Patent ID: 7036560

Claim:
An elongated heat exchange unit for a building, said unit having first and second opposing surfaces; a first fluid conduit and a second fluid conduit formed by a partition connected to a box which extend along the length of the unit, wherein the box includes an undulating foil wall deformable by air pressure, whose undulations are in fluid communication with the first and second conduits; an inlet located substantially midway along the length of the elongated unit to define upper and lower portions of the box, extending from outside the building and being in fluid communication with the first conduit; an outlet extending from the second conduit to outside the building; a first entry fan in the inlet draws fresh air from outside the building into the first conduit, which fresh air exits via first openings formed in the unit into a room in the building; a second extraction fan located at one end of the second conduit, and a third extraction fan located at another end of the second conduit, wherein the second and third extraction fans draw stale air from the room into the second conduit via second openings formed in the unit, respectively, and out the outlet to outside the building, wherein the inlet, the first conduit and the first openings are in continuous fluid communication, wherein the second openings, the second conduit and the outlet are in continuous fluid communication, wherein the fresh air and the stale air move in opposite directions across the foil wall in each portion of the unit, wherein, when all three fans are operating, air pressure is exerted on both sides of the undulating foil wall by the fresh and stale air, thereby opening channels in the wall, with the fresh and stale air on either side of the foil wall exchanging heat, and wherein, when the first and only one of the second and third fans are operating, air pressure is exerted on both sides of the undulating foil wall only in the portion of the box with the operating second or third fan, thereby opening channels in the wall only in that portion of the box having the operating second or third fan, and the fresh and stale air on either side of the undulating foil wall in that portion exchange heat, but in the undulating foil wall in the other portion of the box having only one side of the foil wall under air pressure only from the fresh air, channels are not formed, so that the fresh and stale air in this other portion of the box experiences only minimal heat exchange.