Abstract: A method for conducting suction and compression operation on a gaseous medium of thermodynamic process in the closed chamber of a closed chamber gas equipment said suction operation intended to bring the gaseous medium in to the closed chamber and said compression operation intended to compress the gaseous medium retained within the closed chamber; The gaseous medium is exposed to have direct contact with a gas which is dissimilar in composition to that of said gaseous medium and which is moving away from and towards the gaseous medium with the aid of a gas discharge means performing respectively the suction and compression operation and thereby acting as a gaseous piston. The gaseous piston may do only one of the two operations namely suction or compression. The gas discharge means may comprise a venturi means connected to the closed chamber or a gas reservoir connected to the closed chamber or both. The admittance of gaseous piston in to and out of the closed chamber may be through valve or port means.