Impeller for centrifugal fans

A forward-curved impeller for a centrifugal fan, the impeller comprising:

• a plurality of blades including a first blade, each of the blades of the plurality of blades including a respective curved portion and a respective extended portion, each respective curved portion including a respective leading edge and a respective trailing edge;
• the first blade comprising a first curved portion and a first extended portion;
• the first curved portion including a first leading edge and a first trailing edge;
• and
• wherein:
• the first extended portion extends outward from the first trailing edge of the first curved portion;
• the forward-curved impeller includes an inner diameter and an outer diameter, the inner diameter being associated with a circle extending along the leading edges of the curved portions of all of the plurality of blades, the outer diameter being associated with a circle extending along the trailing edges of the curved portions of all of the blades, and wherein a ratio of the inner diameter to the outer diameter is at most 1;
• and
• the first blade includes:
• an inlet blade angle in a range between 5° and 24°;
• and
• an outlet blade angle in a range between 160° and 180°.