Abstract: Particular embodiments of the inventive technology present a method for optimizing fan performance by, e.g., adjusting fan efficiency and/or acoustics to match, or more closely match, system design requirements or preferences. Embodiments may involve the selection of a size of centrifugal fan 18 from the plurality that can fit inside a certain housing, forming a fan unit that provides an annular output 19; such selection may be made to achieve certain performance goals. Add-on appurtenances such as one or more of, e.g., an annular housing extension 10, fixed vanes 12, and acoustic treatment 8, may be used to tailor the fan unit to meet system requirements, e.g., regarding efficiency, acoustic/sonic performance (e.g., noise generated by the fan), and/or static efficiency.

Abstract: Particular embodiments of the inventive technology may be described as an air handling shroud for establishment at the inlet area of a fan, the shroud adapted to realign and/or redistribute fan inlet flow so as to reduce fan-generated noise without unacceptably impairing fan efficiency and/or performance. Certain embodiments present a lattice arrangement of cells through which air flows; the shroud may protrude up from an inlet face lying in a plane defined by the fan (e.g., by the fan housing or an inlet cone). It may have a hemispherical shape and a lower resistance-per-area sector at the pole (or polar region) thereof. Optional componentry includes but is not limited to a flow obstructer established at a fan proximal portion of the shroud, and acoustic material established on surfaces of the cells of the shroud.

Abstract: Particular embodiments of the inventive technology may be described as an air handling shroud for establishment at the inlet area of a fan, the shroud adapted to realign and/or redistribute fan inlet flow so as to reduce fan-generated noise without unacceptably impairing fan efficiency and/or performance. Certain embodiments present a lattice arrangement of cells through which air flows; the shroud may protrude up from an inlet face lying in a plane defined by the fan (e.g., by the fan housing or an inlet cone). It may have a hemispherical shape and a lower resistance-per-area sector at the pole (or polar region) thereof. Optional componentry includes but is not limited to a flow obstructer established at a fan proximal portion of the shroud, and acoustic material established on surfaces of the cells of the shroud.

Abstract: At least one embodiment of the present inventive technology focuses on a vaneless diffuser adapted for establishment extra-radially of a centrifugal fan, wherein the diffuser may effect an optimal transformation of velocity pressure into static pressure of a fluid (e.g., air) impelled by a centrifugal fan by decreasing that fluid's tangential velocity as it travels through the diffuser, without causing recirculation of air output from the diffuser back into the diffuser. Such diffuser may effect such a decrease in tangential velocity by radially extending the interface through which impelled air is output from the diffuser to a downflow fluid handling environment such as, e.g., a scroll and/or a plenum. The diffuser may converge in a direction parallel with the axis of rotation of the centrifugal fan to avoid fluid recirculation and/or may incorporate acoustical material so as to reduce the amount of material necessary for effective noise reduction as compared with convention noise reduction methods.

Abstract: The present invention includes a system and method for air flow improvement in central air handling systems primarily for buildings and clean rooms. It may include a return flow path, a reversing element, an axial flow device, and a supply flow path where at least a portion of a supply flow path is substantially parallel to the return flow path and one of the flow paths at least partially surrounds the other flow path and could include an annulus between the supply and return flow paths and may provide uniform flow to the axial flow device. The system could include a filter which could be inclined, converging, or a skewed flow face filter, or combinations thereof. It may also include a coil, with a variety of shapes including flat, circular, or frustoconical and could be arranged perpendicular to a primary flow direction of the one or both of the flow paths. The system might also include at least one boundary layer affecting element. A remote access and replacement filter changing element may be included.

Abstract: The present invention includes a system and method for air flow improvement in central air handling systems primarily for buildings and clean rooms. It may include a return flow path, a reversing element, an axial flow device, and a supply flow path where at least a portion of a supply flow path is substantially parallel to the return flow path and one of the flow paths at least partially surrounds the other flow path and could include an annulus between the supply and return flow paths and may provide uniform flow to the axial flow device. The system could include a filter which could be inclined, converging, or a skewed flow face filter, or combinations thereof. It may also include a coil, with a variety of shapes including flat, circular, or frustoconical and could be arranged perpendicular to a primary flow direction of the one or both of the flow paths. The system might also include at least one boundary layer affecting element. A remote access and replacement filter changing element may be included.