Welding Fume Ventilation CFM Calculator

Size local exhaust hoods, welding booths, and dilution airflow for cleaner shop air

Embed this calculator Free · no API key · keep the attribution link

Copy the snippet below to embed this calculator on your site. The attribution link must stay intact and dofollow (no rel="nofollow"). Browse all embeddable calculators

<div class="ttq-embed" style="max-width:100%;margin:0 auto;">
  <iframe src="https://testtalkhq.com/embed/welding-fume-ventilation-cfm-calculator/?theme=light&utm_source=embed" width="100%" height="980" frameborder="0" loading="lazy" scrolling="no" title="Welding Fume Ventilation CFM Calculator — TestTalkHQ" style="border:0;max-width:100%;width:100%;"></iframe>
  <p style="font:400 13px/1.4 system-ui,sans-serif;text-align:center;margin:6px 0 0;">Powered by the <a href="https://testtalkhq.com/welding-fume-ventilation-cfm-calculator/?utm_source=embed&utm_medium=referral&utm_campaign=calculator_embed&utm_content=welding-fume-ventilation-cfm-calculator" target="_blank" rel="noopener">Free Welding Fume Ventilation CFM</a> from <a href="https://testtalkhq.com/?utm_source=embed&utm_medium=referral&utm_campaign=calculator_embed&utm_content=welding-fume-ventilation-cfm-calculator" target="_blank" rel="noopener">TestTalkHQ</a></p>
</div>

Welding

Welding Reference Card

Welding Reference Card

One page. MIG, TIG, stick and flux core settings by thickness.

$3.99

Buy
Complete Welding Settings Guide

Complete Welding Settings Guide

19 pages. Four processes, stainless and aluminum, symbols and inspection.

$12.99

Buy
Welding Job Estimator

Welding Job Estimator

Price the job, then hand over a quote with no internal numbers.

Excel or Google Sheets. Best on a computer.

$29.00

Buy
BEST VALUE
Welding Complete Bundle

Welding Complete Bundle

Card, 19-page guide and the estimator workbook. All six files.

Excel or Google Sheets. Best on a computer.

$34.99

$45.98 if bought separately — save $10.99

Buy

See all Welding products

Checkout opens in a new tab.

Recommended Welding Ventilation & PPE

Capture fumes at the source and protect the breathing zone

Airflow Fluke 62 Max infrared thermometer

Fluke 62 Max Infrared Thermometer

  • Monitor hot work areas
  • Check booth and duct hotspots
  • Non-contact temperature scans
  • Verify ventilation placement
  • Shop troubleshooting tool
Check Price
Shop VASTOOLS welding accessories kit

VASTOOLS 6-Piece Welding Kit

  • Hammer, brush, and pliers basics
  • Keep work area clean for airflow
  • Supports fume capture positioning
  • Everyday fabrication kit
  • Pairs with hood maintenance
Check Price

As an Amazon Associate, TestTalkHQ earns from qualifying purchases.

Why Welding Fume Ventilation Matters

Welding and cutting generate metal fumes, gases, and particulates that accumulate in the breathing zone without adequate ventilation. MIG and flux-core processes typically produce more fume mass than TIG; plasma cutting adds significant particulate and gas loads. OSHA, ACGIH, and NIOSH exposure limits apply to manganese, hex chrome, zinc oxide, and other components depending on base metal and filler. Engineering controls — especially local exhaust — are the first line of defense before relying on respirators alone.

Local Exhaust Hood vs. General Dilution

Local exhaust captures fumes at the source with a hood positioned near the arc. Target capture velocity of 100 fpm or more at the hood face for manual welding. General dilution ventilation replaces room air but does not reliably protect the welder breathing zone — it supplements source capture rather than replacing it. For production shops, dedicated welding booths with filtered exhaust are common; hobby shops often use portable fume extractors on flexible arms.

Process-Specific CFM Baselines

This calculator uses practical shop baselines: TIG at 75 CFM per station (lower fume generation), MIG at 125 CFM, flux-core at 175 CFM, stick at 200 CFM, and plasma at 300 CFM. Actual requirements vary with wire diameter, amperage, confined spaces, and alloy. Stainless and galvanized work may need higher capture rates and filtration rated for fine particulate. Always verify with an industrial hygienist when exposure limits are approached.

Hood Placement and Duct Sizing Tips

Position the hood opening as close to the arc as practical without interfering with the weld — typically within one duct diameter. Keep flexible hose runs as short and straight as possible to maintain static pressure. Size main duct for transport velocity around 2000–4500 fpm depending on particulate loading. Clean filters and inspect airflow regularly; a clogged filter drops effective CFM and defeats the installation.

Related Calculators & Guides