Kaltra - Brazed Aluminum Microchannel Water Coils

The fluid coil core is an all-aluminum construction, assembled for brazing in a controlled-atmosphere furnace from the following components:

• Tubes with standard or enlarged ports. Fins, louvered or flat
• Inlet/outlet manifolds
• Reinforcement beams
• Fluid inlet/outlet connections
• Manifold-side mountings with vibration/corrosion isolators
• Side support fixtures

Microchannel water coils offer significant advantages over traditional finned-tube coils in several key areas, including superior heat transfer efficiency, enhanced corrosion resistance, lighter weight, and lower pressure drops on both the air and fluid sides.

HIGHER HEAT TRANSFER

Since the heat transfer coefficient for single-phase flows depends on the hydraulic diameter of the flow area, microchannel water coils—with their millimeter-scale ports—offer significantly higher heat transfer rates compared to finned-tube heat exchangers.

LOWER WATER VOLUME

Microchannel water coils feature an internal fluid volume that is 7–10 times lower than that of comparable finned-tube coils. This dramatically reduces system water requirements — an essential advantage in open-circuit systems supplied by wet cooling towers, particularly in water-scarce regions.

LONGER SERVICE LIFE

Protective coatings are available for both the outer and inner coil surfaces. For external treatment, options include e-coating, TCP coating, or a nanoscale trichrome film. The nanoscale trichrome film is available for inner surface treatment, ensuring compatibility with a broader pH range of the fluid.

LIGHTER WEIGHT

The coil core is made of aluminum, ensuring a lighter weight than traditional finned-tube coils. Its reduced internal volume further contributes to weight savings in installations. Available fluid connections include aluminum, stainless steel, and copper options.

• Min/Max width [mm] : FROM 50 TO 6000
• Min/Max height [mm] : FROM 50 TO 2000
• Design : HORIZONTAL/VERTICAL TUBE ARRANGEMENT • SINGLE-/MULTI-PASS • SINGLE-/MULTI-CIRCUIT
• Tube width [mm] : 12.0 • 16.0 • 20.0 • 25.4 • 28.0 • 32.0 • 36.0
• Tube spacing [mm] : 7.8 • 9.3 • 9.4 • 9.8 • 10.0
• Manifold diameter [mm] : 16 • 20 • 25 • 30 • 32 • 38 • 42 • 50
• Fin type : FLAT • LOUVERED
• Fin pitch [FPI] : 10.0 • 12.7 • 16.5 • 17.0 • 18.0 • 19.5 • 21.0 • 23.0 • 24.0 • BY REQUEST
• Tube material(s) : AA3102 • HA9153A • AA3F03 • AA3F05 (TEMPER H112) ZINC ARC SPRAY
• Fin material(s) : AA4343 • AA3003 • FA7971 (TEMPER H14)
• Manifold material(s) : AA4343 • AA3003 OR AA4045 • AA3003/AA4045 • AA3005 (TEMPER H14)
• Design pressure [bar] : 10 • 20
• Refrigerant : WATER • GLYCOLS • OILS • SPECIAL FLUIDS
• Protective coating : E-COATING • TCP-COATING • NANO-COATING (EXTERNAL/INTERNAL) • UV-PROTECTION
• Special coating : HYDROPHILIC • HYDROPHOBIC • PAINT

Microchannel water coils seamlessly integrate into various HVAC systems, offering a superior alternative to traditional finned-tube heat exchangers while enhancing efficiency and performance. The most distinctive applications include:

• Chilled water coils, e.g., in free cooling systems or AHU coils in data center applications
• Hot water coils for heating applications
• Cooling and heating coils in process cooling and comfort air conditioning
• Energy recovery and waste heat utilization
• Dehumidification systems