Abstract: An environmental enclosure apparatus is presented with air flow control and air balancing. The apparatus includes a housing having a work chamber, multiple adjustable fans for moving air into the work chamber, a filter for filtering particulate from the air moving into the chamber and a control mechanism for controlling each of the multiple adjustable fans. The control mechanism is responsive to a sensor which determines a change in position of at least one component within the work chamber. The at least one component could comprise a work product, a work tool or other product handling device. Air balancing is achieved through the provision of multiple chases within the enclosure, some of which have inlets at a bottom of the enclosure for drawing in external air and some of which have openings internal to the work chamber adjacent to a work surface for facilitating air flow balancing.