A properly designed dust collection duct system is essential for any woodworking shop, metalworking facility, or CNC operation. Without effective dust collection, airborne particles create health hazards (respiratory disease from fine dust exposure), fire/explosion risks (combustible dust clouds), machine wear, and product quality problems. The duct system is the backbone — it connects every machine to the dust collector and determines whether the system actually captures dust or just moves it around.
This guide covers duct and hose sizing, material selection, system layout, and the critical details that separate a working system from an underperforming one. As a manufacturer of industrial hoses including PU and PVC dust collection hose, we have supplied ductwork for thousands of shop installations across the US.
Duct Sizing by Machine
Every machine in your shop has a minimum CFM requirement — the volume of air needed at the dust port to capture particles before they escape into the room. The duct diameter at each machine must be sized to deliver that CFM at the correct velocity (3,500-4,500 FPM for wood dust, 4,000-5,000 FPM for metal chips).
| Machine | CFM Required | Port Size | Duct Size |
|---|---|---|---|
| Table saw | 350-400 | 4" | 4-5" |
| Miter saw | 400-500 | 4" | 4-5" |
| Jointer (6-8") | 350-400 | 4" | 4-5" |
| Planer (13-15") | 400-600 | 4-6" | 5-6" |
| Router table | 200-300 | 2.5-4" | 4" |
| Band saw | 350 | 4" | 4" |
| Drum sander | 300-500 | 4-5" | 5-6" |
| CNC router | 400-800 | 4-6" | 5-8" |
| Wide belt sander | 600-1,000 | 6-8" | 6-8" |
| Floor sweep | 150-200 | 4" | 4" |
Duct & Hose Material Selection
1. Spiral Metal Duct (Best for Main Trunk)
Galvanized steel spiral duct is the gold standard for dust collection main trunks. It is smooth-walled (lowest friction), durable, naturally conductive (grounding is easy), and non-combustible. Standard gauges: 26 gauge for 4-8", 24 gauge for 10-14", 22 gauge for 16"+. Use slip joints with 3 sheet metal screws at each connection, sealed with foil tape.
2. PVC Pipe (Popular DIY Option)
Schedule 40 PVC drain pipe (not pressure-rated PVC) is commonly used in home workshops because it is inexpensive, smooth-walled, and available at any hardware store. The static electricity concern is real but manageable — ground the system with a bare copper wire taped to the outside of the PVC, connected to building ground at the collector end. Do not use PVC in commercial shops where NFPA 652 or local fire codes require non-combustible duct.
3. Polyurethane (PU) Flexible Hose
PU hose is the premium choice for flexible connections between machines and the main duct. It has 3x the abrasion resistance of PVC hose, is anti-static capable (copper ground wire embedded in the wall), and maintains flexibility down to -30°C. The smooth bore minimizes friction and clogging. Standard sizes: 2.5" to 6" for individual machines.
4. PVC Flexible Hose
PVC flexible hose is the budget alternative to PU. It works well for light-duty dust collection (sanders, routers, hand tools) but wears faster than PU when handling heavy chips or abrasive materials. Available in clear (for visual inspection of blockages) and standard colors.
Material Comparison
| Material | Friction | Static | Durability | Cost | Best For |
|---|---|---|---|---|---|
| Spiral metal | Lowest | Conductive | 30+ yrs | $$ | Main trunks |
| PVC pipe | Low | Static risk | 20+ yrs | $ | DIY shops |
| PU hose | Medium | Anti-static | 10+ yrs | $$$ | Machine connections |
| PVC hose | Medium | Static risk | 3-5 yrs | $ | Light-duty flex |
System Layout Best Practices
Main trunk sizing: Size the main trunk for the total CFM of all machines that could run simultaneously. For a typical home shop (one machine at a time + floor sweep), the trunk carries the highest single-machine CFM plus 200 CFM for the floor sweep. Use blast gates at each machine drop to close off unused branches.
Branch runs: Keep branch runs as short as possible — every foot adds friction and every elbow reduces performance. Use 45° wye fittings (not 90° tees) where branches join the main trunk. The branch should enter the trunk at a 30-45° angle in the direction of airflow.
Transport velocity: Maintain minimum 3,500 FPM in all duct sections to prevent dust from settling and clogging the duct. For heavy materials (metal chips, wet sawdust), increase to 4,500+ FPM. Use the ductulator calculator to verify velocity in each duct section.
Grounding: Bond all metal duct sections with self-tapping screws (which pierce through paint and zinc). Ground PVC and flex hose with copper wire. Connect the entire system to building ground at the dust collector. Test continuity with a multimeter — less than 1 ohm resistance from any point to ground. For a deep dive on static control, grounding requirements, and NFPA compliance, see our anti-static duct guide.
Need dust collection hose for your shop? Our PU hose (anti-static, abrasion-resistant) and PVC hose (budget-friendly) are available in 2.5" to 16" diameters. Request a quote for bulk and custom orders.