Regenerative heat exchanger with low pressure drop for use in heat or energy recovery ventilation

Abstract

A heat exchanger of the regenerative type which is capable of being utilized for transferring heat between incoming and outgoing building ventilation air. The article includes internal elements into which heat is transferred from the air, and from which heat is transferred to the air ( 3 ), between and around which air may flow. It preferably includes staggered internal heat exchange elements within a certain range of dimensions, elements for structural support of the heat exchange elements ( 4 ), and an outermost external wall ( 5 ).

What is claimed is: 
     
         1 . An article, which is a regenerative heat exchanger for transferring heat between volumes of building ventilation in a decentralized manner, said article comprising:
 a. A plurality of solid elements as means for heat exchange, past which air may flow;   b. Means to hold said elements in position relative to each other, wherein said elements as means for heat exchange are staggered, thereby splitting the air stream flowing along the device longitudinally, along the nominal axis of the air flow one or more times as it flows through the device, whereby said staggering leads to increased ratio of the amount of heat energy and or water vapor transferred between air volumes and the air pressure needed to cause a predetermined rate of air flow through said article; and   c. With air flow channels or gaps between said solid elements as means for heat exchange having less than 4.8 mm in the shortest dimension.   
     
     
         2 . The article of  claim 1  wherein said elements as means for heat exchange are in the form of flat plates, spiral walls, concentric circles, concentric squares, airfoil like elements, rods, or any structure of equivalent or nearly equivalent geometry for heat transfer purposes, and which is fixed and non-rotating. 
     
     
         3 . The article of  claim 1  further including an adsorbent or other material as means to retain and release water vapor in the process of transferring it between air volumes, such as zeolite or calcium chloride and which is fixed and non-rotating. 
     
     
         4 . The article of  claim 1  wherein said elements as means for heat exchange are made primarily of polylactic acid coated with an adsorbent to aid the transfer of water vapor, and which is fixed and non-rotating. 
     
     
         5 . The article of  claim 1  wherein said elements as means for heat exchange are made primarily of a material of high volumetric heat capacity, such as alumina, polylactic acid, another plastic, iron, or some combination thereof, and which is fixed and non-rotating. 
     
     
         6 . The article of  claim 1  wherein said elements as means for heat exchange are solid walls around air channels of hexagonal, square, round, triangular, or any other shape equivalent for the purpose of heat transfer, and which is fixed and non-rotating. 
     
     
         7 . The article of  claim 1  wherein said elements as means for heat exchange are solid walls around air channels of hexagonal, square, round, triangular, or any other shape equivalent for the purpose of heat transfer, which is used in a rotating thermal wheel type configuration rather than non-rotating, in which more than 80 percent of the active surface area of said elements as means of heat exchange are staggered relative to surfaces encountered by the most previous single set of elements upstream. 
     
     
         8 . The article of  claim 1  wherein said elements as means for heat exchange are solid walls around air channels of hexagonal, square, round, triangular, or any other shape equivalent or nearly equivalent for the purpose of heat transfer, which is used in a rotating thermal wheel type configuration rather than non-rotating, and wherein said elements as means for heat exchange consist partly or primarily of a polymer material. 
     
     
         9 . The article of  claim 1  wherein said solid elements as means for heat exchange are made primarily of any suitable material for heat storage and release, which may be a thermoplastic such as polyethylene terephthalate or polypropylene, and which may be combined with alumina or other material. 
     
     
         10 . The article of  claim 1  further including small elements to encourage mixing of the air within the air channel as it flows, thereby improving the ratio of flow impediment/drag to heat exchange efficiency. 
     
     
         11 . An article, which is a regenerative heat exchanger for transferring heat between volumes of building ventilation air in a decentralized manner, said article comprising:
 a. Internal solid walls or elements as means for heat exchange with interspersed air channels less than 1.7 mm in the shortest dimension, and   b. means for holding such solid elements in position relative to each other, which may be the elements themselves, and which is fixed and non-rotating.   
     
     
         12 . The article of  claim 11  wherein said internal solid walls or elements as means for heat exchange are of thickness less than 0.65 mm in the shortest dimension. 
     
     
         13 . The article of  claim 11  which is composed primarily of alumina. 
     
     
         14 . The article of  claim 11  made primarily of any suitable material, which may be a thermoplastic such as polylactic acid, polyethylene terephthalate or polypropylene, and which may be combined with alumina or other material. 
     
     
         15 . The article of  claim 11  wherein the air channels are less than 1.35 mm in the shortest nominal dimension. 
     
     
         16 . The article of  claim 11  made primarily of any suitable material, which may be a thermoplastic such as polylactic acid, polyethylene terephthalate or polypropylene, and which may be combined with alumina or other material, and which is coated with zeolite or another adsorbent or other material such as calcium chloride, to aid the transfer of water vapor.