"Never put aluminum radiators"
Many now decide to replace Soviet cast-iron batteries with modern ones. bimetallic or aluminum.
Outwardly, they are no different.
Which one is better to choose if outwardly they are no different? Once a familiar plumber shared his experience, I'll tell you too.
Aluminum sections consist of several sections with gaskets between them, which give complete tightness. Such radiators are made in 2 ways: casting (more durable) and extrusion (light and cheap radiators, but less reliable).
Bimetallic are made of 2 metals. The body is made of an aluminum alloy, and the pipes inside are made of steel or copper (very rare).
If we compare heat transfer, then aluminum will be preferable. A bimetallic radiator has a slightly lower heat dissipation. Aluminum heats up very quickly. Due to this, you can save on fuel (up to 30%).
Cons of an aluminum radiator
During the manufacture, rubber seals are installed, which quickly deteriorate. You cannot use them where there are chemicals or atifreeze.
This metal is susceptible to corrosion. If the pH of the water exceeds 8.5 units, otherwise corrosion will occur. There is a possibility of gas formation inside the sections. Batteries will fail over time due to the destruction of the protective film inside the device.
Ventilation. The presence of a Mayevsky crane is required to bleed off the accumulated air.
The aluminum radiator heats up quickly, and cools down quickly (turning off). Therefore, it is necessary to maintain a constant flow of coolant.
"Weakness" to water hammer. At increased pressure, the tightness inside the device is broken. Therefore, aluminum batteries are not recommended for use in a central heating system. However, this does not apply to models that are produced by casting.
Why bimetallic radiators are better
Aluminum is highly not recommended for use in the center. heating system. Their application will be successful only in autonomous systems.
Bimetallic models, where steel pipes are devoid of these disadvantages. Steel perfectly holds pressure and the quality of the coolant is not important to it. It is bimetallic devices that are more reliable in case of unstable pressure and water hammer.
Such a radiator can easily withstand pressures up to 10 atmospheres. There are models where the core is made of stainless steel and therefore there will be no corrosion.
Minuses:
When the heating is turned off, bimetallic ones cool down just as quickly. Over time, gas appears inside. Therefore, you need to install the device with air valves (manual or automatic). The cost of the device is 20-35% higher than that of aluminum.