Comparison Hertz BM 500/80 vs Borpan 33 500x2000

The general type of radiator determines, first of all, the basic design features.

Nowadays, panel models are most widely used, sectional radiators and a special kind of heaters are also quite popular — convectors. Here is a more detailed description of each variety:

— Panel. In radiators of this type, the front surface is one continuous panel; in general, several panels are often used, and they can be supplemented with convector elements (for more details, see "Type (Panel)"). Anyway, such devices have several advantages: good heat transfer efficiency, low cost, fairly neat appearance and ease of cleaning. Among the disadvantages of panel radiators, one can only note the fixed size of the structure — they cannot be adjusted in width, like sectional ones (see below). However, this point is hardly critical.

— Sectional. Such a radiator consists of separate vertical sections. In modern models, these sections, usually, have a flat front, under which a set of special channels is hidden to create a convection effect. The key advantage of this design is the ability to assemble a radiator from almost any number of sections at your discretion. And in terms of efficiency, such products are not inferior to the panel ones described above. On the other hand, they are more complicated, expensive and difficult to clean: dust accumulates in the channels, w...hich is quite difficult to clean out.
A special kind of sectional radiator are models that are outwardly similar to column ones (see below) and differ only in a collapsible design.

— Convector. Stationary heaters provide heating mostly (if not exclusively) by convection — in contrast to traditional radiators, where thermal radiation also plays an important role. The design of the convector most often provides a hollow body, inside which heating elements are placed in the form of a set of thin vertical plates, usually metal; holes are made in the case in the form of slots, providing air circulation. Most of these models are small in height and are designed to be built into the floor or a low window sill. Accordingly, one of their areas of application is conditions where it is impossible to install a full-sized radiator. In addition, such devices perform well in combination with high windows: the convector creates a thermal curtain that prevents the outflow of heat through such a window. On the other hand, heaters of this type are inferior to traditional radiators in terms of efficiency and uniformity of heating.

The country of origin of the brand.

In most cases, either the homeland of the brand or the location of the manufacturer's headquarters is indicated as the country of origin. Production facilities may well be located in another country. However, it is worth noting here that most of the national stereotypes nowadays are unfounded — the quality of products depends not so much on geography but on the characteristics of the organization of the production process in a particular company. So from this point of view, when choosing, you should focus primarily on the reputation of a particular manufacturer. It makes sense to pay attention to the country of origin of the brand if you fundamentally want (or do not want) to support a company from a certain state.

Nowadays, the production of radiators is mainly carried out by companies from such countries: England, Belarus, Belgium, Germany, Holland, Spain, Italy, China, Norway, Poland, Turkey, Ukraine, Finland, Czech Republic.

The main material used in the design of the radiator.

The most popular nowadays are steel products. Aluminium is also quite common, including in combination with copper; this material is mainly used in convectors (see "Type"), although it is also found among traditional radiators. Rarer options are bimetallic and cast iron. Here is a more detailed description of each of these materials:

— Steel. Relatively inexpensive, but at the same time quite practical material, resistant to corrosion and has good thermal conductivity. The main disadvantage of steel radiators is considered to be low operating pressure and sensitivity to water hammers — this is due to the presence of weak points in the welds. However, the specific reliability of such products may be different, depending on the quality and special solutions used in the design. Nevertheless, in general, such models are inferior to aluminium and, even more so, bimetallic ones in terms of strength. So the main scope of their application is autonomous systems with low pressure, as well as high-rise buildings up to 9 floors high. Also, steel devices are somewhat heavier than aluminium ones; however, this point is rarely critical.

— Aluminium. A material with excellent specs— in particular, it has very low thermal inertia and low weight. In addition, these radia...tors are considered to be less sensitive to water hammers than steel radiators and are better suited for high-pressure heating systems used in apartment buildings. As for the disadvantages, in addition to the relatively high cost, it is worth mentioning the demanding quality of the heating medium: it must have a neutral pH, otherwise, a reaction with hydrogen evolution is possible (which adversely affects the radiator and can lead to clogging). It is also worth considering that not all aluminium devices are designed for high pressure; this point needs to be specified separately.

— Copper/aluminium. A combination used exclusively in convectors: copper tubes for the heating medium, supplemented with aluminium plates (and, most often, an aluminium body). Copper has high reliability, including resistance to pressure drops, as well as good thermal conductivity; and the use of aluminium allows to reduce the cost and weight of the structure without sacrificing specs.

— Bimetallic. The combination of aluminium with another metal — steel, occasionally copper. The outer shell is made of aluminium in such products, the inner pipes are made of steel. This design allows to achieve of excellent efficiency combined with high strength and reliability; it is bimetallic radiators that are considered the best option for heating systems in apartment buildings, where there is a high probability of water hammers, and the standard operating pressure for such products usually turns out to be quite high.
The main disadvantage of bimetal is a rather significant cost. Thus, so-called pseudo-bimetallic (semi-bimetallic) radiators can be found on the market — only vertical channels connecting the upper and lower pipes are made of steel. It allows you to reduce the price, but it negatively affects reliability — in terms of operational features, such products are closer to aluminium ones (see above).

— Cast iron. A traditional material for heating radiators, which, however, is rare nowadays. It is due both to the large weight and bulkiness of this material and to significant thermal inertia, which does not allow you to quickly adjust the heating intensity. In addition, cast iron is quite brittle and does not tolerate water hammers. On the other hand, this material is resistant to corrosion, and the mentioned inertia in some cases turns out to be an advantage: so, even after turning off the heating, the batteries remain warm for a long time. And some cast iron products have an original appearance that fits perfectly into retro-style interiors.

The type to which the panel radiator belongs (see Radiator type).

The type is indicated by a number that describes the number of heating panels and convectors in this model. Panels occupy the entire height and width of the radiator, and convectors are special zigzag structures between panels that improve heat output. As for the designation itself, the first digit in it corresponds to the number of panels and the second to the number of convectors. For example, the popular type 22 provides 2 panels and 2 convectors between them (the convectors are located inside the radiator, each is attached to its panel), and in the less popular type 21, there is only one convector, respectively, common to both panels. There are options without convectors at all — for example, the simplest type 10, with just one panel. And one of the most advanced today is type 33, more convectors/panels are extremely rare.

In general, more elements (with the same device size in width and height) improves the overall efficiency of the radiator but it comes at the expense of price, depth, and weight.

The number of individual sections provided in the radiator of the corresponding design (see "Type"). We are talking about the delivery set: the whole radiator is assembled from separate sections, and it is not even necessary to use them all.

The number of sections in itself does not affect the performance of the product. However, this information may be useful when assembling a radiator of a certain thermal power (see "Heat output"). So, by dividing the total heat output of this model by the number of sections, you can determine the specs of one section and calculate how many of them are needed to provide the desired heat output. However, a fairly large number of modern radiators are initially sold in one section — just so that the user can assemble the battery at his discretion. For finished products, 2 – 5 sections is considered a rather modest indicator, 6 – 10 pcs — average, 11 – 15 pcs — above average, and models for 16 – 20 sections or more can have both horizontal and vertical layouts (in the latter case, sections placed one on top of the other, like the floors of a tower).

The distance between the axes of the inlet and outlet manifolds of the radiator or its separate section.

The dimensions of the product and the possibility of installing the heater in specific conditions, taking into account the peculiarities of the pipe connection, directly depend on this parameter. The parameter is indicated mainly for models of traditional design - with two horizontal pipes at the top and bottom, between which vertical channels of the heat transfer are laid. The centre distance determines at least the overall height of the product, and in radiators with sideward connection (see the corresponding paragraph), it also determines the features of the organization of this connection.

As for specific values, the most common models in our time are 250 mm, 350 mm, 450 mm, 550 mm and 850 mm. Solutions for 150 mm, 400 mm, 500 mm and 700 mm are noticeably less common.

The diameter of the thread used to connect the radiator to the heating system. Modern radiators use standard sizes — for example, 3/4" or 1/2", less often 1" and 1 1/4". This indicator must match the dimensions of the pipes, couplings and other elements directly used for connection — otherwise, at best, you will need to install adapters, and at worst, the radiator will turn out to be unusable at all.

Usually, the larger the thread diameter, the more powerful the radiator (high power requires intensive circulation of the heating medium and an appropriate throughput at the inlet and outlet).

The rated thermal output of the radiator is the amount of heat given off to the air in normal operation.

When choosing this parameter note that the heat output will depend on the temperature difference at the inlet and outlet to the radiator, as well as on the ambient temperature. The greater the temperature difference and the colder it is around, the more intense the heating will be. Therefore, in the specs, it is customary to indicate heat transfer for certain standard conditions. In particular, the designation according to the European standard EN-442 is very popular, which assumes heating medium temperatures of +75 °С and +65 °С at the inlet and outlet, respectively, as well as an air temperature of +20 °С. Real conditions and the actual heat output of the radiator may differ; therefore, when choosing, it is best to choose a model with a certain margin and compensate for excess power with one or another regulator. As for the actual values, in the most modest models, the heat outputdoes not exceed 750 W, or even 500 W, and in the largest, this figure can reach 3.5 – 4 kW or more.

The choice for this parameter depends primarily on the size and specs of the heated space. The simplest calculation formula is as follows: at least 100 W of thermal power is required per 1 m2 of area. This formula is relevant for standard r...esidential/office premises with ceilings of 2.5 – 3 m, without problems with thermal insulation; for more specific conditions, there are more detailed calculation methods, that can be found in special sources.

Radiator height. The most widespread nowadays are standard height sizes: 30 cm, 40 cm, 50 cm, 60 cm and 90 cm. In addition, you can find other options (although much less often) — 20 cm, 45 cm, 55 cm, 70 cm, 75 cm and 80 cm.

Firstly, the height of the product primarily determines the size of the space required for installation. At the same time, for models placed in a niche (see "Mounting"), this dimension actually corresponds to the required depth of this niche. In other cases, it is worth taking a certain margin in height — the radiator cannot be installed close to the floor and window sill (or other similar items). And models with a bottom connection (see above) will require additional space for the pipe connection.

Secondly, this size determines heat output: all other things being equal (including the size in width), a higher radiator will have a larger working surface area and a higher heat output (this is also true for heat exchangers in convectors). Thus, modern radiators are traditionally produced not in separate models, but in series of the same type of devices that differ onl...y in size and thermal power.