Centrifugal Roof Exhauster Parts¶

Run the Centrifugal Roof Exhauster Parts MicroSim Fullscreen

About This MicroSim¶

This MicroSim puts nine numbered markers on FanPedia's exploded views of two centrifugal roof exhausters (page 19). The left column is an upblast unit and the right column a downblast unit, each stacked from the top of the fan down to the roof curb it sits on. Both columns show a direct drive and a belt driven motor plate side by side.

The nine parts are the ones FanPedia names for both roof exhauster types: motor cover, motor housing, motor, bird screen, impeller, shroud, skirt, curb cap and roof curb. Each marker sits on one example of the part, in whichever column shows it best. On a wide screen the labels sit in two columns with leader lines, left and right of the drawing; on a narrower screen, including the chapter page, they move below it as a numbered list. The motor is small, so its marker sits just above it with a short pointer to the part.

The quiz describes each part by its job ("Select the drum that encloses the motor.") instead of naming it, in a shuffled order. You get two attempts per prompt. The first wrong answer shows a hint about where to look; the second reveals the part and counts as missed. Mastery is 8 of 9 correct on the first attempt. Explore mode is never scored.

How to Use¶

Explore mode (the starting mode). Point at a numbered marker, or Tab to it, to see the part's name and description in the panel below the drawing. Click it (or press Enter) to open it; opened parts get a ✓ in the label list and the counter shows how many of the 9 you have visited. Clicking a name in the label list opens that part too.
Quiz mode. Press Quiz. The labels and leader lines disappear and a prompt describes one part:
- Correct: "✓ Correct:" with the part name and its description; the marker turns green with a ✓ badge and its label comes back.
- Wrong on the first attempt: "✗ Not quite.", the name of the part you picked, and a hint. The hint never names the answer.
- Wrong on the second attempt: the answer is marked "Answer" and named, and the prompt counts as missed.
Press Next prompt after each answer. The toolbar shows "Parts correct: n of 9".
After the ninth prompt, the summary shows your first-attempt score, whether you reached mastery (8 of 9), and each missed prompt with its answer. Retry missed practises only the misses (not scored), Start over reshuffles and resets the score, and Back to explore returns to the labels.

Keyboard: Tab moves through the markers in number order and then the buttons; Enter or Space selects a marker. After an answer, focus moves to Next prompt, so Enter goes on.

Data label: "Drawing: FanPedia, Twin City Fan, p. 19", shown under 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/ch05-roof-exhauster-overlay/main.html"
        height="1080px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan¶

Learning Objective¶

The learner will identify the nine labeled parts of a centrifugal roof exhauster on FanPedia's upblast and downblast exploded views, given each part's function (Bloom: Remember, verb: identify).

Audience¶

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

Duration¶

10-15 minutes

Prerequisites¶

Chapter 5, sections "On the Roof and Through the Wall", "Upblast Discharge" and "Downblast Discharge".
Chapter 3, sections "The Impeller" and "The Fan Motor".

Activities¶

Explore (4 min): Open all nine parts. Sort them aloud into the parts that move or guide the air (impeller, shroud, skirt, motor cover), the parts that carry or shelter the drive (motor, motor housing), and the parts that protect the opening or mount the fan on the roof (bird screen, curb cap, roof curb).
Compare (3 min): Find each marked part in the other column too. Which parts look nearly the same on the upblast and the downblast unit, and which part changes the direction the air leaves?
Quiz (5 min): Switch to quiz mode and find all nine parts from their jobs without going back to explore mode.
Review (3 min): Read the missed list, open those parts in explore mode, then press Start over for a new order.

Common Misconceptions Addressed¶

The motor cover is only a rain lid: on a downblast unit the mushroom-shaped cover turns the rising air back down so it spills out around the base.
The curb cap and the roof curb are the same part: the curb cap is the fan's flat base plate, and it rests on and covers the roof curb, the raised frame built into the roof around the opening.
Upblast and downblast exhausters are built from different parts: FanPedia's exploded view names the same nine parts for both types; what differs is where the air is sent after it leaves the impeller.

Assessment¶

First-attempt score shown in the summary as "First-attempt score: n of 9"; mastery is 8 of 9 on the first attempt.
Pointing at markers and opening infoboxes in explore mode is exploration, not evidence.
Follow-up question: a customer asks for a downblast unit on a kitchen hood. Which part on this drawing sends the exhaust back toward the roof, and which discharge type should the quote use instead?

References¶

FanPedia: The Fan & Blower Encyclopedia (PDF) - Twin City Fan; p. 19 is the roof exhauster exploded view used here, p. 5 describes the roof ventilator configurations by discharge direction and p. 181 the butterfly gravity damper on upblast units.
FanPedia online - Twin City Fan's online version of the encyclopedia.
Chapter 5: Roof, Wall and Specialty Exhaust Fans - the section "Downblast Discharge", where this MicroSim is embedded, and "Upblast Discharge".
Roof and Wall Exhaust Path Explorer - predict the air path through roof and wall units on schematic cutaways.