Abstract: A fan assembly includes an internal housing having an outer internal housing, and an inner internal housing partially disposed within the outer internal housing. The inner internal housing defines an internal cavity, and has a curved exterior surface. Stator blades extend between the inner internal housing and the outer internal housing.

Abstract: An exhaust fan assembly can include an outer housing, a fan housing mounted to the outer housing, a fan wheel and an electric motor operably coupled to the fan wheel, the fan wheel and electric motor being mounted within the fan housing, wherein the fan housing defines an open inlet side for accepting airflow in a direction generally parallel to a rotational axis of the fan wheel and an outlet for discharging airflow in a direction generally perpendicular to the rotational axis, wherein the fan housing defines a volute section with an outer perimeter having a continuously curved cross-sectional shape.

Abstract: An airflow valve may comprise a plate assembly located inside an airflow conduit. An actuator may be attached to, and/or otherwise fixed relative to, a plate of the plate assembly. The actuator may be coupled to the airflow conduit. If activated, the actuator may react against the airflow conduit to induce rotation of the plate.

Abstract: A fan assembly includes an internal housing having an outer internal housing, and an inner internal housing partially disposed within the outer internal housing. The inner internal housing defines an internal cavity, and has a curved exterior surface. Stator blades extend between the inner internal housing and the outer internal housing.

Abstract: A fan assembly in which all of the major structural components of the assembly are mechanically fastened together by non-welding means, such as mechanical fasteners, is disclosed. The disclosure also relates to a fan assembly in which the major structural components have planar segments separated by bend lines that approximate a curved shape, and that can be formed, for example, by a press brake machine. Such a construction can eliminate the necessity for rolling, welding, and painting of the structural components of the fan assembly.

Abstract: A high turndown furnace for an air handling system. In one example, the furnace includes a plurality of tubes divisible by four with a first modulating valve supplying gas to ¼ of the tubes and a second modulating valve supplying gas to ¾ of the tubes. In one aspect, the furnace is capable of providing a 16:1 turndown. In one aspect, the furnace is capable of providing seamless turndown operation throughout the entire firing range.

Abstract: A high turndown furnace for an air handling system. In one example, the furnace includes a plurality of tubes divisible by four with a first modulating valve supplying gas to ¼ of the tubes and a second modulating valve supplying gas to ¾ of the tubes. In one aspect, the furnace is capable of providing a 16:1 turndown. In one aspect, the furnace is capable of providing seamless turndown operation throughout the entire firing range.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: An exhaust system for exhausting air from a space includes a variable-volume exhaust air moving system having at least one fan having an inlet and an outlet. A duct is connected to the inlet and an outlet nozzle defining a variable cross-sectional outlet area is fluidly connected to the outlet. A selectively operable bypass damper is fluidly connected to the inlet. A sensor is located in the exhaust system for detecting at least one of a pressure condition and a flow condition therein. A control system controls the at least one fan, the outlet nozzle, and the bypass damper, based on a signal sent from the sensor.

Abstract: A fan assembly in which all of the major structural components of the assembly are mechanically fastened together by non-welding means, such as mechanical fasteners, is disclosed. The disclosure also relates to a fan assembly in which the major structural components have planar segments separated by bend lines that approximate a curved shape, and that can be formed, for example, by a press brake machine. Such a construction can eliminate the necessity for rolling, welding, and painting of the structural components of the fan assembly.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: An exhaust fan assembly is provided for expelling contaminated air from a building. The assembly includes a plenum, a fan assembly attached to the plenum, and a windband mounted on top of the fan assembly. The fan assembly is constructed of cylindrical outer and inner walls which define a bearing chamber and surrounding annular space. A fan driven by a shaft extending downward from the bearing chamber draws exhaust air from the plenum and blows it up through the annular space to a nozzle at the top of the fan assembly.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: An exhaust fan assembly is provided for expelling contaminated air from a building. The assembly includes a plenum, a fan assembly attached to the plenum, and a windband mounted on top of the fan assembly. The fan assembly is constructed of cylindrical outer and inner walls which define a bearing chamber and surrounding annular space. A fan driven by a shaft extending downward from the bearing chamber draws exhaust air from the plenum and blows it up through the annular space to a nozzle at the top of the fan assembly.

Abstract: An exhaust fan assembly is provided for expelling contaminated air from a building. The assembly includes a plenum, a fan assembly attached to the plenum, and a windband mounted on top of the fan assembly. The fan assembly is constructed of cylindrical outer and inner walls which define a bearing chamber and surrounding annular space. A fan driven by a shaft extending downward from the bearing chamber draws exhaust air from the plenum and blows it up through the annular space to a nozzle at the top of the fan assembly.