Heating system in a panel house. Providing heat to apartment buildings: centralized heating system. Battery in the wall: how to get rid of it and is it worth it?

Residents of Russia, especially its northern part, believe that if the walls are thin, it means that the house will be cold in winter. But then what can we say about houses with walls in which several rows of bricks or many centimeters are laid? concrete block? It's still cold anyway. And in panel houses, when constructing buildings, special attention is paid to insulating materials, which, despite the small thickness of the walls, retain heat well in winter.

Not so long ago, on the domestic construction market panel houses have arrived. The technology for creating such houses originates in countries such as Canada and the Scandinavian states. Agree, Canada and Norway have far from hot climates. But people live in panel houses and don’t think about building expensive cottages for themselves, and heating panel house for northerners - not a problem. It's all about the technology, which can withstand temperatures below minus 30 degrees. The fact is that between the two panels the builders lay a special insulation material. It turns out to be a kind of “sandwich” that does not let the cold into the room, but at the same time the walls “breathe” freely.

Also, in the design of a house structure, it is always taken into account which heating system is best installed. The main thing is not to trust crooks, but to turn to experienced craftsmen and engineers. Construction work panel house and installation acceptable and optimal system heating requires high qualifications. Showing into the house heating equipment– the process is labor-intensive. It all depends on the requests of the owners and the total area of the panel house.

There are several optimal and effective ways conduct heating in a panel house, namely: install a convector, heat pump, water heating boilers.

Which heating method should I choose?

Many people prefer mobile heaters: oil radiators, convectors. Convectors operate using electricity; their convenience lies in mobility, but they require large financial costs. Oil heaters work at the expense mineral oil inside a steel case. But the connection comes from the electrical network, and it is advisable to use them only as an additional coolant. Such heating in a panel house is too expensive.

A good solution is to buy heat pumps with high technical indicators. Energy savings reach 30% compared to other types of boilers. But the high cost and long work to install the device force many people to abandon this idea.

If there is no natural gas supply in the area, you can install a water heating boiler using solid fuel (coal, wood, peat) or electric. Boilers for liquid fuel, which burns for a long time, continuously releasing heat into the room.

If the house is led natural gas– there’s no need to even think about it – install heating in a panel house only through a gas boiler. There are many advantages:

cost savings,
gas is much cheaper than electricity, wood and coal,
constant receipt of fuel,
no soot or soot.

Water heating boilers occupy the first place in the list of heating systems. The boiler operation process depends on installed system radiator coolant. Radiators can now be purchased different types: aluminum, cast iron, steel, bimetallic.

Cast iron is becoming a thing of the past due to poor wear resistance and the heaviness of the metal. Aluminum and steel are light in weight and have maximum heat transfer. But the first in the series of batteries are bimetallic radiators. They have maximum heat transfer and lightness, are resistant to any type of coolant and chemical additives in fuel. Exterior finishing modern bimetallic radiators fits easily into any cozy design premises.

Residents of city apartments are usually not interested in how the heating works in their home. The need for such knowledge may arise when owners want to increase the comfort in the house or improve the aesthetic appearance of engineering equipment. For those who are planning to start a renovation, we’ll tell you briefly about heating systems apartment building.

Types of heating systems for apartment buildings

Depending on the structure, characteristics of the coolant and piping layouts, heating of an apartment building is divided into the following types:

By location of the heat source

Apartment heating system, in which a gas boiler is installed in the kitchen or separate room. Some inconveniences and investments in equipment are more than compensated by the ability to turn on and regulate heating at your discretion, as well as low operating costs due to the absence of losses in heating mains. If you have your own boiler, there are practically no restrictions on system reconstruction. If, for example, the owners wish to replace the batteries with warm water floors, there are no technical obstacles to this.
Individual heating, in which one house or residential complex has its own boiler room. Such solutions are found both in the old housing stock (stokers) and in new luxury housing, where the community of residents decides for itself when to start heating season.
Central heating in apartment building most common in typical housing.

The installation of central heating in an apartment building, heat transfer from the thermal power plant is carried out through a local heating point.

According to coolant characteristics

Water heating, water is used as a coolant. In modern housing with apartment or individual heating, there are economical low-temperature (low-potential) systems where the coolant temperature does not exceed 65 ºС. But in most cases and in all standard houses The coolant has a design temperature in the range of 85-105 ºС.
Steam heating apartments in an apartment building (water vapor circulates in the system) has a number of significant disadvantages; it has not been used in new buildings for a long time; old housing stock is being transferred to water systems everywhere.

According to the wiring diagram

Basic heating schemes in apartment buildings:

Single-pipe - both the supply and return of coolant to the heating devices are carried out through one line. Such a system is found in “Stalin” and “Khrushchev” buildings. It has a serious drawback: the radiators are located in series and, due to the cooling of the coolant in them, the heating temperature of the batteries drops as they move away from the heating station. In order to maintain heat transfer, the number of sections increases as the coolant moves. In a pure one-pipe circuit, it is impossible to install control devices. It is not recommended to change the configuration of the pipes or install radiators of a different type and size, otherwise the operation of the system may be seriously disrupted.
"Leningradka" - an improved version single pipe system, which, thanks to the connection of thermal devices via a bypass, reduces their mutual influence. You can install regulating (not automatic) devices on radiators, or replace the radiator with a different type, but of similar capacity and power.

The two-pipe heating scheme for an apartment building began to be widely used in “Brezhnevkas” and is still popular to this day. The supply and return lines are separated, so the coolant at the entrances to all apartments and radiators has almost the same temperature; replacing radiators with a different type and even volume does not have a significant effect on the operation of other devices. Control devices, including automatic ones, can be installed on batteries.

On the left is an improved version of the single-pipe circuit (analogous to the Leningrad circuit), on the right is the two-pipe version. The latter provides more comfortable conditions, precise regulation and provides greater opportunities for replacing the radiator

The beam scheme is used in modern atypical housing. The devices are connected in parallel, their mutual influence is minimal. The wiring is usually done in the floor, which allows you to free the walls from pipes. When installing control devices, including automatic ones, accurate dosing of the amount of heat throughout the rooms is ensured. It is technically possible to have both partial and complete replacement heating systems in an apartment building with a radial circuit within the apartment with a significant change in its configuration.

With a radial scheme, the supply and return lines enter the apartment, and the wiring is carried out in parallel with separate circuits through the collector. Pipes are usually placed in the floor, radiators are neatly and discreetly connected from below

Replacement, relocation and selection of radiators in an apartment building

Let’s make a reservation that any changes to apartment heating in an apartment building must be agreed with executive bodies and operating organizations.

We have already mentioned that the fundamental possibility of replacing and moving radiators is determined by the circuit. How to choose the right radiator for an apartment building? Please note the following:

First of all, the radiator must withstand pressure, which is higher in an apartment building than in a private one. The greater the number of floors, the higher the test pressure can be; it can reach 10 atm, and in high-rise buildings even 15 atm. The exact value can be obtained from your local operating service. Not all radiators sold on the market have the appropriate characteristics. A significant part of aluminum and many steel radiators not suitable for an apartment building.
Whether and how much the thermal power of the radiator can be changed depends on the circuit used. But in any case, the heat transfer of the device must be calculated. One typical section of a cast iron battery has a heat transfer of 0.16 kW at a coolant temperature of 85 ºС. Multiplying the number of sections by this value, we obtain the thermal power of the existing battery. The characteristics of the new heating device can be found in its technical data sheet. Panel radiators are not assembled from sections, have fixed sizes and power.

Averaged heat transfer data various types radiators may vary depending on the specific model

The material also matters. Central heating in an apartment building is often characterized by low quality coolant. Traditional ones are the least sensitive to contamination. cast iron batteries, aluminum react the worst to aggressive environments. Bimetallic radiators performed well.

Installation of a heat meter

A heat meter can be installed without problems using a radial wiring diagram in an apartment. As a rule, in modern houses There are already metering devices. As for the existing housing stock with standard systems heating, this possibility is not always available. This depends on the specific piping layout and configuration; advice can be obtained from your local operating organization.

An apartment heat meter can be installed with radiant and two-pipe scheme wiring, if there is a separate branch to the apartment

If it is not possible to install a meter for the entire apartment, you can place compact heat meters on each of the radiators.

An alternative to an apartment meter is heat metering devices placed directly on each radiator

Please note that the installation of metering devices, replacement of radiators, and other changes to the heating system in an apartment building require prior approval and must be carried out by specialists representing an organization licensed to carry out the relevant work.

Video: how to supply heating in an apartment building

As is known, the provision of heat to a significant portion of the housing stock is carried out centrally. And, despite the fact that recent years more are emerging and being implemented modern circuits heat supply, central heating remains in demand, if not among owners, then among developers of multi-apartment housing. However, it should be noted that many years of foreign and domestic experience in using this heating option have proven its effectiveness and right to exist in the future, subject to trouble-free and quality work all elements.

A distinctive feature of this scheme is the generation of heat outside the heated buildings, the delivery of which from the heat source is carried out through pipelines. In other words, central heating is complex engineering system, distributed over a large area, providing heat to a large number of objects simultaneously.

Structure of a central heating system

Classification of central heating systems

The variety of central heating organization schemes that exist today makes it possible to rank them according to certain classification criteria.

By thermal energy consumption mode

seasonal, provision of heat is required only during the cold season;
year-round requiring constant heat supply.

By type of coolant used

water– this is the most common heating option used to heat an apartment building; such systems are easy to operate, allow you to transport coolant over long distances without deteriorating quality indicators and regulate the temperature at a centralized level, and are also characterized by good sanitary and hygienic qualities.
air– these systems allow not only heating, but also ventilation of buildings; however due to high cost such a scheme is not widely used;

Figure 2 – Air circuit for heating and ventilation of buildings

steam– are considered the most economical, because small diameter pipes are used to heat the house, and hydrostatic pressure there is little in the system that makes it easier to use. But such a heat supply scheme is recommended for those objects that, in addition to heat, also require water vapor (mainly industrial enterprises).

According to the method of connecting the heating system to the heat supply

independent, in which the coolant (water or steam) circulating through the heating networks heats the coolant (water) supplied to the heating system in the heat exchanger;

Figure 3 – Independent central heating system

dependent, in which the coolant heated in the heat generator is supplied directly to heat consumers via networks (see Figure 1).

According to the method of connection to the hot water supply system

open, hot water taken directly from the heating network;

Figure 4 – Open system heating

closed, in such systems, water is drawn from a common water supply, and its heating is carried out in the central network heat exchanger.

Figure 5 – Closed system central heating

The design of a centralized heating system and the principle of operation of its components in an apartment building

It is clear that in order to provide heat to an apartment building, it must be connected to the heating network coming from the boiler house or thermal power plant. For these purposes, they are installed in the pipes leading to the building. inlet valves, from which one or two thermal units are powered.

After the valves, as a rule, they are installed mud scavengers, intended for sedimentation of the formations formed in the pipeline during prolonged contact with hot water metal oxides and salts. By the way, these devices allow you to extend the life of the heating system without repairs.

Further along the house contour there are hot water supply taps: one on the supply, the second on the return. As you know, central heating operates on superheated water(the temperature of the coolant from the thermal power plant is 130-150 0C, and to prevent the liquid from turning into steam, a pressure of 6-10 kgf is created in the system). Therefore, during the cold season, DHW is connected from the return, where the water temperature usually does not exceed 70 0C. IN summer period, when the temperature of the coolant in the heating network is relatively low, the hot water supply is connected from the supply.

After the DHW valves there is the most important unit of the system - heating elevator, the main purpose of which is to cool superheated water (coming from the thermal power plant) to the standard values required for supply directly to the heating devices of an apartment building.

This device consists of a steel body in which there is a nozzle, from which the water coming from the heating plant comes out with reduced pressure and high speed. As a result, a vacuum is created, causing coolant to leak from the return into the elevator, where water mixing occurs, i.e. change in its temperature.

Figure 6 – Heating elevator design

It should be noted that the regulation of the heating system, i.e. determination of the actual temperature difference in it, as well as the level of heating of the working water mixture and, accordingly, heating devices, is carried out by changing the diameter of the elevator nozzle.

Behind the elevator are usually located valves for heating entrances or apartment building as a whole.

House valves allow you to connect and disconnect the heating circuit of the building from the heating plant: in winter they are open, in summer they are closed.

Further, central heating involves the installation of so-called discharges, which are valves for bypassing or draining the system. Sometimes they are connected to a cold water supply pipeline in order to fill radiators with water in the summer.

In recent years, in accordance with the requirements for the mandatory installation of metering devices, heat meters.

Figure 7 – Diagram of the thermal unit of the central heating system

Risers and outlets of a centralized heating system

The scheme for organizing water circulation in the system of an apartment building is, as a rule, a single-pipe option for supplying coolant with top or bottom filling. In this case, the supply and return pipes can be separated either both in the basement, or the supply in the attic or technical floor, and the return in the basement.

Risers, in turn, come with:

associated movement of the coolant;
movement of water from top to bottom;
counter movement from bottom to top.

When using bottom filling schemes each pair of risers is connected by jumpers, which can be located either in apartments on the top floor or in the attic. In this case, an air vent (air vent) must be mounted at the top point of the jumper.

The Mayevsky crane is the simplest in design, but fail-safe vent.

The main disadvantage of this option is the airing of the system after each water discharge, which requires bleeding air from each jumper.

Figure 8 – Possible schemes central heating system with bottom filling

Heating system with top filling provides for installation on the technical floor multi-storey building expansion tank with an air vent valve, as well as separate valves that allow you to cut off each riser.

The correct slope when laying the bottling ensures that when the vents are opened, the water is completely drained from the system in a very short time. But this option has a number of features that must be taken into account when designing.

The temperature of the heating devices decreases as the coolant moves downwards. It is clear that on the lower floors it will be significantly lower than on the upper ones, which is usually compensated by an increase in the number of radiator sections or the area of convectors.
The process of starting the heating is quite simple. To do this, you need to fill the system, open the existing house valves and briefly open the vent on the expansion tank. After this, the central heating and the entire system begin to function fully.

Advantages and disadvantages of a central heating system

The central heating system has the following dignity:

possibility of using inexpensive fuels;
reliability ensured by regular monitoring of performance and technical condition from special services;
use of environmentally friendly equipment;
ease of operation.

Among shortcomings Such a heating scheme for an apartment building should be noted:

the system operates according to a strict seasonal schedule;
the impossibility of individual temperature control of heating devices;
frequent pressure drops in the system;
significant heat loss during transportation and heating in an apartment building;
high cost of equipment and its installation.

Initially, the houses of Khrushchev's projects were conceived as temporary, to solve the housing problem. However, to this day, they occupy a fair share of the fund. The main problem of living is the layout of the heating system of the Khrushchev building and its structure. Given natural wear and tear, it often does not fully perform its functions.

Centralized heating scheme for Khrushchev

The houses of this project are characterized by a single-pipe scheme, when the distribution of coolant starts from the upper (5th) floor and ends with the entry of cooled water into the basement. Such heating systems in Khrushchev have one significant drawback - uneven distribution of heat throughout the apartments.

This is due to the alternate passage of the coolant through the floors, i.e. The greatest degree of its heating will be on the 5th, 4th, and on the 1st the amount of heat is not enough to heat the room. In addition, the heating scheme of a five-story Khrushchev building has the following disadvantages:

Poor condition of heating elements. Limescale build-up on inner surface pipes and batteries lead to a decrease in diameter, and as a result, a decrease in heat transfer;
Lack of temperature control system on batteries. Reducing the flow of coolant using devices is impossible, as this will affect the hydraulic pressure in the entire system. The solution is to install a bypass on each radiator.

To solve these problems, it is necessary to carry out modernization - install modern radiators and pipes. Metal heating devices and pipelines made of polymers have proven themselves to be the best. They have increased heat transfer rates, which helps to heat rooms faster. However, to truly create effective system The heating system in the Khrushchev building needs to be replaced on all floors. If old pipes and radiators are left on the top ones, then the speed of water passage in the system will remain unsatisfactory.

Such modernization can be carried out not only by residents, but also by attracting the resources of the housing office. This organization is obliged to carry out planned replacement of pipelines. They know how the heating system in a Khrushchev building works - the diagram and location of pipelines for a particular house.

Auxiliary heating in Khrushchev

What to do if, even after improving and replacing elements, the temperature in the apartment is far from ideal. The best option is autonomous heating in Khrushchev. However, this is not always possible - installation of a gas boiler is not permitted due to low pressure in the main line or due to inappropriate chimney ducts.

Then they begin to develop alternative ways increase in room temperature. Negative point is that the heating scheme of a five-story Khrushchev house does not provide for the connection of additional radiators. This can lead to reduced pressure in the pipes and significant heat loss for residents living below. To avoid unpleasant moments, you can perform a number of actions that help save energy in your apartment.

Insulation of external walls of Khrushchev building

It is recommended to install a thermal insulation layer on the external walls. It will help reduce heat losses and will not affect the current state of the heating system in the Khrushchev building. It is also necessary to replace the old ones wooden windows to new ones made of PVC or laminated veneer lumber. Special attention You should pay attention to the thickness of the double-glazed windows. For effective thermal insulation this parameter must be at least 28 mm.

Warm floor in Khrushchev

This is one of the best mechanisms for increasing the temperature in the apartment. It can be installed not only in the bathroom and kitchen, but also in living areas. It is best to choose infrared heated floor models, since their installation requires a minimal increase in thickness flooring. The heating circuit of the Khrushchev house is not designed to connect a water heated floor. Its installation can lead to improper operation of the entire heating circuit of the house.

Apartment heaters

They can solve the problem with the speed of heating the air in the apartment and do not affect the operation of the main heating system of apartments in Khrushchev-era buildings. Along with traditional oil and converter-type electric heaters, infrared models have become very popular. They increase the temperature not of the air, but of objects, heating their surface. However, the disadvantage of such devices is the increase in financial costs for electricity.

Before connecting the heaters, you need to check the electrical wiring. Often the wire cross-section is not designed for heavy loads. The heating scheme for a five-story Khrushchev building is designed only for water coolant.
Therefore, it is recommended to replace it first, and only after that install powerful electrical appliances.

Autonomous heating systems in Khrushchev: choosing a boiler and correct pipe routing

Contrary to popular belief, it is possible to install individual heating in a Khrushchev-era building. To do this, it is necessary to select a boiler that complies with the standards and provide the management company with the developed project. She first gives technical specifications, on the basis of which an autonomous heating system in Khrushchev-era buildings is compiled.

What should you pay attention to when solving this problem? Let's look at the main components autonomous heating in Khrushchev - a boiler, a piping system and radiators.

Heating boiler for Khrushchev

Average area two-room apartment in Khrushchev buildings does not exceed 60 m2. Therefore, the optimal power of a gas boiler should be 7-8 kW. The next condition is the type of burner - it must be closed. Since the design of the heating system in the Khrushchev-era building does not include the installation of a boiler, normal air exchange must be ensured for its operation. This is necessary to take air from the street using coaxial chimney. In some cases, it is possible to install carbon monoxide exhaust systems into the building's air ducts. But before this, it is necessary to obtain the approval of the fire service. Often this is precisely the obstacle to installing individual heating in a Khrushchev-era building.

Heating pipes and radiators

For laying the highway it is best to use reinforced pipes made of polypropylene. They are characterized simple installation, affordable price. Their advantages include the possibility of hidden installation. It can only be performed on the floor, since gating of load-bearing walls is prohibited. The heating system in Khrushchev is designed in such a way that the installation location of radiators is most often located under the windows. When designing an autonomous heating system, it is possible to provide for the installation of additional batteries. Most often they are installed in the bathroom.

Project and heating schemes for Khrushchev

When developing a heating scheme for a Khrushchev building, you need to take into account all the nuances. In particular, provision of hot water supply. Therefore, it is best to purchase double-circuit boilers heating.

The requirements for the scheme are no different from the standard ones.

Correspondence temperature regime and pressure operational characteristics pipes, radiators;
Connection to the water supply system for heating replenishment;
Installation of expansion tank and circulation pump.

In this case, it is possible to install a water heated floor. For this purpose, the heating scheme of the Khrushchev house provides for the installation of a collector. It will distribute the coolant through the underfloor heating pipelines; the built-in system for mixing hot and cold water flows (two-way valve) will automatically regulate the temperature.

For a minimal increase in floor thickness, it is recommended to use decorative coating, designed for installation directly on water heating pipes. The packaging must be marked accordingly.

In addition to upgrading the autonomous heating installation, you can perform a number of actions, the result of which will lead to a reduction in current operating costs and payment for housing and communal services. Considering the specific layout of the heating system in a Khrushchev building, installing heat meters in an apartment is impractical. This is due to the absence of a central riser, i.e. even for studio apartment you will have to install at least three meters - in the bathroom, kitchen and living room.

The total cost of installing one device can range from 25 to 30 thousand rubles. The way out of this situation is to install a common house meter. It will take into account the amount of thermal energy consumed for the entire building. Fortunately, the centralized scheme characteristic of all types of heating in Khrushchev allows this to be done. As additional function a mode for adjusting the coolant supply depending on the outside temperature may be provided.

For the central heating scheme of a five-story Khrushchev building, you can install a balancing riser. It will perform the functions of uniform distribution of coolant throughout all floors of the house. However, which project is carried out only in agreement with the housing office, since it falls under the category of changing the principle of hot water supply.

By former union a lot is scattered apartment buildings with an “in-wall” heating system. They can be found both in Moscow and in Murmansk, St. Petersburg, Chelyabinsk, as well as in many cities of Belarus and Ukraine. But what is this “battery in the wall” - a whim or stupidity of Soviet architects? Or an innovation that appeared too early? And what to do with it today: change it or leave it as is?

Reasons for the appearance of houses with in-wall batteries

In Brezhnev’s times, when similar housing was built, main task architects and builders were required to provide the population with their own living space as quickly as possible. And the formation of a centralized heating system at the pouring stage reinforced concrete structures was a completely logical step.

Plus, the batteries inside the walls are truly innovative and practical solution. At correct installation pipes and high-quality production of reinforced concrete with good insulation not heated at all street air, as many believe, but the slabs themselves.

And according to the technology, heat should be reflected inside the premises. As a result, much less energy is required for comfortable heating. And the air in the rooms is not as humid as in normal wall radiators. Similar today technological solution increasingly used in European countries precisely because of economy and practicality.

IN Soviet years The technology of placing batteries inside walls was quite widespread and covered many regions. Such houses were built from series 91, 121, 1-515, 464, 1605 and many others. Each research institute sought to “improve” the design. And in some, only the riser was laid inside the slabs, in others, the entire heating system was installed. In some projects, pipes were installed in the facade walls, while in others, on the contrary, they were installed exclusively in interior walls.

Battery in the wall: how to get rid of it and is it worth it?

The main problem with such batteries is the inability to shut them down when it gets hot. Plus, houses age and naturally the pipes in them do too. An outburst can happen at any moment. And if in a building with “open” heating pipes, they can be replaced with new ones without any noticeable problems. Then you will have to work hard with the “walled up” ones.

Moreover, in most cases, the first thing you will need to do is order a project for rebuilding the heating system, and go through many approvals. Design and estimate documentation can be done externally, but you will have to go to the housing office for approvals. It is best to entrust the work to them.

Battery replacement options

Batteries with pipes are built into the facade walls.

Most likely, any work in this case will be strictly prohibited. After all, the design of the building includes heat from these pipes along the facade. And any individual changes are simply unacceptable. The only solution would be to order a rework of the heating system throughout the entire house with insulation external walls. It will be necessary to break through the ceilings, install risers and only then connect new radiators to them.

Piping in internal slabs.

There are serious restrictions here load-bearing walls. As a rule, batteries were embedded in them. And any demolitions or penetrations are not allowed. The only thing that can be done is to find “mortgages” in the corners of the slabs. These are pockets in the concrete where the slabs and heating risers were connected to each other. These places are easy to find by tapping. After connecting the pipes, the voids were filled with a solution, which sounds very different from industrial concrete. Then the coil in the wall is tightly closed and a new radiator with a bypass is inserted.

The batteries are inside, but there are riser outlets outside.

In some series of houses, although the radiators are located in the walls, pipe bends can be seen in the corners of the rooms. Everything is much simpler here. It won't be difficult to get close to them and crash into the system. In addition, you don’t have to create a project and go through lengthy approvals.

Whatever the situation, you need to clearly understand that the battery embedded in the wall is in fact a common riser for the entire entrance. And any changes in it affect the quality of heating for all neighbors above and below. Whatever is done, the riser must not be blocked or narrowed.

Only a specialist can accurately determine the series of the house and the configuration of the pipes inside the panels. It will be necessary to bring up documents of Soviet projects. You can only roughly find by touch where such a battery is located.

All this work will cost a lot of money. But problems with heat can be completely different.

Before “removing” the radiators from the walls, you should contact the house management company and demand that they identify the reasons for the lack of heat in the rooms. Perhaps, in the embedded pipes, airlock or there are deficiencies in sealing the seams. Or the insulation inside the panels has simply decayed over time. In many cases, they will fix the problems without rebuilding the heating system or will have to install an external radiator for free.