A faster shift to aluminium

Source: Exchange Magazine | Photo: Ben Hu and Fredrik Schlyter | Text: Per-Ola Knutas

Gränges is poised to take a major step forward in the field of stationary heat exchangers, with a new machine for folded tubes soon to come online in Shanghai. The company hopes the new product line will increase the speed at which customers shift from copper to aluminium, and increase sales.

After several months of preparations in Finspång, Sweden, and Shanghai, China, Gränges’ new folded tube machine is now being completed in Germany. Once finished, the machine will be shipped to the Gränges factory in Shanghai where it is expected to be up and running by December or January.

“Gränges has been early to market with rolled aluminium materials for microchannel heat exchangers,” says Claudi Martin Callizo, the Finspång-based Technical Manager for HVAC&R. “But with the new machine, we’re taking the next step and will also be able to deliver ready-made folded tubes for our customers to test in a variety of applications.”

For heating and cooling

Stationary heat exchangers are found in systems for heating and cooling and in locations ranging from private houses and commercial premises to industrial buildings. A common use is air conditioning within homes, an application where Gränges hopes that folded tubes in aluminium will become increasingly common.

Aluminium to replace copper in heat exchangers

Gränges is optimistic about the future use of aluminium in stationary heat exchangers. One of the key reasons for this are predictions that investment in the global construction sector will grow by four percent annually over the coming years. Another is increased levels of interest from customers in using brazed aluminium heat exchangers rather than the traditional round copper tube plate fin design.

Zhu Song is Project Manager for the folded tube machine and globally responsible for HVAC&R within Gränges. “The benefits of using folded tubes are great for our customers and end-users,” he says. “With this product, you will get even stronger, lighter and more corrosion-resistant condensers.”

Decreased environmental impact

Zhu adds that the service lifetime of the new products will be double that of existing, conventional MPE condensers. Previously, service lifetimes of this length were only possible by using a chemical coating – a costly and environmentally unfriendly solution. “With this folded tube technology combined with Gränges’ patented MULTICLAD alloy, we will eliminate the need for this chemical process and help our customers to reduce costs and decrease overall environmental impacts,” he says.

Increased market share within HVACR

Zhu believes the stationary heat exchanger market holds great potential for Gränges, with many large manufacturers located in China and North America and a few smaller operations in Europe.

“We expect our new machine to help us to increase our market share within HVAC&R and to contribute to a faster transition to brazed aluminium heat exchangers,” Zhu says. “Today, stationary heat exchangers account for about five percent of Gränges’ total sales. Our hope is to increase that share in the coming years.”

Big potential for stationary heat exchangers

Up until now, the dominant design for stationary heat exchangers has been round tube plate fin (RTPF) systems using copper tubes.

There is now a shift to aluminium, with the most common technology being multiport extrusion (MPE) systems.

The next step is for the construction industry to follow the vehicle industry and shift to the next generation of microchannel tube designs featuring folded aluminium tubes. This will bring added benefits to customers, including stronger, lighter and more corrosion-resistant condensers, as well as greater efficiency and decreased total environmental impacts.

The transition from copper to brazed aluminium heat exchangers is expected to accelerate over the coming years. This is why Gränges sees major potential in the new product.

We expect our new machine to help us to increase our market share within HVAC&R.
- Zhu Song, globally responsible for HVAC&R within Gränges