Centrifugal fan diffuser

A fluid handling method comprising the steps of:

• accepting fluid into a centrifugal fan having a centrifugal fan axis of rotation and a centrifugal fan impeller element;
• rotationally impelling said fluid through use of a centrifugal fan impeller element;
• imparting a centrifugal force to said fluid;
• discharging said impelled fluid into a diffuser element;
• axially converging said discharged, impelled fluid as a radial distance from said centrifugal axis of rotation increases;
• transforming tangential velocity pressure of said discharged, impelled fluid to static pressure;
• increasing static pressure of said discharged, impelled fluid;
• outputting said discharged, impelled fluid to a a flow turning element that outputs to a plenum;
• and
• outputting said discharged, impelled fluid to a plenum.

An impelled fluid output diffusion method comprising the steps of:

• receiving through a diffuser inlet of a diffuser element a fluid impelled by a centrifugal fan and having a tangential velocity and a radial velocity;
• decreasing said tangential velocity of said impelled fluid;
• increasing static pressure of said impelled fluid as a result of said step of decreasing said tangential velocity;
• controlling radial velocity of said impelled fluid;
• and
• outputting said impelled fluid to a flow turning element;
• and
• outputting said impelled fluid to a plenum,
• wherein said step of controlling radial velocity of said fluid impelled by a centrifugal fan comprises the step of controlling radial velocity of said impelled fluid so as to avoid recirculation of said impelled fluid output to said plenum back into a space defined by said flow turning element.

An air handling method comprising the steps of:

• accepting air into a centrifugal fan having a centrifugal fan impeller element;
• rotationally impelling said air through use of said centrifugal fan impeller element;
• imparting a centrifugal force to said air;
• discharging said impelled air into a diffuser element;
• transforming tangential velocity pressure of said discharged, impelled air to static pressure without using vanes and by decreasing tangential velocity;
• increasing static pressure of said discharged, impelled air;
• sufficiently controlling radial velocity of said impelled air so as to avoid recirculation of said discharged, impelled air;
• turning said impelled air with a flow turning element;
• outputting said discharged, impelled air to a plenum;
• and
• establishing acoustical material substantially outside of and contiguously with said diffuser element,
• wherein said step of transforming tangential velocity pressure of said discharged, impelled air comprises the step of radially extending an interface at which said discharged, impelled air enters said flow turning element.
• wherein said step of sufficiently controlling radial velocity of discharged, impelled air comprises the step of axially converging said discharged, impelled air, and
• wherein said recirculation is recirculation of said discharged impelled air output to said plenum back into as space defined by said flow turning element.

A fluid handling method comprising the steps of:

• accepting fluid into a centrifugal fan having a centrifugal fan axis of rotation and a centrifugal fan impeller element;
• rotationally impelling said fluid through use of a centrifugal fan impeller element;
• imparting a centrifugal force to said fluid;
• discharging said impelled fluid into a diffuser element;
• transforming tangential velocity pressure of said discharged, impelled fluid to static pressure with a regain efficiency of at least 70%;
• increasing static pressure of said discharged, impelled fluid as a result of said step of transforming tangential velocity pressure of said discharged, impelled fluid to static pressure;
• and
• turning said discharged, impelled fluid with a flow turning element;
• outputting said discharged, impelled fluid to a plenum,
• wherein said step of transforming tangential velocity pressure to static pressure comprises the step of transforming tangential velocity pressure to effect at least 90% of the total increase in static pressure observed as said discharged, impelled air travels through said diffuser element.