Is there a risk of corrosion of the SPRING4 exchanger?


The advanced corrosion protection of Dualsun’s SPRING4 panel

At Dualsun , we understand the importance of the durability and reliability of our solar panels. SPRING4, our hybrid solar panel, is specially designed to withstand the challenges posed by corrosion, a natural phenomenon to which aluminum, like all metals, is susceptible.

Advanced materials for optimal protection

To guarantee the longevity of SPRING4, we use an aluminum alloy specially developed for solar applications. This alloy has been tested in accelerated aging at the SPF (Institut für Solartechnik) in terms of corrosion resistance, thus guaranteeing its durability in specific solar usage conditions.

Anti-corrosion paint for environmental protection

The SPRING4 heat exchanger is protected by high-performance anti-corrosion paint, complying with standard NF-P-24351 (2016). This protection is effective even in marine environments (less than 3 km from the coast, classified E16), where conditions are particularly corrosive.

Galvanic corrosion prevention

The stainless steel fittings on our panel are coated with a high-performance anti-corrosion paint to prevent galvanic corrosion, a phenomenon that can occur when there is direct contact between stainless steel and aluminum. This protection has been rigorously tested by CETIM (Technical Center for Mechanical Industries) to guarantee its reliability even in the event of accidental paint peeling.

Galvanic corrosion tests show extremely low material losses:

  • Contact interne between the connection, the exchanger and the glycol: 2 µm

  • External paint defect with exposure to sea water for 10% of the time over 25 years: 60 µm

  • Condensation of mineralized water between the manifold and the fitting for 25 years: 60 µm

These minimal losses which can occur in the most unfavorable cases and over a period of 25 years represent less than 0.05% of the material thickness. It therefore does not affect the tightness of the exchanger, being well below the natural dimensional tolerances of the components.

Optimized heat transfer fluids

The type of glycol recommended in our panels is carefully characterized to guarantee optimal corrosion resistance. This characterization, carried out by CETIM, recommends the use of clean (distilled) water for the dilution of the glycol and the presence of corrosion inhibitors in this glycol. It must also have good thermal stability for operating temperatures ranging from -40°C to +80°C.

For more details on compatible glycols, you can consult our FAQ What heat transfer fluid should be used in a pressurized system with SPRING panels?


Dualsun 's SPRING4 is designed to provide exceptional corrosion resistance, ensuring optimal performance and durability throughout its life.