When To Use Finned Tube Heat Exchangers

Use finned tube heat exchangers when one side of the heat transfer process is a gas or air, because gases have much lower heat-transfer coefficients than liquids. The fins increase external surface area and help transfer more heat without making the unit excessively large.

Typical situations include:

• Air heating with steam, hot water, thermal oil, or exhaust heat

• Air cooling with water, glycol, or refrigerant

• Drying equipment such as ovens, dryers, curing lines, and tumble dryers

• HVAC and ventilation systems such as AHUs, FCUs, and duct heaters

• Waste heat recovery from hot air or flue gas

• Engine and compressor cooling

• Cold room and refrigeration evaporators or condensers

• Industrial process heating or cooling where air passes across the coil

They are especially suitable when:

• the air side is the thermal bottleneck

• space is limited and higher surface area is needed

• forced air from a fan is available

• a compact and economical coil design is preferred

They are usually not the first choice for liquid-to-liquid duty, where shell-and-tube or plate heat exchangers are often more efficient.

A simple rule is:
use a finned tube heat exchanger when you need to efficiently heat or cool air or gas with a liquid, steam, or refrigerant inside the tubes.

For the unit in your photo, this type is commonly used for:

• steam or hot water air heating

• thermal chamber heating

• drying systems

• make-up air units

• industrial ovens and process air heaters