How to choose a bimetallic radiator for an apartment

It often happens that for some reason the owners are not satisfied with the installed heating system or the apartment just needs to replace Soviet batteries that have become obsolete. Removing old equipment is easy, but choosing a new one is usually difficult. Not every product of an aesthetic appearance is able to withstand the pressure of the urban heating system for decades. Therefore, experts advise you to choose bimetal radiatorswhich are not inferior in terms of reliability to cast iron and are comparable with them in durability.

What is a bimetallic radiator?

As can be seen from the name of the heating device, it is made of two metals differing in properties. The case is made of aluminum, which is characterized by good heat dissipation and low weight. To enhance the heating properties of the outer part of the battery, they give a special shape for the free circulation of air flows.

A steel or copper core is placed inside the radiator, through which hot water or other liquid circulates. The pipe material is very durable, therefore it is able to withstand the pressure of the coolant up to 100 atmospheres (some models), and heating up to 135 ° C.

A bimetal product combines the strength of steel and the superior thermal conductivity of aluminum.

Attention! There are semi-metal heating radiators on the market that are equipped only with vertical reinforcing tubes made of steel. In this case, the rest is made of aluminum. Such batteries have a higher heat transfer compared to bimetal, which is a plus, and are significantly cheaper. However, the installation of such products in a centralized network is not recommended due to the low strength and wear resistance.

Bimetal Benefits

The popularity of modern bimetal radiators is not accidental. They are distinguished by a set of unique properties and advantages.

• The thought-over housing design is designed for maximum heat transfer and free air circulation according to the convection principle.
• Radiators are assembled from sections, which makes it easy to increase or shorten them depending on the needs of homeowners.
• Monolithic structures are characterized by the highest resistance to water hammer, complete exclusion of leaks and a service life of up to 100 years.
• Bimetal batteries have an attractive design, are presented in a variety of colors and are coated with a two-layer paint composition protected from damage and burnout.

• The aluminum casing quickly heats up and cools down just as quickly, which makes it possible to thin temperature settings using the controller.
• A steel or copper bimetallic radiator collector is able to constantly withstand chemically active coolant.

Note! To prevent corrosion, air must be vented regularly to prevent prolonged contact of oxygen with the inside of the device.

• The devices demonstrate high resistance to heat and are able to withstand even 130 ° C.
• A well-thought-out connection system makes installation very easy.

Bimetal Battery Selection Criteria

To choose the right radiator, you should start from several basic criteria:

1. Core manufacturing materials (steel, copper).
2. Battery design (monolithic, sectional).
3. The magnitude of the center distance.
4. Manufacturer.

Sectional or monolithic bimetal?

More common on the market is the sectional version of bimetal heating radiators. This is justified by the fact that it gives more room for installation in various conditions. It allows you to easily add or subtract the required number of sections when calculating the heating area and is notable for its affordable price.

Monolithic design has improved performance: it can withstand significantly greater coolant pressure, easily tolerates even the most powerful water hammer and has a service life of 100 years. Leakage between sectional units is also possible with sectional radiators. The described qualities are achieved due to the one-piece steel core, which has no weak points in the form of connecting nipples.

The main disadvantage of monolithic bimetal is its high cost.

Center distance

The center distance is the distance between the location of the lower and upper collectors. As a rule, the parameter is indicated in millimeters. Standard sizes are available from 200 to 800 mm. These options are usually enough to pick up radiators for the wiring installed in the room.

More often on the market there are products with a distance between the cores of 500 and 350 mm. Such sizes are standard for most modern buildings. Difficulties arise in finding narrow 200 mm batteries that are good for small kitchen or toilet, and wide 800-millimeter products are usually supplied individually only to order.

Choose a manufacturer

Since bimetallic radiators are expensive and put on for many years or even decades, it is important to purchase a really high-quality product from a trusted and reliable manufacturer. The following companies have proven themselves well:

• Global
• Sira;
• Rifar;
• STOUT;
• Royal.

Note! Products of European brands, as a rule, are characterized by high quality of assembly and production materials. Nevertheless, it is not always adapted to the peculiarities of domestic heating systems.

Global

Italian radiator models have earned a good reputation in the CIS. The inside of the batteries is made of alloy steel, the outside is aluminum alloy. They have all the advantages of high-quality bimetal. The disadvantages include a small drop in heat transfer while reducing the degree of coolant.

Maximum working temperature - 110 ° С, pressure - 35 atm. The assortment is represented by the following models with a center distance of 350 and 500 mm:

• Global STYLE 350/500. The heat transfer of 1 section is 120 and 168 W, respectively.
• Global STYLE PLUS 350/500. Power section - 140/185 watts.
• Global STYLE EXTRA 350/500. The heat dissipation of one section is 120/171 watts.

Sira

The Italian brand positions its products as premium products. It stood out on the market due to its high quality and pleasant design based on smooth rounded shapes. In addition, the lineup includes models with a fairly rare interaxal distance of 200 and 800 mm. The maximum heat carrier temperature is –110 ° С, pressure - 30 atm.

The range includes such modifications:

• Sira Gladiator 200/350/500 (center distance) - 92/140/185 W (power section).
• Sira RS Bimetal 350/500/800 - 145/201/282 W.
• Sira Ali Metal 500 - 187 watts.

Rifar

The domestic company ranks high in ratings and successfully competes with European brands. The sections of one of the radiator lines - Monolit - are joined by flash butt welding, due to which a monolithic structure is created that can withstand the most extreme operating conditions and temperatures up to 135 ° C.

The lineup includes the following popular models:

• Rifar Base 500. The heat transfer of one element is 136/204 watts.
• Rifar Forza 350/500 - 136/202 W.
• Rifar Monolit 350/500 –134/194 W.
• Rifar Alp 500 - 191 watts.

Radiators STOUT

The domestic brand deserves special attention STOUT, which is not yet so widespread in the market, but has already earned many positive user reviews. Batteries have the best operational characteristics: maximum working pressure - 100 atm, temperature - 135 ° C.

Radiators of this brand have many advantages:

• Production at the largest and most famous domestic plant RIFAR.
• Control at every stage of production.
• Crimping with maximum pressure before and after painting.
• Affordable price, which is achieved not due to a decrease in quality, but thanks to optimized logistics processes and cooperation with trusted suppliers.
• The number of sections is from 4 to 14, so you can install radiators anywhere.
• The correct geometry of each section, which ensures the highest possible level of heat transfer.
• Adapted for operation in both central and autonomous heating systems.
• 10 years warranty from the manufacturer, insurance for 1,000,000 euros in Ingosstrakh.

The line includes 2 models:

• STOUT Space 350 with heat transfer section 130 W;
• STOUT Space 500 with 180 W heat dissipation.

Royal thermo

Another Italian brand of radiators, distinguished by a wide range of products and original design. Particularly interesting is the model PianoForte. It is possible to order radiators of various colors. The design of the batteries is made according to the patented Power Shift technology: additional fins are installed in the vertical collector to increase heat transfer.

Compared to other brands, radiators of this company are designed for lower working pressure - 20 bar. The temperature of the coolant is also not too high - 90 ° C.

Popular models:

• Royal Thermo BiLiner 350/500 - 117/171 W;
• Royal Thermo Revolution Bimetall 500 - 116/168 W;
• Royal Thermo Vittoria 350/500 - 114/167 W;
• Royal Thermo PianoForte 500 - 185 W.

Price comparison

For objectivity, we present models of radiators of comparable power with a center distance of 500 mm.

Title	Heat dissipation in one section, W	Average section price, rub.
Sira gladiator 500	185	680
Rifar Monolit 500	194	850
STOUT Space 500	180	630
Royal Thermo PianoForte 500	185	1250

Radiators with a center distance of 350 mm:

Title	Heat dissipation in one section, W	Average section price, rub.
STOUT Space 350	130	620
Rifar base 350	136	670
Royal Thermo BiLiner Inox 350	117	1575
Global Style Plus 350	86	762

How many sections will be needed?

To determine the desired number of sections for a specific area, you should first look into the technical passport of the radiator. This document contains information about the thermal power of each section, expressed in watts, which will be needed to calculate their amount. The required amount of heat generated by radiators depends on the characteristics of the heated area. Consider common options.

Room Parameters	The required power for heating 1 square. m square
One window, one wall facing the street, ceiling height - 250–270 cm	100 watts
One window, two exterior walls, similar height	120 watts
Two walls to the street and two windows	130 watts

How is the calculation made?

Calculating the right number of sections is easy.

1. To obtain the required thermal power of the radiators for the room, we multiply the size of the area by the heating power indicator determined by the table above. If the apartment has non-standard high ceilings or panoramic windows, then the amendment is applied and the result is additionally multiplied by 1.1.
2. From the passport of the bimetallic radiator, the power value for a separate section is taken. Then the result obtained in paragraph 1 is divided by the figure taken from the instructions for the device. Thus, the desired number of sections for the room comes out. Non-integer values ​​are rounded up. The same applies to the number of sections, since often the radiator consists of an even number of sections.

Calculation Example

To speed up the operation to count sections use the following formula:

Ks = P × Mk / Ms

• Ks - the number of sections;
• P - the area of ​​the heated room;
• Mk - the power required for heating 1 square. m;
• Ms - thermal power of one section.

With high ceilings or large windows, the obtained value of Kc is multiplied by a correction factor of 1.1.

For example, you want to install a bimetallic radiator in a room of 20 squares of standard height with two walls on the street and one panoramic window. Using the formula, we calculate: 20 square meters. we multiply by the required heating power of 120 W and multiply by 1.1. The result is divided by the power of one section, for example, 200 watts.

20 × 120 × 1.1 = 2640 W - the total power of the radiator.

2640/200 = 13.2 - the number of sections.

Due to the fact that more often the number of sections is even, we round up and get a battery with a length of 14 sections.
Other calculation formulas can be found. here.

Note. Some suppliers agree to mount or remove from the radiator the required number of sections at the request of the customer.

Is it worth buying?

Bimetal batteries are the best solution for a modern apartment. Their relatively high price is compensated by a long service life, savings due to simple adjustment, reliability and guarantee of protection against leaks and rupture during water hammer. If the prices of European brands "bite", you can choose radiators from Russian manufacturers at a more affordable cost, with a guarantee and insurance. Some more tips for choosing - in the video below.