An air preheater (APH) is a device designed to heat air before process combustion in a boiler with the primary objective of increasing the thermal efficiency of the process. The purpose of the air preheater is to recover the heat from the boiler flue gas which increases the thermal efficiency of the boiler by reducing the useful heat lost in the flue gas. As a consequence, the flue gases are also sent to the stack at a lower temperature, allowing simplified design of the ducting and the flue gas stack. It also allows control over the temperature of gases leaving the stack.

Metapow is a leading manufacturer, supplier and exporter of air preheaters in Bhosari, Pune, India.