Daikin plans to produce heat exchangers using recycled aluminium

JAPAN: Daikin is looking to produce air conditioner heat exchangers made from recycled aluminium after perfecting a method of horizontal recycling.

Air conditioner heat exchangers traditionally use high-purity aluminium, which is easy to process, but recycled aluminium fins from used heat exchangers contain copper and impurities, and have previously only been downgraded for other uses, such as automobile engine parts. Once it has been downgraded, it is difficult to return aluminium to its original grade.

In collaboration with recycling firm Nippon Magnetic Dressing and global aluminium company UACJ, Daikin has been exploring a method of resource circulation through horizontal recycling, in which the use is unchanged before and after recycling.

By improving the accuracy of aluminium and copper sorting and the ease of press-forming aluminium, the project is said to have succeeded in manufacturing heat exchangers using recycled aluminium fins on a production line.

It is said that CO2 emissions from producing recycled aluminium can be reduced by 97% compared to producing it from virgin metal. 

Recycler Nippon Magnetic Dressing developed advanced aluminium and copper sorting technology and succeeded in reducing the copper content from an initial level of around 3% to less than 0.1%, while UACJ developed aluminium material with improved press formability, which is an issue when copper and other impurities are present. Daikin used this aluminium material to perform fin press forming and manufacture heat exchangers.

Daikin says it will work toward mass production of heat exchangers made from recycled aluminium, targeting used heat exchangers that are disposed of as industrial waste at Daikin factories and after-sales services.