Replies

1. 
   Buster2000 | Nov 15, 2006 02:37am | #1

   Does the furnace draw air from the garage?  I'd be very nervouse about pumping dust into the house.  Besides being a nusance dust is a health hazard.

   Review Bill Pentz web page, he has lots of great information regarding dust collection set up.

   Essentially here is my understanding:  You need a certain amount of airflow at the tools to collect dust.  Piping, filters, blast gates etc. all work against you here, as they reduce the flow.  When you add a filter bag to your collector, it clogs quickly and kills the flow.  A catridge is slight better since it has more surface area, but again it clogs ups and kills the flow (but better than the bag).  The argument for a cylcone is that it separates the particles out of the flow before it reaches the filter.  So the flow rate should be even.  Further many 1 micron bags and filters and not truly 1 micron, rather than filtering them out it pumps them back into the air.  Cyclones theortically filter these out, and don't use the filter as much.

   The catch is that just owning a cyclone is not enough.  All your tools have to be set up appropriatly to catch dust.  That 4" port on the bottom of your table saw is fine, but you also need collection above.  Hence the suggestion to plumb in each tool.

   A cyclone with dedicated lines is the best solution to your problem.  Since there is the oportunity that you could pollute the air inside your house, it would be worth the money.

1. 
   garrick | Nov 15, 2006 02:45am | #2

   Combustion air is drawn from the garage.  The circulation air should be a "closed" system in the garage, but obviously is not completely or I would not have this problem.  I buy quality air filters, but I think dust is getting though small gaps in the system.  I am thinking of taping over the cracks in the filter door between changes of the filter.  I have started shutting off the furnace while I am working (and up to an hour afterwards to let dust settle) so as not to actively draw dust into the system.

1. 
   joepez | Nov 15, 2006 03:52am | #3

   Garrick,

   I am addressing the same problem with my shop. I have a basement shop and the furnace draws combustion air from the shop, and the dust with it. I have talked with two plumbers, and they both have advised me to to draw the combustion air from outside the house. Thats the first thing. Secondly, I am willing to live with a small amount of dust in the shop, but dont want to just blow the dust back into the air with any filter bag. I have the Delta 1 1/2 hp collector and I have decided to put the filter bag outside. I'll run another line outside and blow the air outside, attaching the filter bag to the vent pipe. I'll suffer the heat loss for the small time that I run my DC, and crack a window to equalize the air. I have used my DC with the filter bag and a air cleaner for 2 yrs, but I know they dont catch the most dangerous particles <1 micron. I dont want to spend a ton of $$ on a cyclone and still not catch the smallest particles.

    You should definatly read the article metioned by the earlier poster about dust and the machines. There are too many variables for me too put any stock in what the advertisements claim.

   Joe P

    

    

2. 
   jako17 | Nov 15, 2006 04:03am | #4

    Your best bet is to seal off the furnace ,water heater from the rest of the garage with steel studs and drywall .Put in an intake for combustion air from outside and a filtered vent to allow heat to escape from the enclosure.There are VERY strict regulations governing the size and position of these openings,based on the input of the furnace etc.Starve the combustion air and your furnace produces carbon monoxide.This is a fast way to become worm food!!!!!

3. 
   Buster2000 | Nov 15, 2006 06:55pm | #6

   Okay makes sense.  I would check with a heating specialist to see what they recomend in terms of sealing up gaps.

   At bare minimum I'd get the cartridge, and optimize dust collection at the machines.  A filter upgrade on the furnace would be a good idea, something that can be cleaned often (rather than replaced).  Finally some sort of air cleaner in the shop to collect dust after the machines are shut down, and befor eyou turn the furnace back on.

   Buster

4. 
   Dave45 | Nov 16, 2006 02:32am | #8

   Last year, I got a large furnace filter that covers the side of my furnace that's open for makeup air and just taped in place with some aluminum duct tape.  It worked like a charm!!  WAY less dust coming inside!!

   I was a little concerned about restricting the makeup air flow, but didn't see any problems.  I left that one on all winter and it was seriously grungy when I took it off last spring.  This year, I got three of them and will pay closer attention to changing it before it gets really filthy. - lol

2. 
   Jfrostjr | Nov 15, 2006 05:09pm | #5

   I have a Penn State 1 1/2 HP dust collector. I started with a 2 bag system (chips below, dust above). Every time I started the DC a good sized "puff" of dust came out of the top, filter bag. I switched to Penn State cartridge and was amazed at the difference: much greater airflow, no dust puff and it was noisier. I am well pleased with the performance now.

   I hate emptying the plastic chip bag and thus would go to a cyclne but I don't have room for the different connections.

   Frosty

   Don't forget to turn the crank at the top of the cannister to "shake off" the fine dust which collects inside and reduces air flow.

1. 
   Rich14 | Nov 15, 2006 08:41pm | #7

   Frosty,

   Your change from the bag to a cannister was a good move. This is not meant to be critical, but even the cannister is not good enough. The visible "puff" of dust on start-up was enough to get you to upgrade. What you didn't see was an even more enormous cloud of fine dust beyond the visible stuff.

   Fine dust is probably still escaping the cannister. The reference given above is very good and gives advice about building or buying a proper cyclone system, which is about the best way to capture the most harmful component(s) of shop dust. It's really remarkable to see a properly-configured cyclone system in operation. It's like a black hole for dust. Almost nothing escapes it.

   Rich

1. 
   Buster2000 | Nov 16, 2006 10:33am | #9

   I think Bill's site is great, but I find it has too much information.  It's literally taken me a year to wade through it and understand it.  Although I feel he's missing some crucial tests, I can not fault the information.  He's really provided a service to woodworkers.

   In the end it really comes down to we as woodworkers recognizing dust collection as a workshop system, not a tool.  A cyclone is just a high power vacuum if the system as a whole is poorly designed.  As Rich pointed out the system must be properly configured. 

2. 
   Jfrostjr | Nov 16, 2006 04:16pm | #10

   RichThanks for your comments. I would love to go to a cyclone - I've had many conversations with Oneida - but the configuartion of the ducts simply will not fit in my "compact" shop area.Aside from that I fail to see how a 1 micron "dust filter" on a cyclone is any different than a 1 micron "their dust filter on a two-bag DC. I know the cyclone directs the large paricles (because of weight) to the drum, but dust is dust and eventually the air 'sucked in' has to return to the shop through a canister "dust filter".FrostyCan you convence my wife to leave her car out? (of course while mine stays inside.)

1. 
   Rich14 | Nov 16, 2006 06:03pm | #11

   Frosty,

   In a well-designed cyclone, amazingly little dust (of any kind) reaches the filter. It is truly remarkable to see a cyclone system which has been in operation weeks or even months with almost no discoloration,at all, of the filter element. Everything is in the collection cannister. The cyclone action separates the dust from the air and deposits it in the collection can, and that's just about all she wrote.

   With a "standard" system that relies completely on the filtration action of a series of membranes to catch, and separate the dust from the air, the abrasive action of the dust, especially fine dust, breaks down the filter material and dust eventually starts to escape.

   A good standard system can do an excellent job. But it seems that cyclone systems get better designed from the get-go. And the basic principle of operation is inherently better as I've described. (Of course, either could be poorly configured, then all bets are off)

   Rich

    

   Edited 11/16/2006 11:48 am ET by Rich14