Corsi–Rosenthal XXL — One-Page Cut List & Wiring Diagram (24 V Blower)
Filters: 20×20×4″ (nominal) • Power: 24 V DC • Connector: SB50/XT60 • Buck/boost: 9–36 → 24 V
Cut List (Top/Bottom, Bracing, Panels)
| Part | Qty | Material | Dimensions (in) | Notes |
|---|---|---|---|---|
| Top Plenum Panel | 1 | Double-wall cardboard or ¼″ ply/HDPE | 28 × 28 | Size = 20″ + 2×filter thickness. For 4″ nominal filters, outer is ≈28″. Adjust if your filters are 3.5–3.75″ actual. |
| Bottom Base Panel | 1 | Double-wall cardboard or ¼″ ply/HDPE | 28 × 28 | Same as top. Tape/seal fully to prevent bypass. |
| Blower Cutout | 1 | (in top panel) | Ø 6.0–6.5 (or per blower template) | Center or offset. Drill flange holes per blower stencil. |
| Panel Jack Hole | 1 | (side panel) | per bracket | SB50 panel kit (rectangular) or XT60 (17×8 mm). Use the jack’s metal stencil. |
| Rocker Switch Cutout | 1 | (side panel) | 30 × 22 | KCD4 style; confirm your switch drawing. |
| Stiffener Angles | 4 | Alu angle ¾″×¾″×1/16″ | 16″ each | Inside vertical corners (optional but recommended). |
| Filter Ring | 4 | MERV-13 20×20×4″ | — | Arrows point inward. Tape all seams inside & out. |
| CO₂ Pocket Window | 1 | Clear vinyl + Velcro | 6 × 4 | On outlet side; don’t block flow. |
Dimension sanity: Measure actual filter thickness (often 3.5–3.75″). Top/Bottom side = 20″ + 2×actual thickness. If using 1″ filters, side ≈22″.
Fasteners: #8×½″ pan screws for blower flange; M3 standoffs for buck/boost board.
Mini BOM (one unit)
| Item | Spec | Qty |
|---|---|---|
| Centrifugal blower, 24 V | ≥250–400 CFM @ ≥0.3–0.6″ H₂O, ≤10 A | 1 |
| DC-DC buck/boost | 9–36 → 24 V, ≥10 A, ≥90% eff | 1 |
| Inline fuse | Source-side; 1.25× max A (e.g., 12–15 A) | 1 |
| Panel connector | SB50 or XT60 (panel) | 1 |
| DC rocker switch | ≥30 VDC, ≥15–20 A | 1 |
| Wire | 16 AWG (≤8 A) / 14–12 AWG (higher/longer) | ~6–8 ft |
| Mesh guard | Over blower intake | 1 |
| HVAC foil tape | — | 1 roll |
Hazards: Fuse at power source, verify polarity, keep intake/exhaust clear, no ionizers/ozone add-ons.
Wiring Diagram (24 V DC)
Fuse near source
Strain-relief every pass-through
Seal all seams
Mesh guard on intake
Speed options: (A) PWM controller between switch and blower. (B) Two-speed rocker selecting 18 V/24 V presets on the buck.
Assembly Snapshot (5 Steps)
- Form the filter ring (arrows inward). Tape inner & outer seams airtight.
- Cut and tape the bottom panel (28×28″ typical) to the ring.
- Cut blower opening in top panel, mount blower with foam seal + mesh guard.
- Drill panel jack & switch, mount buck/boost on standoffs; wire per diagram.
- Seal top to ring; smoke-test for leaks; confirm strong intake on all faces.
Tip: Measure your filters—“4″” is often 3.5–3.75″. Recompute side = 20″ + 2×thickness. Use two units in room corners for better mixing.