Sizing dust collection: CFM, static pressure and port sizes from the makers' manuals

What do CFM and static pressure mean on a dust collector?

WEN's Dust Collection 101 describes pressure as force distributed over an area, often expressed in PSI, kilopascals or inches of water column, and flow rate as the volume of air moving through an area in a given time, often expressed in cubic feet per minute (CFM). It adds that dust collectors are often rated by CFM. (WEN Products)

Powermatic's PM1300TX manual lists air flow of 1,300 CFM, static pressure of 11.31 (inch of water) and a velocity at 6" of 5,374 FPM.

Taikra doesn't rank or test tools; every figure here is from the maker's own page or manual, linked.

Why one collector can list two different CFM figures

Harvey lists the GYRO AIR G-700 at a max air flow of 1110 CFM and a max static pressure of 18-1/2 inches of water, then gives 700 CFM and 5-5/8 inches of water as the figures at a 4 inch hose. (Harvey Woodworking)

RIKON labels the 60-2500 cyclone's 1470 CFM figure as air flow at a 4" diameter, although the machine's ports are listed as 1 @ 8" and 3 @ 4". (RIKON Power Tools)

The sections below keep each maker's condition label next to its figure, because the labels differ from brand to brand.

What inlet sizes do dust collectors have?

Powermatic's PM1300TX manual lists the inlet port diameter as two at 4", or one at 6".

RIKON's 60-200 manual has a 'Y' inlet that mounts over the 5" opening on the fan housing and provides two 4" hose connections, with a plastic cap to plug one 4" inlet when only one machine hose is connected. (RIKON Power Tools)

Harvey lists the G-700 with a 6 inch main inlet and two 4 inch adapter inlets, and says it is compatible with 2 inch, 4 inch and 6 inch hoses. (Harvey Woodworking)

What dust-port sizes do tool makers list?

Delta lists the 36-5000T2 contractor saw's dust port as fitting a 2.5 in. (63.5mm) hose, with a 4 in. (102mm) adapter. (Delta Machinery)

DEWALT lists a universal 1-1/4-in dust port on the DWS520K track saw.

WEN lists a 3-in-1 dust port (1-3/4, 2-3/4, 4 inches) on the 3962T 10-inch band saw. (WEN Products)

Port sizes for other models are on each tool's Taikra page, taken from the maker's spec table.

What do makers say about hose and duct runs?

WEN says most permanent setups use 4-inch to 6-inch diameter rigid tubing, and that flexible hoses cause approximately 5 times the pressure loss per linear foot as rigid tubing, depending on the diameter, flow rate and construction. (WEN Products)

The same WEN guide says long lengths of tube cause more losses than shorter ones even in rigid tubing, that every 90-degree elbow causes a pressure loss equivalent to 5 to 10 feet of rigid tubing, and that 45-degree turns or wyes cause about half that loss. (WEN Products)

WEN also notes that larger-diameter ducting generally suffers less loss than smaller-diameter ducting but is bulkier, heavier and more expensive. (WEN Products)

Setup and operating instructions are in each maker's manual.