What materials are typically used for chiller coils?

Chiller coils are manufactured from different materials depending on heat transfer efficiency, corrosion resistance, operating pressure, and application environment. The most commonly used materials are outlined below.

Typical Materials Used for Chiller Coils

1. Copper Tubes + Aluminum Fins (Cu–Al)

Most common HVAC configuration

• Excellent thermal conductivity

• Cost-effective and lightweight

• Easy to fabricate and repair

Typical applications:
Commercial HVAC chillers, air-cooled condensers, DX evaporator coils

Limitations:

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• Susceptible to corrosion in coastal or industrial atmospheres

• Not suitable for ammonia (R717)

2. All-Copper Coils (Copper Tubes + Copper Fins)

• Higher corrosion resistance than Cu–Al

• Strong mechanical integrity

• Good compatibility with most HFC and HFO refrigerants

Typical applications:
Industrial chillers, harsh environments, long service-life requirements

3. Stainless Steel Coils

• Excellent corrosion and chemical resistance

• Suitable for high pressure and high temperature

• Fully compatible with ammonia (R717) and aggressive fluids

Common grades:

• AISI 304 / 304L

• AISI 316 / 316L (marine and chloride environments)

Typical applications:
Food processing, pharmaceuticals, chemical plants, marine chillers

4. Aluminum Microchannel Coils

• Compact, lightweight design

• Low refrigerant charge

• High heat transfer efficiency on air side

Typical applications:
Modern air-cooled chillers, rooftop units, energy-efficient systems

Limitations:

• More sensitive to fouling

• Limited repairability compared to tube-fin coils

5. Carbon Steel Coils

• High mechanical strength

• Suitable for high-pressure water or oil circuits

Typical applications:
Special industrial chillers, oil coolers, closed-loop water systems

Limitations:

• Requires corrosion protection (coating or inhibitors)

6. Cu-Ni (Copper-Nickel) Alloys

• Excellent resistance to seawater corrosion

• Good biofouling resistance

Typical applications:
Marine chillers, offshore platforms, seawater-cooled condensers

7. Coated and Protected Coil Materials

To enhance durability, coils may use:

• Epoxy or phenolic coatings

• Hydrophilic aluminum fins

• Anti-corrosion treatments (E-coat, Blygold)

Typical applications:
Coastal, polluted, or high-humidity environments

Material Selection Summary