Cast iron heating radiators: battery characteristics, their advantages and disadvantages

Modern technological progress has practically not affected cast iron heating radiators in all 167 years of their existence.Consumers still choose these devices due to the many positive characteristics of the products.

And even some shortcomings do not prevent the installation of cast iron batteries when installing heating systems. Next, we will talk in detail about all the advantages and disadvantages of cast iron radiators, as well as the characteristics that you need to pay attention to before purchasing.

Advantages of cast iron radiators

The use of cast iron batteries has a lot of advantages that make you choose these devices for installing heating systems. Some positive qualities are not always voiced by salespeople in stores, although they should also be known and taken into account when purchasing.

Among the advantages of cast iron batteries, resistance to aggressive coolant parameters should be noted. It is due to the material they are made of – cast iron does not corrode for a long time, even at high temperatures.

Various chemical additives to the coolant, as well as iron oxides formed in the main pipes, also do not lead to the destruction of cast iron.

In addition to resistance to corrosive processes, such batteries have the following advantages:

• possibility of repair in case of blockage and leakage;
• inertia of heat transfer;
• reasonable cost;
• possibility of operation at high temperatures and high pressure;
• high percentage of heat transfer due to radiation;
• ease of installation;
• long working life.

Battery blockages and leaks can occur due to the fault of the coolant. Thus, the circulation of untreated water with a high content of calcium and magnesium salts in cast iron radiators leads over time to a narrowing of the internal cavities. This impairs the heating rate of the sections and the efficiency of heat transfer.

Cast iron radiators with designer finishes are produced mainly by European factories, which is why they are in little demand on the domestic market

In addition, due to the high temperature of the water in old-style batteries, the intersection gaskets gradually wear out and a leak may occur.

Problems associated with long-term operation of cast iron radiators can be quickly eliminated in the summer. The internal cavities of the sections are easily cleaned of deposits with a special tool.

Due to the resistance of cast iron to mechanical processing, the quality of the radiators does not suffer. When reassembling the sections, you can immediately replace worn gaskets.

The increased inertia of heat transfer from cast iron radiators is ensured by the weight of the structure and the large internal volume of coolant.

If steel and aluminum models cool down within a few minutes after the water circulation stops, then cast iron batteries continue to effectively heat the room for an hour

As for the cost of one cast iron section, it is within the same range as the price of its aluminum or steel counterparts. Therefore, the cost of purchasing batteries made of cast iron will not be more than radiators made of other materials.

However, cast iron products are much better tolerated water hammer, firmly resist short-term pressure increases up to 16 bar.

The ability to operate at high temperatures and high pressures is ensured by the small coefficient of thermal expansion of cast iron. Among all the materials from which heating batteries are made, it has the smallest.

Because of this, cast iron is most resistant to microcracks during long-term use. The same property ensures stable tightness of threaded connections and gaskets at a pressure of 8-9 atmospheres.

And such an advantage as high heat transfer due to radiation allows cast iron radiators to be placed near the wall. To maximize the direction of thermal radiation deep into the room, it is recommended to mount special reflectors on the wall behind the battery.

The ribs between the columns are ordinary cast iron plates and do not have internal cavities. Their function is to enhance heat transfer

In addition, cast iron radiators are convenient and easy to install. Sections of cast iron batteries are connected to pipes and to each other using threaded connections and paronite gaskets. A special key allows you to separate any sections without removing the outer radiators.

And the long service life once again confirms the quality and reliability of this heating equipment - cast iron radiators are guaranteed to last 50 years.

But they will last this long only with regular maintenance, which consists of periodically removing internal deposits and replacing gaskets.

The listed advantages of cast iron batteries make them indispensable in large rooms with an extensive heating network and high operating pressure.

Disadvantages of cast iron batteries

Despite many advantages, cast iron radiators have a number of disadvantages. This was facilitated by both the design features and the properties of the cast iron itself. For example, cast iron batteries have difficulty integrating into automatic temperature control systems.

Due to the inertia of heat transfer, it is quite difficult to control the set temperature in the room. After all, after turning off the boiler, cast iron radiators will give off their heat for another hour, warming the surrounding air.

It takes about half an hour to reheat the entire mass of the battery and the water it contains. Throughout this period, the room will practically not warm up.

There are also other disadvantages, including:

• large volume of coolant;
• significant weight of one radiator;
• design uniformity.

The large volume of water in the battery also has its disadvantages. Warming up the entire coolant requires more time and energy resources.

In addition, the load on the pump increases, which is forced to pump a significant amount of water in one heating cycle.

The volume of the cavities of a cast iron battery is at least 2 times larger than that of an aluminum battery and 4 times larger than that of a bimetallic battery

The heavy weight of the devices is also a disadvantage that worries installers and service departments more than residents.However, when assembling a heating system yourself, you cannot do without an assistant when attaching the cast iron battery. The weight of one section is about 7 kg.

Such a disadvantage as design uniformity is due to the technological features of cast iron - they do not allow creating elegant parts from this material. The batteries look the same.

Due to the simplicity of the design, the energy efficiency of the MS-140 battery models is one of the worst, but the price of such devices is also the lowest

To diversify the model range, manufacturing companies produce cast iron radiators with a beautiful pattern on the surface, but their cost is 10-20 times higher than the price of simple models.

However, if you do not have the funds for expensive exclusive models, you can purchase ordinary radiators and then disguise them using battery screen.

The intricate patterns and varying heights and widths of the radiators provide some variety among the more expensive radiators. This allows designers to integrate cast iron batteries into sophisticated interiors

Another drawback is the equipment’s vulnerability to water hammer. The fact is that cast iron is a strong, but rather fragile material. According to GOST 8690-94, radiators must withstand short-term pressure of 1.5 MPa.

But sometimes the pressure can exceed this value. This happens when the pump starts abruptly and there are no compensators. As a result, cast iron batteries may crack or burst.

Battery rupture is often accompanied by preliminary clicks and hissing. These sounds should alert you and force you to block the coolant's access to the radiator.

In many cases, the advantages of cast iron radiators greatly outweigh their disadvantages.It is this fact that helps such batteries maintain a good position in the heating systems market.

Technical characteristics of radiators

Competition in the radiator market is extremely high, so there are not many manufacturers producing and selling cast iron batteries on the domestic market.

Before purchasing, you should familiarize yourself with the technical characteristics of the most common cast iron heating radiators. This will allow you to choose exactly the products that are most suitable for the planned or existing heating system.

Manufacturers of cast iron batteries

A market feature of cast iron batteries is the large share of transportation costs in their final cost. Therefore, models from manufacturers from far abroad are not represented on the domestic market.

If German batteries are particularly sophisticated, then the products produced by ChAZ are not inferior to them in their technical characteristics. Moreover, the batteries of the Cheboksary Aggregate Plant are the best among Russian manufacturers

The main factories that offer cast iron batteries are:

• Adarad (Türkiye);
• Cheboksary Aggregate Plant (Russia);
• Viadrus (Czech Republic);
• Demrad (Türkiye);
• Minsk Heating Equipment Plant (Belarus);
• KIRAN (Ukraine);
• Konner (China).

There are many European manufacturers of cast iron radiators, but their products are not competitive. It has a high price, and the quality is comparable to domestic samples.

Devices for organizing heating in a vintage style are offered by a St. Petersburg manufacturer:

Overall dimensions of radiators

The sizes of radiators in the post-Soviet space were standardized. The distance between the center of the axes of the supply and discharge coolant pipes was 300 or 500 mm.

The depth of the sections and their width were not regulated and differed from one manufacturer to another.Most modern radiators are also adapted to these standards.

Cast iron radiators can be selected to any size required for placement under a window sill or in a wall niche

The most common model of cast iron batteries is MS-140. This is what stands in most Khrushchev and nine-story buildings built in the 60-80s of the last century.

The dimensions of its section are: center distance – 500 mm, total height – 588 mm, width – 93 mm, depth – 140 mm.

The wider the sections, the fewer of them are required to gain the required power, which means the number of potentially problematic joints is reduced.

The main goal of creating cast iron radiators with different dimensions is to enable the buyer to choose a model that best fits into the interior. Batteries with a total height of up to 400 mm, for example, fit perfectly into rooms with low window sills.

Appearance and structure of equipment

Almost all cast iron radiators are stacked. They are made of gray cast iron and consist of detachable sections that are connected using nipple bushings. This design allows you to form a solid battery of the required length and power. Paronite gaskets are placed between the sections.

Multi-column cast iron radiators are difficult to clean externally from dust, which significantly reduces the heat transfer of the batteries

In the horizontal plane between sections, water moves in only one direction. Vertically, the fluid flow occurs through one or more channels. With their number, the area of ​​​​radiators and their power increases.

The disadvantage of multi-channel sections is their high cost and increased hydrodynamic resistance.

The classic "accordion" look of radiators is becoming a thing of the past. Due to the predominantly radiant method of heat transfer, manufacturers are seeking to increase the area of ​​the battery façade, which results in a flatter appearance. An example is the Konner Modern500 model.

Radiators made of cast iron from the Konner Modern series, at a low cost, have a beautiful polished surface identical to aluminum panels

A number of imported models have decorative patterns on the surface, but the cost of such batteries is incomparably high.

The weight of cast iron sections is quite large. The need to maintain wall strength and maximum heating surface area does not allow engineers to greatly reduce the weight/power ratio. The weight of the section of the standard MS-140 model is 7.1 kg.

The unwinding of sections of cast iron radiators must be carried out gradually and synchronously from above and below, otherwise the threaded connection can be irreversibly damaged

The large mass of cast iron radiators also requires good fastenings. Batteries usually do not have special design elements for fixing to the wall. They are simply hung on special brackets, which are pushed into the spaces between the sections. There are also special feet for installing batteries on the floor.

Thermal power of devices

The power of radiator equipment is characterized by the ability to release thermal energy at the maximum operating temperature of the coolant. This indicator in cast iron radiators depends mainly on their surface area.

Depending on the model, the power can range from 80 to 200 W per section. These are passport values, which in real conditions can be much lower.

The recommended power of heating radiators is approximate. For regions with severe frosts, it may differ greatly from the standard

There is a classic formula for calculating the required power of a cast iron heating battery, based on the volume of the room: for every 25-30 m³ Radiators with a total capacity of 1 kW must be installed. If there are 2-3 external walls, this indicator should be adjusted towards increasing power. For more information on how to calculate the required number of batteries for heating, read this material.

To enhance heat transfer due to convection, some models of cast iron radiators are equipped with ribs between the columns. This design can increase the power of the section by 20-40%. You should remember the need to regularly clean such jumpers from dust.

Other equipment characteristics

When choosing radiators, you should pay attention to their other characteristics:

• maximum working pressure;
• coolant volume in the section;
• maximum coolant temperature.

All of the above indicators for cast iron batteries are higher than for aluminum and bimetallic analogues. But the characteristics may differ for different models, which should be taken into account when selecting the components of a new heating system.

Models of the Minsk Heating Equipment Plant

Maximum settings are especially important when replacing batteries connected to a central heating system. When it is pressurized in the fall, excess pressure is supplied to the pipes, which can rupture unsuitable radiators.

This can result in flooding of both your own and the apartment located below, so special attention must be paid to the operating values ​​of pressure and temperature of the coolant.

Conclusions and useful video on the topic

The presented video materials on cast iron radiators will help when choosing a specific model and will further explain their technical characteristics.

Cast iron radiator review:

Comparison of thermal characteristics of radiators made of different materials:

Choice heating radiators, including cast iron, must be produced taking into account their technical characteristics. This will avoid rupture of the heating circuit at maximum loads and provide sufficient heat to the heated rooms.

Please write comments, share your experience of using cast iron radiators, and ask questions in the block below. We are always ready to clarify unclear points.