Foils

Foils are responsible for a surprising 65% – 70% of the heat transfer on any coil, while tubes are responsible for the remaining 30% – 35%. Foil tube heat exchangers are often used in circumstances where air is the preferred medium for the cooling or heating, particularly where there is limited or poor quality water.

In a foiled tube heat exchanger, heat is exchanged between a thermally efficient fluid that transports heat efficiently, such as a liquid which has some viscosity, and a fluid that does not, such as air or gas with little density. On the ‘air side’, the tube surface is enhanced by the addition of fins or other elements such as looped wires, designed to increase the surface area of the tube and improve its thermal performance.

Applications

Finned tube heat exchangers have a wide range of applications, a few of which are:

  • diesel charge air coolers;
  • oil coolers;
  • hydrogen coolers;
  • waste heat recovery;
  • driers;
  • air conditioning;
  • air heaters;
  • steam condensers;
  • generator coolers