Water Heater Blower Housing, Impeller, and Static Tap System

A blower comprising:

• a blower housing;
• an impeller within the blower housing, the impeller being rotatable about an impeller axis, the impeller axis defining perpendicular axial and radial directions, the impeller having a backplate and impeller blades, the impeller blades being spaced from one another circumferentially about the impeller axis, the impeller blades extending axially forward from the backplate to a blade forward end of the respective impeller blade, the backplate including an axially rearward facing backplate back surface region, the impeller blades having radially outer ends that combine to define an impeller outer circumference, the impeller outer circumference having an impeller outer diameter;
• the backplate back surface region having a first axial end and a second axial end, the second axial end being axially rearward of the first axial end, the backplate back surface region generally circumscribing the impeller axis, and the backplate back surface region converging radially inwardly as the backplate back surface region extends axially rearwardly from the first axial end toward the second axial end, the first axial end of the backplate back surface region having a first diameter and the second axial end of the backplate back surface region having a second diameter, the second diameter being not more than 75% of the first diameter and the first diameter being not less than 50% of the impeller outer diameter;
• a back ring connected to the front side of the backplate and to the impeller blades, the back ring having a back ring outer diameter and a back ring inner diameter, the back ring outer diameter being greater than the backplate outer diameter;
• a front ring connected to the forward ends of the impeller blades, the front ring having a front ring outer diameter and a front ring inner diameter, the front ring outer diameter being greater than the back ring outer diameter;
• the blower housing having a scroll back wall axially rearward of the impeller and a scroll front wall axially forward of the impeller, the backplate back surface region being spaced axially forward from the scroll back wall by a generally uniform axial gap distance to form a generally uniform axial gap extending axially rearward from the backplate back surface region to the scroll back wall.

A blower comprising:

• a blower housing;
• an impeller within the blower housing, the impeller being rotatable about an impeller axis, the impeller axis defining perpendicular axial and radial directions;
• the impeller comprising a backplate, impeller blades, and a ring;
• the backplate of the impeller having a backplate front surface and a backplate back surface, the backplate front surface facing axially forward, the backplate back surface facing axially rearward;
• the ring having a ring front surface and an outer circumference, the ring front surface facing axially forward, the ring being spaced axially forward of the backplate;
• the impeller blades being spaced from one another circumferentially about the impeller axis, the impeller blades having radially outer ends that combine to define an impeller outer circumference, the impeller outer circumference having an impeller outer diameter, each of the impeller blades extending axially forward from the ring to an impeller blade forward end of the respective impeller blade;
• the impeller having an impeller exhaust width, the impeller exhaust width being defined as an axial distance between the ring outer circumference and the impeller blade forward ends;
• the blower housing comprising a scroll back wall spaced axially rearward of the impeller, and a scroll front wall axially forward of the impeller, the scroll back wall facing the backplate back surface, the scroll front wall facing the impeller blade forward ends;
• the blower having a scroll width, the scroll width being a greatest axial distance from the scroll front wall to the scroll back wall at the impeller outer circumference;
• a ratio of the scroll width to the impeller exhaust width being not less than 1.5 and not greater than 4.0.

A blower comprising:

• a blower housing comprising a first molded housing member and a second molded housing member, the first molded housing member and the second molded housing member being joined together in a clamshell configuration;
• an impeller within the blower housing, the impeller being rotatable about an impeller axis, the impeller axis defining perpendicular axial and radial directions, the impeller having a backplate and impeller blades extending axially forward from the backplate, the backplate including a backplate back surface region, the backplate back surface region facing axially rearward, the impeller blades having radially outer ends that combine to define an impeller outer circumference, the impeller outer circumference having an impeller outer diameter;
• an exhaust pressure static tap;
• the backplate back surface region generally circumscribing the impeller axis;
• the blower housing having a scroll back wall axially rearward of the impeller and a scroll front wall axially forward of the impeller, the scroll back wall having a scroll back wall front surface region facing the backplate back surface region, the backplate back surface region having a shape, the scroll back wall front surface region having substantially the same shape as the backplate back surface region, the backplate back surface region being spaced axially forward from the scroll back wall front surface region to form a generally uniform axial gap extending from the backplate back surface region to the scroll back wall front surface region;
• the scroll back wall having an exhaust pressure static tap opening adjacent the axial gap, the exhaust pressure static tap being connected to the exhaust pressure static tap opening.