illustrates that the upper cap piece 46 provides clearance for the toilet seat 22 when in the position the width of the hollow air plenum is approximately 3 u00bd to 4 u2033 to permit its location between the seat hinges 26 fig4 a and 4 b show two views of the asymmetrical exhaust duct modular units 75 76 which are specially adapted to permit clearance for the toilet seat hinge bolt shoulder 33 fig5 illustrates that the present invention communicates with a hollow toilet seat 100 when the seat is in the lowered position the intake orifice 50 of the hollow air plenum 38 aligns with a matching orifice 104 in a hollow seat 100 to permit the contained movement of air from within the seat into a hollow air plenum 38 additional intake orifices 108 are incorporated into the lower surface of the seat so that air may be drawn from the interior of the bowl 14 into the hollow seat 100 through the intake orifice 50 through the hollow air plenum 38 through the exit ports 54 through the exhaust ducts 70 and ultimately to the outdoors fig6 and 7 illustrate a variation of the invention incorporates a third exhaust port 120 in the lower surface of the exhaust manifold 30 the third exhaust port 120 mates to a specially provided exhaust orifice 122 in the upper surface of the toilet bowl generally behind and between the toilet seat mounting hinges 26 reference to fig7.