-Flue-water heat exchanger made up of steel or stainless steel tube divided into serpentine groups. Isolated case, arranged with conic connectionsto chimney and directly integrate on the boiler top flue exit or installed separate with a conic connection behind the boiler flues flange.
-The economizer permits to utilize residual heat from flue gas, otherwise lost at the chimney, preheating the feeding water. In this way the boiler efficiency increase of 5-6%.