Is there a risk of corrosion of the SPRING4 exchanger?

At Dualsun, we understand that durability and reliability are key when it comes to solar panels. That’s why our hybrid solar panel, the SPRING4, is specifically engineered to withstand corrosion — a natural process that affects aluminum like all metals.

To ensure the SPRING4’s longevity, we use an aluminum alloy developed specifically for solar applications. This alloy has undergone accelerated aging and corrosion resistance testing at SPF (Institut für Solartechnik), proving its durability under real solar operating conditions.

The SPRING4’s heat exchanger is coated with a high-performance anticorrosion paint that complies with NF-P-24351 (2016). It’s built to perform even in coastal environments (within 3 km of the shore, rated E16), where corrosion risks are significantly higher.

Our stainless steel fittings are covered with a high-performance anticorrosion coating to prevent galvanic corrosion — a risk when stainless steel contacts aluminum. CETIM (Technical Center for Mechanical Industries) rigorously tested this coating, even simulating cases where the paint might be chipped.

Galvanic corrosion testing showed extremely low material loss:

• Internal contact (fitting, exchanger, glycol): 2 µm

• External paint defect, seawater exposure (10% over 25 years): 60 µm

• Mineralized water condensation between manifold and fitting over 25 years: 60 µm

These minimal losses (less than 0.05% of material thickness) do not affect the exchanger’s sealing, as they are well within natural dimensional tolerances.

We’ve replaced the corrugated stainless-steel fittings with forged, black-anodized aluminum elbows — designed for better ergonomics and long-term reliability.

Aluminum, known for its lightness and durability, is 100% compatible with the SPRING4 exchanger. To prevent galvanic interaction with other metals (like brass), we’ve added an insulating part made of black POM-C (polyacetal copolymer).

✅ UV-Resistant: Black POM-C contains carbon black pigment, shielding it from UV damage and degradation outdoors.

🌡️ Temperature Range: Operates from -40°C to +100°C continuously, up to 120–140°C in peaks. Remains tough and unbrittle even in extreme cold.

💪 Mechanical Strength: High rigidity and wear resistance. Low friction — ideal for mechanical and sealed parts. Excellent fatigue resistance under pressure.

🌧️ Moisture & Weather Resistance: Low water absorption (~0.2%), stable in wet, salty, and freezing conditions — unlike more water-sensitive plastics (e.g., PA6).

🧪 Glycol Resistance: Compatible with glycol-based antifreeze (e.g., ethylene, propylene glycol), at ambient or moderate temps (-40°C to +85°C).

Thanks to these innovations, galvanic corrosion is fully eliminated in the latest generation of SPRING4 panels.

The recommended glycol used in SPRING4 systems is carefully selected for maximum corrosion resistance. CETIM testing confirms: use clean (distilled) water for dilution, ensure corrosion inhibitors are present, and check thermal stability for a working range of -40°C to +80°C.

inhibitors in this glycol. It must also have good thermal stability for operating temperatures ranging from -40°C to +80°C.

In Conclusion, the SPRING4 hybrid solar panel by Dualsun is built with cutting-edge materials and tested protections — offering exceptional corrosion resistance, and ensuring optimal performance and durability throughout its lifespan.

📌 For more information on compatible heat transfer fluids, check out our FAQ: What heat transfer fluid should be used in a pressurized system with SPRING panels?