Dust Extraction Calculator — Workshop Sizing

The CFM requirement depends on your primary machine. At a 4" (100mm) port a benchtop planer/thicknesser needs ~400 CFM, a table saw ~350 CFM, and a router table ~195 CFM. Full-size floor-standing machines on a 6" (150mm) port draw far more — a 15-20" planer wants ~750-800 CFM. Size your system for the most demanding machine plus 20% margin.

Main ducts are typically 100-150mm. Branch runs to individual machines use 100mm for table saws and planers, 65mm for routers and small sanders. The main duct must be large enough to carry the full air volume at 20 m/s transport velocity.

Yes. Blast gates close off branch pipes to machines not in use, concentrating suction at the active machine. Without blast gates, air flow is split between all branches, reducing effectiveness at each machine.

A minimum of 20 m/s (4000 ft/min) is recommended for wood dust to prevent particles settling in the pipes. Fine dust from sanders may need slightly less, but coarser chips from planers need the full 20 m/s.