Knowledge base

What is the difference between chemical and ultrasonic cleaning in heat exchangers?

And when do you choose which method? Heat exchangers are fouling faster than many companies realize. Lime, sludge, salt, oil, biofouling and process residues accumulate in plates, fins and tubes. The result: higher energy costs, reduced cooling capacity and risk of downtime.

Fortunately, there are two very effective ways to get heat exchangers back in top condition: dry cleaning and ultrasonic cleaning. But which method is right for your plant?

In this article, we explain the differences, including pros and cons and industry-specific applications.

Chemical cleaning: perfect against limescale, sludge and waterborne contamination

In dry cleaning, special cleaning fluids are circulated through the heat exchanger or the exchanger is immersed in a chemical bath.

This method is ideal for fouling that occurs on the water side of a heat exchanger.

When do you choose dry cleaning?

  • calcification (scaling)
  • rust / corrosion products
  • silt / sediment
  • mineral deposit
  • water/glycol pollution
  • dirty plate heat exchangers
  • shell & tube heat exchangers

Advantages of dry cleaning

  • completely dissolves hard deposits
  • quick result
  • suitable for large industrial heat exchangers
  • often possible on site
  • safe for stainless steel, steel and CuNi (with proper inhibitors)

Less suitable for

  • fins / slats
  • fine contamination deep in plates
  • salty maritime pollution

Chemical cleaning is a specialized method that is very effective at scaling – something ultrasonic cleaning barely addresses.

Ultrasonic cleaning: extremely deep and safe

Ultrasonic cleaning uses high-frequency sound waves. These create microscopic air bubbles (cavitation) that implode against the surface, loosening dirt – deep into fins, fins and small openings.

Heat exchangers with fine structures or marine fouling especially benefit.

When do you choose ultrasonic cleaning?

  • contamination between fins/blades
  • salt deposits / seawater residues
  • oil and grease deposits
  • biological contamination (biofouling)
  • fine silt particles
  • charge air coolers
  • air coolers
  • oil coolers
  • marine coolers

Advantages of ultrasonic cleaning

  • extremely thorough depth effect
  • Reaches places where manual or chemical cleaning does not reach
  • safe for stainless steel, CuNi and aluminum
  • perfect for marine systems
  • Fully restores cooling capacity and flow

Less suitable for

  • heavy lime (scaling)
  • thick mineral deposit

In those cases, dry cleaning is more effective.

Chemical vs. ultrasonic: the real difference

Part Chemical cleaning Ultrasonic cleaning
Best for Scaling, water side fouling Fins, fins, deep structures
Material Stainless steel, steel, CuNi Stainless steel, CuNi, aluminum
Depth effect Medium-high Very high
Salt tarnish Good Excellent
Lime/sludge Excellent Limited
Oil/Lubricant Good Very good
Biofouling Moderate-good Very good
Implementation Workshop and location Workshop only
Lead time 4-24 hours 1-2 days

Briefly:

  • Dry cleaning = best choice for hard water-side soiling.
  • Ultrasonic cleaning = best choice for marine and fine fouling between fins/lams.

What is best for your industry?

Industry

  • heavy scaling → chemical
  • sludge / rust / process residues → chemical
  • compact coolers → ultrasonic for detail cleaning

Maritime

  • salt deposition → ultrasonic
  • dirty CACs and air coolers → ultrasonic
  • engine water coolers → chemical

Agricultural

  • water/glycol pollution → chemical
  • biofouling on cooling blocks → ultrasonic
  • lime → chemical

So what is the best method for your heat exchanger?

It depends on:

  • type of contamination
  • heat exchanger type
  • material
  • location (workshop or on board/in operation)
  • sector

Blue Orange always inspects, analyzes and then chooses the method that provides the greatest return – never standard, always customized.

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