The quality of heating radiators: a look from the inside

Sophisticated consumers know that a well-known manufacturer’s brand is not just a big name. Behind it – a lot of experience in production, a strong research base, proven raw materials, well-functioning production processes and control. Such a company can afford not to save here and there, and produce stable quality products at reasonable prices. Small or young enterprises usually can not afford it and their main weapon in the competition becomes austerity, the aim of which is dumping policy. In this article we will compare the approaches to the production of aluminum heating radiators at a well-known European and typical Chinese companies. We do it on the basis of independent research of several manufacturers’ radiator samples and take a look at the main external quality indicators of these products.

Global ISEO – the embodiment of modern technology and more than 40 years of experience in the production of aluminum radiators.

exterior coating

Let’s start with not the most critical, but no less important for the consumer, aesthetic qualities of radiators. Chinese manufacturers often apply lacquer coating in one layer, and the aluminum, which shows through, can tell about it. Also, the painting is performed in such a way that in hard-to-reach places between the side blades, on the water duct between the sections remain unpainted.

Powder coating used by Chinese provides a very short life cycle of the paint coating – often within 1-2 years the surface of such a radiator becomes covered with gray spots or an “eggshell” effect occurs when the paint flakes off the aluminum surface and cracks like eggshells.

No such coating defects are visible on Global radiators, because a more sophisticated two-step painting system is used – anaphoresis technology. First of all, the entire radiator including the radiator section must withstand the pressure of the working pressure. ch. and its hard-to-reach places is lowered into the paint bath and, under the influence of an electric current, it is covered with an even base coat of paint which acts as a protective coating, preventing aluminum from coming into contact with the external environment. Then the base layer is coated with an epoxy-polymer finishing coat in an electrodeposited environment. Global paints its radiators with the globally renowned DuPont paint.

This painting technique keeps the appearance of the radiators unchanged throughout their lifetime, and Global’s warranty period is 10 years.

Global VOX

Has a stylistically mature, elegant design with rounded lines

Duct wall thickness

The thickness of the water duct wall plays a major role in making the radiators resistant to high pressures. All the peculiarities of a radiator profile become visible in its cross-section. Almost all sawed samples of Chinese radiators, the thickness of the wall was less than 1.5 mm required by GOST 31311-2005 and almost two times thinner than their European counterparts Global .

Too thin walls mean higher probability of section rupture even at working pressure levels, and yet, radiators must withstand the test pressure test , which is 1.5 times higher than the working pressure. In addition, the reduced thickness of the walls of the water duct reduces the life of the radiator by more rapid corrosion. But such a risky savings means not only low strength characteristics, but also reduced heat capacity, and hence heat output.

In Global radiators walls are certainly thicker than 1.5 mm for example, 2.2 mm , which guarantees a higher performance with full compliance with GOST and durability of operation in conditions of low-quality heat-carrier due to a larger margin of safety of water-conducting channel.

Also, the inner surface of Global radiators is treated against corrosion.

Model Global STYLE EXTRA has a classic European design, simple and concise form, elegant appearance.

Quality of water ducts

Sections of aluminum radiators are made by casting, and a cast part is placed in the mold to form a water-conducting duct. Ideally, it should be completely stationary during the molding process, but almost all samples of Chinese radiators show that the embedded part is displaced from the axis of the channel during their manufacture. The main reason for this is the lack of control procedures during the casting process, because they are quite complicated and costly.

The displacement of the embedded part causes the walls of the water duct to be uneven in thickness.

This has a significant impact on the strength of the radiator, because under the influence of coolant pressure the thinner least durable area of the channel wall is the weakest point, and the rupture of the radiator will happen at a much lower than stated in the passport pressure level.

European manufacturers, and Global in particular, use sophisticated control systems where the position of the embedded part during casting is checked every four hours. This avoids shifting of the embedded part and virtually eliminates the possibility of uneven wall thickness of the water duct.

Global

Style Plus

has an important distinguishing feature: its inner part, which is in direct contact with water, is made entirely of steel, while the outer layer is made of aluminum

Side blades

Compared to the Global radiator, all the Chinese models have a considerably smaller side fin area: their side fins are significantly narrower and shorter. This means that the heat output of such radiators is also lower – by 30-40%, according to the research of the Milan Polytechnic Institute and Vitaterm Ltd. in New York.

The side blades of Chinese radiators are not only smaller but also thinner than those of Global radiators. Too thin blades break quite easily and can be a safety hazard.

Used raw materials

Chinese manufacturers of radiators often use recycled aluminum alloy, and in order to obtain lamellas less than 0.9 mm thick, provide the necessary fluidity of the alloy by increasing the level of silicon impurities in it.

But the excessive silicon content makes the aluminum radiator as a whole more brittle. Global only uses an alloy certified and designed specifically for the production of aluminum radiators, EN AB 46100, with guaranteed chemical-physical properties and composition.

This makes it possible to ensure the advertised high strength and corrosion resistance.