The AIRATHERM flue recovery units (FRU) are the optimal solution for boiler flue gas heat recovery. In principle it acts as an air to water heat exchanger. Flue gases, considered wasted energy, are passed over/through the copper finned tube heat exchanger of the FRU system. The process of cooling and the condensing, transfers excess energy from the flue gases to the liquid flowing through the tube bundle.
Essentially converting standard boilers into condensing boilers, the FRU can increase the efficiency of the existing boiler by as much as 7%, thereby delivering real energy cost savings.