A tube bundle heat exchanger, comprising: a shell defining a containment volume, said shell having an inlet duct and an outlet duct from the containing volume suitable for conveying a first fluid in a liquid state to be cooled or heated, and at least one perforated tube plate with through holes suitable for allowing tubes, of a tube bundle, pass throughout them in a waterproof manner, a tube bundle, each tube of said tube bundle being inserted in a waterproof manner through a respective hole of said through holes of the perforated tube plate, a delivery chamber of a second fluid under pressure to be heated or cooled with a phase change, defining an inflow opening suitable for being placed in fluid communication with a delivery conduit of the second fluid, and a plurality of outflow openings, each one of said outflow openings being suitable for being placed in fluid communication with a respective tube of the tubes of the tube bundle, a suction chamber of the second fluid, defining a plurality of inflow openings, each one of said inflow openings being suitable for being placed in fluid communication with a respective tube of said tubes of the tube bundle, and a drain opening suitable to be placed in fluid communication with a return conduit of the second fluid, the tubes of said tube bundle are inserted in the through holes of said perforated tube plate and have first ends and second ends which are fixed to the perforated tube plate of the shell of the heat exchanger; characterized in that each chamber of said delivery chamber and of said suction chamber is delimited by respective walls and all said respective walls are distinct and separated among them and from said shell, so that all the respective walls of the delivery chamber and of the suction chamber are lapped by air of an environment in which the heat exchanger is installed; each end of said first ends of the tubes of the tube bundle is fixed in fluid communication and in a non-removable manner to a respective opening of said outflow openings of the delivery chamber either by brazing, or by welding, or by gluing, or by mechanical expansion or by mechanical connection; each end of said second ends of the tubes of the tube bundle is fixed in fluid communication and in a non removable fashion to a respective opening of said inflow opening of the suction chamber either by brazing, or by welding, or by gluing, or by mechanical expansion or by mechanical connection. a shell defining a containment volume, said shell having an inlet duct and an outlet duct from the containing volume suitable for conveying a first fluid in a liquid state to be cooled or heated, and at least one perforated tube plate with through holes suitable for allowing tubes, of a tube bundle, pass throughout them in a waterproof manner, a tube bundle, each tube of said tube bundle being inserted in a waterproof manner through a respective hole of said through holes of the perforated tube plate, a delivery chamber of a second fluid under pressure to be heated or cooled with a phase change, defining an inflow opening suitable for being placed in fluid communication with a delivery conduit of the second fluid, and a plurality of outflow openings, each one of said outflow openings being suitable for being placed in fluid communication with a respective tube of the tubes of the tube bundle, a suction chamber of the second fluid, defining a plurality of inflow openings, each one of said inflow openings being suitable for being placed in fluid communication with a respective tube of said tubes of the tube bundle, and a drain opening suitable to be placed in fluid communication with a return conduit of the second fluid, the tubes of said tube bundle are inserted in the through holes of said perforated tube plate and have first ends and second ends which are fixed to the perforated tube plate of the shell of the heat exchanger; characterized in that each chamber of said delivery chamber and of said suction chamber is delimited by respective walls and all said respective walls are distinct and separated among them and from said shell, so that all the respective walls of the delivery chamber and of the suction chamber are lapped by air of an environment in which the heat exchanger is installed; each end of said first ends of the tubes of the tube bundle is fixed in fluid communication and in a non-removable manner to a respective opening of said outflow openings of the delivery chamber either by brazing, or by welding, or by gluing, or by mechanical expansion or by mechanical connection; each end of said second ends of the tubes of the tube bundle is fixed in fluid communication and in a non removable fashion to a respective opening of said inflow opening of the suction chamber either by brazing, or by welding, or by gluing, or by mechanical expansion or by mechanical connection.