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Flow Control Method Selector

Run the Flow Control Method Selector MicroSim Fullscreen

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About This MicroSim

Every device in Chapter 18's flow-control section answers one of three needs: stopping reverse flow when the fan is off, setting airflow once, or changing airflow while the fan runs. This MicroSim gives ten illustrative job cards and the same ten devices for each:

A. Butterfly gravity damper · B. Wall or ceiling gravity damper · C. Manual damper · D. Motorized damper · E. Parallel blade outlet damper · F. Opposed blade outlet damper · G. Parallel blade inlet box damper · H. External variable inlet vanes · I. Speed control with a VFD · J. EC motor speed controller

For each card you recommend a device, and then the three possible deciding conditions appear (the correct one and two others, in a shuffled order); you pick the one that decided your choice. A card is correct only when both the device and the condition are right. The cards come in a shuffled order, so the first card differs from learner to learner. You get two attempts. A wrong device gets a hint chosen by your answer: picking a gravity or manual damper for a job that needs control while the fan runs, picking speed control for an infrequent reduction, or mixing up the parallel and opposed blade ranges each has its own hint; any other wrong device gets a hint that points at the card's deciding job condition without naming the device. A right device with the wrong condition says so. After a second wrong attempt the device, the condition and the reason are shown and the card counts as missed.

"Recommendations correct: n of 10" counts cards with both selections right on the first attempt. Mastery is 8 of 10. After card 10 the summary lists every card with your first device, your second device if you used one, and the correct device, marked ✓ (right first time), ½ (device right, condition wrong) or ✗ (device wrong). Review card shows the reason for any card.

How to Use

  1. Read the job card and choose a device in the Device list. The ten devices are also listed beside the card.
  2. Choose the deciding condition in the Condition list (it appears after the device), then press Check (or Enter). The device and the condition are marked ✓ or ✗ separately.
  3. If a hint appears, change your device or condition and check again.
  4. Press Next card (or Enter) and continue. After card 10, press See summary, read the reason for each card with Review card, and press Start over for a new shuffled round.

Keyboard: Tab reaches both lists, every button and the review list; the arrow keys change a focused list; Enter checks, then goes to the next card.

Data label: "Illustrative job cards · Source: FanPedia pp. 68, 70, 139, 181–183, 188", at the bottom left of the drawing.

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

<iframe src="https://moroshek.github.io/FanTASTIC-textbook/sims/ch18-flow-control-method-selector/main.html"
        height="602px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Learning Objective

The learner will recommend the flow-control or backdraft device that best fits each of ten job descriptions and justify the choice by naming the deciding job condition, scoring at least 8 of 10 (Bloom: Evaluate, verb: recommend).

Audience

Adult professional development: new application engineers, sales staff, representatives and facilities staff.

Duration

15 minutes

Prerequisites

  • Gravity, butterfly, manual and motorized dampers (Chapter 18)
  • Parallel and opposed blade outlet dampers and the inlet box damper (Chapter 18)
  • External and variable inlet vanes, speed control, VFDs and EC motor speed controllers (Chapter 18)
  • Turndown and blade flutter (Chapter 18)

Activities

  1. Job cards (8-10 min): Before choosing a device, sort the job into one of the three needs: stop backflow, set once, or change while running.
  2. Summary review (3 min): Read every card marked ½ or ✗ with Review card and say which word in the job decided it.
  3. Discussion (2 min): Cards 5 and 9 both reduce airflow. Why is a parallel blade outlet damper right for one and a VFD for the other?

Common Misconceptions Addressed

  • Any damper can control airflow in operation: choosing a gravity or manual damper for a running reduction gets a dedicated hint.
  • Speed control is always right: the hot, dirty process fan with a monthly trim is an outlet damper job, and choosing a VFD there gets a hint.
  • Parallel and opposed blade dampers are interchangeable: the modulation-range hint separates them.
  • An outlet damper saves about as much power as inlet vanes, and a gravity damper works at any airflow: the inlet vane, inlet box damper and motorized damper cards turn on exactly those points.

Assessment

  • "Recommendations correct: n of 10" counts first-attempt cards with both selections right; mastery is 8 of 10. The summary shows the first-attempt score and the mastery line.
  • The ½ marks show where a learner picks the right device for the wrong reason; ask them to restate the deciding condition for each.

References

  1. FanPedia: The Fan & Blower Encyclopedia - Twin City Fan's reference; pp. 181-183 cover gravity, manual, motorized, outlet and inlet box dampers, pp. 139 and 188 inlet vanes, pp. 68 and 70 EC motors and the GridPoint controller.
  2. Damper (flow) - Wikipedia overview of dampers in air-handling systems.
  3. Variable-frequency drive - Wikipedia overview of VFD speed control and its energy savings on fans.