Some consider district heating in apartment buildings a relic of the Soviet era, while others consider it an undeniable boon of civilization. But we all continue to use this method of heating.
The main element of such a system are the apartment heating batteries, which stand under the window in the living rooms of apartment buildings. About their types and features and will be discussed in our article. We will also briefly consider the main advantages and disadvantages of cast iron, aluminum, steel and bimetallic radiators.
Content of the article:
- Principles of classification of radiators for apartments
- Features of different designs
- Division by material of manufacture
- Option #1 - corrosion-resistant cast iron
- Option #2 - practical steel
- Option #3 - durable aluminum
- Option #4 - practical bimetal
- Conclusions and useful video on the topic
Principles of radiator classification for apartments
In centralized heating systems, the heat transfer medium is usually water heated to 95 °C water. And it is not used purified distilled but technical water with dissolved salts and additives.
As a result the material of the radiator in the apartment should safely withstand the temperature changes, humidity and impurities contained in the heat carrier during a long time.
For a long life the apartment heating radiator must:
- have the operating pressure of up to 9 atm (ideally 12-15 atm);
- made of metals resistant to chemical and electrochemical corrosion;
- have a high heat output.
The pressure in apartment radiators varies in the range 4-7 atm. Much depends on the number of floors in the apartment building, the temperature outside the window and the conditions of the heating system. But during pressure testing and water hammer pressure may rise briefly up to 15 atm and higher.
All heating radiators are made of metals (aluminium or iron) - only they are able to stand operating loads formed in heating systems
Also the radiator in question must be easy to install, have presentable appearance and low cost. But most importantly, it must have excellent heat output characteristics.
The main task of the radiator is to give the heat that comes through the pipes with water to the room. The more effectively it does this the better for the apartment owner.
There are two main criteria for classification of radiators:
- Manufacturing material.
All other parameters are technical features of the particular radiator model.
Features of different designs
The functionality of radiators is determined not only by the material they are made of but also by their construction.
For example, the radiators are:
- sectional (block);
The first two are a set of several elements assembled into a single heater, while the third is a monolithic block.
The now widely used aluminum radiators are among the sectional water-heating devices. A classic example of a columnar counterpart is the old cast-iron radiator.
Column radiators assume only lateral connection, while sectional and panel versions can be connected from the side and bottom, you just need to choose the appropriate model
In a columned heater, the jumper blocks, on the contrary, have internal cavities for water circulation. And the panel is a completely hollow single unit at all.
Division by material
In terms of design, batteries are vertical and horizontal. In apartments the second variant is usually chosen as it is easier to install them under the window and connect them to the pipes of the existing heating system.
But if there is a strong desire, the installation of the vertical type is quite possible. But this type of installation is more complicated and more expensive.
But all this is more a matter of aesthetics and personal preferences of the owner of the apartment in the matter of interior design. The main point in choosing a household heating radiator is the metal of its manufacture. It can be cast iron, steel, aluminum or bimetal (aluminum + steel). In order to determine exactly which radiator is better for a certain apartment, it is necessary to carefully study all the features of the available variants.
In some cases the cast-iron radiator is the best choice, while in others only the steel analogue is suitable for installation.
Option #1 - corrosion-resistant cast-iron
The cast-iron radiators left in some apartments from Soviet times look ugly now and sometimes outright ugly. Especially devices with many layers of partially peeling paint.
Its cast iron as a material for radiators was originally chosen because of the cheapness of the metal and ease of mass production of devices for heating.
The modern cast-iron radiator, a beautiful and efficient device that retains all the advantages of the old good-quality \"cast-iron\" in the form of high resistance to corrosion and undemanding cleanliness of the heat medium
Such radiators continue to heat many apartments today even half a century after installation. It is the best choice among all analogues in terms of corrosion resistance.
Plus clogs and air blockages in such heaters are formed only in extremely rare cases. The openings in their internal cavities are initially too large for the suspended solids and air bubbles in the heat transfer medium.
The main advantages of cast iron are:
- long life;
- resistant to corrosive processes;
- high price;
- high thermal inertness;
- unpretentious in terms of water purity.
The main advantage and at the same time the disadvantage is their inertness in heating and cooling. On the one hand a cast iron radiator heats up slowly, but on the other hand it does not cool down as quickly as an aluminum or steel one.
It has a big enough water volume inside. In a situation of temporary disconnection of the central heating and the interruption of the coolant circulation, the cast-iron battery for some time will still gradually give up the heat. Whereas other options on the contrary will cool down instantly.
Besides steel, aluminum and cast iron, there are also copper batteries in heat stores, but because of their high cost and problems with electrochemical corrosion for urban apartments with central heating \"copper\" is not recommended to choose
The disadvantages of cast iron appliances include:
- large weight - one section weighs 5-6 kg;
- low protection against water hammer;
- fragility of cast iron - a split from water frozen inside such a battery is far from uncommon;
- pinch shock - susceptible to damage by pitting mechanical shocks.
Another significant disadvantage of cast iron is the relatively low working pressure of 6-8 atm. For apartments in old panel buildings or stalinkas such an option is quite suitable. But for the dwelling in a modern apartment house with 12-16 floors it is better to choose something else.
As a minimum before buying a cast-iron battery for installation in the high-rise it is necessary to clarify the existing pressure in its heating system of the coolant, usually it is above 10 atm.
More on the pros and cons of cast iron batteries we wrote in the following article.
Option #2 - Practical Steel
Steel batteries are practical and come in two types - tubular or panel. The former are a direct analogue of the above described cast iron appliances. They have similar characteristics in terms of heat output and weight, but a more presentable appearance.
The second ones are made of two steel sheets welded together to form a thin layer-cavity inside for water circulation.
This variant has higher heat output, so they are often joined together in several pieces. As a result, the total heat transfer area increases dramatically.
All steel surfaces in these batteries are coated with a special paint to increase protection against corrosion. As a result, their service life reaches 15-20 years, but at the slightest damage to the protective coating steel begins to rust quickly
Steel batteries better withstand waterstrikes than their cast iron counterparts. But they have one very weak spot - the welds. This is where rusting most often begins, this is also where ruptures mostly occur when the water pressure surges in the system.
Pros of steel radiators are as follows:
- Small inertia - heats quickly and quickly gives away heat to the room.
- Light weight - for the same heat emission the steel device obviously weighs less than the cast-iron one.
- High cost.
- Ability to install a thermostat.
- Attractive and often original design.
What concerns negative moments, they also exist. So, these radiators definitely should not be put in bathrooms. There is a high humidity, in which the steel will quickly go rusty. Steel radiators will not last long in such conditions.
For apartments in high-rise buildings it is not recommended to take steel radiators. They are more intended for installation in private houses with a lower operating pressure of the heating medium than in a central heating system. More information about pressure standards and ways to increase pressure we gave here.
Option #3 - durable aluminum
Aluminum radiators are the most common today in the market of household heating equipment. This is due to their cheapness, durability and lightness in weight, as well as the extreme ease of installation.
Batteries made of aluminum are produced by casting and by extrusion technology. The first variant is more durable and belongs to the sectional variety, while the second is cheaper and is a single monoblock
Casting creates separate sections which are then joined to form a common radiator by a set of several of these blocks. If necessary, such a battery can be expanded by adding new elements even after the installation has been completed.
Extrusion analogue is made at once in the factory. It is not possible to add parts to increase the heat transfer area later on. But it is cheaper than the cast version.
Functional characteristics and installation features of aluminum radiators we reviewed in detail in our other article.
The advantages of aluminum radiators are as follows:
- high heat-transferring performance;
- low weight;
- modern design;
- affordable cost;
- can be equipped with thermostat;
- last 30 years;
- lack of paint peeling.
The main disadvantage of the aluminum heater is the demanding nature of the heat transfer medium. The slightest solid particles as the water circulates begin to scratch the protective coating inside. As a result, aluminum is left unprotected and begins to gradually corrode.
Aluminum surfaces react actively with acids and alkalis, plus they are contraindicated in the heating system elements of copper and stray currents
Other rather unpleasant point is the formation and accumulation in aluminum radiators hydrogen. If such radiators are not equipped withblowers, they can slightly inflate from the inside.
The heater will not burst, but small leaks may well form in the joints of the sections. Plus the chance of the formation of air stoppers in the system increases, which is called a plus or an advantage also difficult.
The maximum working pressure at different models of aluminum radiators varies in the 10-20 atm.
In this index they are superior to cast iron and steel analogues, but inferior to bimetal competitors. This is the variant recommended in most cases to put in city apartments.
Option #4 - practical bimetal
The most durable and long-lasting among all household radiators of heating are bimetallic ones. They have a steel core through which water circulates and an aluminum outer layer. As a result, they combine the reliability of steel and the heat output of aluminum.
We recommend reading about the existing varieties of bimetallic batteries, their characteristics and selection rules here.
In terms of heat transfer, the bimetal radiator is slightly inferior only to its purely aluminum competitor, but greatly exceeds it in durability
These batteries were originally created to replace old cast-iron ones. They were immediately designed taking into account the peculiarities of Russian central heating.
Not for nothing they are called universal radiators, which can be installed without problems in almost any apartment.
The bimetal radiator has the following advantages:
- Rugged - working pressure is around 35 atm.
- Indifferent to the chemical composition of the heat transfer medium.
- High corrosion resistance.
- Compact and modern appearance of the device.
- Low weight.
The main and only significant disadvantage of this device is the high price. They are the most expensive of all analogues. But these costs will be compensated by long lifetime and absence of leaks with floods.
Bimetallic radiators are especially actual in the houses where the water pressure in the heating system is frequently fluctuating.
Conclusions and useful video on the subject
To make it easier for you to understand which radiator is better, we made a selection of videos with a breakdown of the different nuances of these devices.
The following video will help you understand the radiator types and determine which are better for your specific conditions:
10 mistakes when replacing old radiators in the apartment:
Expert advice on choosing the best radiator in the following video:
Choosing which radiator to put in your apartment you should first of all follow the parameters of the central heating system.
In an old house it is often possible to install only cast iron radiators. Aluminum variants are ideal for new buildings and panel five-storey buildings. And the reliable bimetallic analogues are universal devices suitable almost in any situation, but they cost a lot.
And what batteries do you personally consider the best and which ones are installed in the heating circuit of your house/apartment? Share your impressions of their use, add unique photos of your radiators and useful recommendations for newcomers.