How to set up dust collection in a garage shop

A garage woodshop has three problems a basement shop does not. The dust gets on the car and into the paint. It gets into the house through the shared wall and the door. And it mixes with a rotating cast of other garage air: fuel, fumes and moisture. Wood dust is also a health matter. The fine particles that stay in the air for hours are the ones that matter, and a broom and a shop vac do not stop them. A collector pulls chips and coarse dust at the machine; a filter takes the fine dust out of the air; a respirator protects you while those two work. You need all three. The first two are the setup. The third is a habit; keep a P100 half mask where you will actually reach for it.

This guide builds the system in the right order: list the machines, find the CFM, choose the duct, choose the collector, plan the runs, then handle the fine dust and the electrical. The dust collector calculator automates the middle of it, and the best dust collector for a garage shop compares models.

A collector does not move "dust". It moves air, and the air has to be fast enough to carry chips. The target is the flow each machine needs at its dust port. The site's standards data uses these values, from common tool-maker and woodworking-magazine guidance (your machine manual always wins):

Most one-man garage shops run one machine at a time. That is the single most useful fact in this guide, because it means you size the collector for the biggest single machine (about 400 to 550 CFM), not for the sum. A shop with two people, or a shop where you want the planer and a sander to run together, needs more.

The ports matter as much as the CFM. A hybrid table saw usually has a 4 in port, and a planer is often a 4 in port that chokes the flow. A collector with a 6 in inlet needs a reducer at every machine. Check the listing for each of your machines.

Duct velocity is how fast the air moves; 4,000 feet per minute is the common design value for wood chips (the site's standards data uses it). Flow equals velocity times duct area, so the same speed moves more air in a bigger pipe. At 4,000 fpm:

Read it as a rule: a 4 in drop to a table saw (350 CFM) is correct. A single 4 in hose cannot carry a 550 CFM sander, so the sander wants a 5 in pipe or two ports. A 6 in main trunk carries about 785 CFM, plenty for one machine at a time, and it matches the 6 in intake of the Grizzly G0860 and the 6 in inlet Y of the G1028Z2. An 8 in main matches the 8 in inlet of the G0441 and carries about 1,396 CFM, which is why that collector is described as able to run three machines at once. Use smooth metal or rigid plastic pipe for the main runs and a short flexible hose only for the last 2 to 3 ft, because corrugated hose has several times the resistance of smooth pipe.

There are four families of collector. Pick the family by the shop, then the model by the numbers.

1. Shop vac with a cyclone separator. A wet-dry vacuum such as the DEWALT 12 gal or the Shop-Vac 12 gal with a Dust Deputy cyclone on top is the entry system. The cyclone drops chips into a bucket, and the vac filter stays clean. It suits sanders, routers, a drill press and a small saw, with small hoses. It does not move enough air for a planer. The layout engine uses a vac with a separator as the dust choice in the mixed (car-in-the-bay) packages, because it is small and rolls out of the way.
2. Single-stage bag portable. A 1 HP or 1-1/2 HP unit on casters, with filter bags and a collection bag. The POWERTEC 560 CFM portable and the Grizzly G1028Z2 (1,300 CFM bag rating, 6 in inlet Y with two 4 in openings, 42.6 gal bag, 120V or 240V per the listing) are the two benchmarks. Chips go through the fan, which wears it, and the bag filters finish early, but it is the cheapest way to get real airflow at a planer.
3. Portable cyclone. The Grizzly G0860 is a two-stage cyclone on 120V: 1-1/2 HP, 868 CFM at 1.8 in static pressure, 6 in intake, 1 micron canister filter and a 20 gal drum, about 78 dB, with a wireless remote, per the listing. The cyclone drops chips in the drum before they reach the filter, so the filter stays clear much longer. Its listed footprint is 27.5 x 44 in and its height is 70 in, small enough for a 12 x 20 ft bay. See the fit sheet for the G0860.
4. 3 HP cyclone. The Grizzly G0441 is 240V, 22 A, with 1,654 CFM at 2.0 in static pressure, an 8 in inlet and a 55 gal drum. It is rated for three machines at once. It stands 109 in tall by the listing, which is taller than even a 9 ft (108 in) ceiling, so measure and plan for a lower mount or a different model before you order. See the G0441 fit sheet and the G0860 vs G0441 comparison.

For a one-person woodshop in a one- or two-car garage, the G0860 is the sweet spot: 120V, plenty of air for one machine at a time, and a clean filter. For a 24 x 24 or three-car garage with a fixed duct network and a 240V subpanel, the G0441 is the layout engine's choice. For a wall-mounted unit that frees the floor, see the POWERTEC wall mount and the Grizzly G0785.

Put the collector where the pipe is short. Every foot of pipe and every elbow takes airflow away, so the layout goal is the shortest straight route from the collector to the machines. Rules that work in a garage:

• Collector on a wall, near the center of the machines, not in the corner farthest from the table saw. Keep it out of the car's side of the bay.
• A main trunk along the wall at about 7 ft, with 4 in drops down to each machine. Use long-radius or two-45-degree elbows, not sharp 90s.
• Blast gates at every drop. With one machine running and the other gates closed, all the air goes where you need it. Without gates, the airflow goes to the shortest path.
• Short flex at the machine. Use 2 to 3 ft of flexible hose from the end of the pipe to the machine, so the machine can move on its mobile base.
• Machines on wheels get a quick-connect. A table saw on a mobile base needs a hose long enough to move; use a coupling you can pull in one second.
• Ground the plastic. Rigid plastic pipe builds a static charge. Run a bare copper wire inside or along the pipe, ground it, and keep the fittings electrically continuous. This reduces shocks and, more importantly, the dust ignition risk.

In a garage where the car stays, run the pipe along the wall at the ceiling or high on the wall, not across the open ceiling. A pipe at 7 ft clears most vehicles, but a pickup truck with a roof rack may not. The park-the-car calculator and the 22 x 22 woodshop layout show how the collector and the machines share the floor with a vehicle. In a mixed shop, skip the fixed duct altogether: a cyclone on casters and a short hose to each machine is easier than pipe you must work around a car to reach.

A collector is only as good as its capture. A table saw captures best at the blade shroud under the table and at the blade guard overhead; a 4 in port on the cabinet alone leaves a lot of dust on the table. A bandsaw needs a port below the table and one at the lower guide. A planer and a jointer need their own chip ejection port, and often a hood. A router table needs a fence port and a below-table port. A miter saw needs a hood or a back box, and a sander needs a table port. A shop built on 350 CFM at the hood works only when the hood is close to the cut.

Use the shortest, straightest hose to each machine. Use smooth-wall hose for the last connection when you can. If a machine has a 2.5 in port, use a reducer and expect lower flow. A common mistake is to put a 6 in pipe on a collector and a 2.5 in hose on the sander and expect the system to work. Match the diameter, and use a separate vac with a small hose for hand sanders.

Even a good collector misses the finest dust, and it stays in the air for hours. A ceiling-hung air filter cleans that. The Grizzly G0738 has three speeds (260, 362 and 409 CFM), a timer of 1, 2 or 4 hours, a 5 micron outer filter and a 1 micron inner filter, an IR remote and hanging chains, per the listing. The POWERTEC AF4001E is the Amazon equivalent, and the WEN 3410 (300, 350 and 400 CFM) and the DEWALT DWXAF101 are other options. Run the filter during the work and for an hour afterward.

The standard way to size it is to change the room's air several times an hour. The air filtration calculator does it for any bay, and the sizing pages give a result for each: for example air filtration for a 22 x 22 two-car garage. See also the best air filtration for a garage woodshop.

A collector is a motor, and motors have rules. NEC Table 430.248 gives single-phase full-load current: 1-1/2 HP is 20 A at 115V and 10 A at 230V, and 3 HP is 34 A and 17 A. The G0860 is a 120V, 15 A machine by the listing; it wants its own 20 A circuit. The G0441 is a 240V, 22 A machine; its circuit should be sized by an electrician from the nameplate, using 125 percent of the running current for the conductor (NEC 430.22). In the layout engine a 3 HP collector is the one that moves the woodshop shop from a 120V layout to a 240V one, and it lands at a 30 A, 10 AWG circuit with a NEMA 6-30R receptacle in the package. The 240V circuit calculator and 240V in a garage explained take it from there.

Also consider a remote switch. A wireless remote on the G0860 lets you start the collector from the saw. For a fixed machine, an automatic switch that starts the collector when the machine starts is the safest habit, because the collector is only useful when it is on.

1. A bag collector with no cyclone in front of the planer. The bag fills in minutes and the airflow collapses.
2. A 2.5 in hose on a 6 in collector. The air has nowhere to go and the motor works hard for nothing.
3. Too much flex hose. Ten feet of corrugated hose is worth a fraction of the same length of pipe.
4. No blast gates. The air takes the easy path and the saw gets nothing.
5. Never emptying the bin. A full drum overflows into the filter. Keep a bag liner and an emptying schedule.

Also, never leave a collector running unattended, and keep sparks out of the system: a grinder or a welder near a collector is a fire hazard. In a garage that also hosts a car, keep the exhaust or filter side pointed away from the vehicle.

Here is where the numbers land for each kind of bay, using the layout engine's woodshop and mixed packages:

• 12 x 20 or 12 x 22 ft one-car, car out. A portable cyclone on 120V such as the G0860, 4 in drops by hose, a hanging filter, a P100 mask. See the 12 x 20 layout and the dust collector sizing for 12 x 20.
• One-car with a car in it. A shop vac with a cyclone separator on wheels and a hanging filter. Run machines one at a time with the vac, and roll everything aside when the car comes in.
• 20 x 20 or 22 x 22 ft two-car. A G0860, with a short fixed 6 in main and 4 in drops if you like. See dust collector sizing for 22 x 22.
• 24 x 24 ft or three-car. A 3 HP cyclone such as the G0441 on a 240V circuit and a fixed 8 in main with 4 in drops, if you can solve its 109 in height.

Whatever you choose, add the collector to the budget planner and the amps calculator together. And for the overall order of work, read how to set up a workshop in a garage.