The Minneapolis Blower Door has long been recognized as the best designed and supported building airtightness testing system in the world. Combined with specialized accessories and testing procedures developed by The Energy Conservatory, the Minneapolis Blower Door is the system of choice for utility DSM programs, energy raters, HVAC contractors and weatherization professionals. Complete with everything you need for fully automated Blower Door testing. Built-in Cruise Control allows you to automatically control the Blower Door fan to maintain a constant 75 Pa, 50 Pa, 25 Pa or 0 Pa building pressure without having the gauge connected to a computer. Our lightweight, rugged, injection molded fan housing has a 5 year “no questions asked” warranty. Precise, stable flow measurements without the need for gauge dampening. The Model 3 Fan provides quick and accurate flow measurements from 300 to 6,300 CFM (includes Flow Rings A and B). Optional Flow Rings C, D and E will measure down to 11 CFM. Variable fan speed control (solid state – cruise control compatible). This Model 3 Minneapolis Blower Door system includes a Model 3 (230V/50Hz) Fan and Controller.