Heat recovery units are heat exchangers installed in chimneys or at the exhaust of combustion gases from boilers, furnaces, kilns, and other sources of hot gases.
Their function is to extract residual heat from these gases and redirect it to other thermal processes, such as:
- Process or sanitary water heating
- Secondary steam generation
- Thermal fluid heating
- Preheating of raw materials or ventilation air
 

Types of recovery: 
- Gas/water heat exchangers
- Gas/thermal fluid heat exchangers
- Gas/air heat exchangers (for indirect processes)
 

Features: 
- Materials: Carbon steel, stainless steel, or special alloys resistant to corrosion and high temperatures
- Gas temperature: Up to 400 °C (depending on design)
- Thermal efficiency: Recovery of up to 95% of residual heat