Copper radiator VS aluminum radiator


Weight, life, cost, these are not to mention, let's just talk about the heat dissipation capacity, and make a simple comparison of some physical properties of the two materials: pure copper and pure aluminum:

Everyone thinks that copper has a strong thermal conductivity, because the thermal conductivity of copper is much higher than that of aluminum (here, pure copper and pure aluminum). This is indeed what I learned in middle school. However, the heat dissipation capacity of a radiator is not only related to the thermal conductivity of the material, but also related to the heat dissipation area, the shape of the radiator, and the air flow.

Looking at the last two parameters, if you look at the number of specific heat capacity, you will definitely say, wow, the specific heat capacity of copper is smaller, its temperature rises faster, and it is not easier to dissipate heat. The sooner), it seems to be correct, have to look at their density.

The density of copper is 3.3 times that of aluminum. The radiator is a size-sensitive product and cannot be made infinitely large. Under the same size, is the heat capacity of copper or aluminum small? It may be simple to calculate.

Assuming they are all materials of the size of one cubic centimeter, the weight of copper is 8.9 grams. To make it rise 1K, it needs 3.4KJ of heat. Under this size, the weight of aluminum is 2.7 grams. To make it rise 1K, the heat required is 2.4KJ. In other words, the heat capacity of aluminum per unit volume is only 70% of copper, and its heat dissipation is faster.

Therefore, although the thermal conductivity of copper is higher than that of aluminum, and the resistance to heat transfer from the CPU to the environment is small, it has a larger heat capacity and a slower temperature rise under the same volume, so that the temperature gradient is small, and the comprehensive heat transfer capacity is lower. Not necessarily better than aluminum.

In thermodynamics, the heat transfer rate equation is Q=KAΔt, where Q is the heat transferred, K is the thermal conductivity of the material, A is the heat transfer area, and Δt is the temperature difference. In the same volume, assuming that A is the same, Q It is mainly determined by the temperature difference between the thermal conductivity of the material and the heat transfer medium. The heat dissipation of the CPU is actually two processes, one is from the CPU to the radiator, and the other is from the radiator to the environment (air). For a pure copper radiator, the heat from the CPU to the radiator, because K is larger, and Δt is also large (the temperature difference between the radiator and the CPU is because copper heats up slowly in the same volume), and the heat transfer rate in this process is obvious It’s better than a pure aluminum radiator, but in the second stage, when the heat is transferred from the radiator to the air, K is the same (all air), and Δt is smaller for the pure copper radiator (here is the difference between the radiator and the air). Temperature difference). In this process, the efficiency of pure copper radiator is lower than that of aluminum radiator. There has always been a saying that copper absorbs heat quickly, and aluminum quickly dissipates heat, which is quite reasonable.

The pure copper radiator is not unheard of. The pure copper Ultra 120E weighs 1.89kg, while the ordinary Ultra 120E radiator is only 785g, which is a full 1.1kg, but the performance is as follows:

Under the premise of such high cost and heavy weight, the performance gains brought by pure copper radiators are actually very low, and it is only 4 degrees lower than ordinary aluminum radiators. Of course, if you pursue the ultimate, it’s not a bad idea. , But the price is too high.

In general, pure copper radiators are not cost-effective, the cost is too high, the processing is more difficult, the cost performance is low, and the eyeballs are acceptable, and they are definitely not mainstream. And aluminum radiators have been playing the leading role for so many years. The result of the correct choice, such as it is cheap, low density, easy to process and shape, and good hardness. Another point is very important. The heat dissipation performance of the radiator made by it is very close to that of pure copper products.

In addition:

The copper radiator still has the following problems

1, too expensive

2, too heavy

3. The surface is easily oxidized.