October 25, 2026 · Technical Guide

Laser Cutting Fume Extraction: Airflow, Filters and Real Cost

A 3000 x 1500 mm fiber laser cutting machine needs about 2,000 to 3,000 m3/h of extraction airflow at the capture point, not at the fan outlet. Through a 250 mm duct at 15 m/s you get roughly 2,650 m3/h. Size the duct and the static pressure properly and one cartridge set lasts a season. Size it by the laser badge and you will change filters every six weeks while the shop still smells of burnt metal.

I quote extraction with the machine most weeks. Most buyers were offered a collector based on laser power alone, which is the wrong number. Here is how it actually works.

How much airflow does a laser cutting table need?

Start at the duct, not at the machine. Airflow through a round duct is Q = 3,600 x A x v, where A is the duct area in square metres and v is air speed in metres per second. Fifteen metres per second is a common target for metal fume. Slower air drops particles in the duct. Faster air adds noise and pressure loss without capturing more.

Duct size	Area	Airflow at 15 m/s	What it suits
200 mm	0.031 m2	about 1,700 m3/h	one branch, light duty
250 mm	0.049 m2	about 2,650 m3/h	single 3015 bed, 2-6 kW
300 mm	0.071 m2	about 3,820 m3/h	4020 bed or two branches

Then look at the bed. A single 3015 table with bottom extraction usually lands at 2,000 to 3,000 m3/h. A 4020 bed, or two tables on one collector, needs 4,000 to 5,500 m3/h. The reference table extraction suppliers publish looks like this.

Reference airflow	Fan motor	Cartridges	Typical job
1,000 m3/h	2.2 kW	1	single small bed, thin sheet, one shift
2,000 m3/h	3.0 kW	2	3015 bed, 1-3 kW source
3,000 m3/h	4.0 kW	3	3015 bed, 3-6 kW, production
4,000 m3/h	5.5 kW	4	4020 bed, 6-12 kW
5,500 m3/h	7.5 kW	6	twin tables or gantry, 12 kW and up

Two things to notice. The cartridges scale with airflow, not with laser watts. And a 12 kW source on a small bed does not automatically need a bigger collector than a 6 kW source on the same bed, because fume volume follows cut length, material and bed area.

Watch out for desktop units sold as laser fume extractors. One common pair moves 150 m3/h and 700 m3/h. Both are fine for a desktop engraver in a spare room. Neither belongs on an industrial fiber table, whatever the listing says.

What is actually in the fume?

Fiber laser cutting does not burn the metal, it vaporises and ejects it. The plume is mostly metal oxide particles, and a large share sits below one micron. That is the part you cannot see, and the part that reaches deep into the lung.

What is in it depends on what you cut:

Carbon steel — iron oxide plus manganese from the alloy
Stainless steel — nickel and chromium oxide, including hexavalent chromium. Our stainless steel sheet page lists the grades we cut most
Galvanised sheet — zinc oxide, the one behind metal fume fever
Aluminium — aluminium oxide, plus fine dust with a fire risk. Grades and tempers are on the aluminium alloy page
Coated or painted sheet — whatever the coating contains, and that is often the nastiest part

The legal side is not optional in most export markets. In the US, OSHA 29 CFR 1910.1026 caps hexavalent chromium at 5 micrograms per cubic metre as an 8-hour average, with an action level at 2.5. Manganese fume has a ceiling of 5 mg/m3 under 29 CFR 1910.1000 Table Z-1. Machine safety sits under EN ISO 11553-1, and EU employers carry a duty to control cutting fume as a carcinogen exposure.

You do not need a lab to start. You need capture at the source, a filter that holds sub-micron particles, and a check that the air in the operator's breathing zone is actually clean. If nobody has ever measured that, assume it is not.

Bottom extraction, top extraction, or zoning?

Open-bed machines pull through the bed. Coarse sparks and hot particles drop out there, which is good, but part of the fume still rises above the sheet. Enclosed machines contain that rising plume, so bottom extraction plus an upper branch works better.

Zoning is the detail most quotes skip. A zoned bed opens dampers near the cutting head and keeps the rest closed, so the same fan pulls hard where the cut is happening. An unzoned bed spreads that airflow over 4.5 square metres of table and captures much less at the arc.

If you run two tables, price one collector per table and compare it with a central unit on balanced branches. Long duct runs eat the airflow you paid for, and balancing a central system after installation is painful.

What do the filter stages actually do?

Stage	What it catches	Notes
Spark arrestor	hot particles and coarse dust	mandatory on aluminium and thick plate
PTFE cartridge	more than 99.9% of particulate	one common 2,600 m3/h unit runs 3 cartridges with 30 m2 of media
H13 HEPA	sub-micron polish	needed if you recirculate indoors, no substitute for stage two
Activated carbon	odour, gas and VOC from coatings and oils	needed for recirculation, not for outdoor venting

Pulse-jet cleaning on 5-6 bar compressed air knocks the dust cake off the cartridge and drops it into the hopper. That is why the unit needs an air line as well as power. A cartridge with no pulse cleaning loads up in weeks, and then the airflow drops while the fan keeps burning power.

Recirculate indoors or vent outside?

Venting outside is simpler and cheaper to buy. It is not free. If you pull 3,000 m3/h out of the hall, 3,000 m3/h has to come back in, or the building goes negative. Doors fight you, gas burners backdraft, and in winter you heat cold air all day.

Recirculation keeps the heat but puts the whole filtration job on the unit. That means HEPA plus carbon, a differential pressure gauge, and a hard rule that nobody runs the laser with the extractor off. In a cold climate recirculation usually pays for itself in one or two heating seasons. In a mild climate with a big shop, outside venting with a proper stack is fine.

Check the discharge route before you sign. I have seen a good 5,000 m3/h collector installed against a wall with nowhere to send the air.

What does extraction cost to run?

The fan is a small load next to the laser, but not zero. A 2,600 m3/h unit runs a 2.2 kW motor, 4,000 m3/h takes 5.5 kW, and 5,500 m3/h takes 7.5 kW. Run 2.2 kW for eight hours a day, 300 days a year, and you use 5,280 kWh. At USD 0.10 a kWh that is about USD 530 a year. A VFD blower trims that on part load.

Filters are the bigger number, and it is the one buyers forget. On two-shift stainless cutting with a 2,600 m3/h unit we see two to three cartridge sets a year. Ask for the per-cartridge price and the media area in writing, because a cheap unit with small cartridges and no pulse cleaning loses that comparison fast.

The honest way to compare two quotes is total cost of ownership: purchase price plus replacement filters plus energy plus maintenance plus downtime. Buying price is maybe a third of the story.

Five mistakes I see in extraction quotes

Sizing by laser power. Fume follows cut length, material and bed area.
Ignoring static pressure. A 3,000 m3/h fan behind 12 metres of duct, four elbows and a loaded filter does not deliver 3,000 m3/h.
No spark arrestor on aluminium or thick plate. That is a fire claim waiting to happen, and aluminium dust in contact with water also generates hydrogen.
No zoning or dampers on a multi-table system. One branch starves while the other floods.
No make-up air plan. Extraction without supply air just puts the hall under vacuum.

Checklist before you order a laser cutting dust collector

Measure the bed and count the extraction ports on the machine
Confirm port diameter and how many branches you will run
Decide bottom only, or bottom plus top extraction
Calculate duct flow at 15 m/s through your real route, elbows included
Add 20-30% margin for filter loading and bends
Check fan motor kW against your power supply
Confirm compressed air at 5-6 bar for pulse cleaning
Decide recirculation or outdoor venting, and plan make-up air
Get cartridge price, media area and expected life in writing
Confirm the unit meets the rules in your market, not just ours

Frequently Asked Questions

Do I need fume extraction for fiber laser cutting?

Yes, in almost every market. Cutting stainless, galvanised or coated sheet releases sub-micron metal oxide particles, and stainless fume includes hexavalent chromium, which OSHA caps at 5 micrograms per cubic metre as an 8-hour average under 29 CFR 1910.1026. Our fiber laser cutting machine pages list the extraction port size for each bed so the collector can be sized before the machine ships.

How much airflow does a 3015 laser cutting table need?

Plan on 2,000 to 3,000 cubic metres per hour measured at the capture point. A single 3015 bed with bottom extraction sits in that range, and a 4020 bed or two tables on one collector needs 4,000 to 5,500 m3/h. Check the duct as well: a 250 mm duct at 15 m/s carries about 2,650 m3/h, so a bigger fan on a small duct buys nothing.

Can I just vent the extractor outside instead of buying filter cartridges?

You can vent outside if you capture the fume first, but the air you pull out has to come back in. A 3,000 m3/h collector removes 3,000 m3/h from the hall, so doors fight you, gas burners backdraft and you heat cold air in winter. Many shops run a cyclone or cartridge pre-filter and then vent. Decide this before you buy, not after the unit is on the wall.

How often do the filters need changing?

It depends on duty, not on the calendar. Watch the differential pressure gauge and change when it stops recovering after a pulse-jet cycle. On two-shift stainless cutting with a 2,600 m3/h unit we see two to three cartridge sets a year. Ask for the cartridge price and the media area in writing before you order the machine, because that is the cost that repeats.

Is aluminium dust a fire risk in a laser cutting dust collector?

Yes. Aluminium and other reactive metals produce fine dust that can ignite, so a spark arrestor and a proper dust discharge plan are not optional. Wet collectors reduce some ignition risk but aluminium in contact with water also generates hydrogen, so the system needs its own risk review. Dry cartridge collectors with an integrated arrestor are what we usually supply for mixed sheet work.

Sources: collector selection table and duct airflow formula from 7US laser cutting dust collector documentation (2026), Q = 3,600 x A x v at 15 m/s giving roughly 1,700 / 2,650 / 3,820 m3/h for 200 / 250 / 300 mm ducts; ORiSK ORKSJ-2600G datasheet (2,600 m3/h, 2.2 kW, 30 m2 filter area, 3 PTFE cartridges, above 99.9% efficiency); Xinhong laser cutting fume extraction system specification (4-stage filtration with H13 HEPA, 3,000-10,000 m3/h, pulse-jet cleaning, VFD blower); xTool AP2 and AP2 Max airflow figures as published September 2026 (150 m3/h and 700 m3/h); OSHA 29 CFR 1910.1026 chromium (VI) permissible exposure limit 5 micrograms per cubic metre as an 8-hour TWA and action level 2.5; OSHA 29 CFR 1910.1000 Table Z-1 manganese fume ceiling 5 mg/m3; EN ISO 11553-1 laser processing machine safety. Filter change intervals and energy figures are FANY LASER field observations from 2026 installations, not a guarantee. Confirm airflow, motor rating and local exposure limits against your own machine datasheet and a local industrial ventilation engineer before you buy.

Written by David Chen, Sales Engineer at FANY LASER. Connect on LinkedIn for laser cutting machine specs, extraction sizing and price data.

Buying a laser and a dust collector together? Send us your bed size, the materials you cut and the duct route you have space for, and we will confirm the airflow and filter setup before you order. Talk to our engineers here.