Abstract: A roller door apparatus is provided that includes a roller means and a means journalling the roller means for reversible rotation about a central longitudinal roller axis. The roller door also includes end rail means for a reciprocal linear movement between a first position adjacent the roller means and a second position away from the roller means. Also included is a flexible curtain means with one end attached to the end rail means and the other end attached to the roller means, such that the curtain means closes a door opening with the end rail means in the second position. The curtain means winds onto the roller means when the end rail moves from the second position to the first position and vice versa.

Abstract: A frost control system is described for inhibiting and removing frost from the door of a storage locker. Relatively cool air is received by an inlet to the frost control system at an inlet placed above the door. The air is drawn into the system by a blower which forces the air through the ducts of the system. The air passes through strip heaters within the vertical ducts of the defrost system positioned on either side of the door. The warm air is discharged horizontally across the bottom portion of the door and simultaneously rises creating a blanket of relatively warm air in comparison to the ambient area. Discharge apertures are included in the ends of the vertical ducts which blow a portion of the warmed air to the base of the door to enhance coverage of the door by the warmed air.

Abstract: A frost control system is described for inhibiting and removing frost from the door of a storage locker. Relatively cool air is received by an inlet to the frost control system at an inlet placed above the door. The air is drawn into the system by a blower which forces the air through the ducts of the system. The air passes through strip heaters within the vertical ducts of the defrost system positioned on either side of the door. The warm air is discharged horizontally across the bottom portion of the door and simultaneously rises creating a blanket of relatively warm air in comparison to the ambient area. Discharge apertures are included in the ends of the vertical ducts which blow a portion of the warmed air to the base of the door to enhance coverage of the door by the warmed air.