Chilled water coil design enhanced for application flexibility and extended lifespan

As part of its ongoing strategy to expand the applications and market reach of microchannel heat exchangers, Kaltra has introduced a new line of air-to-water microchannel coils, meticulously designed and optimized for specific uses.

The new coil series is tailored to serve the following key applications:

• Chilled water coils, such as free cooling coils
• Fluid coils designed for cooling and heating purposes

Engineered with a strong emphasis on application-specific performance, these coils feature advanced anti-corrosion treatments, compatibility with a broader fluid pH range, and an optimized design for efficient condensate drainage.

The new chilled water coil series uses a manganese-rich 3F05 aluminum alloy, delivering superior corrosion protection. This advanced material withstands over 6,000 hours of salt fog testing (SWAAT) without leaks or structural damage. Microchannel tubes are zinc arc-sprayed.

Corrosion resistance can be further enhanced with electrophoretic epoxy coating (e-coating) on the outer surfaces or nano-scale coating on both the outer and inner surfaces, making these coils perfectly suitable for C4 and C5 corrosivity zones. The nano-scale coating also allows compatibility with a broader pH range of working fluids.

The coil design has been optimized for fluid applications. Its vertical tube arrangement reduces fluid resistance for typical coil dimension ratios and facilitates effortless, gravity-driven condensate removal. Microchannel tubes with enlarged port sizes prevent clogging, even when handling contaminated fluids. Meanwhile, the tube wall thickness is maintained, ensuring coil reliability in harsh environments. Large-diameter inlet and outlet manifolds further reduce pressure losses in the coil and accommodate larger fluid connections.

Comprehensive field and laboratory performance analyses confirm that the new chilled water coils deliver valuable improvements in capacity, reliability, corrosion resistance, and resistance to environmental stress compared to previous designs.