Cold weather suit with vapor barrier and heat recovery

Abstract

In a first embodiment, a gas-impermeable vapor barrier inner layer of a cold weather suit prevents condensation of body moisture in outer layers, thus preventing degradation of outer-layer insulating value. Body moisture vapor is collected by a network of tubes inside the inner layer, and fed through a one-way valve into a facemask, where it is added to inhaled air. Heat of vaporization of body moisture, and body heat lost to air convection, is thus recovered by displacing a like amount of heat of vaporization of moisture, and heat added to exhaled air, respectively, that would have been added by the lungs. The basic system can be further improved by additional gas-impermeable insulating layers, and by providing a coupling to detach the facemask from the tube network, so that the remaining tube network is inconspicuous within the suit. In a second embodiment, a heat exchanger also recovers heat, and heat of condensation, from exhaled air and uses it to pre-warm air entering the suit to be inhaled.

What is claimed is: 
     
         1 . A cold weather garment to be worn by a person in an environment, said cold weather garment comprising:
 an inner layer comprised of a material that is impermeable to gas, including water vapor, the inner layer comprising
 a right arm sleeve, 
 a left arm sleeve, 
 a right pant leg, 
 a left pant leg, and 
 a torso section; 
   a tube network situated between the inner layer and the person, said tube network comprising
 an output port, 
 a plurality of input ports comprising
 an input port situated at the end of the right arm sleeve, 
 an input port situated at the end of the left arm sleeve, 
 an input port situated at the end of the right pant leg, and 
 an input port situated at the end of the left pant leg; 
 
 wherein the tube network is configured to allow a first flow of air from a space between the person and the inner layer into the plurality of input ports and thence through the tube network to the output port; and 
   a facemask to be worn over the nose and mouth of the person, said facemask comprising a one-way inlet valve connected between the output port of the tube network and the facemask, said one-way inlet valve being configured to allow air to pass from the output port of the tube network to the facemask but not allow air to pass from the facemask to the output port of the tube network.   
     
     
         2 . The cold weather garment of  claim 1 , further comprising
 a two-way port that is configured to allow air from the environment to enter the facemask to be inhaled and to allow exhaled air to exit the facemask to the environment,   a plurality of holes in the torso section that are adequate to carry a second flow of air from outside the inner layer to inside the inner layer at a rate equal to the first flow of air.   
     
     
         3 . The cold weather garment of  claim 2 , further compromising one or more outer layers impermeable to gas, including water vapor, said outer layers being situated on the outside of the inner layer and containing a plurality of holes adequate to carry a third flow of air at a rate equal to the first flow of air. 
     
     
         4 . The cold weather garment of  claim 2 , wherein said one-way inlet valve is connected to said output port of said tube network by a coupling configured to allow the one-way inlet valve and facemask to be disconnected from the tube network. 
     
     
         5 . The cold weather garment of  claim 1 , further comprising
 a condensing heat exchanger that comprises a warm chamber, a cold chamber, a warm chamber inlet, a warm chamber outlet, a cold chamber inlet, and a cold chamber outlet;   a condensate tank that is configured to collect water condensing within the warm chamber; and   a one-way outlet valve that is configured to allow exhaled air to flow from the facemask to the warm chamber inlet, from whence it flows through the warm chamber and out through the warm chamber outlet to the environment;   wherein the cold chamber is configured to allow outside air to flow into the cold chamber inlet and through the cold chamber, where it receives heat from the warm chamber, from which it travels as pre-warmed air out of the cold chamber outlet into the space between the person and the inner layer.   
     
     
         6 . The cold weather garment of  claim 5 , further compromising one or more outer layers impermeable to gas, including water vapor, said outer layers being situated on the outside of the inner layer. 
     
     
         7 . The cold weather garment of  claim 5 , wherein said one-way inlet valve is connected to said output port of said tube network by a coupling configured to allow the one-way inlet valve, facemask and condensing heat exchanger to be disconnected from the tube network.