Air Clean Systems Total Exhaust Rotary Evaporator Enclosure. Controlled exhaust enclosure. Safely encloses rotary evaporator, vacuum pump and waste bottle. The model 300 controller features microprocessor control and digital display. The total exhaust version simply connects to the laboratory HVAC system via a 4-inch duct connection located on top of the enclosure. Exterior dimensions of approximately 31.5â€W x 45â€H x 23.5â€D.