A press apparatus comprising: a pressure vessel (1, 8, 9), arranged to hold pressure medium therein during use of the press apparatus, the pressure vessel comprising a top end closure and a bottom end closure; a furnace chamber arranged within the pressure vessel so that pressure medium can enter and exit the furnace chamber, the furnace chamber at least in part defining a treatment space arranged to accommodate at least one article, wherein the press apparatus is configured to subject the at least one article to a treatment cycle including a cooling phase; at least one outer convection loop pressure medium guiding passage (10, 11) in fluid communication with the furnace chamber and arranged to form an outer convection loop within the pressure vessel, wherein the outer convection loop is arranged to guide the pressure medium after having exited the furnace chamber in proximity to an inner surface of wall(s) of the pressure vessel to a space between the furnace chamber and the bottom end closure; a pressure medium flow generator arranged within the pressure vessel and in fluid communication with the furnace chamber, wherein at least during a cooling phase of the treatment cycle, the pressure medium flow generator is arranged to generate a transport of pressure medium from at least the space between the furnace chamber and the bottom end closure into the furnace chamber so as to cool the pressure medium in the treatment space; characterized in that at least one pressure medium guiding passage arranged within the pressure vessel such that, during a cooling phase, the pressure medium after having exited the furnace chamber may be guided from the furnace chamber to the space between the furnace chamber and the bottom end closure via the at least one pressure medium guiding passage without having to pass through the outer convection loop before the pressure medium enters the space between the furnace chamber and the bottom end closure, wherein each of the at least one pressure medium guiding passage is arranged such that a cross-section thereof in a plane perpendicular to a flow direction of the pressure medium through the pressure medium guiding passage is formed as a gap having a width, wherein each of the at least one pressure medium guiding passage has a corresponding width, and wherein a sum of the width(s) is less than 4 mm. a pressure vessel (1, 8, 9), arranged to hold pressure medium therein during use of the press apparatus, the pressure vessel comprising a top end closure and a bottom end closure; a furnace chamber arranged within the pressure vessel so that pressure medium can enter and exit the furnace chamber, the furnace chamber at least in part defining a treatment space arranged to accommodate at least one article, wherein the press apparatus is configured to subject the at least one article to a treatment cycle including a cooling phase; at least one outer convection loop pressure medium guiding passage (10, 11) in fluid communication with the furnace chamber and arranged to form an outer convection loop within the pressure vessel, wherein the outer convection loop is arranged to guide the pressure medium after having exited the furnace chamber in proximity to an inner surface of wall(s) of the pressure vessel to a space between the furnace chamber and the bottom end closure; a pressure medium flow generator arranged within the pressure vessel and in fluid communication with the furnace chamber, wherein at least during a cooling phase of the treatment cycle, the pressure medium flow generator is arranged to generate a transport of pressure medium from at least the space between the furnace chamber and the bottom end closure into the furnace chamber so as to cool the pressure medium in the treatment space; characterized in that at least one pressure medium guiding passage arranged within the pressure vessel such that, during a cooling phase, the pressure medium after having exited the furnace chamber may be guided from the furnace chamber to the space between the furnace chamber and the bottom end closure via the at least one pressure medium guiding passage without having to pass through the outer convection loop before the pressure medium enters the space between the furnace chamber and the bottom end closure, wherein each of the at least one pressure medium guiding passage is arranged such that a cross-section thereof in a plane perpendicular to a flow direction of the pressure medium through the pressure medium guiding passage is formed as a gap having a width, wherein each of the at least one pressure medium guiding passage has a corresponding width, and wherein a sum of the width(s) is less than 4 mm.