Inlet orifice of blower fan of fan coil unit

Abstract

A blower fan of a fan coil unit includes a fan wheel including a first end ring, a second end ring, and a plurality of blades that extend between the first end ring and the second end ring. The plurality of blades define a wheel inner diameter, and each of the first end ring and the second end ring define an end ring inner diameter. The blower fan also includes a housing including an inlet orifice having an orifice diameter. The fan wheel is located within the housing. The orifice diameter is substantially equal to the end ring inner diameter and greater than the wheel inner diameter.

1 . A blower fan of a fan coil unit, the blower fan comprising:
 a fan wheel including a first end ring, a second end ring, and a plurality of blades that extend between the first end ring and the second end ring, wherein the plurality of blades define a wheel inner diameter and each of the first end ring and the second end ring define an end ring inner diameter; and   a housing including an inlet orifice having an orifice diameter, wherein the fan wheel is located within the housing and the orifice diameter is substantially equal to the end ring inner diameter and greater than the wheel inner diameter.   
   
   
       2 . The blower fan as recited in  claim 1  wherein each of the plurality of blades has a length, and a cross-section of each of the plurality of blades taken substantially perpendicularly to the length is substantially arc-shaped. 
   
   
       3 . The blower fan as recited in  claim 1  wherein a space is defined between each of the plurality of blades, and each of the spaces is approximately equal. 
   
   
       4 . The blower fan as recited in  claim 1  further including a wheel disc attached to each of the plurality of blades at a location that is substantially equidistant from a first end and an opposing second end of the plurality of blades. 
   
   
       5 . The blower fan as recited in  claim 4  wherein the wheel disc includes a hub that receives a shaft of a motor, and the motor rotates the shaft to rotate the fan wheel about an axis of rotation. 
   
   
       6 . The blower fan as recited in  claim 1  wherein a first end and an opposing second end of each of the plurality of blades is partially exposed by the inlet orifice and uncovered by the housing. 
   
   
       7 . The blower fan as recited in  claim 1  wherein the fan wheel draws air over a coil of a heat exchanger and into the inlet orifice of the housing and discharges the air through an outlet of the housing. 
   
   
       8 . The blower fan as recited in  claim 1  wherein the plurality of blades are substantially parallel. 
   
   
       9 . The blower fan as recited in  claim 1  wherein the fan wheel is substantially cylindrical. 
   
   
       10 . A fan coil unit comprising:
 a coil, wherein refrigerant flows through the coil; and   a blower fan that draws air over the coil to exchange heat with the refrigerant flowing through the coil, wherein the blower fan includes a fan wheel including a first end ring, a second end ring, and a plurality of blades that extend between the first end ring and the second end ring, wherein the plurality of blades define a wheel inner diameter and each of the first end ring and the second end ring define an end ring inner diameter, and the blower fan includes a housing including an inlet orifice having an orifice diameter and an outlet, wherein the fan wheel is located within the housing to draw the air over the coil and into the inlet orifice and discharge the air through the outlet, and the orifice diameter is substantially equal to the end ring inner diameter and greater than the wheel inner diameter.   
   
   
       11 . The fan coil unit as recited in  claim 10  wherein each of the plurality of blades has a length, and a cross-section of each of the plurality of blades taken substantially perpendicularly to the length is substantially arc-shaped. 
   
   
       12 . The fan coil unit as recited in  claim 10  wherein a space is defined between each of the plurality of blades, and each of the spaces is approximately equal. 
   
   
       13 . The fan coil unit as recited in  claim 10  further including a wheel disc attached to each of the plurality of blades at a location that is substantially equidistant from the first end and the opposing second end of the plurality of blades. 
   
   
       14 . The fan coil unit as recited in  claim 13  wherein the wheel disc includes a hub that receives a shaft of a motor, and the motor rotates the shaft to rotate the fan wheel about an axis of rotation. 
   
   
       15 . The fan coil unit as recited in  claim 10  wherein a first end and an opposing second end of each of the plurality of blades is partially exposed by the inlet orifice and uncovered by the housing. 
   
   
       16 . The fan coil unit as recited in  claim 10  wherein the plurality of blades are substantially parallel. 
   
   
       17 . The fan coil unit as recited in  claim 10  wherein the fan wheel is substantially cylindrical. 
   
   
       18 . A refrigeration system comprising:
 a compressor for compressing a refrigerant;   a condenser for cooling the refrigerant;   an expansion device for expanding the refrigerant; and   a fan coil unit including an evaporator coil and a blower fan, wherein the refrigerant flows through the evaporator coil and the blower fan draws air over the evaporator coil to reject heat to the refrigerant,   wherein the blower fan includes a fan wheel including a first end ring, a second end ring, and a plurality of blades that extend between the first end ring and the second end ring, the plurality of blades define a wheel inner diameter and each of the first end ring and the second end ring define an end ring inner diameter, and the blower fan includes a housing including an inlet orifice having an orifice diameter and an outlet, and   wherein the fan wheel is located within the housing to draw the air over the evaporator coil and into the inlet orifice and discharge the air through the outlet, and the orifice diameter is substantially equal to the end ring inner diameter and greater than the wheel inner diameter.