Heat exchange apparatus

Claim 1

Heat exchange apparatus comprising an outside casing, means defining in the casing a first inlet, a first outlet, a second inlet and a second outlet, means for mounting the outside casing relative to an outside wall of a building such that the first inlet and the second outlet are arranged on one side of the wall facing within the building and the first outlet and the second inlet are arranged on the other side of the wall facing outside the building, a heat exchange block defining therethrough two separate air paths mutually at right angles, means mounting the block in the casing such that air can pass in a first and a second separate path respectively from said first inlet through said block to said first outlet and from said second inlet through said block to said second outlet, a first fan for pumping air in said first path and a second fan for pumping air in said second path, said heat exchange block comprising a plurality of thin sheets of plastics material lying in planes parallel to the first and second flows and arranged so as to divide the first and second flows into a plurality of alternate portions separated by the sheets, a plurality of elongated parallel spacer strips arranged to support and space each sheet on one side thereof relative to the adjacent sheet on that side, each spacer strip being at right angles to the sheets and extending from one edge thereof to an opposing edge, the strips being parallel to the second air path as it passes through the block and spaced by a distance of the order of the spacing between the sheet and the adjacent sheet each sheet, its respective adjacent sheet and the plurality of spacer strips being formed integrally from a plastics extrusion, and a plurality of elongated spacer members on the other side of each sheet and arranged parallel to the first air path as it passes through the block and spaced so as to support said sheet at positions including opposed edges thereof spaced widely relative to said spacing between the sheet and the next adjacent sheet, each member being formed from a strip of said plastics extrusion.