Bi-flow inflatable door seals

A door adjacent a doorway member exposed to air, the door comprising:

• a door panel that is movable relative to the doorway member;
• an inflatable seal interposed between the doorway member and the door panel, the inflatable seal includes a supply conduit and a return conduit, the supply conduit has a downward-flow section having an average supply diameter, the return conduit has an upward-flow section having an average return diameter, the downward-flow section and the upward-flow section are within a certain lateral distance of each other, wherein the certain lateral distance is less than the average supply diameter plus the average return diameter;
• and
• a blower in fluid communication with the supply conduit such that air discharged from the blower flows down through the supply conduit and back up through the return conduit.

A method of providing heated supply air to an inflatable seal having a cross-sectional shape, the method comprising:

• providing a source of forced heated air;
• conveying air from the source of forced heated air, down through a supply air path, to a lower end of the inflatable seal;
• and
• exhausting air from a return air path adjacent to the source of forced heated air, wherein a cross-sectional shape of the seal is divided into the supply air path and the return air path.