Apparatus and method for passively cooling an interior

• US 10,704,794 B2
• Filed: 02/27/2017
• Issued: 07/07/2020
• Est. Priority Date: 04/07/2015
• Status: Active Grant

• Current Assignee: Brown University
• Original Assignee: Brown University
• Inventors: Stein, Derek Martin
• Primary Examiner(s): Russell, Devon
• Application Number:
  US15/443,001
• Publication Number:
  US 20170167738A1
• Time in Patent Office: 1,226 Days
• Field of Search: 165 481, 165 55
• CPC Class Codes: E04B 1/74 Heat, sound or noise insulation, absorption, or reflection forms of, or arrangements in, rooms for influencing or directing sound E04B1/99; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls fire protection E04B1/94; elements chiefly adapted for structural purposes E04C1/00 - E04C3/00; chiefly adapted for surface coverings E04F13/00; as underlayers for floor coverings E04F15/18; closures for wall or like openings E06B
• CPC Class Codes: E04C 2/28 combinations of materials fully covered by groups E04C2/04 and E04C2/08
• CPC Class Codes: F24F 13/0227 using parts of the building, e.g. air ducts inside the floor, walls or ceiling of a building
• CPC Class Codes: F24F 2003/1435 comprising semi-permeable membrane
• CPC Class Codes: F24F 2005/0082 Facades
• CPC Class Codes: F24F 2221/17 mounted in a wall
• CPC Class Codes: F24F 3/1411 by absorbing or adsorbing water, e.g. using an hygroscopic desiccant
• CPC Class Codes: F24F 5/0035 using evaporation
• CPC Class Codes: Y02B 30/54 Free-cooling systems

Abstract

A system passively cools, regulates humidity and/or rectifies diffusive transport of water vapor in an interior area within a structure. The system includes a membrane assembly covering a portion of the structure, wherein the membrane has an interior side facing the interior area and an exterior side. The membrane assembly defines a plurality of pores. When cooling, a supply of fluid is provided to the membrane assembly so that capillary action of the pores redistributes the fluid to create evaporation and, in turn, the desired heat flow. The membrane assembly can include an architectural membrane coated with a porous matrix coating to form the pores. A pump can provide the fluid to the interior side of the membrane assembly. Preferably, the architectural membrane is woven PTFE-coated fiberglass and the porous matrix coating is titanium dioxide, zeolites and/or silica gel.

Claims

1. A structure for rectifying diffusive transport of water vapor into an interior area of an enclosure comprising:

a wall structure having a frame; and

a membrane assembly covering a portion of the frame to form the enclosure, wherein the membrane assembly has;

an interior side and an exterior side;

a porous layer on the interior side that exhibits humidity-dependent water adsorption; and

a water vapor barrier on the exterior side that exhibits humidity-dependent permeability to water vapor, wherein the water vapor permeability of the water vapor barrier increases with increasing relative humidity.

2. A structure as recited in claim 1, wherein the porous layer defines a plurality of pores that spread liquid.

3. A structure as recited in claim 1, further comprising a liquid on the membrane assembly such that capillary action of the membrane assembly pores to create evaporation and, in turn, cooling.

4. A structure as recited in claim 1, wherein the pores spread liquid by branching into smaller channels.

5. A structure as recited in claim 1, further comprising a fan system for increasing air flow across the membrane assembly.

6. The structure of claim 1, wherein the porous layer is nanoporous.

7. The structure of claim 1, wherein the porous layer is formed from a zeolite or silica gel.

8. The structure of claim 1, wherein the water vapor barrier.

9. The structure of claim 1, wherein the water vapor barrier is formed from nylon.