Dual air admittance valve

A valve assembly for use with an enclosed environment, comprising:

• (a) a housing having an interior volume, an inlet disposed at a first end of the housing and fluidly coupled to an environment surrounding the housing, and an outlet disposed at a second end of the housing, wherein said interior volume is divided into a first zone, a second zone, a third zone, wherein said first zone occupies a predetermined volume of said interior volume proximate said outlet, wherein said third zone occupies a predetermined volume of said interior volume proximate said inlet, wherein said second zone occupies a predetermined volume of said interior volume between said first zone and said third zone, wherein a first zone pressure exists in said first zone, wherein a second zone pressure exists in said second zone, and wherein a third zone pressure exists in said third zone;
• (b) a first valve inside said housing, comprising a first valve seat, wherein said first valve seat is disposed between said first zone and said second zone wherein said first valve seat has a first opening, wherein said first valve further comprises a first sealing member, wherein said first sealing member has a dimension greater than said first opening, wherein said first sealing member dimension is less than the inner diameter of said housing, wherein said first sealing member has a predetermined weight, and wherein said first sealing member moves inside said first zone and away from said first valve seat, wherein said first valve is in an open position when said second zone pressure is greater than said sealing member predetermined weight and said first zone pressure, and wherein said first valve is in a closed position when said second zone pressure is less than said sealing member predetermined weight and said first zone pressure;
• (c) a second valve inside said housing, comprising a second valve seat, wherein said second valve seat is disposed between said second zone and said third zone wherein said second valve seat has a second opening, wherein said second valve further comprises a second sealing member, wherein said second sealing member has a dimension greater than said second opening, wherein said second sealing member dimension is less than the inner diameter of said housing, wherein said second sealing member has a predetermined weight, and wherein said second sealing member moves inside said second zone and away from said second valve seat, wherein said second valve is in an open position when said third zone pressure is greater than said sealing member predetermined weight and said second zone pressure, and wherein said second valve is in a closed position when said third zone pressure is less than said sealing member predetermined weight and greater than said second zone pressure;
• wherein the first sealing member comprises a first upper hemispherical section, a first lower hemispherical section, a first neck section connecting the first upper and lower hemispherical sections, the first neck section having a first diameter less than a first opening diameter of the first opening of the first valve seat, a portion of each of the first upper and lower hemispherical sections being sized larger than the first opening diameter forms a seal when abutting against the first valve seat, and the second sealing member comprises a second upper hemispherical section, a second lower hemispherical section, a second neck section connecting the second upper and lower hemispherical sections, the second neck section having a second diameter less than a second opening diameter of the second opening of the second valve seat, a portion of each of the second upper and lower hemispherical sections being sized larger than the second opening diameter forms a seal when abutting against the second valve seat.