A gas injection hose comprising: a hose having a coupler at a distal end thereof, wherein the coupler is adapted to be detachably coupled to a gas inlet/outlet valve of a thermal exchange apparatus; a movable depressor disposed in the coupler, wherein the depressor is configured to depress a valve core, wherein the valve core is disposed in the valve 7 to open or close the valve, wherein the depressor extends from the coupler into the hose in a length direction of the hose; a depressor-adjustment unit disposed on a middle region of the hose, wherein the unit is configured to allow forward or reward movement of the depressor toward or away from the valve core, wherein when the coupler is coupled to the valve, a depressed extent of the depressor is adjustable by the depressor-adjustment unit, the gas injection hose being characterized in that: the hose is divided into first and second sub-hoses with the depressor-adjustment unit being interposed between the first and second sub-hoses, wherein the depressor-adjustment unit includes first and second hollow plungers coupled to the first and second sub-hoses respectively; and a rotatable hollow cylinder constructed to receive the first and second plungers, wherein the plungers are slidably received in the cylinder, wherein an adjustment plate is received in the cylinder and is integral with the cylinder, wherein the plate has a rectangular hole through which the depressor passes, wherein the depressor is received in a guide tube, wherein the depressor is partially thread-coupled to the tube, wherein a rotation of the cylinder allows a rotation of the depressor to allow forward or reward movement of the depressor toward or away from the valve core along the tube. a hose having a coupler at a distal end thereof, wherein the coupler is adapted to be detachably coupled to a gas inlet/outlet valve of a thermal exchange apparatus; a movable depressor disposed in the coupler, wherein the depressor is configured to depress a valve core, wherein the valve core is disposed in the valve 7 to open or close the valve, wherein the depressor extends from the coupler into the hose in a length direction of the hose; a depressor-adjustment unit disposed on a middle region of the hose, wherein the unit is configured to allow forward or reward movement of the depressor toward or away from the valve core, wherein when the coupler is coupled to the valve, a depressed extent of the depressor is adjustable by the depressor-adjustment unit, the gas injection hose being characterized in that: the hose is divided into first and second sub-hoses with the depressor-adjustment unit being interposed between the first and second sub-hoses, wherein the depressor-adjustment unit includes first and second hollow plungers coupled to the first and second sub-hoses respectively; and a rotatable hollow cylinder constructed to receive the first and second plungers, wherein the plungers are slidably received in the cylinder, wherein an adjustment plate is received in the cylinder and is integral with the cylinder, wherein the plate has a rectangular hole through which the depressor passes, wherein the depressor is received in a guide tube, wherein the depressor is partially thread-coupled to the tube, wherein a rotation of the cylinder allows a rotation of the depressor to allow forward or reward movement of the depressor toward or away from the valve core along the tube.