Radiators: specifications, types

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.

Type of convection — air movement — implemented in the convector (see "Type")

— Natural. Convection occurs naturally — due to a decrease in the density of air when it is heated (as a result, warm air moves up). Such a process is less intense than forced convection, which is why “natural” convectors are somewhat inferior to “forced” ones in terms of the rate of heating the room. However, the speed and efficiency of such heaters are quite good (especially since manufacturers often include various tricks in the design that increase traction and speed up air movement); besides, they operate completely silently and do not consume energy over that which goes directly to heating. Because of this, most modern convectors use this particular method of operation.

— Forced. The movement of air is carried out due to the influence of external forces — most often the operation of fans. Technically, such convection does not replace but only complements the natural one. However, the forced mode of operation significantly increases the speed of air movement, allowing you to quickly warm up even a fairly large room. On the other hand, fans create additional noise, require an electricity connection and significantly affect the dimensions and price of the convector. Therefore, this option is very rare.

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 manufacturer's warranty period for this model.

Usually, the terms of the warranty provide free rectification, replacement and/or compensation if the radiator fails during the stated period due to manufacturing defects. The greater the guarantee, the higher the quality of the product and the higher its cost (the latter, however, is usually compensated by high reliability). In modern radiators, the warranty period can be up to 10 years.

Note that the end of the warranty does not mean the product will immediately fail: with proper workmanship, the total service life exceeds the warranty significantly.

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).

Radiator operating pressure.

This term usually means the highest pressure of the heating medium that the radiator can sustain without consequences for an indefinitely long time. Higher rates are also allowed for a short time (see "Maximum pressure"). However, the standard operating pressure in the heating system should not exceed the specs of the radiator; otherwise, the product is likely to be damaged. In general, it is believed that this indicator should be at least 2 bar higher than the actual working pressure in the system — this will give an additional margin of safety in case of emergencies.

The highest heating medium pressure that the radiator is capable to sustain without consequences during short-term exposure.

This figure is always greater than the operating pressure (see above). It directly shows the resistance of the product to emergencies, primarily the water hammer. Other things being equal, higher maximum pressure means greater strength and reliability — however, such radiators are more expensive.

The burst pressure of the radiator is the water pressure, upon reaching which the product will inevitably be damaged.

The main practical specs of the radiator are the working and maximum pressure (see above); it is on them that one should focus when choosing. The burst pressure is given in the description mainly for promotional purposes: other things being equal, a higher value means greater reliability and resistance to emergencies.

The volume of water or other heating medium required to fill the radiator.

This information is relevant mainly when building an autonomous heating system: it is useful when calculating the total volume of heating medium in the system and related parameters. If the radiator is purchased for use in centralized heating, you can not pay much attention to its internal volume.

The maximum heating medium temperature allowed for a radiator is the highest temperature the product can withstand without consequences for a sufficiently long time.

The maximum temperature for heating systems (both centralized and autonomous) is +95 °С as standard. Thus, most radiators have an upper temperature limit of +110 ... 120 °C — this allows you to withstand such conditions confidently.

The regular way to install a radiator.

— Wall. The traditional, most popular way to install heating radiators. The procedure itself is somewhat more complicated than floor installation — after all, you need to fix hooks or pins on the wall, on which the radiator is then hung. On the other hand, wall-mounted radiators do not take up floor space, and in general, they require very little space.

— Floor. The main advantage of floor installation is simplicity: no need to prepare fasteners, and a more or less flat surface is enough. In addition, such a radiator does not have to be strictly against the wall — it can be placed even in the middle of the room. On the other hand, such models require free space on the floor, and from a practical point of view, they do not have any special advantages over wall-mounted ones. So this installation method is rare — mainly among retro-style cast-iron radiators, as well as in certain models of convectors.

— Into niche. Installation in a niche in the floor or other horizontal surfaces is a method of installation used exclusively in convectors (see "Type") and, at the same time, the most popular among such heaters. This installation allows you to completely hide the structure from sight — only a decorative grille remains outside. The disadvantage of this option is traditional — the need to prepare a niche, whic...h can be quite a laborious process.

How to connect a radiator to a heating system. It is indicated by the location of the inlets for connecting the supply and return.

In modern radiators, both side and bottom connections are found. In the latter case, the inlet and outlet pipes can be located both on the sides (on different sides of the structure) and in the centre, side-by-side. Anyway, this feature does not affect the functionality and specs of the radiator. At the same time, it must be borne in mind that the sideward connection can involve both one-sided and dual-sided (from different sides) pipe connection; many models allow both options at once, to choose from, but this point needs to be specified separately.

Note that the available connection methods depend to some extent on the type of radiator (see above). For example, panel devices can have any type of connection, and in sectional products, the sideward method is mainly used — other options are extremely rare, mainly in models of a specific design.

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.

Radiator width.

In modern models, this size can be from 10 cm or even less(in separately sold sections from sectional radiators, see "Type") to 2.5 m or more(in the largest panel products and convectors). At the same time, the design uses mainly standard widths — their list is very extensive, it mainly includes options in increments of 10 cm: 30 cm, 40 cm, 50 cm, 60 cm, 70 cm 80 cm, 90 cm, 100 cm, 110 cm, 120 cm, 130 cm, 140 cm, 150 cm etc. The actual dimensions may differ slightly from the standard, but this difference does not exceed 1 cm: for example, the category "60 cm" includes models with a width of 590 to 610 mm.

The width determines two features of the radiator at once: the size of the space required for installation, as well as heat output. In the first case, everything is quite obvious; we only note that the radiator heater should be placed close to surrounding objects so that it's ok to take a certain margin in width (and if the pipes are c...onnected sideward, it is worth considering the space required for them). As for heat output, other things being equal, a wider device 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 only in size and thermal output.

The size of the radiator from the front to the back wall.

This parameter determines both the size of the space occupied by the device and its efficiency: other things being equal, a greater depth means a higher heat output (due to an increase in the area of contact with air). Specific nuances depend on the type of radiator and the method of its installation (see above). So, the most critical depth is for convectors with a horizontal layout, mounted in a niche — in them, this size directly determines both the required dimensions of the niche and the area of the working surface. In column models, this dependence is somewhat less pronounced. In panel devices, the efficiency depends not so much on the depth as such, but on the number of working elements (see "Type (panel)") — although a larger number of panels/convectors inevitably affects the dimensions. And sectional radiators most often have a relatively small depth: the differences between them in this parameter are not fundamental.