700 CFM collector with 4" duct enough for 440 sq ft shop?

[Sean Rainaldi]

Due to my floor plan it seems that I would have to locate the dust collector in the corner of my garage.

I plan on running 4" dia overhead drops to my table saw, jointer, planer, a chop saw, oscillating spindle sander and a future band saw, and 2.5" drops to my router table and belt sander and drill press.

Shop measures 21' x 21', furthest run to a machine is around 22 to 23 feet.

I am assuming that I would have to have a blast gate set up which only pulls dust from the one machine I have running at the time...

If I set up the duct work and blast gates correctly, is 700 cfm enough "pull" for this set up to overcome friction? I have a Steel City 700 CFM unit...Model 65110...

Thanks.

[Mike Wellner]

6" duct is better. There is a very good dust collection page but I can't remember the name offhand.

[Sean Rainaldi]

Yeah but my dust collector only has a 4"port...are you saying I should go with 6" and then reduce down to 4" at the machine?

[paul cottingham]

I would use 4". Better velocity.

[Jim O'Dell]

Yeah but my dust collector only has a 4"port...are you saying I should go with 6" and then reduce down to 4" at the machine?

No, if your collector is set up for 4", going to 6" would hurt you, not help. If it is an adapter on the machine that is 4", and behind it is open to 6" (some have reported their machines are that way) then 6" would be best. Jim.

[Rod Sheridan]

Hi Sean, unfortunately we're missing a few pieces of information;

- CFM requirements for your machines

- fan curve for your dust collector

- layout of your shop indicating pipe runs with number of elbows, wyes, feet of pipe etc.

I've measured the airflow of a couple similar collectors and have the following comments

- the actual CFM of the collector is aproximately half of the claimed airflow

- the motor HP is overstated. (For example the motor current from the manual indicates 8.5 amperes, which is about 5/8 to 3/4 HP). Not uncommon.

I suggest that you search for a site by Bill Pentz, and spend a few evenings reading it, it's easy to understand and very informative.

You'll find that North American style machines aren't designed to any engineering standard for dust collection, the only consideration is that it have a 4" port.

A tablesaw will need 500 to 600 CFM at the cabinet and 100 to 200CFM at the blade guard to collect the dust, far in excess of the 400CFM generally mentioned. The 400 CFM will only collect some of the larger particles, it won't collect the fine particles that are dangerous to your health.

If you don't want a cyclone type collector, a larger single stage unit with a good quality pleated filter would be the best approach.

The smaller collectors are at or beyond their limit unless connected dirctly to the machine with a short flex hose.

Regards, Rod.

[Jim Becker]

Sean, the physical maximum CFM you can get through 4" duct at the expected velocities is about 300-350 CFM; maybe 400 CFM if you are lucky. Don't go by the manufacturer's "rating", either...that's what it will move with no duct work and right at about the point where the motor fries...

[David Kumm]

Sean, As others have hinted at, you are starting out with too small a unit and accordingly fitting it with piping too small to be effective for your size shop and machines. Find some way to test it before putting up a lot of ductwork you will tear out in the future. To really get 700 cfm you will need 6" pipe and a collector rated at more like 1000-1200 depending on whether the rating is a real fan curve or free rating. Dave

[Sean Rainaldi]

Thanks for the comments,

It might be better to utilize those casters on the collector and set up my shop so that it is easy to move the collector to the machine itself and collect right at the machine - until I get a bigger one.

That brings me to another question - is it feasable to buy a second identical collector and tie them together into the same duct system?

[Dan Hintz]

That brings me to another question - is it feasable to buy a second identical collector and tie them together into the same duct system?

You're opening a huge can of worms with this question, one that has been beat to death here. As a beginner, you're better off splitting your system into two separate, appropriately-sized pieces and running each piece off of its own collector.

[Craig Gates]

FWIW:
I decided to try setting up two Rockler wall mount dust collectors rated at 600 cfm on opposite walls of my similarly sized garage workshop. This was dictated by the low ceiling height and not wanting to give up too much floor space to a fixed dust collector assembly as well as the cost and aggrivation of putting up all the piping etc. and a lower capital investment.

The one side will collect from my Oliver 270 and the Delta RC 33 planer and maybe the 6" jointer, using a 10-14' flex hose. The other will be used for the bandsaw, RAS, and disk sander, that one will involve some short length of hard piping to have all machines connected at he same time, but run one at a time.
So far I've only set up the first DC and added a top hat Thien seperator. It collects everything from the planer save for a small amount of chips falling thru the bed roller slots. This is planing 12" width Doug fir. The table saw throws some chips thru the blade slot but the DC gets everything else.
This started out as an experiment to test the viability of this approach...so far so goodBTW the Thein seperator works great and was easy to build.
Best,
Craig

[Jim Becker]

It might be better to utilize those casters on the collector and set up my shop so that it is easy to move the collector to the machine itself and collect right at the machine - until I get a bigger one.

Good solution. That collector is pretty much designed to be used that way...one machine at a time with a short hose for best results.

[Chris Fournier]

For quite a few years I had a 500 square foot shop and used a 650 cfm (rated) DC on casters with about 15' of 4" flexible hose. I used this set up in my new shop until I upgraded some equipment which needed a more serious DC.

In a small shop, likely with lower ceilings, all the fixed ducting is another space hog that is not welcome. Keep it simple and go the caster and flexible hose route. Perfect solution? Perhaps not but it's hard to beat for value.

[David Nelson1]

Thanks for the comments,

It might be better to utilize those casters on the collector and set up my shop so that it is easy to move the collector to the machine itself and collect right at the machine - until I get a bigger one.

That brings me to another question - is it feasable to buy a second identical collector and tie them together into the same duct system?

Sean, Do yourself a favor and don't throw good money away. I had a rockler collector and it did so so with the planer and jointer because they are throwing the chips and dust @ it. Band saw, table saw, sanders, and anything that requires CFM to get the chips and dust moving it didn't have the umph to do it. It clogged @ the intake all the time, the bag is to small for anything other than some one that is building small boxes, if mounted to the wall with the hanger its rotates and needs to be adjusted all the time, the filter bag is not 1 mircon, you have to figure out how to mount it so you can roll it around etc etc etc. You can find if look real hard and wit a decent collector for 200.00 or less. Matter of fact there is one right now in out classified ads for 140.00 with the Wyn filter. I dont know where you are but its worth waiting a bit. I wasted around 500.00 on the rockler cause I bought all kinds of stupid crap to go along with it. Now if you already have one mack the best of it and save a few bucks.