The guys just completed this venting project in Sioux Falls, SD. This job consisted of: 2- 12” 22 gauge exhaust stacks for 2 separate paint mixing booths. 1-intake louver sized to account for the cfm blown out of the building through the exhaust fans on the paint mixing booths 1- whole shop exhaust fan 1-intake louver sized to account for the cfm blown out of the building from the exhaust fans 1- 80k btu radiant tube heater used to make up for the heat lost through the exhaust fans The intake louvers are designed to work simultaneously with the exhaust fans to keep the building from falling into a negative pressure.