Valleyslim Posted July 6, 2022 Report Share Posted July 6, 2022 i've ordered the filters and fans and im going to do this build. He has the fan blowing inside the box so the dust collects on the inside of the filters (pull) as opposed to (push) where the fan blows upwards and the dust collects on the outside. He makes some good points as to why he does pull so dust doesnt get blown around in the shop nor having the dust that sits on the outside of the filter to get disturbed and possible get loose and float around the shop. However my thoughts are its only collecting dust from the top via sucked from the back of the fan instead of through 8 potential ways for the dust to get sucked it. Which do you think is a better setup push or pull Quote Link to comment Share on other sites More sharing options...
wtnhighlander Posted July 6, 2022 Report Share Posted July 6, 2022 The only possible issue I see with that setup is that the fan runs in 'dirty' air, and will eventually fail from buildup of contaminants in or around the motor. In most hobby shops, that would take a long, long time. Larger dust collectors run the fan 'dirty' quite often, but those fans are driven by a motor that is outside the air stream entirely. Quote Link to comment Share on other sites More sharing options...
Valleyslim Posted July 7, 2022 Author Report Share Posted July 7, 2022 On 7/6/2022 at 5:56 PM, wtnhighlander said: The only possible issue I see with that setup is that the fan runs in 'dirty' air, and will eventually fail from buildup of contaminants in or around the motor. In most hobby shops, that would take a long, long time. Larger dust collectors run the fan 'dirty' quite often, but those fans are driven by a motor that is outside the air stream entirely. thats why he specifically picked that caterpillar fan because the motor is enclosed so no dust can get in the motor Quote Link to comment Share on other sites More sharing options...
woodprox Posted July 31, 2022 Report Share Posted July 31, 2022 There is no one definitive answer to this question. Some people might prefer to use a push filter because it is less likely to cause dust particles to become airborne. Others might prefer to use a pull filter because it is easier to clean. Ultimately, it is up to the individual to decide which type of filter works best for them. Quote Link to comment Share on other sites More sharing options...
Tom King Posted July 31, 2022 Report Share Posted July 31, 2022 I like pull with disposable furnace filters. Quote Link to comment Share on other sites More sharing options...
CharlesR Posted January 21, 2023 Report Share Posted January 21, 2023 I'm about to build an air filtration system along the same line but it's going to be (L x W) 63" x 30" with 3 MERV 13 filters on each side and a drum fan at one end. On the other end I'll be able to coil the power cable. It'll be on locking casters and height will be the same as my table saw so it can do triple duty as a platform for moving sheet goods, an infeed table and air filtration. I'm going with pull for a few reasons: - I'll be able to see the "dirty" side of the filters and have a visual reminder to clean or replace - like you, I like the idea of having (16 x 25 x 3) 1200 sq. in. of surface opening on each side of the unit to draw dust into vs a single 255 sq in. portal through the fan. - I think a laminar airflow out from the fan will lead to better overall air circulation than the turbulent flow that would come out of the box (and without directional baffles, the confused air being pushed into the box might reduce overall airflow) - All the commercial air filtration units seem to use pull. There must be a reason ... If you've built it, which did you choose and how did it work? Would love to hear more on the subject. 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Valleyslim Posted January 22, 2023 Author Popular Post Report Share Posted January 22, 2023 On 1/21/2023 at 2:04 PM, CharlesR said: I'm about to build an air filtration system along the same line but it's going to be (L x W) 63" x 30" with 3 MERV 13 filters on each side and a drum fan at one end. On the other end I'll be able to coil the power cable. It'll be on locking casters and height will be the same as my table saw so it can do triple duty as a platform for moving sheet goods, an infeed table and air filtration. I'm going with pull for a few reasons: - I'll be able to see the "dirty" side of the filters and have a visual reminder to clean or replace - like you, I like the idea of having (16 x 25 x 3) 1200 sq. in. of surface opening on each side of the unit to draw dust into vs a single 255 sq in. portal through the fan. - I think a laminar airflow out from the fan will lead to better overall air circulation than the turbulent flow that would come out of the box (and without directional baffles, the confused air being pushed into the box might reduce overall airflow) - All the commercial air filtration units seem to use pull. There must be a reason ... If you've built it, which did you choose and how did it work? Would love to hear more on the subject. i went with the push configuration as because my filter is on wheels and i move it to where im working, any movement could dislodge dust on the outside of the filter. So mine blows inside the box and it works better than i thought. The fan is big enough where i can see all the filters inside to see the condition they are in. If you watch the video, a single filter can only take so much cfm, meaning if your fan is 1000 cfm and only 1 filter than your cfm is only as good as the how much the filter lets through. Mine has 8 merv 13 filters (1 inch thick) to accomadate my 4000 cfm fan. But anyways, he says blowing up is better but would take longer to filter your shop as your blowing dust up so to get rid of the dust it would need to take a couple cycles. i was surprised at how fast the dust that i could see get pulled towards the fan though. I also run this filter with my jet 1000 so i run both. A tip if you do make it is use tape to hold down the filters. i used hot glue and they held up for a while but all failed eventually. I built mine with particle board instead of 2x4 and just laminated 2 pieces together 5 Quote Link to comment Share on other sites More sharing options...
Popular Post CharlesR Posted February 28, 2023 Popular Post Report Share Posted February 28, 2023 Finally finished this air filtration system and my first comment is "Wow, what a difference to air quality". I have very good dust collection but, as has been pointed out by many, that's not air filtration. Used 6 MERV 13 filters and a Dewalt drum fan in a pull configuration. My shop is 20x40x8' and I estimate 4000 cfm so I get multiple air changes an hour. System is on casters so I move it around even though it's a bit bulky. Made it the same height as my table saw so also acts as an in-feed table, secondary assembly table, etc. The "arms" are for loading sheet goods and easily swinging them up on the table, then rolling them into place (thank you Nick Engler and workshopcompanion.com). So far, really happy with it. 5 Quote Link to comment Share on other sites More sharing options...
Tom King Posted February 28, 2023 Report Share Posted February 28, 2023 Charles, that's worthy of copying! Quote Link to comment Share on other sites More sharing options...
wtnhighlander Posted February 28, 2023 Report Share Posted February 28, 2023 That's an excellent design for a shop with enough space. And you are right, Mr. Engler has some great tips to share! Quote Link to comment Share on other sites More sharing options...
Mark J Posted March 1, 2023 Report Share Posted March 1, 2023 Do you find airflow from the exhaust fan much of a nuisance in the rest of the shop? Quote Link to comment Share on other sites More sharing options...
Coop Posted March 1, 2023 Report Share Posted March 1, 2023 That’s a pretty cool setup! Quote Link to comment Share on other sites More sharing options...
Chestnut Posted March 1, 2023 Report Share Posted March 1, 2023 Very nice. A few air changes per hour.... your shop is 6,400 cu ft. you get almost 40 air changes per hour. Quote Link to comment Share on other sites More sharing options...
CharlesR Posted March 3, 2023 Report Share Posted March 3, 2023 On 2/28/2023 at 7:13 PM, Mark J said: Do you find airflow from the exhaust fan much of a nuisance in the rest of the shop? Thanks folks for the comments. I'm new to this forum and your comments are very encouraging. Hi Mark. Much to my wife's amazement, I try to keep the floor of my shop reasonably clean so blowing dust around hasn't been a problem. When I roll the unit in place, I try to direct the fan so it's blowing down one side of the shop to max circulation. One additional comment: as was noted and bothered me with the pull configuration, the dust accumulates on the external side of the filter. Also, the filters are in there pretty snug and I realized would be a pain to take out for cleaning. My solution is to roll the unit to the exterior door and with my shopvac outside, I vacuum them and all the micro stuff not captured by the shopvac filters goes the the four winds. Quote Link to comment Share on other sites More sharing options...
Coop Posted March 4, 2023 Report Share Posted March 4, 2023 Nick Engler? Never heard the name. Anyone recommend anything in particular? Quote Link to comment Share on other sites More sharing options...
wtnhighlander Posted March 4, 2023 Report Share Posted March 4, 2023 @Coop, I can't say that his videos cover a ton of ground-breaking info, but he has an entertaining way of explaining stuff with great clarity. An example: Inspire Woodcraft is another channel that really examines the how and why of various woodworking technuques in great detail. Lot's of thought goes into these videos, like this example. 2 Quote Link to comment Share on other sites More sharing options...
CharlesR Posted March 4, 2023 Report Share Posted March 4, 2023 On 3/3/2023 at 9:36 PM, Coop said: Nick Engler? Never heard the name. Anyone recommend anything in particular? Here's the video I referenced on Cutting & Handling Plywood in a One-Person Shop: 1 Quote Link to comment Share on other sites More sharing options...
Tom King Posted March 5, 2023 Report Share Posted March 5, 2023 That's exactly the kind of saw guide I've used for almost 50 years. It's easier to use one than not even when cutting stuff like roof sheathing. I have several different lengths for different saws and cutting plywood the 8' or 4' way, plus one for trimming the bottoms of house doors. Never had the need to buy a track saw. When I get too old to manhandle a sheet of 3/4 plywood, I'm going to build one of his racks. Quote Link to comment Share on other sites More sharing options...
Mark J Posted March 5, 2023 Report Share Posted March 5, 2023 Nice presentation and good ideas. One point he doesn't address is how straight the 2x4's need to be (and where you can find straight 2x4's ). Quote Link to comment Share on other sites More sharing options...
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