In recent times, thermic fluid heaters have found wide application for indirect process heating. Instead of water, petroleum based fluids are the heat transfer medium, and provide constantly maintainable temperatures for the user equipment. The combustion system comprises of a fixed grate with mechanical draft arrangements.

The advantages of these are:
- Closed cycle operation with minimum losses as compared to steam boilers.
- Non-Pressurized system operation even for temperatures around 250 Deg. C as against 40 kg/cm2 steam pressure requirement in a similar steam system.
- Automatic control settings, which offer operational flexibility.
- Good thermal efficiencies as losses due to blow down, condensate drain and flash steam do not exist in a thermic fluid heater system.