Cover your food in the fridge – reduce the likelihood of gas leaks from your commercial refrigeration evaporator coil.

A common cause of refrigerant gas leaking from evaporator coils, especially those used in commercial refrigeration is corrosion.
Sometimes referred to as formicary corrosion, this can occur when oxygen and moisture, along with other organic compounds come into contact with the copper tubing of the evaporator coil as part of the refrigeration process.

As refrigerated air is distributed around the refrigerated space of the fridge or coolroom it also flows over the copper tubes of the evaporator where the heat transfer process takes place.
Unfortunately – the airflow that is providing the refrigerating effect is also allowing moisture and organic compounds to be deposited on the copper tube, eventually a chemical reaction occurs.

Over time, the chemical reaction will attack the copper surface and progress into the tube wall, resulting in the copper tube becoming porous and eventually leaking refrigerant.
Generally this situation will only occur when oxygen, moisture, and an organic acid are simultaneously present on the copper surface.

So – where does the organic acid come from ?

A fun fact that some of us forget to appreciate – All foodstuffs are acidic to varying degrees.

Common types of acids in food include –

• Acetic Acid (fruits and berries, as well as vinegar)
• Citric Acid (citrus fruits)
• Fatty Acids (fats and oils)
• Lactic Acid (sour milk products, sourdough bread making)

When uncovered food products are stored in a refrigerated space, the airflow over the food product speeds up oxidisation and the release of organic acid into the airstream.


Simple solutions are generally the best –

  • Foodstuffs must be well covered or ideally stored in containers with sealing lids (not just cling wrap)
  • Clean your fridge regularly with a cloth, water and PH neutral detergent – don’t forget the inside too.
  • Tomato, onions, olives, brine products are especially notorious coil eaters – any spills or dropped food need to be cleaned as soon as possible.

Talk to MNK TECHNICAL SERVICES for routine programmed maintenance to your refrigeration assets – MNK continue to invest in the latest leak detection equipment and methods of finding and solving refrigerant gas leaks.