What is an Aftercooler?
An aftercooler is a heat exchanger that cools compressed air immediately after it exits an air compressor, reducing its temperature by 50-200°F (30-110°C). This process:
- Condenses moisture from the air
- Protects downstream equipment
- Improves system efficiency
Key Differences: Aftercooler vs. Intercooler
| Feature | Aftercooler | Intercooler |
| Location | After the final compressor stage | Between compressor stages |
| Primary Function | Final air cooling before use | Intermediate cooling between stages |
| Typical Temp Drop | 110-200°F (60-110°C) | 50-150°F (30-80°C) |
| Common Applications | Industrial air systems | Turbocharged engines |
Types of Aftercoolers
1. Air-Cooled Aftercoolers
- How it Works: Uses ambient air to cool compressed air via finned tubes
- Best For:
- Small to medium compressors (5-200 HP)
- Outdoor installations
- Advantages:
- No water required
- Low maintenance
- Disadvantages:
- Less effective in hot environments
2. Water-Cooled Aftercoolers
- How it Works: Uses circulating water to cool compressed air
- Best For:
- Large industrial compressors (200+ HP)
- High ambient temperature areas
- Advantages:
- More consistent cooling
- Compact design
- Disadvantages:
- Requires water supply
- Higher maintenance
3. Refrigerated Aftercoolers
- How it Works: Uses refrigeration cycle for precise temperature control
- Best For:
- Critical applications needing exact air temps
- Medical/pharmaceutical uses
- Advantages:
- Most effective cooling
- Can reach dew points below ambient
- Disadvantages:
- Highest energy consumption
- Complex installation
Why Your Compressed Air System Needs an Aftercooler
- Moisture Removal – Condenses 60-80% of water vapor
- Equipment Protection – Prevents damage to:
- Air dryers
- Pneumatic tools
- Piping systems
- Energy Savings – Cooler air is denser, requiring less energy to compress
- Improved Air Quality – Reduces contamination in sensitive processes
Aftercooler Efficiency Factors
| Factor | Effect on Performance |
| Cooling Medium Temp | Lower = better cooling |
| Air Flow Rate | Must match compressor output |
| Surface Area | More area = better heat transfer |
| Fouling | Dirty fins reduce efficiency |
Maintenance Requirements
- Daily: Check for proper operation
- Weekly: Inspect for leaks
- Monthly: Clean fins/tubes
- Annually: Replace worn components
Pro Tip: Install an automatic drain to remove condensed water!