Energy exchange assembly with microporous membrane

Abstract

An energy exchange assembly may include one or more membrane panels. The one or more membrane panels may include a microporous membrane that has a pore size between 0.02 and 0.3 micrometers (μm) and a porosity between 45% and 80%. Optionally, the energy exchange assembly may further include a plurality of spacers that define air channels. The air channels may be configured to receive air streams therethrough. Each of the one or more membrane panels may be disposed between two spacers. The one or more membrane panels may be configured to allow a transfer of sensible energy and latent energy across the one or more membrane panels between the air channels.

What is claimed is: 
     
         1 . An energy exchange assembly, comprising:
 one or more membrane panels, wherein the one or more membrane panels include a microporous membrane that has a pore size between 0.02 and 0.3 micrometers (μm) and a porosity between 45% and 80%.   
     
     
         2 . The energy exchange assembly of  claim 1 , further comprising a plurality of spacers that define air channels configured to receive air streams therethrough, the one or more membrane panels each disposed between two spacers, the one or more membrane panels configured to allow a transfer of sensible energy and latent energy across the one or more membrane panels between the air channels. 
     
     
         3 . The energy exchange assembly of  claim 2 , wherein the plurality of spacers includes a first group of spacers and a second group of spacers, the first group of spacers is orthogonally oriented with respect to the second group of spacers. 
     
     
         4 . The energy exchange assembly of  claim 1 , wherein the microporous membrane is devoid of at least one of a hydrophilic or hydrophobic coating. 
     
     
         5 . The energy exchange assembly of  claim 1 , wherein the pore size of the microporous membrane is between 0.04 and 0.2 μm. 
     
     
         6 . The energy exchange assembly of  claim 1 , wherein the porosity of the microporous membrane is between 50% and 75%. 
     
     
         7 . The energy exchange assembly of  claim 1 , wherein the microporous membrane of the one or more membrane panels has a thickness between 15 and 30 μm. 
     
     
         8 . The energy exchange assembly of  claim 1 , wherein the microporous membrane has a vapor diffusion resistance below 40 seconds/meter (sec/m) and an air permeability below 0.06 ft 3 /min/ft 2 . 
     
     
         9 . The energy exchange assembly of  claim 1 , wherein the one or more membrane panels further include a backing layer bonded to the microporous membrane for support, the one or more membrane panels having a stiffness of at least 20 MPa·mm. 
     
     
         10 . The energy exchange assembly of  claim 8 , wherein the backing layer includes a non-woven mesh with a larger pore size and porosity than the microporous membrane, wherein the backing layer does not significantly affect the transmission of vapor or air through the one or more membrane panels. 
     
     
         11 . The energy exchange assembly of  claim 1 , wherein the microporous membrane is formed of at least one of expanded polytetrafluoroethylene (ePTFE), polypropylene (PP), nylon, polyvinylidene fluoride (PVDF), or polyethersulfone (PES). 
     
     
         12 . An energy exchange system, comprising:
 a supply air flow path configured to channel supply air to an enclosed structure;   a regeneration air flow path configured to channel regeneration air from the enclosed structure to an outside environment; and   an energy exchange assembly disposed within the supply air flow path and the regeneration air flow path, wherein the energy exchange assembly comprises:
 a plurality of spacers; and 
 a plurality of membrane panels, each membrane panel including a microporous membrane that has a pore size between 0.02 and 0.3 micrometers (μm) and a porosity between 45% and 80%, 
 wherein each of the spacers is positioned between two of the membrane panels to define air channels through the spacer between the two membrane panels, the air channels configured to receive air streams therethrough, the membrane panels configured to allow a transfer of sensible energy and latent energy across the membrane panels between the air channels. 
   
     
     
         13 . The energy exchange system of  claim 12 , wherein the microporous membrane is devoid of at least one of a hydrophilic or hydrophobic coating. 
     
     
         14 . The energy exchange system of  claim 12 , wherein the pore size of the microporous membrane is between 0.04 and 0.2 μm. 
     
     
         15 . The energy exchange system of  claim 12 , wherein the porosity of the microporous membrane is between 50% and 75%. 
     
     
         16 . The energy exchange system of  claim 12 , wherein the microporous membrane has a vapor diffusion resistance below 40 seconds/meter (sec/m) and an air permeability below 0.06 ft 3 /min/ft 2 . 
     
     
         17 . The energy exchange system of  claim 12 , wherein the plurality of spacers includes a first group of spacers and a second group of spacers, the first group of spacers is orthogonally oriented with respect to the second group of spacers. 
     
     
         18 . The energy exchange system of  claim 12 , wherein the membrane panels further include a backing layer bonded to the microporous membrane for support, the membrane panels having a stiffness of at least 20 MPa·mm. 
     
     
         19 . The energy exchange system of  claim 18 , wherein the backing layer includes a non-woven mesh with a larger pore size and porosity than the microporous membrane, wherein the backing layer does not significantly affect the transmission of vapor or air through the membrane panels. 
     
     
         20 . The energy exchange system of  claim 12 , wherein the microporous membrane is formed of at least one of expanded polytetrafluoroethylene (ePTFE), polypropylene (PP), nylon, polyvinylidene fluoride (PVDF), or polyethersulfone (PES).