Air Assist & Fume Extraction

Air assist (a focused jet of air at the laser head) keeps the lens clean, blows debris out of the kerf, suppresses flare-ups, and drastically cleans up edges. Fume extraction (whole-machine ducted exhaust + filtration) is non-optional for safety — laser cutting wood, leather, MDF, and especially acrylic releases formaldehyde, acrolein, hydrogen chloride, and fine particulates. This category is "you can die slowly without it" not "nice to have." For enclosure / interlock / fire safety see Laser Safety.

Air assist pumps (point-of-cut nozzle)

• ★ 30 L/min aquarium pump (HAILEA ACO-208 / ACO-318) — cheap (~$30), quiet enough, fine for diode + light CO2 engraving. Plenty for K40-tier work.
• ★ 60 L/min HAILEA ACO-318 / HAILEA ACO-388D 60 L/min — the sweet-spot diode/CO2 air pump; ~$60, cuts wood cleanly with the right nozzle.
• ★ 80–100 L/min commercial diaphragm pump — required for clean cuts on 6+ mm acrylic and 8+ mm wood. ~$100–$200.
• OMTech / Cloudray bundled air pump — usually 30–60 L/min diaphragm; fine to start.
• Compressor + regulator (1–4 bar) — premium choice; quietest is a silent oil-less compressor (California Air Tools, Stealth). Far higher CFM than diaphragm pumps.
• Solenoid valve add-on — switch air on/off with M8/M9 from G-code; LightBurn supports it. Saves pump life.

Exhaust fans (machine-to-outdoors)

• ★ 6" inline duct fan (AC Infinity Cloudline T6 / S6) — ~$120–$170, quiet, variable speed, controller. The default home-shop pick. Pair with 6" insulated flex duct.
• 8" inline duct fan (AC Infinity Cloudline T8) — for 80+ W CO2 or larger beds. Higher CFM, louder.
• Fantech FG / FKD inline fans — older industrial alternative; very loud, very durable.
• Centrifugal blower (squirrel-cage) — usually too loud and too high static-pressure for hobby work, but standard on industrial cutters.
• Dual fan setup — push fan inside enclosure + pull fan outside; recommended over a single fan for long duct runs.

Fume / particulate filtration (when you can't vent outside)

• ★ BOFA AD350 / AD500 — closed product, paid ($2,500–$5,000); industry-standard fume extractor with HEPA + activated carbon stages. Used in commercial laser shops; replacement filters are pricey ($300–$500 every 6–12 mo). The "I have to filter, not vent" answer.
• BOFA AD250 / DustPro — smaller BOFA unit for diode / small CO2.
• Purex / IQAir GC MultiGas — alternatives in the BOFA price band.
• xTool Smoke Purifier / Cloudray fume extractor — vendor-branded BOFA-class units; cheaper, lower CFM, similar idea.
• OMTech / Atomstack consumer fume extractors — ~$300–$700; HEPA + carbon, lower-grade than BOFA but better than nothing.
• DIY HEPA + activated carbon box — community designs combining a high-CFM fan + true HEPA + 5–10 kg loose-fill activated carbon. Cheaper if you have time; never quite reaches BOFA-level VOC capture.

Ducting and adapters

• ★ 6" insulated flex duct (R-6 or R-8) — quieter than bare aluminum; standard.
• 6" rigid HVAC pipe — best airflow per length; loud transfer of vibration; use for short straight runs.
• Backdraft damper — passive flap that closes when fan is off; stops cold-weather backdraft.
• Fume hood / lid skirt — keeps capture local to the machine.
• Clamps + foil tape — Nashua 324A foil tape is the standard duct seal.

Window / wall / roof exit options

• Window adapter kits (xTool / OMTech) — pre-made plates for casement / sash windows.
• Through-wall vent (4"/6" aluminum hood) — permanent install; better seal long-term.
• Roof vent (RV-style) — maritime / shed installs.
• Dryer wall cap — often used for hobby installs; passable.

Acrylic-specific note

Cutting acrylic releases methyl methacrylate vapor and (with PVC contamination, which you should NEVER cut) hydrogen chloride / chlorine gas. Acrylic is the easiest material to cut and the meanest material to filter — vent outdoors if at all possible. Charcoal alone is not enough.

Pick this if…

• Default home-shop combo: 60 L/min aquarium pump (air assist) + AC Infinity T6 (exhaust) + foil-taped 6" insulated duct outside.
• Cutting clean acrylic: silent compressor + regulator at 30–60 PSI for air assist; vent outdoors.
• Apartment / can't vent outside: BOFA AD350 (and accept filter replacement costs) + sanity-check by NOT cutting acrylic indoors.
• K40 / small diode: 30 L/min aquarium pump + 4" inline fan to a window.
• Pro shop, daily cutting: 8" exhaust + BOFA AD500 standby for off-hours / smoke-test runs.