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References: Inlets, Outlets and Flow Control

  1. Damper (flow) - Wikipedia - Overview of dampers in ducts and air-handling equipment, including manual and automatic types and opposed blade designs, supporting the chapter's damper families and their uses.

  2. Variable-frequency drive - Wikipedia - Explains how a VFD varies supply frequency to change AC motor speed, and why fans and pumps save energy at reduced flow, the basis of the chapter's speed control section.

  3. Affinity laws - Wikipedia - States the fan and pump laws: flow proportional to speed, pressure to speed squared, power to speed cubed. Used in the chapter's 70% and 80% airflow power examples.

  4. Fan Engineering (9th ed.) - Robert Jorgensen (editor) - Buffalo Forge / Howden Buffalo - The long-standing Buffalo Forge handbook is known for teaching flow control through the intersection of fan and system curves, the method this chapter uses to compare dampers, vanes and speed control.

  5. Fan Handbook: Selection, Application, and Design - Frank P. Bleier - McGraw-Hill - Bleier is noted for practical, application-centered comparisons of fan accessories and capacity control methods, written for engineers selecting and specifying industrial fans.

  6. FanPedia: The Fan & Blower Encyclopedia (PDF) - Twin City Fan - Primary source for inlet funnels, inlet boxes and positions, transitions, evasés, companion flanges, silencers, dampers, inlet vanes and EC motor controllers.

  7. FanPedia online - Twin City Fan - Web edition of FanPedia with Accessories galleries for dampers, evasés and inlet boxes, useful for recognizing the hardware compared in this chapter.

  8. Fan Damper Selection (FE-2600) - Twin City Fan Engineering Letter - Covers automatic, manual and motor-operated dampers, parallel versus opposed blades, inlet box dampers and pre-swirl, and blade flutter at low flow.

  9. Pressure Losses from Fan Accessories (FE-2900) - Twin City Fan Engineering Letter - Explains how accessories such as inlet vanes, dampers and evasés change the pressure a fan must supply, quantifying the chapter's point that every accessory belongs on the system curve.

  10. A Practical Guide for Using Variable Frequency Drive Systems in Air Movement Applications - Twin City Fan White Paper - Walks through VFD principles, sizing, installation, building-management connection and commissioning for fans, complementing the chapter's speed control discussion.