Manufacturer's warranty
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.
Material
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.Operating pressure
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.
Max. pressure
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.
Burst pressure
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.
Heat transfer medium volume
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.
Heat tranfer medium max. temperature
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.
Heat output
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 output
does 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
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.