Until some time, owners of private apartments knew only cast-iron radiators.
The device of aluminum radiators in the heating system.
Today, bimetallic models and those made of a material such as aluminum have appeared.
When people got the opportunity to choose, the question before them was which radiators can be considered better than all the others, so you should consider each product individually to understand which one should be preferred.
It should be noted that according to the characteristics of heat transfer, radiators made of non-ferrous metals were able to bypass cast iron. But this does not mean that traditional batteries are now in the past.
Features of cast iron radiators
Connection diagram of aluminum radiators.
If you want to change the heating once and for all, you should pay attention to cast-iron radiators. They are cast using a special mold made of sand, due to which the metal surface has a silicon layer that can protect it from the effects of an aggressive environment, this significantly extends the product life cycle. In addition, the production of such radiators is less expensive. Due to the low price, such radiators are more affordable for the mass consumer.
Cast iron is a material that is practically incapable of corroding. During operation, the so-called so-called dry rust, a layer of which is able to protect from destruction. These radiators exhibit temperatures of up to 150 degrees, so the products can be used in systems where steam is used as a heat source.
Unlike aluminum radiators, cast iron is not able to act as a cause of electromechanical corrosion. Cast iron radiators are also better because they have excellent heat transfer quality. Stones and debris, which often cause blockages when they enter the system, will not harm heating appliances made of cast iron. Such radiators exhibit a fairly high abrasive wear.
Like every product, cast iron radiators have their own life, but in this case it is extremely long. This is due to the thickness of the walls, they are very thick, it is for this reason that the probability of leakage is practically eliminated. The service life, if we take into account the assurances of the manufacturers, is 30 years or more.
Disadvantages of Cast Iron Batteries
Connection diagram for radiators.
One of the main disadvantages that cast iron radiators have is, of course, weight. According to this indicator, such products lose in that they are made of aluminum and steel. Bimetal radiators also benefit in this regard. This is especially true for those owners of apartments whose housing is located on the upper floors, and the house is deprived of an elevator. However, weight can be a serious problem, not only in the matter of product delivery, but also in the matter of installation. After all, cast-iron radiators will not only be difficult to hold in the process of fastening, but it will also be impossible to fix them to a wall that has a not-so-reliable construction, for example, from drywall.
The disadvantages include not so high heat transfer, as other types of radiators can demonstrate. So, unfortunately, the section, which is part of a cast-iron radiator, is capable of radiating heat up to 150 W, which is 2 times lower than that of aluminum radiators. Radiators made on the basis of cast iron operate by the inertial principle, that is, temperature is set within half an hour, for this reason it is not necessary to install a thermostatic valve.
The strength characteristics of cast-iron radiators are also inferior to bimetallic batteries. For a cast-iron product, the pressure in the system can be considered favorable, which does not exceed 15 atmospheres, but bimetal will be able to withstand up to 40 atm.
Features of aluminum radiators
Scheme of installation of heating systems.
Today, bimetallic and aluminum radiators have become the most common, they can be considered the most popular among other types of heating elements. But are they as good as they might seem, and is their popularity justified?
As the main advantage of aluminum batteries, one can distinguish their rather high heat transfer with small dimensions, this is due to the high thermal conductivity of the metal that underlies the product. Aluminum batteries show an insignificant reaction time to changes in the temperature of the heat carrier, which means that radiators will quickly "respond" to the temperature control.
Aluminum radiators have a modern design, compact dimensions, high-quality high-temperature enamel is applied to their surface during the production process. Thus, products do not need regular updating of a paint layer. Such radiators transfer heat through convection. For this reason, dust in the cooling fins of the battery almost does not accumulate.
The disadvantages of aluminum batteries
Aluminum radiators, when compared with bimetal radiators, are more susceptible to destruction under the influence of water shocks. Such batteries are designed for lower working pressure, which is due not only to the low strength of the metal, but also to the design of the product. So, in pursuit of the highest possible heat dissipation, the manufacturer seeks to reduce the wall thickness of the radiator. Another drawback is that aluminum radiators cannot be directly connected to copper-based pipes, because the formation of a galvanic pair will result in a fairly rapid degradation of the place where the connection was made, which will lead to the formation of a leak.
It is better to prefer the radiator that will last as long as possible, because the savings on the purchase of a new product will be more expedient than the pursuit of heat dissipation, however, in this matter, as in all others regarding the choice of the battery, the decision will remain with the owner of the house or apartment.
So, aluminum is extremely sensitive to the acidity of the water that will flow through the product. The required pH level of the water to be supplied to the aluminum battery should vary from 7 to 8. In order to regulate the acidity of the water, there are many additives that can provide the optimum acidity. But, as a rule, thermal central networks do not deal with this issue. And the document that regulates the acidity of water flowing in heat supply systems sets a limit equal to 8.3–9.5 pH.
For this reason, it is natural that the acidity of water in central heating systems is markedly increased. This means that the oxidation process will begin in the radiator, which can quickly destroy the aluminum wall. So, chemical destruction will be added to the mechanical erosion of the metal. The result is the life of such products within 7 years. However, manufacturers are not able to get rid of the influence of this harmful factor.
Solution to the problem
Speaking of the above, it is better to use an aluminum radiator in private houses, where water supply networks are closed. Often such radiators are also installed where it is possible to ensure the installation of additional filters designed for cleaning. There are systems that allow the use of acid-regulating additives.
Features of bimetallic radiators
Scheme of the heating radiator.
Among the advantages that bimetallic radiators possess are all the above advantages that aluminum radiators have, but this is not a complete list of them. Due to the special composite structure, which consists of a steel case that makes up the inside, and an aluminum frame that is located outside, the coolant in contact only with steel. This allows you to achieve higher corrosion resistance of a bimetallic radiator when compared with aluminum. Speaking of the above, this allows us to provide a significant coolant pressure equal to tens of atmospheres. Bimetal radiators can be directly connected to any type of fittings and pipes, including steel, copper, bronze, brass.
Disadvantages of Bimetal Batteries
In the production process of bimetallic type radiators, more sophisticated technologies are used compared to those used in the production of aluminum. So, you need to make a high-quality joint of the inner steel frame with the outer aluminum case, otherwise the aluminum layer may break, which may occur due to different coefficients of thermal expansion of metals. The complexity of the production process makes the price of bimetallic radiators slightly higher than that of aluminum radiators.
If you decide to lean in favor of bimetallic radiators, you should choose only the supplier who has already established himself on the market, as there is a tendency to behavior of some unscrupulous manufacturers who want to save by making steel only the vertical, widest channels of the product, which leads to zero almost all the advantages of radiators of this type. When compared with aluminum-based batteries, bimetallic ones have a reduced heat transfer and increased hydraulic resistance to the flow of the coolant. Thus, we can conclude: if you decide to abandon the cast-iron radiator, then, choosing between aluminum and bimetal, you should choose the latter. However, if you want to ensure maximum heat transfer at low pressure, you should choose an aluminum radiator.
Recently, craftsmen have advised using aluminum and bimetallic radiators in tandem when installing the heating system at home, adding to those that do not use convection heat radiation. The use of exclusively aluminum or bimetallic radiators will lead to air drying, in addition, such heating will not be very effective. Having studied all the above characteristics, it is necessary to take into account certain conditions that will act on the radiator. Then you can understand which battery will be better in a particular case. A good battery is one that will last a long time and will have good heat dissipation.