Individual Dust Collectors Versus a Centralized System

Centralized setups save labor, but your whole shop is vulnerable to a breakdown on one machine. May 14, 2006

Question
What is the advantage to having a large centralized dust collector as opposed to individual units on each machine? I am about to add a CNC router to the shop and am wondering if it makes sense to hook everything up to one big unit.

Forum Responses
(Dust Collection, Safety and Plant Operation Forum)
From contributor P:
This is what we had in our shop for the last 15 years. It was fine as we grew. We would add a machine and add a point of use dust collector (cheap Delta units to 10hp Dustiks units), turning them on when we were running that machine. We are in the process of at least putting our CNC router, CNC panel saw, CNC dowel drill-inserter and edgebander on a central collection system that will set outside the building. This will have a return air so as not to lose all our heat. The main reason for this is the noise and the barrels of sawdust we're producing. Individual units have worked well (less ductwork). But the noise and waste removal has become a chore, so we are investing in a central system.



From Curt Corum, forum technical advisor:
Central System -
Pros: All of the waste is deposited in one location. Saves a lot of floor space. Collector will normally run all day and employees only have to open and close blast gates as they go from one machine to the next. Low maintenance.

Cons: Unit's down, the whole shop is down. All of your eggs in one basket. May have to be located outdoors, permits, etc. Spark detection requirement. Adherence to NFPA codes.

Individual Units -
Pros: Units down, roll over another one. Can be obtained in both single stage and two stage according to the requirement. Much less of a capital expenditure.

Cons: Requires a lot of additional floor space. High maintenance - my dust bag is full, I'll see you guys in about 15 minutes, I have to dump it out back (X how many employees). Many high speed production machines that are being used today can not be serviced with a portable dust collector. Additional electrical wiring throughout the shop.



From contributor R:
If there was no benefit to the central system, why would people go to all the expense? In my shop I got sick of listening to the roar of the cheap units and cleaning the bags.


From contributor D:
When I worked solo, I had a bag type indoor collector. One day, after emptying 3-4 bags of shavings, I calculated the time I spent performing this chore and multiplied by my shop rate. I had already paid for a central collector, I just didn't have it, so to speak. And this was in a one man shop. I called Oneida the next day.

I once saw a 25 man shop go up and they decided on individual collectors for flexibility. They spent 60 m/hrs/wk dumping bags/barrels. They said it was the biggest mistake they ever made.

A good central collection will be quieter, more energy efficient, cleaner, and of greater value than the options. If you are touching dust or containers of dust, you are losing. Don't let the fear of committing to rigid pipe scare you away. Do your best planning, get an expert collector company involved, and install. You can change it if needed, as you need it. With multi collectors, you pay all day every day for convenience.



From contributor J:
Single, large, remote unit is my vote. I worked in a shop that had a large unit for each machine and it was noisy and a mess to empty barrels so often. Also consider the fine dust that escapes the bags in close proximity to work area. It is much easier to contain when bagged in one location, further away from the work area or even better outside, provided you return conditioned (warm) air back into the work space.

When considering the size of unit needed for a large panel saw and CNC, the mobility is not usually an option. They are usually mounted units that are not mobile. Small, single units will always have a place in wood shops (i.e. backup unit, temporary unit for new machine). Keeps the shop going while moving machines or altering duct work.



From contributor T:
What about combining the pros of each system? Have individual portable units so that the whole system isn't down, but duct them all to one large, easily emptied location such as an enclosed trailer, silage wagon, etc. instead of them all going into separate bags/barrels. In other words, are we wrong for doing it this way? We are not really big enough for a very large central system that runs all day. So we have 2 collectors with stationary ducting, some machines are on one, some on the other (we used to have only one but expanded/added machines). The collectors are switched at 2 different locations each and each machine has a blast gate. Then, they both exhaust into one pipe going outside to a small trailer we enclosed with a homemade cyclone-type interior. Is pretty primitive compared to larger factories, but it works very well for our 2 man shop. The blowers themselves are located in the rafters of the building. Would be nice to maybe have a remote switch or an eco-gate type system, but switching on and off and opening/closing the gates is not a huge deal for now.