Abstract: A regulator of air pressure within a hot or cold storage chamber which comprises a damper and frames. The damper is disposed within an opening provided at a wall of the storage chamber defining an air passage, and the frames are airtightly in contact with peripheral surfaces of the opening and the damper at the inside and outside of the storage chamber to close the air passage. The damper and either one of the frames are moveable in the inside or outside direction of the storage chamber in accordance with variations of air pressure within the storage chamber to thereby release the sealing of the air passage and establish pressure equilibrium between the inside and outside of the storage chamber.

Abstract: A regulator of air pressure within a hot or cold storage chamber which comprises a damper and frames. The damper is disposed within an opening provided at a wall of the storage chamber defining an air passage, and the frames are airtightly in contact with peripheral surfaces of the opening and the damper at the inside and outside of the storage chamber to close the air passage. The damper and either one of the frames are moveable either inside or outside direction of the storage chamber in accordance with variations of air pressure within the storage chamber to thereby release the sealing of the air passage and establish pressure equilibrium between the inside and outside of the storage chamber.