What is the difference between aluminum batteries and bimetallic batteries
Aluminum radiators are made of a single metal and do not have a core, bimetallic radiators, on the contrary, have internal steel tubes for the circulation of the coolant and external aluminum fins for good heat transfer.
However, both types of products are similar in appearance and have an attractive aesthetic appearance that can match any interior.
РАДИАТОРЫ Алюминиевые VS Стальные (Полный Разбор Радиаторов )
Heat dissipation performance
Since the external part responsible for heat dissipation in both types of batteries is made of aluminum, they have good heat dissipation rates.
But in products made of only one metal it is about 1520 % higher.
Resistance to corrosion
Corrosion resistance is higher in bimetallic batteries, as the coolant circulates through steel pipes, more resistant to corrosion, as well as aggressive environment.
However, steel is also susceptible to rust when air masses enter the system, which is possible during seasonal drains of coolant.
Resistance to pressure and water hammer
Due to the internal steel pipes to withstand high operating fluid pressure and its fluctuations, the bimetal battery is more resistant to water hammer.
Ease of installation
Both types of described elements of the heat supply system are easy to install, but aluminum batteries have less weight, which makes their installation somewhat easier.
The possibility of long-term operation depends on many factors:
- The working pressure in the system;
- chemical composition of the heat transfer medium;
- the presence / absence of water hammer;
- the temperature of the circulating liquid;
- of seasonal coolant drains.
If the radiator is chosen and installed correctly, the declared lifetime of the manufacturer is:
Interaction with heat transfer fluids
Aluminum radiators greatly depend on the quality of the coolant. If the pH level rises above a certain value they are vulnerable to corrosion and further leakage.
In bimetallic products with the coolant in contact with a steel tube, more resistant to the adverse environment and pH fluctuations.
Let’s start comparing bimetal and aluminum radiators
What is each type of radiator
Aluminium radiators, neat and stylish, consist of several sections connected by nipples. The gaskets that are present between the sections, give the necessary tightness. The ribs, located on the inner side, allow you to significantly increase the area of heat output up to 0.5 square meters. Radiators are made in two ways. The extrusion method produces cheap and light products that are not of the highest quality (this method is not used in Europe). expensive, but more durable will be radiators made by casting.
One of the types of aluminum radiators.
Bimetallic radiators are made of two different metals. The body, equipped with the ribs, is made of aluminum alloy. Inside this body there is a core of pipes through which the coolant flows (hot water from the heating system). These pipes are either made of steel or copper (and the latter is practically uncommon in our country). Their diameter is smaller than that of aluminum models, so there is a greater chance of clogging.
The appearance of a bimetallic radiator is very aesthetic, and the design satisfies the most sophisticated demands. All of its steel components are hidden inside.
What will give more heat. bimetal or aluminum?
If we compare the heat output, the aluminum radiators will immediately come out on top. They have one section capable of giving more than 200 watts of thermal energy. Half of the heat is emitted by radiation and the other half by convection. Thanks to the ribs that protrude from the inside of the sections, the heat output is even higher. So, in this respect, aluminum is unrivaled. Note that it also has minimal thermal inertia. Turn on the radiators. and 10 minutes later the room is already warm. In a private home, it saves a lot of money.
Now let’s look at bimetal devices. The heat output of a single section depends on the model and on the manufacturer. It is slightly lower than that of an all-aluminum radiator. After all, the steel core contributes to reducing the overall heat output, which can be one-fifth less than that of an aluminum radiator of the same size.
As for the method of heat transfer, it also includes convection and radiant heat. And they also have a small thermal inertia.
On the ability to withstand high pressure (especially water hammer)
Here aluminum is disappointing. the figures of its working pressure is not very impressive. Only 6 to 16 (some models up to 20) atmospheres, which may not be enough to withstand pressure surges in the central heating. And there will be no escape from water hammer. the radiators will burst like empty nutshells, and the apartment will have a big hot flood. That is why you should not take the risk. in multi-storey buildings do not put aluminum radiators.
Bimetallic models with a strong steel core inside are well prepared for high pressure head. From 20 to 40 atmospheres is quite good. Even if the tap on the pumping station will be closed or opened in case of an accident they will not be damaged with lightning speed. Exactly bimetallic radiators are most reliable if the pressure in the system is unstable, when water hammer is likely to occur.
This parameter is important if you choose radiators for an apartment with a centralized heating system. If you choose these radiators for a private house, then this parameter is not a disadvantage for aluminum radiators. к. there is no overpressure in the local heating system.
What is better bimetal or aluminum radiators in relation to the coolant?
Aluminum with pleasure enters various chemical reactions, that is why for it the water in the central heating is simply “treasure house”. After all it contains so many chemical admixtures that there can be almost nothing left from the walls of the battery. they will be eaten by corrosion. As soon as the pH of running hot water in the system exceeds 8 units. wait for trouble. But it is impossible to keep track of this indicator at a centralized heating system. In the process of chemical reactions, aluminum releases hydrogen, which is a fire hazard. That is why it is necessary to constantly bleed such radiators.
Steel pipes in the middle of the bimetallic radiator are less demanding to the quality of water flowing through them. Steel is not as chemically active as aluminum alloys. Of course, corrosion gets there, but not so fast. In addition, manufacturers cover it with a special protective layer. And sometimes they use stainless steel, but it is quite expensive. But in any case the bimetallic radiator is more protected from the too active coolant. The only danger is oxygen getting into that water. That’s when the steel starts to rust, and very quickly.
The maximum temperature of the coolant. which radiators have more?
The question is logical. often our radiators are “burning with fire” so that it is impossible to touch them. Well, aluminum can withstand boiling water up to 110 degrees, which is average. For bimetallic products, this indicator is slightly higher. 130 degrees. That’s why they win here.
And what is more reliable, stronger and durable?
And again the radiators made of the two metals come out on top, since they combine the best qualities of each of them. Such devices can serve for 15-20 years, not less (of course, we are talking about quality products of reliable brands). Their aluminum counterparts, as a rule, are characterized by twice shorter life. up to 10 years.
What is easier to install?
Both aluminum and bimetal are quite comfortable to install, since they weigh a little (compared to the same cast iron). For their fixing does not need especially powerful brackets. even plasterboard can withstand such a small weight. If the pipes are plastic, for installation you only need a set of wrenches and shaped elements. But it is easier to install bimetallic radiators. because steel pipes can not undergo deformation, unlike aluminum, which is a soft metal.
Non-ferrous metal models in the heat engineering market appeared comparatively recently. In fact, products are not made of aluminum, but of its alloy. silumin, where the basis is added 12. 14% silicon and a small amount of various metals. Compared with aluminum, silumin has greater strength and durability.
The main advantage of silumin heating panels is their complete immunity to corrosion. The products are very popular with owners of both small houses and huge mansions. To show all the advantages of silumin floor heaters, you need to consider the spectrum of a number of the following features.
The technology of production
Silumin products are produced by extrusion. To do this, you make a mold for pouring (opoka) the molten metal.
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The peculiarity of the process is that the filling of the mold is by forcing the molten alloy under pressure through the hole in the investment ring. This action achieves a high-density array of the appliance, which completely eliminates the appearance of cavities in the metal.
Peculiarities of design
There are two types of manufacturing. the creation of monolithic panels and prefabricated sections. In both cases, each section consists of a standard set of elements. These are two manifolds (horizontal top and bottom manifolds) with a diameter of 25 mm. They are connected by vertical shafts of oval cross-section with the taps in the form of vertical convection ribs on the sides and front of the radiator.
In contrast to the monolithic batteries prefabricated products consist of sections connected to each other by steel nipples with multidirectional threads and gaskets. Aluminum heating devices of the standard assembly consist of 3, 4, 5, 6, 8, 9, 10, 12, 15, 17 and 21 sections. The height of the ribs is 200, 250, 300, 350 and 500 mm.
Prefabricated structures allow the host to select the number of sections for each model. This plays an important role in determining which batteries for the apartment is still better, aluminum or bimetallic.
Difficulties of installation
All silumin models are hinged radiators. They are mounted on brackets fixed on walls. Due to the lightness of silumin, no heavy supports are required to fix the batteries. For the installation of heaters, you may need a peorator and dowels. If plastic pipes are connected to the radiator, you will need a welder and plastic adapters.
The installation process does not cause any difficulties. When installing, a number of conditions must be met. Is the horizontality of its upper surface, the gap between the wall and the back of the radiator must be at least 4 cm, and the gap between the top of the device and the bottom of the window sill must be 5. 7 cm.
In addition to the finished panels the radiators are assembled by interconnecting the sections with nipples and gaskets right at the place of installation. The operation is so simple that it is available to everyone who wants to assemble the sectional structure of the required size.
Aluminum radiators can withstand hot water at the temperature 100°С, which is the maximum limit for it. In autonomous heating systems in private homes, the water is replaced by a synthetic liquid coolant with a maximum heating temperature of about 130 0 C, which can withstand silumin.
In order to exclude crisis exceeding the temperature threshold, a thermostat is built into the heating system. Also, heating panels are equipped with thermal heads, which do not allow overheating of heating panels.
Thermostats can be with manual and automatic adjustment, and the most expensive devices can be adjusted online with a smartphone through the “Smart House” system.
What is the difference between bimetal heating radiator and aluminum?
Comparison of the technical characteristics of the most common 500 mm models made of different materials.
|Heat output, W||175200||120-185||It depends on the brand and size of the radiator section. The higher the radiator, the higher the sectional heat output. The cheap Chinese models often have the parameter overstated by 20-25%.|
|Operating pressure, atm.||16||20||Average data. It may be slightly higher or lower in different brands.|
|Pressurizing pressure, atm||24||30||In the case of the bottom connection, when the pipes approach the body from below, the index is reduced by half.|
|Weight of one section, kg||1,5||2,0||Depends on the size of the section.|
|The maximum heating of the heat transfer medium, deg||110||110||Fluid temperature does not rise above 80-90°C in the heating network.|
|Warranty, years||5-10||5-15||Depends on manufacturer.|
|Service life, years||25||25||The index varies depending on the brand of heaters, their design and production features.|
|Price,||900||1000||Average value shown. The price depends on the manufacturer, quality of materials and assembly, the pricing policy of the trade organization and other factors.|
To summarize, let’s assess the similarities and differences between bimetal and aluminum:
- Aluminum models are lighter. This is due to the properties of silumin, which is 2.9 times lighter than steel.
- Bimetal is more expensive than aluminum because of the higher cost of materials and complicated production technology.
- Bimetallic products are more resistant to pressure, because the steel of which the water part is made is 4 times stronger than aluminum alloy.
- The temperature of the coolant in both types of batteries is the same and is 110 degrees. Fluid in heating systems can not be hotter than 90 °. in this parameter, both configurations are equal.
- The leader in thermal conductivity is silumin, which gives off heat better than bimetal. Manufacturers are trying to raise this indicator. optimize the body and integrate additional fins that enhance heat exchange.
- All heat appliances have approximately the same service life, but the warranty period is longer for bimetallic ones. When buying quality products of any design, the consumer is unlikely to encounter the need for warranty repair.
After estimating the characteristics it is impossible to say unequivocally what is better. bimetal or aluminum. Both designs have advantages, disadvantages and work well in the right conditions. Only products made of low-quality raw materials, manufactured with violations of technology can be considered bad.
The outer part of bimetallic radiators is made of aluminum (the same as aluminum radiators), but they have a steel core inside. Water flows through the steel pipes into the radiator. The design of bimetallic radiators is almost identical to aluminum radiators, usually they are separate sections of 8 centimeters wide. On each side of such products side lamellas are installed, whose main task is to increase the intensity of heating. Each section in the inner part has a tube through which water flows, the scheme of the arrangement of such tubes resembles a Roman numeral Ⅰ, with two horizontal and one vertical rod. Each section is connected to each other using special gaskets, at the end sections stubs are installed, they ensure tightness of the system.
Designs are similar for a reason, this scheme is optimal, with this system, the radiator works most efficiently. Hot air flows up and forward, warming the room evenly.
Important difference of bimetallic radiators is their resistance to dirty water and increased acidity of the coolant. Almost immediately after their invention in 1995 (at the factory Global in Italy) bimetallic radiators appeared in Russia. At the same time, aluminum radiators Global were already present in the Russian market, they served much less than in European countries. The reason for their shorter service life was precisely because of water quality. In the Russian water, due to poor communications in the homes of Soviet construction, not only the high pH value (more than 7.5 points), but also foreign impurities, including sand. Under pressure and temperature drop such water very quickly destroys the walls of aluminum radiator channels. What exactly is the pH of your water, you can ask your water management company, if it is less than 7, the house and utilities are new, you can install aluminum radiators. At pH greater than 7.5 it is better to install bimetallic products, as the inner steel filling is much more resistant to acids and abrasive impurities. In addition, bimetallic radiators have other advantages, these:
- Maximum heat output and a large margin of safety.
- Such radiators can withstand any pressure in the system.
- Joints of the sections are characterized by high reliability (steam seals are used).
- Thanks to the resistant painting, such a product has an attractive appearance for a long time.
The disadvantages of such radiators include:
- The main disadvantage of such products is their rather decent cost.
- The second drawback may appear if the product is used incorrectly. The steel core in simultaneous contact with water and air can be covered by corrosion.
These are the main advantages and disadvantages, design features and characteristics of bimetallic radiators. We conclude that such products are more reliable than aluminum, but cost more.
Features of design
The main feature of any bimetallic heater can be considered the fact that it combines two different metals. As a rule, a strong steel frame is used. the tubes through which the coolant will circulate, must withstand a possible hydraulic shock and pressure in the heating system, but the fins must have a high coefficient of thermal conductivity.
That is why the fins of bimetallic batteries are made of aluminum. Other combinations of metals are also possible, such as copper manifold fins made of another metal, but the idea remains the same.
This is the difference between aluminum and bimetallic radiators. Aluminum models are made of a special alloy, so that no collector is out of the question.
What radiators are better in terms of heat output
If you are deciding about the difference between aluminum radiators and bimetallic radiators, it is worth comparing them also according to the intensity of heat return. Aluminum radiators are ahead in this matter. One section is capable of delivering approximately 200 watts or more of thermal energy. Half of the heat is emitted as radiation. The other half is convection. The fins of the radiator allow you to increase the level of heat return. Aluminum in this matter is unrivaled. Among other things, it has minimal thermal inertia. If you turn on such a radiator, it will be warm in 10 minutes in the premises of the house or apartment.
If we are talking about a private building, then with the help of aluminum radiators it is possible to save a lot of money. Today, aluminum and bimetallic heating radiators are becoming popular, the characteristics of which are presented in the article. The latter differ in the heat return, which depends on the manufacturer and model. This parameter will be lower compared to the aluminum radiator. This is because the steel core reduces the heat emission which is 1/5 that of an aluminium battery of the same dimensions.
What is better, aluminum or bimetallic radiators for heating? Let’s compare the main parameters
It becomes clear that the two types are similar only in appearance. Let’s compare their basic properties.
Resistance to high pressure
One of the most important characteristics for the battery. The heating medium in the network moves under pressure, and in different systems its value can vary considerably. So, for low-rise and detached houses it is relatively small. For high-rise buildings of 16 floors and more, the values are much higher. This is due to the fact that the higher the room to be heated, the greater the pressure required to raise it.