Deposits in HEX are called what?

Deposits in HEX are called what?

• A. Fouling
• B. Scaling
• C. Corrosion
• D. Erosion

Answer: (A)

Fouling is the broad term for deposits that build up on heat exchanger surfaces and reduce heat transfer efficiency. In HEXs, any unwanted accumulation—whether minerals that form scale, organic matter, or other particulates—falls under fouling. Scaling is a common type of fouling, but the general idea is the surface buildup that impedes performance. Corrosion and erosion describe material loss or wear, not deposits, so they don’t fit the concept of surface buildup. That’s why fouling is the best answer.

Fouling is the broad term for deposits that build up on heat exchanger surfaces and reduce heat transfer efficiency. In HEXs, any unwanted accumulation—whether minerals that form scale, organic matter, or other particulates—falls under fouling. Scaling is a common type of fouling, but the general idea is the surface buildup that impedes performance. Corrosion and erosion describe material loss or wear, not deposits, so they don’t fit the concept of surface buildup. That’s why fouling is the best answer.