Fouling is one of the most common causes of declining performance in shell & tube heat exchangers. As deposits build on tube surfaces, heat transfer efficiency drops, pressure increases, and operating costs rise. When fouling reaches a certain point, cleaning becomes necessary—and the method you choose can significantly impact the condition and longevity of your equipment.
This guide compares mechanical cleaning and chemical cleaning, helping facility teams understand when each method is the right approach.
Why Cleaning Method Matters
Not all fouling is the same, and not all heat exchangers respond equally well to each cleaning approach. The best cleaning method depends on:
- The type of fouling (scale, biological growth, sediment, hydrocarbons, etc.)
- The exchanger’s tube configuration (straight, U-tube, pitch pattern)
- Material compatibility and corrosion sensitivity
- Accessibility for tooling or chemical circulation
For general preventative steps to slow fouling, see
Preventative Maintenance for Shell & Tube Heat Exchangers.
Mechanical Cleaning
Mechanical cleaning physically removes deposits from the tube walls using rods, brushes, scrapers, or high-pressure water jetting. It’s the most direct way to clear hard, compacted fouling.
Best for:
- Hard scale and stubborn mineral deposits
- Sludge and sediment buildup
- Exchangers with straight, easily accessed tubes
- Situations where chemical compatibility is a concern
Advantages:
- Immediate, visible results
- No disposal of chemical cleaning fluids
- Effective on thick or crystallized deposits
Limitations:
- Not ideal for U-tube bundles due to limited accessibility
- Improper tooling can scratch or damage tube surfaces
- May not fully remove deposits trapped in crevices or under rust layers
For a deeper look at tube configurations, read
Straight Tube vs. U-Tube Cleaning Requirements.
Chemical Cleaning
Chemical cleaning uses formulated solvents or cleaning solutions to dissolve fouling from tube surfaces. It reaches areas that mechanical tools cannot, making it ideal for complex or densely pitched tube bundles.
Best for:
- Under-deposit fouling
- Biological growth
- Complex bundles where mechanical tools cannot reach
- Systems requiring minimal mechanical disturbance
Advantages:
- Deep cleaning, including hard-to-reach areas
- Less risk of tube surface damage
- Effective at removing layered or embedded deposits
Limitations:
- Requires careful chemical selection to avoid corrosion
- Spent chemical disposal must follow environmental regulations
- May take longer than mechanical cleaning depending on buildup
If fouling has already impacted performance or caused pressure drop changes, review
5 Early Warning Signs Your Heat Exchanger Needs Maintenance.
Choosing the Right Cleaning Method
The ideal cleaning strategy often depends on the exchanger’s design and service environment. In many facilities, a combination of mechanical and chemical cleaning is used over time to maintain optimal heat transfer.
General guidelines:
- Choose mechanical cleaning for hard, crystalline fouling.
- Choose chemical cleaning for deposit layers, biological fouling, and complex tube layouts.
- Consider both methods when fouling is severe or varied.
For organizations planning refurbishment, replacement, or upgrades, KAM Thermal Equipment provides custom shell & tube manufacturing and replacement tube bundles tailored to each application.
Explore upgrade considerations in
Benefits of Custom Shell & Tube Manufacturing.
Additional Resources
- How to Prevent Corrosion in Heat Exchangers
- Troubleshooting Heat Exchanger Leaks
- Tube Bundle Removal & Replacement Guide
Service Areas
KAM Thermal Equipment supports industrial operators nationwide with custom fabrication and replacement solutions. Explore service coverage by region:
Mid-Atlantic
Southeast
Midwest
South Central
Need a Replacement Tube Bundle?
KAM Thermal Equipment manufactures custom replacement tube bundles designed to improve long-term performance after fouling or material degradation. If your heat exchanger cleaning schedule reveals wear or tube damage, our engineering team can build a drop-in, application-matched solution.