Fume Extraction Strategy
Purpose: Industrial-style negative-pressure ventilation system for hazardous fumes and vapors in the garage workshop.
Critical Safety Note: Fume extraction is NOT dust collection. These are fundamentally different systems with different requirements. Never route chemical vapors through dust collection systems.
Related:
- Workshop Dust Collection System - Separate system for sawdust/debris
- Compressed Air System - Separate utility system
- Electrical Planning - Circuit requirements
- Source Document - Original planning reference
Why Fume Extraction is Different from Dust Collection
| Dust Collection | Fume Extraction |
|---|---|
| Sawdust, wood chips, debris | Chemical vapors, solvent fumes, smoke |
| Standard PVC ducting acceptable | Metal duct ONLY (static/fire risk with PVC) |
| Standard shop vac motors fine | Explosion-proof motors required for solvents |
| Can recirculate with HEPA filter | Must exhaust outdoors - no recirculation |
| Lower CFM needed (100-400 CFM) | High CFM required (500-4000+ CFM) |
| Fire risk: low | Fire/explosion risk: HIGH with solvents |
Bottom Line: A central vacuum or shop vac cannot handle fumes because:
- Motor sparks create ignition risk
- PVC causes static buildup (ignition source)
- Filters clog with solvent and paint
- Cannot move enough CFM for vapor dilution
- Not explosion-proof rated
Fume Sources in This Garage
Based on planned activities (Corvette and Boat Restoration Planning):
System A - Hobby/Light Fabrication (Loft + Light Stations)
- FDM/filament 3D printers - Ultrafine particles (UFPs) and VOCs vary by material:
- ABS/ASA: Styrene vapors and high UFP emissions - ventilation strongly recommended
- PETG: Moderate VOC emissions - ventilation recommended
- Nylon: Caprolactam emissions - ventilation recommended
- PLA: Low emissions but still produces UFPs - enclosure with filtration usually sufficient
- Specialty filaments: Various VOCs depending on additives - check MSDS
- Resin 3D printers - VOCs from UV resin curing
- IPA wash station - Isopropyl alcohol fumes from resin cleaning
- Soldering station - Flux smoke and lead fumes
- Laser cutter (future) - Smoke and fumes from cutting materials
- Airbrushing - Small-scale paint overspray
System B - Heavy-Duty Automotive (Main Floor)
- Automotive painting - Solvent-rich primers, base coats, clear coats
- Parts cleaning - Brake cleaner, degreasers, solvents
- Fiberglass/body work - Resin vapors, sanding dust with chemicals
- Temporary paint booth - Corvette restoration painting
System A: Hobby/Light Fabrication Fume Extraction
Overview
Centralized negative-pressure ventilation serving upstairs loft workstations and light fabrication areas on main floor.
Specifications
Ducting:
- Main trunk: 6” spiral steel duct (26-30 gauge)
- Branch lines: 4-6” spiral steel to each workstation
- Flex connections: 3-6 ft anti-static flex hose at each workstation only
- No PVC anywhere in fume-handling paths
Blower:
- Type: Outdoor-rated inline blower OR sealed mechanical closet blower
- Location: Outside vapor path (roof, exterior wall, or sealed closet)
- CFM: 400-800 CFM for hobby-level system
- Motor: Standard (not explosion-proof) acceptable for light fumes
Controls:
- Blast gates/dampers at each branch line
- Close unused stations to maintain suction at active station
- Optional: Smart relay for remote control via Home Assistant
Exhaust:
- Direct outdoor exhaust (gable wall or roof penetration)
- Never recirculate - all fumes must exit building
Branch Locations (Planned)
| Station | Location | Branch Size | Notes |
|---|---|---|---|
| FDM printer enclosure | Loft workbench | 4” | For ABS/ASA/PETG; PLA may use filtered enclosure only |
| Resin printer enclosure | Loft workbench | 4” | Primary use case |
| IPA wash station | Loft workbench | 4” | Adjacent to resin printer |
| Soldering station | Loft electronics bench | 4” | Flux fume capture |
| General fume hood | Loft | 6” | Chemical handling, airbrushing |
| Future laser cutter | Main floor or loft | 6” | High priority when added |
Integrating Equipment with Built-In Exhaust Fans
Some equipment (like enclosed 3D printers) includes built-in exhaust fans for internal temperature control and filtration. When connecting these to the centralized fume extraction system, special considerations apply.
The Problem: Backpressure
Built-in equipment fans are sized for their enclosure volume, not for pushing air through 15-30+ feet of ductwork. Without the main blower running:
- The equipment fan must overcome all duct resistance (friction, elbows, length)
- Actual airflow drops significantly despite fan running at speed
- Temperature control becomes unpredictable (fan speed no longer correlates to airflow)
- Fan motor works harder, runs hotter, and may fail prematurely
The Solution: Run Both Fans
When exhausting equipment outdoors through the fume extraction system, always run the main blower:
- Main blower creates negative pressure, “pulling” air through the duct
- Equipment fan handles enclosure circulation and temperature sensing
- Backpressure on equipment fan is minimal (assisted flow)
- Temperature control remains accurate
Automation Options:
| Method | Complexity | Notes |
|---|---|---|
| Manual switch | Low | Turn on main blower when starting equipment; easy to forget |
| Smart plug/relay | Medium | Trigger blower via Home Assistant, OctoPrint, Klipper, etc. |
| Pressure-activated damper | High | Barometric damper senses equipment fan and triggers main blower |
Makeup Air Requirement:
When the main blower runs, it creates negative pressure in connected enclosures. Equipment with built-in fans needs an intake air path:
- Ensure enclosure has a filtered inlet vent
- Allows equipment fan to pull fresh air in while exhausting to duct
- Without makeup air, enclosure starves and actual airflow drops
Practical Example: 3D Printer with Variable-Speed Exhaust
A 3D printer enclosure with built-in exhaust fan that varies speed for temperature control:
- Connect enclosure exhaust port to 4” branch line with blast gate
- Ensure enclosure has filtered air intake
- Run main fume blower whenever printing materials requiring outdoor exhaust (ABS, ASA, PETG)
- For PLA, built-in filtration with recirculation is usually sufficient (no duct connection needed)
- Consider smart relay to auto-start blower when printer begins heating
Flow Balancing for Temperature-Sensitive Equipment
The main blower (400-800 CFM) is sized for the entire system, but a 3D printer enclosure may only need 20-50 CFM for effective fume extraction. Excessive airflow causes problems:
- Chamber cools faster than heater can compensate
- Air currents cause warping and layer adhesion issues
- Impossible to maintain 45-60°C chamber temps needed for ABS/ASA
Flow Control Methods:
| Method | How It Works | Pros | Cons |
|---|---|---|---|
| Partially close blast gate | Restrict flow at the branch | Simple, no cost | Manual, imprecise |
| Variable-speed blower | Run main blower at lower speed | Good control, already spec’d | Affects all branches equally |
| Inline balancing damper | Fixed restrictor limits max flow | Set once, always right | Reduces max flow permanently |
| Orifice plate | Metal plate with sized hole | Cheap, precise, permanent | Fixed - can’t adjust |
| Dedicated small fan | Separate 4” fan (50-100 CFM) for branch | Independent control, perfect sizing | Extra cost, complexity |
Recommended Approach for 3D Printer Branch:
-
Use variable-speed main blower - The AC Infinity CLOUDLINE S6 has 10-speed control. Run at speed 2-3 for printer-only use, higher speeds for other stations.
-
Install inline balancing damper (~$15-25) on printer branch - Dial in maximum flow regardless of main blower speed. Even at full blower, printer branch only pulls what’s needed.
-
Keep blast gate for on/off isolation - Use balancing damper for flow tuning, blast gate for complete shutoff when not in use.
This provides gentle extraction for temperature-sensitive prints while maintaining full power for other workstations.
Balancing Damper Products:
- Master Flow 4 in. Damper D-4 - Home Depot, galvanized steel manual balancing damper (~$8-12)
- PATIKIL HVAC Manual Volume Damper 4” - Amazon, stainless steel with external adjustment handle (~$12-18)
- AC Infinity Backdraft Damper 4” - Galvanized steel, spring-loaded (~$15-20)
Systems That Cannot Share Fume Extraction Ductwork
IMPORTANT: Certain exhaust systems are prohibited by code from sharing ductwork with the fume extraction system.
Kitchen Range Hood / Over-Range Microwave Exhaust
Per IRC (International Residential Code) and Michigan Residential Code:
“The duct serving the hood shall have a smooth interior surface, shall be airtight, shall be equipped with a back-draft damper, and shall be independent of all other exhaust systems.”
Kitchen exhaust cannot share ductwork with the fume extraction system because:
- Code explicitly requires independence
- Grease from cooking would contaminate fume extraction ductwork
- Grease + solvent fumes = significant fire hazard
- Airflow interference affects both systems’ effectiveness
- Cross-contamination risks (chemical vapors entering kitchen, cooking odors entering shop)
Loft Kitchen Exhaust Plan:
Kitchen is Phase 2/3 (deferred 3–5+ years; see Loft Apartment Conversion Plan). The owner cooks frequently and sears/pan-fries often, and specifically wants real outdoor-vented capture — not a recirculating over-the-range microwave like the main house (which just filters air back into the room and lets odor linger for hours). The plan below is sized for that.
This is a separate system from the roof sewer-gas vent
The only roof penetration is the DWV (sewer-gas) vent stack — see Roof Penetrations. The range hood is an independent gable-wall penetration that does not exist yet and must never tie into the DWV stack, the bath fan, or the shop fume extraction (code requires each to be independent — see above).
Exhaust (range hood) — east gable wall:
- Type: Ducted updraft hood (wall-mount chimney or canopy). No over-the-range recirculating microwave; no downdraft — both fail at capturing a searing plume.
- Penetration location: East gable wall (full-height, exterior; range sits on this wall so the duct goes straight through the wall thickness and out a sidewall cap — no roof boot, no long run).
- Duct size: 6” round, kept 6” the entire way — do not neck down to 4” (a reducer chokes airflow and adds noise).
- Duct material: Smooth-interior galvanized steel spiral; backdraft damper required; insulated exterior cap (MI cold — prevents backdraft and condensation).
- CFM: 400–600. Induction throws little ambient heat but still smokes hard when searing cast iron, so capture still matters.
- Capture geometry > raw CFM: hood ≥ cooktop width (36” hood over a 30” range), deep enough to cover the front burners, mounted 28–36” above the cooktop.
- Noise: prefer a remote/inline or exterior-mounted blower — high CFM with a fraction of the in-room noise, which matters a lot in an open studio loft.
- Termination clearances: ≥3 ft from windows, doors, and other vents (incl. the bath exhaust); ≥10 ft from powered air intakes (or 3 ft above).
- Prevailing wind: West→east, so the east wall is downwind — wind carries the exhaust away from the building. The house is east/southeast; rare east winds could push exhaust back, but windows would be closed then anyway.
Makeup air — west gable wall (upwind):
A hood over 400 CFM requires makeup air under Michigan/IRC M1503.4. Beyond code, a strong fan in a tight, well-insulated loft pulls the space negative, which can backdraft the bath exhaust and is worth a hard look given the gas boiler in the mechanical room below. Two paths:
- Stay at ~400 CFM with a deep, well-covered hood (often plenty on induction) → dodges the makeup-air mandate.
- Go 600 CFM with a powered makeup-air damper interlocked with the hood (Broan/Fantech), ideally tempered (raw −5°F air next to the cook is miserable).
Makeup-air intake location: west gable wall (owner decision, 2026-06-23). This is the opposite gable from the hood exhaust (~40’ away) and upwind under the prevailing W→E wind, so the intake can never re-inhale the hood’s grease plume — the cleanest possible separation of intake from exhaust.
- Routing: carry the makeup-air duct east from the west gable through the kneewall void (the kneewall triangle runs the full 40’ length and is a natural chase) to a discharge near the kitchen. Reserve/pre-run this chase before drywall — see Critical Pre-Insulation Requirements.
- Sizing: size up for the long run — a passive 6” duct only moves ~150–200 CFM, so a 40’ passive run feeding a 400–600 CFM hood needs 8–10” duct or a powered damper. Match (or slightly exceed) hood CFM.
- Condensation: the duct carries cold outside air, so no condensation inside it; insulate it where it passes through the conditioned loft so room humidity doesn’t condense on the cold duct surface. In a cold (unconditioned) kneewall triangle, no insulation needed. (If the triangles get conditioned per the Loft Apartment Conversion Plan storage option, insulate the full run.)
- Discharge: aim the makeup-air register away from where the cook stands, or use a tempered unit, so a cold draft doesn’t hit you at the range.
Crowded-gable note: the east gable may carry the 6” hood exhaust and (if used) a makeup-air provision; the bath 4” exhaust is also east-end. Keep ≥3 ft between any two terminations, and never place a makeup-air intake where it can ingest the hood exhaust (the west-gable intake solves this by construction). The ERV pre-rough’s two penetrations go on opposite walls away from the boiler flue — keep them off the same gable face where practical.
What to lock now vs. what's safely deferred
The exterior duct hole itself is genuinely low-regret to defer — it’s a straight shot through the wall thickness, and the pre-insulation plan already classifies kitchen vent as an add-later, cut-through-finished-siding item. What is not cheap to retrofit, and should be done while the gable is open: (1) solid blocking for the heavy hood, (2) the 240V range circuit + hood circuit, (3) the makeup-air interlock wire + the west-gable→kitchen kneewall chase, and (4) simply reserving the gable location so the mini-split head, a window, or tall cabinets don’t land where the range/hood need to be. See the kitchen-vent items in Critical Pre-Insulation Requirements.
Open variables — confirm on site (kitchen venting):
These two are the only undecided inputs to the venting plan; both are easiest to verify while framing is exposed, and both can move the range/chase layout:
- Kitchen’s usable share of the east gable — after the bathroom and stair landing take their bites of the east end, how much full-height gable wall is left for the range + 6” hood duct? This sets whether the range fits on the gable at all, or shifts toward the peninsula.
- Clear kneewall path, west gable → kitchen — confirm an unobstructed run for the makeup-air chase through the kneewall void: no attic girder truss (AX 2-ply), blocking, or insulation baffle in the way along the full ~40’ length.
Fallback routing — dip into the garage ceiling below the loft floor:
If the kneewall path is blocked (girder/blocking/insulation conflict), if the conditioned-triangle storage plan claims that space, or if the duct needs a downward grade the kneewall can’t give, the duct can drop through the loft floor and run in the garage ceiling space below, then rise where needed. Constraints to respect:
- The garage ceiling is the fire separation (5/8” Type X, IRC R302.6). A duct crossing it must keep that separation: min. 26-ga steel, no openings into the garage, firestopped at each penetration (IRC R302.5.2 governs ducts through the garage/dwelling separation).
- Don’t drill the loft-floor 2×10 joists for a large duct — code caps holes at ~1/3 depth (~3”). Run the duct parallel within a joist bay (an 8” duct fits a 9.25” bay) or surface-mount it exposed below the garage ceiling (the shop aesthetic tolerates exposed duct — simplest, zero joist drilling).
- Never notch or drill the truss bottom chords (existing project constraint — same rule as the DWV drops).
- This is the natural place to gain a downward slope for a condensate-draining run; pitch toward an exterior cap or drip leg.
Loft Bathroom Exhaust Plan:
Bathroom planned for east end of loft (between stairs and kitchen). Exhaust routing:
- Penetration location: East gable wall (separate from kitchen exhaust)
- Duct size: 4” round (standard bathroom exhaust)
- Duct material: Insulated flex or rigid duct (insulation prevents condensation in cold weather)
- Backdraft damper: Required
- Fan sizing: 50-110 CFM depending on bathroom size (with shower, recommend 80+ CFM)
- Spacing from kitchen exhaust: At least 3 ft between terminations to prevent cross-contamination
East Gable Wall Layout (two exhaust penetrations):
East Gable Wall (24' wide)
looking from outside
┌─────────────────────────────────────┐
│ /\ │
│ / \ │
│ [Bath] / \ [Kitchen] │
│ vent / \ vent │
│ ○ / \ ○ │
│ / \ │
└──────────/────────────\─────────────┘
↑ Stairs end Kitchen end ↑
Both exhausts benefit from:
- Prevailing west-to-east wind (downwind dispersion)
- Short duct runs from fixtures
- Easy access from mechanical room below
Pre-Drywall Recommendation: Rough-frame a 4” opening in the east gable wall for bathroom exhaust. Position closer to the stairs/east edge, maintaining 3 ft spacing from kitchen exhaust penetration.
Note on Heat Pump Dryer: Heat pump dryers do not require external venting - they recirculate air and condense moisture internally. Only a drain line is needed (similar to a dehumidifier). This eliminates the need for a dryer vent penetration.
Other Systems Requiring Separate Exhaust:
- Dryer vents (if using traditional vented dryer instead of heat pump)
- HVAC combustion exhaust
- Radon mitigation (if applicable)
Duct Routing Strategy
Hybrid approach (recommended for this garage):
- Upstairs: Vertical riser hidden in wall, horizontal branches exposed in loft
- Downstairs: Entire fume trunk exposed for maximum flexibility
Advantages of exposed ducting:
- Easy to modify and expand
- Easy to inspect for leaks
- Industrial aesthetic fits workshop
- Easier maintenance access
System B: Heavy-Duty Paint Booth Extraction
Overview
Completely separate system from System A. Handles automotive painting and heavy solvent work.
Specifications
Ducting:
- Size: 12-24” metal duct
- Material: Spiral steel, all connections sealed
Blower:
- Type: Explosion-proof blower (C1D1 or C1D2 rated)
- CFM: 2,000-4,000+ CFM
- Motor: Must be rated for flammable atmospheres
Filtration:
- Intake filters (prevent overspray from leaving building)
- Exhaust filters (capture paint particles before outdoor discharge)
- Regular filter replacement schedule
Implementation:
- Temporary/portable paint booth setup for Corvette restoration
- Dedicated exhaust fan location pre-planned during framing
- Can upgrade to permanent booth in future
Paint Booth Options
Option 1: Temporary Portable Booth (~$500-2,000)
- Portable spray shelter/tent
- Dedicated exhaust fan
- Intake filter for makeup air
- Set up as needed, store when not in use
- Suitable for occasional automotive painting
Option 2: Semi-Permanent Booth (~$2,000-5,000)
- Dedicated bay (Bay 1 or Bay 3) with curtains
- Mounted exhaust fan with filter
- Makeup air handling
- More professional results
Option 3: Professional Booth (~$10,000+)
- Full enclosure with controlled environment
- Heating for curing
- Commercial-grade filtration
- Only if doing regular paint work
Recommendation: Start with Option 1 (temporary portable booth) for Corvette restoration project. Pre-frame exhaust location now to allow future upgrade to Option 2 or 3.
Optimal Duct Materials
Best Choice: Spiral Steel Duct (26-30 gauge)
Why spiral steel:
- Anti-static (critical for flammable vapors)
- Fire-safe
- Smooth airflow (less turbulence than corrugated)
- Industrial standard for fume extraction
- Easy to branch and seal
- Long service life
Branch Fittings
Preferred: Wye Fittings
- Best airflow characteristics
- Lowest turbulence
- Ideal for laser and resin extraction where CFM matters
Acceptable: T-Fittings
- More compact in tight spaces
- Slightly higher turbulence
- OK for soldering or resin printer branches
Materials to Avoid
- PVC - Static buildup creates ignition hazard
- Dryer duct - Not rated for fumes, poor airflow
- Long sections of flex hose - High resistance, turbulence
- Galvanized in wet applications - Corrosion with some chemicals
Permanent Sealing Method
For concealed ductwork (before drywall), use the industrial triple-seal method:
- Slip-fit / crimped duct joint - Mechanical connection
- UL 181 Foil HVAC tape - 3M 3340 or 3M 3381
- Duct mastic - RCD #6 or Hardcast 181 over seams and screw heads
Once cured, the system is airtight, permanent, and safe for concealed or exposed use.
Pre-Drywall Requirements
CRITICAL: These items must be installed during framing, before insulation and drywall.
Must Install Now (December 2025)
-
6” vertical fume duct riser (capped) from main floor to loft — stage:: 3
- Route through utility chase near stairway
- Cap both ends with metal caps
- Label clearly: “FUME EXTRACTION - DO NOT CONNECT TO DUST COLLECTION”
-
Frame exhaust penetration location for System B (paint booth) — stage:: 3
- Gable wall or rear wall location
- 12-18” opening rough-framed
- Can install actual exhaust later
-
Electrical stub for fume blower — stage:: 3
- Junction box in loft ceiling area
- 20A circuit from panel (see Electrical Planning)
- Location near planned exhaust penetration
-
6” kitchen exhaust penetration (capped) in east gable wall — stage:: 3
- For future stove/over-range microwave exhaust
- Position to maintain 3 ft clearance from windows
- East wall is downwind (prevailing west-to-east wind assists dispersion)
- Cap with metal cap until kitchen installation
-
4” bathroom exhaust penetration (capped) in east gable wall — stage:: 3
- For future bathroom ceiling exhaust fan
- Position closer to stairs/east edge of gable
- Maintain 3 ft spacing from kitchen exhaust penetration
- Cap with metal cap until bathroom installation
Recommended (Before Drywall)
-
1-2 empty conduits for future sensors/automation — stage:: 3
- Air quality sensors
- Blast gate automation
- Integration with Home Assistant
-
Ceiling-mounted outlet location for future paint booth fan — stage:: 3
- Near bay 1 or bay 3 (whichever will be paint area)
- Consider 240V if using large exhaust fan
Design Principles
- All fume systems must exhaust outdoors - Never recirculate
- Use blast gates to isolate inactive stations
- Keep paint booth extraction separate from hobby fume system
- Avoid any PVC in fume-handling paths
- Inline/rooftop blowers must be outside the vapor path - Motor not in fume stream
- Label all ducting clearly - Distinguish from HVAC and dust collection
Cost Estimates
System A - Hobby Fume Extraction
| Component | Estimated Cost |
|---|---|
| 6” spiral steel duct (50 ft) | $150-250 |
| 4” branch duct (30 ft) | $60-100 |
| Wye fittings, elbows, caps (10 pcs) | $80-150 |
| Inline blower (400-600 CFM) | $150-300 |
| Blast gates (6×) | $60-120 |
| Anti-static flex hose (20 ft) | $40-80 |
| Mounting hardware, mastic, tape | $50-100 |
| System A Total | $590-1,100 |
System B - Paint Booth Extraction
| Component | Estimated Cost |
|---|---|
| Temporary portable booth | $500-1,500 |
| Explosion-proof exhaust fan | $300-800 |
| Intake/exhaust filters | $100-200 |
| Ducting and connections | $150-300 |
| System B Total (Temporary) | $1,050-2,800 |
Pre-Drywall Rough-In Only
| Component | Estimated Cost |
|---|---|
| 6” vertical riser (10-15 ft) | $50-80 |
| End caps and labels | $20-30 |
| Mastic and tape | $30-50 |
| Electrical rough-in (by electrician) | Included in electrical bid |
| Pre-Drywall Total | $100-160 |
Recommendation: Install pre-drywall rough-in now (~$100-160). Complete System A and System B later when ready for each use case.
Implementation Timeline
Phase 1: Pre-Drywall Rough-In (December 2025 - During Framing)
- Install 6” vertical riser stub (capped)
- Frame exhaust penetration for paint booth
- Install electrical stub for blower
- Run empty conduits for sensors
Phase 2: System A Completion (After Loft Finish)
- Install horizontal branch lines in loft
- Mount inline blower
- Connect workstation drops with blast gates
- Test and commission system
Phase 3: System B Paint Booth (Before Corvette Painting)
- Set up temporary portable booth
- Install dedicated exhaust fan
- Set up intake filtration
- Test airflow and capture efficiency
Actions
Pre-Drywall (Stage 3 - December 2025)
- Order 6” spiral steel duct for vertical riser (15 ft) — stage:: 3
- Confirm fume extraction riser location in utility chase with contractor — stage:: 3
- Mark exhaust penetration location on framing plans — stage:: 3
- Add 20A fume blower circuit to electrical schedule — stage:: 3
Future (Stage 6+)
- Complete System A branch installation after loft drywall — stage:: 6
- Select and install inline blower — stage:: 6
- Set up temporary paint booth before Corvette bodywork — stage:: 6
- Install air quality sensors for monitoring — stage:: 6
Procurement
Pre-Drywall Materials
Spiral Steel Duct:
- Home Depot - 6” x 5 ft Galvanized Spiral Pipe - ~$15-20 each (need 3-4)
- Grainger - 6” Spiral Duct - Professional grade
Sealing Materials:
- 3M 3340 Foil Tape - ~$15-25
- RCD #6 Duct Mastic - ~$10-15
End Caps:
- 6” Galvanized End Cap - ~$5-8 each
Future System Components
Inline Blowers:
- AC Infinity CLOUDLINE S6 - ~$150 (hobby-grade, not explosion-proof)
- Fantech FG6XL - ~$250-350 (commercial grade)
Blast Gates:
- 4” Blast Gate - ~$8-12 each
- 6” Blast Gate - ~$12-18 each
Safety Considerations
Fire/Explosion Prevention
- Never use PVC ducting for solvent fumes
- Ensure blower motor is outside fume stream
- Use explosion-proof equipment for paint booth (System B)
- Ground all metal ductwork to prevent static buildup
- Keep fire extinguisher (Class B) near painting areas
Health Protection
- Always use appropriate respirator when working with fumes (P100 with organic vapor cartridge)
- Fume extraction supplements but does not replace PPE
- Monitor for symptoms of solvent exposure
- Ensure adequate makeup air when extraction is running
Makeup Air
- Fume extraction creates negative pressure in space
- Must have makeup air path to prevent:
- Back-drafting of combustion appliances (boiler)
- Reduced extraction effectiveness
- Door suction issues
- Options: Passive vents, powered makeup air, door gap allowance
References
- Source Planning Document
- Dust Collection (Separate System)
- Compressed Air System
- Electrical Planning
- Pre-Insulation Requirements
- Corvette Restoration Planning
Last Updated: December 2025 Status: Planning - Pre-drywall items critical before framing closes