating also has disadvantages, and the most significant of them are the following:

• Heat losses in such systems are usually very significant. So, when the coolant enters an apartment, it travels a long distance, during which time it has time to cool down considerably. That is why, to maintain a comfortable temperature in a home, a much larger volume of energy source is required compared to autonomous equipment (read: " ");
• it is almost impossible to regulate the heating temperature, which is due to complete control by the boiler room. At the same time, there are very frequent cases of both lack of heat and excessive overheating, which negatively affects the microclimate in the apartment;
• unauthorized disconnection from central heating is strictly prohibited, since such measures can only be considered in court;

In addition, due to regularly rising tariffs, many owners prefer to equip an autonomous heating system, however, as mentioned earlier, before disconnecting from central heating, it is necessary to obtain special permission from the relevant authorities.

Options for optimizing central heating operation

As you know, the coolant, passing through a pipe system, loses a significant part of its temperature, which necessitates the need to optimize the functioning of the heating system in order to reduce heat loss.

This problem can be solved in one of two ways:

1. The first method will be relevant if the boiler room and the entire pipe system are fully regulated by the owners themselves.

   In this case, improvements could be as follows:
   

   
   - installation of more modern and efficient equipment with higher performance indicators is allowed. As a result, this will change the pressure in the central heating system, reduce fuel consumption, and also reduce financial costs;
   - the possibility of equipping the system pipeline with high-quality insulating material, which will reduce heat loss as it moves to the batteries. In addition, the thermal insulation material protects the entire structure from possible freezing, which is especially important in cold winters.
2. The essence of the second method is as follows: the thermal energy supplied by a boiler house or thermal power plant to a specific residential premises is strictly fixed. Typically, this method involves installing special energy-saving meters (read also: ""). Thus, all subsequent payments for heating services will be made solely based on their readings.

Possibility of switching to autonomous heating

If you are dissatisfied with the operation of the centralized heating system, there is the option of switching to autonomous heating of the apartment. However, as mentioned earlier, such work will be associated with a number of obstacles; in particular, it is especially important to obtain appropriate permission to carry out such work, since any replacement of central heating pipes must be carried out under the control of special authorities of the housing and communal system. Read also: "".

To be more clear, permission to install individual heating equipment can usually be obtained only if the entire house, and not just one of its apartments, is deprived of central heating.

One way or another, any work related to the installation and connection of heating is recommended to be carried out under the supervision of specialists in order to protect yourself and nearby residents from possible troubles caused by improper installation or repair. In addition, professional craftsmen usually have a variety of photo and video materials available that can help in setting up an alternative to centralized heating.

Watch also the video about the possibility of disconnecting from centralized heating:

On November 29, a heating network pipeline broke on Baikalskaya Street in Moscow. Boiling water from a pipe with a diameter of 800 millimeters flooded the area around the accident site, several people were injured, one of whom died a week later in the hospital. Due to the fact that the accident occurred on a section of the heating plant 27 kilometers long, according to various sources, from 900 to 2 thousand houses in the east of Moscow were left without hot water and heating. As the head of the capital’s housing and communal services department, Hasan Gasangadzhiev, put it, “about 600 thousand residents of the capital found themselves in the reduced heating zone.” Heat supply was restored by the morning of November 30.

Why doesn’t Russia simply give up central heating and what is it being replaced with all over the world?

Warmth of the world

Condensing gas boiler

The approach to heat supply in different parts of the world depends on several factors, but primarily on the severity of the climate, the availability of energy resources and the attitude towards the environment. Depending on this, space heating can be carried out in very different ways - from burning coal or biomass to using the energy of the earth’s crust.

Germany

In this country, heat supply is decentralized. This means that heat does not come into houses from a large common pipe, but is generated by each house (apartment or area) independently. The main advantage of this approach is the ability to regulate consumption and choose its source. Private houses in Germany are heated by boilers, multi-apartment houses are usually heated with separate gas equipment. At the same time, the Germans keep a clear record of the heat used in each apartment: all radiators have valves that regulate the temperature in the room, there is a meter that takes into account the amount of coolant consumed by each apartment. In recent years, the popularity of heat supply has been growing significantly due to the use of environmentally friendly fuels - biomass, wood waste, solar panels and others. Government programs reimburse up to 15% of the costs of purchasing and installing such equipment.

Finland

Residents of Suomi have the opportunity to choose a heating method - centralized gas or individual electric. Both are quite expensive - 100–150 euros. One of the strangest heating methods in Finland is heat pumps that run on geothermal energy. To do this, pipes are laid in the ground and connected to such a heating system. 40% ethyl alcohol circulates through the pipes, which delivers heat from the depths of the Finnish soil to the house. Installing a heat pump is not cheap, but it allows you to save a lot on electricity, due to which the system pays for itself within five to seven years. This type of heating is usually used in small private households.

Norway

Norway has fairly cheap electricity, so the country's heating system runs 70% on electricity and is therefore decentralized. But there is also district heating, which warms about 3% of households nationwide and 10% in its capital Oslo. At the same time, the main source of energy (49%) for central heating is various types of waste that are burned in special plants.

Iceland

Iceland, like Russia, is one of the few countries in the world where the main thing is central heating, but it is organized in an unusual way. 90% of homes in the country are heated using geothermal energy. There are a lot of active volcanic zones and geysers in Iceland, it is cheap to get energy from them, and therefore prices for heat supply in Iceland are significantly lower than the European average. The warmth of the hot waters of the geysers here even warms the sidewalks in winter and heats the water in municipal swimming pools. The remaining 10% of the population warms their homes with various decentralized systems, such as boilers.

USA

In the States, heating systems are predominantly decentralized. In apartment buildings, electrical appliances are mainly used to heat rooms - fan coil units and air conditioners; in country cottages - gas-powered systems. It is believed that in a country with a fairly mild climate, this is not only a way to abandon an expensive central heating system, but also an opportunity for everyone to calculate their needs.

Canada

In terms of climatic conditions, this country is perhaps closest to Russia, but the population settlement here is much less dense. Largely because of this, the main thing is intra-house heating, that is, decentralized heating. The most commonly used units in Canada are electric air heaters (air conditioners) and gas boilers. Air conditioners are also convenient because in the summer they easily switch to cooling mode.

China

Due to the rather mild climate in the country, electricity is mainly used for heating. In addition to air conditioning, the Chinese warm themselves with electric blankets and electric heaters. In poor areas they use stoves that burn wood or coal. District heating is only used in a few regions north of the Yangtze River, where the climate is harsher. At the same time, winter tourists often complain about the cold in hotels, where the temperature can drop below 10 degrees.

How they drown in Russia

Thermal power plant

In our country, heat generation is closely related to electricity production. In fact, all stations that produce electricity, except hydroelectric ones, also generate heat. A simplified diagram of heat generation can be presented using the example of the operation of a combined heat and power plant (CHP). The energy from the burned fuel turns water into steam, which spins turbines to generate electricity. After this, the steam is collected to heat the coolant of the central heating system. It is sent to consumers through the heat supply system.

Through heating plants, the heated coolant is supplied to the radiators of city apartments. Through heat exchangers, it also heats tap water at central or individual heating points (CTP and ITP). The cooled water from the batteries returns to the station to go into the boilers, turn into steam, spin the turbine to generate electricity and warm the coolant again.

As a rule, in large Russian cities the entire heat supply system is connected and operates as a single network. In addition to thermal power plants, it includes a network of small thermal boiler houses that heat remote areas or provide insurance in case of an accident.

Kirill Lushin

Director of the Institute of Engineering-Environmental Construction and Mechanization (IIESM) NRU MGSU

Due to the climate in Russia, centralized heat supply is the best option. This is not an ideological decision, but rather a forced one: nowhere in the world is there such a dense settlement of people in the harsh northern latitudes as we have. There are no analogues to Moscow - a gigantic city in such a cold climate - in the world. Decentralized heat supply to Russia would be much more expensive, and the tariffs for it would most likely be higher, because we need much more heat than even Scandinavia or Canada. At the same time, there are other examples of the use of central heating systems in the world: among the Danes, in some regions of Asia, but again, due to the climate, this is not in great demand there.

The main disadvantages of such a system are inflexibility and lack of alternatives. City residents have no choice about how to receive heat, and the city heating network acts as a monopolist here. Although its tariffs are restrained by the authorities, in general any monopoly is vicious. But this is an economic problem; on the technical side, I think in Moscow, for example, the central heating system is very well done.

Accidents, like the one that happened the other day, mainly occur due to individual errors in the device and system operation. Often the fact is that, to save money, too much heated coolant circulates in it, and frequent changes in its temperature accelerate the wear of the pipeline. But, again, the existing heating network performs well, and in a critical situation the emergency section is closed, and the heat supply to the cut-off area is carried out through backup heating systems (which is what happened last week). This is enough to prevent all heating systems in the affected area, and at the same time its residents, from defrosting.

It is worth noting that in Russia, decentralized heat supply is significantly limited by current laws in territories where there is a central one. Many houses with their own boiler rooms, for example, are still connected to the central heating system most of the year and only in certain periods (during a preventive shutdown of hot water or an emergency) turn on their own boilers. But even if the homeowner succeeds in completely generating heat on his own, this will only lead to the replacement of one monopolist by another - the heat supplier with a gas or electricity supplier.

Photos: cover – StockphotoVideo – stock.adobe.com 1 – caifas – tock.adobe.com, 2 – Alexander Zamaraev – stock.adobe.com