More Dust Collection Questions

[John Neel]

How much outside noise does a 2 hp single stage dust collector or a 2 hp cyclone make if exhausted outside with no filter?

In one of the older threads, someone stated that it is not legal to exhaust outside in their community. Is this because of noise?

Could noise be abated by such techniques as directing the exhaust up, thus sending some of the noise up and away from the neighbors? Or, perhaps by directing the exhaust into a somewhat large, but baffled box?

I am obviously into the stage of adding a dust collector. I have found many opinions but one constant seems to be that many problems can be solved by exhausting outside. That raised these noise concerns.

[Dave Tesch]

mine makes about as much noise as a dryer vent through the hose; maybe a little louder.

i dont know about the legality of exhausting outside. i dont do it myself.

remember that the air you exhaust outside has to be refreshed somehow, the air will come from somewhere so its best to have a planned draft.

i have seen two cyclone setups outside around here, but both run the exhaust back inside the buildings.

[Kirk Simmons]

I wrote a letter to the enforcement division of my city and asked them if it was legal for me to vent dust outside from my home workshop. They wrote back and told me it was fine, as long as I didn't generate excessive construction noise during the neighborhood quiet periods (10 pm - 7 am).

I saved the email, and they also put a copy in my 'parcel file', whatever that is.

- Kirk Simmons
- Eagan, MN

[John Coloccia]

The advice about venting is spot on. If you don't have a source of makeup air (i.e. an open window) you will draw in from whatever convenient source there is. In many homes, especially if you're in the garage or basement, this will be the chimney for your furnace, and you will fill your shop and home with carbon monoxide. You'll also be exhausting all your wonderfully air conditioned air in the summer, and warmed air in the winter. I live in New England, so throwing out my 75 degree air and replacing it with sub-freezing air made this a totally non-practical option. If I lived in San Diego, assuming California would let me I would totally vent outside and leave a window open!

[James Baker SD]

I live in San Diego and I don't vent outside. My wife does not like saw dust blown in her face when she is working in the garden

James

[Mitchell Andrus]

Originally Posted by James Baker SD

I live in San Diego and I don't vent outside. My wife does not like saw dust blown in her face when she is working in the garden

James

Christmas is coming.... Buy her one of those forced air hoods.

[Jim O'Dell]

I have a 5 hp cyclone, and vent outside. Much louder outside than insede the shop. Sounds like a small turbine engine running if you stand outside. If you have neighbors close, normal city lots, I'm sure they would complain no matter what the time of day. Not sure what a muffler would do to the noise. Most cyclone mufflers are designed after the glass pack style muffler for a car. You could possible build a muffler with some switchbacks (baffling-find an exploded view of a stock vehicle muffler, not a glass pack , to copy.) This design will help cancel sound waves, thus quieting the noise. It does add some back pressure though which robs some of you air flow, or power. That's why dragsters don't use mufflers. So if you are on the edge performance wise with your dust collection, this would be detrimental.
If you already have your dust collector, play with it and see what happens. Jim.