Attic Insulation with Desiccant

Abstract

A method of reducing the amount of cooling energy required to cool a building is provided. The method includes disposing a porous insulating material substantially covering the ceiling in the attic space of the building to a substantial depth. The porous insulating material includes a desiccant. The method further includes permitting the desiccant-bearing porous insulating material to adsorb water moisture from the attic space and then permitting the adsorbed water moisture to desorb from the desiccant-bearing porous insulating material into the enclosed room of the building, whereby the temperature of the desiccant-bearing porous insulating material is reduced, resulting in a reduction in the amount of cooling energy required to cool the building.

1 . A method of reducing the amount of cooling energy required to cool a building, said building having an enclosed room partially defined by an outer wall, a horizontal upper wall plate, and an attic space disposed above said upper wall plate, said attic space defined by a ceiling of said room and a roof of said building; said method comprising:
 a) disposing a porous insulating material substantially covering the ceiling in said attic space to a substantial depth, said porous insulating material including a desiccant;   b) permitting said desiccant-bearing porous insulating material to adsorb water moisture from said attic space; and   c) permitting said adsorbed water moisture to desorb from said desiccant-bearing porous insulating material into said enclosed room, whereby the temperature of said desiccant-bearing porous insulating material is reduced resulting in a reduction in the amount of cooling energy required to cool said building.   
   
   
       2 . The method of  claim 1  wherein said porous insulating material comprises inorganic or cellulosic fibers. 
   
   
       3 . The method of  claim 1  wherein said permitting step (c) comprises desorbing said adsorbed water moisture from said desiccant via convective mass transfer. 
   
   
       4 . The method of  claim 1  wherein said building is located in a cooling dominated climate. 
   
   
       5 . The method of  claim 1  wherein said attic space has a relative humidity which is higher than the relative humidity of said room. 
   
   
       6 . The method of  claim 1  wherein said desiccant comprises a silica gel. 
   
   
       7 . The method of  claim 6  wherein said silica gel is disposed within an aqueous slurry precursor of said desiccant. 
   
   
       8 . The method of  claim 6  wherein said silica gel is disposed as a dry powder. 
   
   
       9 . The method of  claim 1  wherein said building experiences an exterior temperature greater than 72° F. 
   
   
       10 . The method of  claim 1  wherein said building comprises spaced-apart attic floor joists disposed above said upper wall plate, and spaced-apart roof rafters disposed below and supporting said roof of said building. 
   
   
       11 . The method of  claim 1  wherein said desiccant-bearing porous insulating material is disposed at least between said attic floor joists. 
   
   
       12 . The method of  claim 1  wherein said permitting step (b) reduces a relative humidity level in said attic space. 
   
   
       13 . The method of  claim 1  wherein said outer wall is defined by a plurality of substantially parallel studs, an outer sheathing, and an inner drywall layer, said desiccant-bearing porous insulating material being further disposed between said outer sheathing and said inner drywall layer. 
   
   
       14 . The method of  claim 1  wherein said building is air-conditioned. 
   
   
       15 . A building insulating material comprising:
 a) randomly oriented fibers made of a cellulosic or inorganic composition disposed in a substantial thickness to provide insulation for a building, and   b) a desiccant in an amount sufficient to enable said insulating material to adsorb enough water moisture to reduce the temperature of said insulating material by at least 1° F.   
   
   
       17 . The building insulating material of  claim 1  wherein said desiccant consists of one or more of the following ingredients: montmorillonite clay, silica gel, synthetic zeolite (molecular sieve), calcium oxide (CaO), calcium sulfate (CaSO4), carbon molecular sieve, activated alumina, or activated carbon, or sodium polyacrylate. 
   
   
       18 . The building insulating material of  claim 15  wherein said desiccant comprises at least 5 volume % based upon the volume of said randomly oriented fibers. 
   
   
       19 . The building insulating material of  claim 15  wherein said cellulosic composition comprises recycled paper fibers and said inorganic fibers comprise rotary glass fibers or textile glass fibers. 
   
   
       20 . The building insulating material of  claim 15  wherein said desiccant comprises a uniform mixture of silica gel. 
   
   
       21 . A method of manufacturing an insulating material comprising:
 a) forming glass fibers from molten streams of glass;   b) combining the glass fibers with a desiccant; and   c) consolidating the fibers and desiccant onto a conveyor.   
   
   
       22 . The method of  claim 21  wherein said combining step (b) combines said desiccant with said glass fibers when said glass fibers are still hot. 
   
   
       23 . The method of  claim 21  wherein said combining step (b) disposes said desiccant in a dry powderous form by blowing said dry powderous desiccant into an upper area of a forming section of a rotary glass plant. 
   
   
       24 . The method of  claim 21  wherein said combining step (b) comprises adding said desiccant to a water slurry and spraying said water slurry containing said desiccant onto a plurality of hot mineral fibers in a forming section of a rotary glass plant. 
   
   
       25 . The method of manufacturing an insulation material comprising:
 a) forming cellulosic fibers from a paper source; and   b) admixing a fire retardant and desiccant onto said cellulosic fibers.   
   
   
       26 . The method of  claim 25  wherein said forming step (a) comprises forming said cellulosic fibers from a recycled paper source. 
   
   
       27 . The method of  claim 25  wherein said admixing step (b) comprises spraying a solution containing said fire retardant and said desiccant onto said cellulosic fibers. 
   
   
       28 . A method of making an insulation material comprising:
 a) forming cellulosic fibers from a paper source;   b) admixing a fire retardant with said cellulosic fibers; and   c) adding a desiccant to said fire retardant-containing cellulosic fibers in a blowing machine hopper before said fire retardant-containing cellulosic fibers are blown into an attic cavity, wall cavity or crawl space of a building.