Comparison of copper and aluminum heater radiators for a car

Which has better heat dissipation: aluminum or copper?

I was somehow also puzzled by the aluminum-copper problem for the radiator.
I bought aluminum. The idea was this: copper conducts heat better, but a lot depends on the shape. A copper radiator is thinner and has much fewer fins than an aluminum one. IMHO, aluminum will have a larger cooled surface area. . Incorrect installation. The fact is that due to the better heat dissipation properties of copper, the smaller area of ​​the copper radiator is identical in heat transfer to the larger surface of the aluminum

My copper one is 2 centimeters thick, as opposed to probably 6-8 cm of aluminum, but it works better.

In addition, do not forget that if the copper one is made at a factory, and not in the basement, then its plates are soldered. to the tubes and not crimped like on aluminum, and this greatly improves heat transfer.

The installation is no more incorrect than comparing a 16-year-old clogged aluminum radiator with a new copper one by eye. No wonder it works better.

IMHO, the incorrect setting is contained in the phrase: “The fact is that due to the better heat-removing properties of copper, the smaller area of ​​the copper radiator is identical in heat transfer to the larger surface of the aluminum one.” There are concepts: heat capacity, thermal conductivity and heat transfer. For example, for a computer radiator, both thermal conductivity and heat transfer are equally important - heat must first be effectively removed from a point source (crystal), and then effectively dissipated. In a car radiator, the thermal conductivity of the material plays a lesser role (the tubes are thin, the losses due to thermal conductivity are small, the liquid is inside the tubes), but heat transfer plays a huge role, which depends not so much on the material and its thermal conductivity, but on the shape of the radiator and the area of ​​its cooled surface.

It would also be nice, when quoting is used, not to cut off important sentences, somewhat distorting the meaning. (I repeat once again: “These are obviously speculative conclusions. Of course, it would be nice to measure heat transfer in laboratory conditions, but who would do it.”). This is so, by the way, it had to be.

Source

How it works

First you need to understand how the heater cores in your car function. The heat inside the cabin comes from the running engine. This is a kind of side effect of the operation of the power unit. It generates heat, which engineers have learned to use for the benefit of humans, that is, to heat the interior of the car with it. The heat itself is created as a result of the combustion of the air-fuel mixture and friction between the surfaces of engine elements. To remove this heat from the heated components of the motor, its design includes a cooling system. One of its functions is to heat the car interior.

A logical conclusion follows from this. The hotter the engine is, the warmer it can be inside the cabin. The coolant becomes hot, removing heat from the engine, and passes into the heater core. Here the fan comes into operation, blowing air through the heated radiator and distributing it throughout the car. To be more precise, around the cabin. The driver and passengers can regulate the temperature of the supplied hot air using deflectors and a tap, which are located on the line between the power unit of the car and the stove itself. This is the simplest shut-off type valve, which has a mechanical or electrical drive type. With its help, the amount of cooling liquid passing through the heating system is regulated.

If you raise the temperature on the control unit, the tap will open more. When the temperature decreases, the opposite effect occurs. Its functionality directly affects the operation of the machine's stove. If the system cannot provide full passage for the coolant heated by the engine, then the driver and passengers will feel cold. The temperature outside plays a big role. In the case of a serviceable and well-functioning heater, even it will not be able to warm up the interior as much as possible if the outside temperature is at a very low level. The colder it is outside, the more difficult it is for the stove to warm up the interior.

A little about thermal conductivity

In physics, thermal conductivity is understood as the movement of energy in an object from more heated small particles to less heated ones. Thanks to this process, the temperature of the object in question as a whole is equalized. The magnitude of the ability to conduct heat is characterized by the thermal conductivity coefficient. This parameter is equal to the amount of heat that a material 1 meter thick passes through a surface area of ​​1 m2 for one second at a unit temperature difference.

Copper has a thermal conductivity coefficient of 394 W/(m*K) at temperatures from 20 to 100 °C. Only silver can compete with it. And for steel and iron this figure is 9 and 6 times lower, respectively (see table). It is worth noting that the thermal conductivity of products made from copper largely depends on impurities (however, this also applies to other metals). For example, the rate of heat conduction decreases if substances such as:

Copper wire

If you add zinc to copper, you get brass, which has a much lower thermal conductivity coefficient. At the same time, adding other substances to copper can significantly reduce the cost of finished products and give them characteristics such as strength and wear resistance. For example, brass is characterized by higher technological, mechanical and anti-friction properties.

Since high thermal conductivity is characterized by rapid distribution of heating energy throughout the entire object, copper is widely used in heat exchange systems. At the moment, radiators and tubes for refrigerators, vacuum units and cars are made from it for rapid heat removal. Copper elements are also used in heating installations, but for heating.

Copper heating radiator

In order to maintain the thermal conductivity of the metal at a high level (and therefore make the operation of copper devices as efficient as possible), forced airflow by fans is used in all heat exchange systems. This decision is due to the fact that as the temperature of the environment increases, the thermal conductivity of any material decreases significantly, because heat transfer slows down.

The best aluminum heating radiators: manufacturer ratings

The quality of aluminum equipment and its main characteristics directly depend on who produced it. We offer a small rating, which includes the most famous manufacturers.

Italian appliances

Perhaps the best here will be the Italian brands Sira, Global, Ferroli and Faral. They produce high quality devices with good performance characteristics. Most of them are coated with a special heat-resistant enamel that can withstand even hot boiling water. The inner surface is covered with a polymer coating. It reliably protects the metal from corrosion. True, only if it itself is not damaged by poor-quality coolant.

The operating pressure is located in a wide fork from 16 to 25 bar. These are very good indicators, allowing you to work in high-pressure systems and withstand water shocks. The appearance of the Italian equipment is also excellent. Manufacturers offer various designs and colors. The products of these brands are not cheap, but they are reliable and durable, provided that the rules of their use are followed.

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Beautiful and reliable radiators from an Italian manufacturer will last a long time and decorate any interior.

Russian equipment

In this segment, two brands are considered leaders: Rifar and Royal. Equipment manufactured under the first brand is assembled under license from Global. Therefore, it is quite comparable with it in quality and characteristics. Can work in networks with high pressure. Special processing makes it extremely resistant to mechanical damage. Equipped with technological holes for washing sections. The main disadvantage is sensitivity to the acidity of the coolant.

Royal products are a completely Russian product, well adapted to local operating conditions. This matters when you're thinking about how to choose the right equipment. An alloy with titanium and silicon additives is used to produce the case, which significantly increases strength. They have increased heat transfer and durable enamel coating. Intersectional gaskets made of special material are maximally resistant to leakage.

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Russian equipment is in no way inferior to European equipment, and in some respects even surpasses it

Aluminum and copper - which is better?

Aluminum has one disadvantage compared to copper: its thermal conductivity is 1.5 times less, namely 201–235 W/(m*K). However, compared to other metals, these are quite high values. Aluminum, like copper, has high anti-corrosion properties. In addition, it has advantages such as:

• low density (specific gravity 3 times less than that of copper);
• low cost (3.5 times less than copper).

Aluminum heating radiator
Thanks to simple calculations, it turns out that an aluminum part can be almost 10 times cheaper than a copper part, because it weighs much less and is made of cheaper material. This fact, along with high thermal conductivity, allows the use of aluminum as a material for cookware and food foil for ovens. The main disadvantage of aluminum is that it is softer, so it can only be used in alloys (for example, duralumin).

For effective heat transfer, the rate of heat transfer to the environment plays an important role, and this is actively facilitated by the cooling of radiators. As a result, the lower thermal conductivity of aluminum (relative to copper) is leveled out, and the weight and cost of the equipment are reduced. These important advantages allow aluminum to gradually replace copper from use in air conditioning systems.

Use of copper in electronics

In some industries, for example, in the radio industry and electronics, copper is essential. The fact is that this metal is very ductile in nature: it can be drawn into extremely thin wires (0.005 mm), and also can be used to create other specific conductive elements for electronic devices. And high thermal conductivity allows copper to extremely effectively remove the heat that inevitably arises during the operation of electrical appliances, which is very important for modern high-precision, but at the same time compact equipment.

The use of copper is relevant in cases where it is necessary to deposit a certain shape on a steel part. In this case, a copper template is used, which is not connected to the element being welded. Using aluminum for these purposes is impossible, as it will melt or burn through. It is also worth mentioning that copper can act as a cathode when welding with a carbon arc.

Which aluminum radiators are better: casting or extrusion

The characteristics of the equipment largely depend on the method of its production. There may be two of them.

Liteva

Involves the use of silumin, an alloy of aluminum and silicon. It is more durable than “pure” metal. The melt is poured into prepared molds, where it cools. The result is separate sections, which are subsequently welded in an inert gas environment. This technology guarantees high strength of the product.

Cast models are characterized by tightness and reliability of connections, and are characterized by high operating pressure. If necessary, the number of sections can be increased or decreased. It is better to have specialists do this work. A significant disadvantage of the device is its high cost, which is determined by the complexity of production.

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Injection molding models are reliable and durable, they can be installed in high-pressure systems. Their cost is noticeably higher

Extrusion

The method appeared as an alternative to casting in order to reduce production costs. The parts are not cast, but pressed using an extruder. It seems to squeeze out the metal, giving it the desired shape. The finished elements are pressed into cast manifolds. This is how the section turns out. To align them, threaded connections with gaskets or composite glue are used for the most inexpensive models.

The main advantage of extrusion varieties is their low price. Their heat transfer is slightly higher due to the use of recycled metal as a raw material. But this is not significant. But the strength is lower for the same reason. The tightness is also worse, since the gaskets may fail. Composite glue is also not very reliable. Despite the fact that the design is sectional, adding/subtracting elements is not recommended.

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Extrusion radiators are made from recycled aluminum. They are noticeably inferior in strength to injection molded ones.

Which conducts heat better: aluminum or copper?

Today, radiators are made from a variety of materials, the most common being steel, stainless steel and aluminum.

Always have doubts about which radiator to choose for installation in your home? Obviously, this depends on personal taste, as well as on the requirements that you have set for yourself regarding the quality of the heating of the room.

Aluminum is by far the most environmentally friendly material and has a huge number of advantages.

How to choose a heating radiator: expert advice

In this article we will not consider cast iron radiators, because... they are losing popularity among buyers.

Let's focus on the most popular models.

The material will tell you in detail about the advantages of aluminum and steel batteries.

Aluminum radiators are lightweight

Aluminum radiators are lighter than traditional steel or cast iron radiators, this fact makes it possible to place such a radiator on any wall in the room.

Aluminum batteries can be hung on the wall, even in situations where the thickness does not allow for deep fastening.

This significantly saves the cost of paying for construction work, since they can be hung very quickly and reliably.

We recommend that you familiarize yourself with the range of heating radiators presented in online stores; on the manufacturers' websites you can buy aluminum radiators from leading European manufacturers (ESPERADO, FERROLI, GLOBAL, FARAL, FONDITAL) with a 10-year guarantee!

Aluminum is a corrosion resistant material

Aluminum is not subject to corrosion, which makes it an ideal material for the production of radiators that are intended to be installed in areas such as bathrooms and kitchens where there is high humidity.

Aluminum conducts heat well

Aluminum heats up quickly, making it an excellent heat conductor.

Aluminum radiators have a low water content, which means that once turned on, such devices give an intense burst of heat and heat up rooms quite quickly.

By installing aluminum radiators, you can quickly achieve the required temperature in the rooms, as they have the shortest response time.

The main advantage is a significant saving in energy costs during the heating season and, as a wonderful bonus, saving money, since aluminum radiators can be turned off while you are away from the house, and when you return home, turn them on and quickly get a warm home without spending a long time waiting.

Aluminum radiators come in a wide range of designs and colors

There is a common belief that efficient heat cannot be beautiful and original. Fortunately, the days when design must give way to superior performance are over.

Aluminum radiators have a diverse range of designs and offer even the most demanding buyer a decent choice.

You can choose your own finishing color that will perfectly match the style of your home, the shape of the radiator will be one hundred percent in harmony with your home or office atmosphere.

Style sacrifice? Absolutely not when you choose aluminum radiators for your home!

Stainless steel

The use of steel for the production of heat exchangers allows us to obtain durable products, which are mainly used for individual heating systems in houses and cottages.

Due to the ability to control the quality of the coolant and the pressure in the system, steel appliances will be an excellent choice for autonomous heating systems.

Provided that high-quality coolant is supplied and the working fluid pressure is moderate, such devices will last more than 30 years.

Steel radiators have low thermal inertia, which means there will be no problems with rapid changes in room temperature. In addition to low thermal inertia, steel radiators have other advantages:

Comparison with other types of radiators

A potential buyer is always interested: which radiators are better: aluminum, copper or something else? It is impossible to answer unequivocally, since each type is designed for specific operating conditions. We will try to name the leaders based on their most important performance characteristics.

Thermal power

The best performance is for copper and aluminum, slightly lower for bimetal. They deliver up to 200 W. This figure is slightly lower for cast iron and steel. Overall, any of these devices will be good. The only caveat is inertia. It is maximum for cast iron, so it takes a very long time to heat up. But it also releases the accumulated heat slowly. Therefore, the operation of such devices is difficult to regulate.

Liquid temperature

In systems where sudden changes in the temperature of the transported liquid are possible, it is important that the metal can withstand them without compromising its characteristics. Copper and cast iron do this best. If, based on this indicator, we compare which radiators are better, steel or aluminum, then it turns out that the former lose. It is better not to install them where the liquid can heat up to 110C.

Operating pressure

An important characteristic that determines the scope of application of the equipment. The bimetal withstands the most, from 16 to 36 bar. It can be used in any systems. Copper is not far behind it with its 16 bar. Steel batteries can carry a slightly smaller load. This is 10-12 bar. Aluminum “holds” from 6 to 25 bar. It all depends on the manufacturer and model.

Coolant type

In a centralized system, only water can be used, while in autonomous systems other liquids are also used. This is possible for cast iron, copper and steel. It is not advisable to use aluminum devices in such cases, although there are mixtures specifically for such batteries.

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When choosing a radiator, it is important to decide on the type of connection. It can be bottom or top

Effect of carbon concentration

The carbon concentration in steel affects the amount of heat transfer:

1. Low carbon steels have a high conductivity index. That is why they are used in the manufacture of pipes, which are then used to create the heating system pipeline. The coefficient value varies from 54 to 47 W/(m* K).
2. The average coefficient for common carbon steels is a value from 50 to 90 W/(m* K). That is why such material is used in the manufacture of parts for various mechanisms.
3. For metals that do not contain various impurities, the coefficient is 64 W/(m* K). This value does not change significantly under thermal influence.

Thus, the considered indicator for alloyed alloys may vary depending on the operating temperature.

What does thermal conductivity depend on?

Studying the ability of heat transfer by metal products, it was revealed that thermal conductivity depends on:

• type of metal;
• chemical composition;
• porosity;
• sizes.

Metals have different crystal lattice structures, and this can change the thermal conductivity of the material. For example, in steel and aluminum, the structural features of microparticles affect differently the rate of transfer of thermal energy through them.

The thermal conductivity coefficient can have different values ​​for the same metal when the exposure temperature changes. This is due to the fact that different metals have different melting degrees, which means that under other environmental parameters, the properties of the materials will also differ, and this will affect thermal conductivity.