A durable dew point corrosion resistant heat exchanging system for transfer of heat between a first gas and a second gas, comprising: a. at least one first gas inlet, said inlet adapted to direct said first gas into the heat exchanging system; b. at least one first gas outlet adapted to direct said first gas out of said heat exchanging system; c. a plurality of hollow heat transferring tubes (212, 312, 412a,b) aligned parallel to each other in a first direction substantially perpendicular to said first gas inlet , said heat transferring tubes extending between said first gas inlet and said first gas outlet ; d. said plurality of hollow heat transferring tubes adapted to direct said second gas through said hollow heat transferring tubes; wherein the system further comprises: e. a subset of hollow heat transferring tubes from said plurality of hollow heat transferring tubes, wherein the subset of hollow heat transferring tubes comprises at least one third of the total number of hollow heat transferring tubes and less than the total number of hollow heat transferring tubes of the plurality of hollow heat transferring tubes, each of the hollow heat transferring tubes in the subset of hollow heat transferring tubes comprising an inner liner , said inner liner of each hollow heat transferring tube in the subset of hollow heat transferring tubes being spaced from an outer wall of each corresponding heat transferring tube and forming a space between the inner liner and the outer wall of the corresponding heat transferring tube, said space defining a sealed fluid chamber ; f. at least one seal sealing the sealed fluid chamber between the inner liner and said outer wall of said subset of hollow heat transferring tubes; g. said sealed fluid chamber extending through a first tube sheet ; and h. each said inner liner having a first predetermined axial length. a. at least one first gas inlet, said inlet adapted to direct said first gas into the heat exchanging system; b. at least one first gas outlet adapted to direct said first gas out of said heat exchanging system; c. a plurality of hollow heat transferring tubes (212, 312, 412a,b) aligned parallel to each other in a first direction substantially perpendicular to said first gas inlet , said heat transferring tubes extending between said first gas inlet and said first gas outlet ; d. said plurality of hollow heat transferring tubes adapted to direct said second gas through said hollow heat transferring tubes; wherein the system further comprises: e. a subset of hollow heat transferring tubes from said plurality of hollow heat transferring tubes, wherein the subset of hollow heat transferring tubes comprises at least one third of the total number of hollow heat transferring tubes and less than the total number of hollow heat transferring tubes of the plurality of hollow heat transferring tubes, each of the hollow heat transferring tubes in the subset of hollow heat transferring tubes comprising an inner liner , said inner liner of each hollow heat transferring tube in the subset of hollow heat transferring tubes being spaced from an outer wall of each corresponding heat transferring tube and forming a space between the inner liner and the outer wall of the corresponding heat transferring tube, said space defining a sealed fluid chamber ; f. at least one seal sealing the sealed fluid chamber between the inner liner and said outer wall of said subset of hollow heat transferring tubes; g. said sealed fluid chamber extending through a first tube sheet ; and h. each said inner liner having a first predetermined axial length. <EOS>