Trip Posted March 2, 2015 Report Share Posted March 2, 2015 ==>1 - 1.5 SP loss Depends on filter type, surface area etc. Planning number for a typical 90sf spun-poly/MERV15 is 1.8... A 120sf PTFE/HEPA is closer to 2.5+ -- these are design baselines only and vary with specific implementaitons. The diference can be as much as 2->3HP or 3->5HP ----- which is why so many DC mfgs spec sans-media... Quote Link to comment Share on other sites More sharing options...
estesbubba Posted March 2, 2015 Report Share Posted March 2, 2015 Mike - how would you put that in context? Is that a lot or a little? How much extra power do you need to make up for 1 - 1.5 SP loss? On my machine, going from 9.0 to 7.5 SP loss increases the CFM from 1100 to 1250. Quote Link to comment Share on other sites More sharing options...
dwacker Posted March 2, 2015 Report Share Posted March 2, 2015 On my machine, going from 9.0 to 7.5 SP loss increases the CFM from 1100 to 1250. SP loss on the filter side is meaningless to the operator. Filters reduce air speed. Even if you were set up to measure its only a go or no go measurement that is only useful to determine wether or not the media is coming to the end of it useful life. Quote Link to comment Share on other sites More sharing options...
Trip Posted March 2, 2015 Report Share Posted March 2, 2015 ==>meaningless to the operator Once the system is setup and running, sure… But you need some numbers in the planning stage… For spun-poly, 1.8WC worked for years… But sealed-PTFE came along, and that's another animal --- one that starts around 3WC… The easy way around the issue is a filter bank – but at $750 a cartridge that gets prohibitive in a hurry… Of course, you could get a mongo DC and ignore the entire issue… That works… Quote Link to comment Share on other sites More sharing options...
Beechwood Chip Posted March 2, 2015 Report Share Posted March 2, 2015 [...] some people might opt to just use a rolling dust collector next to the machine. I have tried that, and I hated it! The damn dust collector was always in the way! Drove me crazy. So I will embark on what probably is the smallest duct solution ever I'm playing around with the the opposite idea. A fixed dust collector right next to my table saw, with a short length of 6" flex hose. Every other tool is on a mobil base. I roll whatever tool I want to use up to the DC, plug in power and the dust collector, and go to work. Each tool would have a 6" quick connect permanently attached to the dust port, adapter, wye for over/under, or whatever else was needed. No blast gates needed. The down side is that I have to roll out a tool whenever I want to use it, and roll it back to its "parking place" when done. But, with my weird space layout, that might work better than trying to find a permanent home for each tool. Quote Link to comment Share on other sites More sharing options...
estesbubba Posted March 2, 2015 Report Share Posted March 2, 2015 SP loss on the filter side is meaningless to the operator. Filters reduce air speed. Even if you were set up to measure its only a go or no go measurement that is only useful to determine wether or not the media is coming to the end of it useful life. Everything that causes SP loss you must include when doing your calculations. Kind of like counting calories but not including the cheesecake because it's "after dinner". Quote Link to comment Share on other sites More sharing options...
dwacker Posted March 2, 2015 Report Share Posted March 2, 2015 Everything that causes SP loss you must include when doing your calculations. Kind of like counting calories but not including the cheesecake because it's "after dinner". You don't need to do calculations unless your setting up a big shop with multiple users. Waste of perfectly good brain cells. Quote Link to comment Share on other sites More sharing options...
Trip Posted March 2, 2015 Report Share Posted March 2, 2015 ==>Waste of perfectly good brain cells. Yea, not a lot of math needed when you’ve got a 5HP cyclone setup mounted/vented outdoors… Now for the rest of us, some math may be needed at times... Quote Link to comment Share on other sites More sharing options...
Jfitz Posted March 2, 2015 Report Share Posted March 2, 2015 Waste of perfectly good brain cells. I can't speak for others....... but I think you're overestimating the quality of my brain cells - and I appreciate the vote of confidence Quote Link to comment Share on other sites More sharing options...
estesbubba Posted March 2, 2015 Report Share Posted March 2, 2015 At one end of the spectrum we have HHH saying you need to spend $300 for a design service and use 5 different diameters of pipe, otherwise your system sucks... At the other end we have PB saying don't waste any brain cells on your design because your system will still suck... I think most of us here fall somewhere in between, and if there is any dust in the bag, then we tell the forum our system kicks ass Quote Link to comment Share on other sites More sharing options...
Trip Posted March 2, 2015 Report Share Posted March 2, 2015 Ahhh, true... PB and I are frequently in violent agreement…. But when it comes to DC, we do have one thing in common: our systems work to the limit of our tools' ability to collect dust... We just get to the same place from opposite directions… PB has a small shop, larger tools than a typical hobby shop, operating one tool at a time, short duct runs to a 5HP mongo-cyclone mounted outside... He solves the problem with power… This approach is a no-brainer… It works... I also have a small shop, larger tools than a typical hobby shop, operating one tool at a time, short duct runs, but lack the ability to mount or vent my DC externally --- so I needed a smaller HEPA-based solution… To get a small system to perform as well as a large one, you need efficient ductwork... To get efficient ductwork, you need design input… To prevent recirculating the captured damaging dust, you need HEPA filtration... Aside from these two approaches, there aren’t many that will reliably collect and transport sub-0.5u dust and prevent its recirculating… Don can speak for himself, but I don’t wear a respirator when milling stock… And certainly won’t wear one for twenty minutes after the machine is switched-off to allow the free-circulating sub-0.5u micron dust to settle-out... Quote Link to comment Share on other sites More sharing options...
dwacker Posted March 2, 2015 Report Share Posted March 2, 2015 If you can get away with it the best system is the redneck dust collector. A blower blowing into a container outside or into a big pile. My buddy blows into a garden shed. When its full he just scoops it into the trailer. A single phase 5hp single phase dust blower will outperform any small shop sized cyclone hands down at less cost. Quote Link to comment Share on other sites More sharing options...
Trip Posted March 2, 2015 Report Share Posted March 2, 2015 ==>blowing into a container outside or into a big pile. That’s like the guy who fills his landscape trunk with leaves from a fall-cleanup job and drives down the Garden State Turnpike on his way home --- 'forgetting' to secure a tarp over the bed --- and ‘magic’ no leaves… The State Troopers catch one every year… Quote Link to comment Share on other sites More sharing options...
andrew-in-austin Posted March 4, 2015 Author Report Share Posted March 4, 2015 I am still leaning towards metal ducts, but the prices for quick clamp-together ducts is holding me a back a bit. The main problem is shipping. I got one quote for ducts at ~$700, plus shipping at just over $300! This is just crazy. I need to find a local supplier of this type of ducting. Meanwhile I ordered a new cyclone (the new SDD XL) and a stack of two hepa filters, plus some plumbing to put that together. Quote Link to comment Share on other sites More sharing options...
dwacker Posted March 4, 2015 Report Share Posted March 4, 2015 One thing most don't think about is split return ducts. We have this at the shop direct vent for the summer and filter box in the winter. Saves on filters and we can shut down the booster in the summer due to better perfomance. Quote Link to comment Share on other sites More sharing options...
andrew-in-austin Posted March 6, 2015 Author Report Share Posted March 6, 2015 I finally found a good place to order Nordfab: https://www.ductingsystems.com/ Their prices were reasonable as well as their shipping. The also have a much bigger selection than I found at Grizzly and Oneida. And you can customize many of the parts (for example hose-end instead of quick-fit end). All of this can be done online, too. Quote Link to comment Share on other sites More sharing options...
estesbubba Posted March 6, 2015 Report Share Posted March 6, 2015 Holy crap that Nordfab is expensive compared to spiral! 6-6-6 wye: $116 vs $33 plus you need 3 clamps at $20 each 6" pipe: $7 per ft vs $1.60 The Nordfab sure looks like and saves you some time, but spiral looks pretty decent and wrapping tape around a joint doesn't take that long. My $500 ducting would have been over $2500! Quote Link to comment Share on other sites More sharing options...
Trip Posted March 6, 2015 Report Share Posted March 6, 2015 Norfab is pricy, but it's very well made... Quote Link to comment Share on other sites More sharing options...
andrew-in-austin Posted March 7, 2015 Author Report Share Posted March 7, 2015 Yes it is pricy. I made a small order to get me two drops. After I have some experience with it, I'll decide if I want to buy more, or just add on with spiral pipe, etc. I am in only a two car garage, so there's only so much ductwork I can install anyway. I've been researching quite a bit on filters as well. The documents Oneida have are really good, with lots of independent tests run. I think I have a better idea of the "faux" hepa vs hepa now. Quote Link to comment Share on other sites More sharing options...
Dnorris1369 Posted March 9, 2015 Report Share Posted March 9, 2015 Let us know what u think. I've been considering nordfab also Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Nemmy Posted May 11, 2017 Report Share Posted May 11, 2017 Old topic but as I'm researching my own dust collection & ducting I'm wondering if the last few posters had any updates on their experiences here. Quote Link to comment Share on other sites More sharing options...
Eric. Posted May 11, 2017 Report Share Posted May 11, 2017 My shop still remains unexploded. 1 Quote Link to comment Share on other sites More sharing options...
andrew-in-austin Posted May 11, 2017 Author Report Share Posted May 11, 2017 I ended up with nordfab. It's very expensive but very pleasing to install. That being said, there's nothing wrong with PVC or other metal ducts. One advantage of metal ducts in general is that many more sizes are available. Quote Link to comment Share on other sites More sharing options...
Nemmy Posted May 11, 2017 Report Share Posted May 11, 2017 For metal ducting, a few questions as I think through my own design for a 20'x30' space in which I'm looking at around 4-5 inputs (1 floor sweep, 1 miter saw station, 1 bandsaw, 1 double input from a combo saw/shaper in center of the room, 1 'flex tool' input): 1. Besides Nordfab or the Home Depot HVAC metal 6" ducting, are there other winning options? 2. Nordfab: do you purchase this direct based on a design, go to a local dealer for parts, etc? 3. I'm thinking that I want the flexibility to vent inside or outside depending on use/weather/etc. Any suggestions or tips there from a ducting material and gate setup? 4. Any way to mix and match with Nordfab or other name brand setups? 5. Any specific recommendations for the plastic and flexible 'last mile' connectors to the tools themselves? I was searching on the forum for a ducting primer and couldn't find anything. I did read about a dozen threads on the topics which did give me some cool ideas and photos. Thanks for the feedback Quote Link to comment Share on other sites More sharing options...
drzaius Posted May 11, 2017 Report Share Posted May 11, 2017 Beware of the HD duct. It's usually 28 or 30Ga with snap lock seams. They can collapse if you leave all the blast gates closed & need lots of solid support. I used 26Ga spiral duct & long sweep elbows & it's plenty strong. I couldn't justify the Nordfab because of cost & I can't imagine it being much easier to install the spiral duct. The hardest part of the installation was doing the layout & getting all the supports perfectly lined up (I was excessively anal about that). Here's my installation, not entirely complete at the time of photo. the cyclone is on the other side of the back wall. 2 Quote Link to comment Share on other sites More sharing options...
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