Abstract: A method for condensing fumes or gases from a tank containing a liquid. The method includes leading the liquid into a venturi to create a low pressure at the venturi. Ports are provided in the venturi at the area where the low pressure is created, and gas/vapor is lead to the ports in the venturi in the low pressure area in such a way that the liquid entrains the gas/vapor and forms a fluid, such that the velocity is reduced and the pressure increased to condense the gas/vapor. The fluid is then led from the chamber to a lower part of the tank for further condensation due to the hydrostatic pressure. An apparatus, a system and uses thereof are also described.