Abstract: Systems and methods for controlling operation of one or more fans of an air handling system having one or more filters or filter banks. A current air volume at an inlet side of the fan(s) is determined. In some embodiments, the inlet side air volume is determined via sensed pressure at the inlet side (e.g., pressure transducer open to a flow station at the inlet side). A controller operates to control or regulate a speed of the fan in a manner that maintains a constant air volume through the air handling system, for example based upon a comparison of the current air volume at the fan with a target air volume.

Abstract: A suspended ceiling construction includes fill-in panels, diffusers and/or light fixtures which are retained in their openings by spring clips that have been pre-attached to the ceiling grid frame members. The clips bear against edges of the panels to keep them in place normally, but they can be deflected out of the way by pushing up on the panels when necessary. As the tips of the clips contact the frame members during deflection, they provide increasing resistance to further deflection.

Abstract: Provided is a filtering system and method that incorporates a portable filter device. The portable filter has a front side and a back side. A medical gurney is positioned proximate the portable filter device. An air intake provided in the back side of the portable filter device and an air outlet diffusion plate provided in the front side of the portable filter device. A first filter is disposed across the air intake and a second filter is disposed behind the air outlet diffusion plate. Also provided is an air drawing device which draws air into the portable filter device through the first filter and sends air out of the filter device through the second filter. Filtered streams of air are then formed above and below a patient supporting area of the gurney, such that the filtered streams of air have a laminar flow. Rollers are provided for permitting the portable filter device to be moved across a floor surface.