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The heat exchanger coil (primary cooling coil) in a closed-circuit cooling tower (CCT) is a critical component, and its material must balance thermal efficiency, corrosion resistance, durability, and cost. Below are the most common materials used, along with their pros, cons, and typical applications:

• Advantages:
  • Excellent thermal conductivity (best heat transfer).
  • Naturally corrosion-resistant (forms a protective patina).
  • Lightweight and easy to fabricate.
• Disadvantages:
  • Vulnerable to ammonia, sulphides, and acidic water (in spray loop).
  • Higher cost than carbon steel.
• Best for:
  • HVAC systems, chillers, and light industrial use.

2. Stainless Steel (SS 304 / SS 316) – Corrosion-Resistant Choice

• Advantages:
  • Highly resistant to rust, chlorides, and harsh environments (SS 316 > SS 304).
  • Long lifespan with minimal maintenance.
• Disadvantages:
  • Lower thermal conductivity than copper (~15% of Cu).
  • More expensive upfront.
• Best for:
  • Coastal areas (salt exposure), chemical plants, food/pharma industries.

3. Carbon Steel (with Epoxy/Galvanized Coating) – Budget Option

• Advantages:
  • Lowest cost material.
  • Strong and durable if properly coated.
• Disadvantages:
  • Prone to rust if coating degrades.
  • Requires regular maintenance (inspections, recoating).
• Best for:
  • Non-corrosive environments with tight budgets (often used in power plants).

4. Titanium (Ti) – Premium for Extreme Conditions

• Advantages:
  • Ultra-corrosion-resistant (handles seawater, acids, high chlorides).
  • Lightweight and strong.
• Disadvantages:
  • Very expensive (5–10x copper/stainless steel).
• Best for:
  • Offshore oil rigs, desalination plants, aggressive chemical processes.

5. Cupronickel (90/10 or 70/30 Cu-Ni) – Marine & High-Salinity Use

• Advantages:
  • Combines copper’s conductivity with saltwater resistance.
  • Good biofouling resistance.
  • Disadvantages:
    • Higher cost than pure copper.
  • Best for:
    • Ships, coastal cooling towers, brackish water applications.
  • Material Selection Guide
  • Key Factors Influencing Material Choice
  • Water Quality (chlorides, pH, contaminants).
  • Environmental Conditions (coastal, industrial pollution).
  • Budget (upfront vs. lifecycle costs).
  • Maintenance Capability (e.g., can you inspect/recoat carbon steel?).
  • Recommendations by Industry
  • HVAC & Data Centres → Copper (best efficiency).
  • Oil/Gas, Chemical Plants → Stainless 316 or Titanium.
  • Marine/Desalination → Cupronickel or Titanium.
  • General Industry (Low Budget) → Epoxy-Coated Carbon Steel.