M&I's Column Fan is a product of M&I's extensive research and development efforts that kept M&I at the forefront in the field of HVAC design. The system consists of an outlet diffuser / silencer, an inlet flow concentrator and an axial fan.
Movement for "Green Buildings" is gaining momentum; developers, architects and engineers are finding that the best methods for saving energy and ameliorating the environment of office workers are those that have been around for a long time but have fallen out of use. This has been termed as "New Old Technologies".
One such technology is "under floor air system", which promises to cut building operation cost, dramatically improve indoor air quality and improve office layout flexibility. The system also known as access flooring and displacement ventilation, uses a floor cavity or plenum, about 12 to 14 inches high into which cool air is pumped and then released into the offices through special diffusers.
Under low pressure the cooled air swirls gently through the diffuser and mixes with the air in the room where employees work. The air rises in a plume to overhead exhaust locations.
With everything in the floor - a system once used only for computer rooms - companies can put down mobile partitions anywhere in an open plan space and create an instant office by simply lifting a tile.
M&I's Column Fan design has an excellent fit for this design concept due to its compactness, flexibility and acoustical superiority over other designs.
It incorporates four sided acoustic supply diffuser that converts high velocity at fan discharge from 5000 fpm to less than 700 fpm at the diffuser within a compact distance of 4 to 5 feet. There are no components in the air stream disturbing the flow pattern leaving the fan. Air leaving fan outlet gradually reduces to diffuser velocity without causing measurable turbulence or flow separation thus eliminating the need for a long duct. This efficient aero-acoustic design provides both aerodynamic and absorptive insertion losses.
The diffuser is made of 22 gauge galvanized perforated sheet metal. At the back of the sheet metal there is 2" thick, 3lb/cu.ft. density mat faced acoustic insulation, erosion free even at velocities of 6000ft/min. Insulation material is not allowed to come in contact with the air stream thereby guaranteeing longer life without any wear and tear. All ferrous materials used in the diffuser construction are galvanized and all welds are coated with zinc rich paint. The outer skin of the diffuser is made of 18 gauge galvanized sheet metal.
The extended acoustical inlet flow concentrator with similar construction as outlet diffuser has a large lip radius to accommodate the filters and a center pod. It gradually reduces to the fan inlet size designed to guide air straight into the impeller blades.
The column fan unit uses an axial fan that is wrapped with a high density sound absorbing material that attenuates 10 dB from 1st an 2nd bands respectively.
The entire fan, including the vibration isolators is placed on a slide-out or roll-out assembly for quick and easy removal of the fan.
