Copper versus Aluminium

In most liquid cooled solutions, the main cooling components used are water blocks for GPUs, CPU coolers and radiators to disperse the heat into the air. Although the materials those components are made of may differ, the two most used materials are copper and aluminium.

azultec chooses copper over aluminium as the main component in almost all used water-cooled products but why is that? Here are some insights into the everlasting copper vs aluminium battle

In one word: Performance

Both materials differ in their thermal conductivity. Thermal conductivity is measured in W/mK (Watt per meter and Kelvin) and shows how well a material conducts heat and how well it is suitable for thermal insulation. The lower the thermal conductivity value, the better the thermal insulation – which, most of the time, you do not want in a liquid cooling system for computers. Copper brings a thermal conductivity of 401W/mK to the table while aluminium barely scratches on passes the 200 mark with 205W/mK. Unfortunately double the thermal conductivity does not bring double the performance. The difference in cooling performance is about 5-10%.

With having a higher capacity for heat than aluminium, copper while being equal to a certain point, surpasses aluminium when the water used gets heated up to a certain degree, from that point on copper is straight out better. It is also notable that aluminium absorbs heat faster but copper releases the heat faster to the surroundings such as air or water.

Copper dictates the possibilities of our products. On the first glance 10% does not sound much but by using only copper products for cooling of our systems we are for example able to make the Cube a silent machine. With aluminium the fans would have to run faster, making the whole machine not silent anymore. Our high-density rendering products, which strongly rely on low temperatures, would be prone to thermal throttling – and thus loose performance. So basically: The 10% make all the difference.

Our cooling solutions are made possible by our partner alphacool , which is the only company able to produce full-copper radiators used in our products.

No team players – Never mix!

Aluminium and copper are rivals and not team players. It cannot be stressed enough. Copper and Aluminium should never be used in the same conductive circuit.

The effect that occurs is called galvanic corrosion. It is an accelerated form of corrosion, destroying the components through an electrochemical process.

Whenever different metals are placed in an electrolyte near each other, corrosion becomes an important factor to watch out for. Galvanic corrosion typically attacks the joint areas of dissimilar metals and occurs when the following three conditions are met.

  • Condition 1: The metals mused have a galvanic incompatibility (voltage difference of over 0.2)
  • Condition 2: An electrolyte must be present (water in our case).
  • Condition 3: There must be an electrical conducting path between the metals.

For those willing to dig deeper into the topic of galvanic incompatibility here is an overview which metals do not correspond well with each other.

The choice of material is depending heavily on the situation it is going to be used in! So, to summarize:

Aluminium:

The cheaper solution – cheaper and easier in production.

Aluminium is lighter than copper which can play a part in the decision-making process which material to use.

Although it might do the job for gaming enthusiasts who do not seek the maximum performance, it is not recommended for high density VGA solutions because of the lower thermal conductivity and capacity.

The usage in the industry is always accompanied by the need of a regular maintenance.

Copper:

Copper is the heavier of both metals.

It is the go-to cooling solution but more expensive due to a harder and more complicated production process.

Copper has double the thermal conductivity of aluminium and the cooling result is about 10% better making it the optimal solution for high density servers and industry applications.

Both have their pros and cons, the deciding point being the application it is meant for. So, choose wisely and whatever you do, do not mix!

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