in the stool 12 is exhausted it will be seen that the suction housing 28 is adapted to be used with flush type toilet stools of conventional configuration and is so designed as not to require any modifications to such toilet structure air flow through the toilet is in opposition to the direction of water passage up to the point of reaching the water inlet opening 22 but from that location air passage circumvents the path of the water flow in being exhausted from the system referring to the preferred variation illustrated in fig1 and 11 the suction housing or spacer 28a functions somewhat like spacer 28 of fig1 through 6 and corresponding reference numerals have been carried over with an 34 a 34 designation appended thereto to describe features common between these two versions the embodiment of fig1 and 11 is designed for retrofitting to existing flush type toilets and is designed to obviate several of the problems common to the embodiment of fig1 through 7 and u s pat no 2 777 137 to mcfadden in both the applicant 39 s version illustrated in fig1 through 6 and the mcfadden patent the vent or exhaust pipe extends rearwardly from the toilet beneath the flush water supply tank necessitating either that the toilet be spaced away from a wall or that any wall immediately behind the tank be provided with a hole so that the exhaust venting system may pass through the wall and away from a bathroom with the embodiment illustrated in fig1 and 11 the exhaust fitting.