Central Vac vs. Dust Collector

Lets assume you will require 5 pick up points, one per counter. How big/small are the counter machines. What size dust particles and how much dust is to be collected per day.

As a starter I would be inclined to install a remotely located central vac unit with cyclone separator and a micro pore final filter for toxic dust if needed.

The counters are about 2-3 feet wide and about 5 feet long and stand about 4-5 feet tall. They will all be in a row about 20 feet apart and the first one will be about 40 to 50 feet away from the Central vac. and the last one will be about 150 feet away from the central vac. unit.

Any recommendations on a central vac unit?

Thanks

Here is a link to a company that makes central vac systems for home use. I have installed one in my house. The power units have more than enough lift but are short on the flow rate. I also do woodworking and have a dust collector system, but I do not have any spec to list. I'm sure the flow rate is good with this type blower, but unsure about the lift capacity.

http://www.beamvac.com/products/residential/power_unit_specs.htm

Either system would work fine.

The difference from a dust collection system and a central vacuum system is the air volume in a dust collection system is a lot higher than a vacuum system.

Another major difference is the vacuum rate. Vacuum systems produce higher mercury inches of vacuum than a dust collection system and have higher energy and structural requirements

Another difference is air velocity. Air velocity in a central vacuum system has to travel at a faster rate of speed than a central dust collection system. Where a central dust collection system may have velocitys of 2,500 to 5,000 feet per minute a central vacuum system would have a minimum velocity of 5,000 feet per second.

Vacuum systems work great for powder transfer systems or in dust collection systems where the dust is heavy (like lead dust) and the velocity has to be higher to keep the dust or product from settling in piping.

If your system is mainly lighter dust like flour, powder sugar or saw dust, than I would say that a central dust collection system would be the more cost effective route.

Designing your system is easy. A few key things to remember when designing.

-There are four components of the system. The system's performance is limited to the weakest component.

-Maintaining a consistent air velocity is a key factor in designing and specifying the duct work. (e.i., 325 cfm through a 4inch duct will have a velocity of 3,300 feet per minute while 750 cfm will travel at the same rate of speed through a 6 inch duct).

-Branches in the duct work should intersect at a 30 degree angle. 90 degree intersects are a poor design practice.

-The dust collector should be sized to handle the cfm. There are two standards:

as an air to media ratio like 10:1, this means for every 10 cubic feet of air there should be 1 square foot of media

or

the canned (upward) velocities, if your dust is very light it will never settle out into the hopper where it can be emptied and will plug (also called "blinding" the filter media).

If you want some further help you can contact me anytime. I would like to look at your proposed system and offer any assistance if I can.

You can also check-out my website at www.dustcollectionsystemsinc.com

Ed