Abstract: A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

Abstract: A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

Abstract: A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

Abstract: A damper assembly for use with an axial fan to prevent air from entering the discharge side of the fan when the fan is at idle. The damper assembly includes a damper door having multiple sections. The sections are able to pivot independently in response to the air flow created by the fan to minimize airflow resistance when the fan is operating.

Abstract: A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

Abstract: A damper assembly for use with an axial fan to prevent air from entering the discharge side of the fan when the fan is at idle. The damper assembly includes a damper door having multiple sections. The sections are able to pivot independently in response to the air flow created by the fan to minimize airflow resistance when the fan is operating.

Abstract: A ventilation fan assembly (10) having a fan (22) mounted in a housing (12) and a shutter assembly (60). The housing has a square inlet portion (12C), a circular center portion (12E) and a conical outlet portion (12D) having rifling grooves (20). The shoulder (16) formed between the inlet portion and the center portion is radiused to reduce disruption of air flowing from the inlet portion to the center portion. The shape of the blades (32) of the propeller (28) is such that the axial velocity produced as the propeller rotates is essentially constant along the length of the blades. The shutter assembly has a large, radiused entrance and airfoil shaped blades which reduce air disruption. The blades have a flexible flap (68) along the trailing edges (64D) which form a seal between adjacent blades to prevent air from leaking from the housing through the shutter assembly.

Abstract: A ventilation fan assembly (10) having a fan (22) mounted in a housing (12) and a shutter assembly (60). The housing has a square inlet portion (12C), a circular center portion (12E) and a conical outlet portion (12D) having rifling grooves (20). The shoulder (16) formed between the inlet portion and the center portion is radiused to reduce disruption of air flowing from the inlet portion to the center portion. The shape of the blades (32) of the propeller (28) is such that the axial velocity produced as the propeller rotates is essentially constant along the length of the blades. The shutter assembly has a large, radiused entrance and airfoil shaped blades which reduce air disruption. The blades have a flexible flap (68) along the trailing edges (64D) which form a seal between adjacent blades to prevent air from leaking from the housing through the shutter assembly.

Abstract: A ventilation fan assembly (10) having a fan (22) mounted in a housing (12) and a shutter assembly (60). The housing has a square inlet portion (12C), a circular center portion (12E) and a conical outlet portion (12D) having rifling grooves (20). The shoulder (16) formed between the inlet portion and the center portion is radiused to reduce disruption of air flowing from the inlet portion to the center portion. The shape of the blades (32) of the propeller (28) is such that the axial velocity produced as the propeller rotates is essentially constant along the length of the blades. The shutter assembly has a large, radiused entrance and airfoil shaped blades which reduce air disruption. The blades have a flexible flap (68) along the trailing edges (64D) which form a seal between adjacent blades to prevent air from leaking from the housing through the shutter assembly.