261 – Air Quality Upgrades

Written on 03/31/2016

Marc Spagnuolo

Venting the cyclone outside and a new exhaust fan will help keep the shop air free of dust!

I’ll be the first to admit that I have a slight problem: I’m a little paranoid about dust. I want as little of the stuff in the shop air as possible so I continually seek out means to achieve that end. While I do wear a respirator while I work, I frequently have to talk on camera shortly after making cuts that put dust directly into the air. Recently I decided to address two concerns with two separate upgrades.

Cyclone Exhaust

First, I got rid of my cyclone’s double filter stack and instead opted to vent the fine dust through the wall and outside. The Wynn filter stack I had worked well but it does require frequent maintenance. You have to blow the dust out of the pleats periodically and then empty out the fine stuff that falls into the bottom cleanout. I’m never totally confident that the filter is clean enough and it’s not clear to me at what point the filters need to be replaced. By venting the fine dust directly outside, there’s nothing to clean and I can be 100% sure the fine dust isn’t landing in the shop. A simple 8″ dryer vent is installed in the wall and a piece of flex hose is used to make the connection to the cyclone exhaust port. Special thanks to the folks at ClearVue Cyclones for helping me with the fitting I needed to make the connection!

Exhaust Fan

Next up is an exhaust fan. As good as my dust collection system is, it doesn’t catch everything. And it’s not necessarily the dust collector’s fault. Many woodworking tools are designed with dust collection as an afterthought. So if I’m in a situation where I need to talk on camera and the shop air is laden with dust, a high capacity exhaust fan would allow me to clear the air quickly and get back to work. So I installed a 30″ 5500CFM Maxxair Exhaust Fan. Within minutes, the entire volume of shop air is forced out and replaced with fresh air. I installed the fan in the back of the shop which allows me to open the front door to create something of a wind tunnel. Works like a charm!

The Test

To test out the fan system, I kicked up a bunch of dust into the air and used a Dylos DC1100 Air Quality Meter to monitor the air quality. After turning on the fan, it took about 10 minutes for the shop to return to normal. Given how much dust I kicked up (enough to be visible to the naked eye) I was pretty impressed.

Things To Be Concerned About

1 – Air loss. If you condition your shop space in the Winter and Summer, punching holes in the wall will certainly create a source of air loss, and not just while in use. There isn’t much I can do about the cyclone exhaust but the exhaust fan can be easily covered. My plan is to simply build a hinged insulated box that will cover the fan when not in use. And I’ll need to be very strategic about when I use the fan during the Summer months.

2 – Safety. Many shops are located in basements and garages that share space with furnaces and water heaters. Venting outside and running exhaust fans creates a pressurized situation that could very well draw dangerous gasses into your shop space. My standalone shop doesn’t have any of those things within it so all I need to do is open my front door to create the needed return air. DO NOT install either of these upgrades without doing your research first!

3 – Neighbors. Both of these upgrades are noisy and depending on how close your neighbors are and how noise-tolerant they are, there could be a major issue. I’m fortunate in that there’s quite a bit of space between the houses in my neighborhood as well as the fact that being located near an air force base makes the neighborhood very noise-tolerant. Furthermore, I rarely run loud tooling after 8pm.

So if you want cleaner shop air and you have the means/desire, consider venting your dust collection outside and installing an exhaust fan!

Richard Spencer

on 03/31/2016 at 09:35 AM

Does exhausting outside reduce the air flow for your dust collector? Small shops who use a single stage collector often upgrade the “bag” to a canister with a pleated filter to gain air flow. My initial thought is now your air flow is reduced to an 8″ hole vs all that surface area in your filter. Maybe I am wrong and don’t know the full mechanics of this…

on 03/31/2016 at 10:41 AM

No I think it would be the opposite, though I can’t be sure just how much of an air flow gain there is. The old setup actually connected via a 6″ port between the blower and the filter. As big as the filter stack was, there was at least some resistance to air flow. Now, I have an 8″ port and almost ZERO resistance since the air is just being blown outside. So again, I can’t be sure how much of an increase it is, but I definitely don’t think there’s a net loss.

Kevin Chu

on 03/31/2016 at 01:57 PM

For the test, both the fan in the wall and the dust collector remove air from the shop and blow it outside, without returning that air to the shop. Air in the shop would be replenished through an open window or door etc.. So why weren’t the results from both tests the same? Why did the dust collector make the shop air cleaner? Was the difference in test results just due to the fact that the dust collector was left on “for another ten minutes” replacing more air, and if the fan were left on for another ten minutes, the meter would again read in the 40s?

Dan

on 03/31/2016 at 02:32 PM

For the truly manic about their air quality in shops, you *have* to check out Bill Pentz’s site. He suffered some bad health issues due to the fine particles from his shop, and has a wealth of information. It’s heavy stuffy but if you really, really, really want to know about the nitty gritty of taking care of your shop air, check it out. Url is http://billpentz.com//woodwork...../index.cfm. Oh, and Marc, your videos are awesome. Really a treasure trove of good stuff here. Thanks.

on 03/31/2016 at 04:54 PM

You’re confusing the dust collector with the air cleaner. The air cleaner is the thing mounted in the ceiling that filters the interior shop air. The dust collection system wasn’t part of the test and wouldn’t have any impact on ambient air, for the most part.

on 04/01/2016 at 02:28 AM

Ah, sorry. :) I guess there are still some filters you have to deal with then.

Mark Warnow

on 04/01/2016 at 09:59 AM

Looks like you’ve got a good handle on your dust. As an EHS professional, I’m curious if you looked at EPA/AZ air permitting requirements for emitting dust (“particulate matter”) outside your shop? As a business, there are generally requirements for this and I wouldn’t want you to get a surprise :). I will admit I’m not familiar with AZ laws as I’ve been away from Tucson for several years. My guess is you wouldn’t be generating enough, but there still may be a requirement to submit. I have dealt with similar situations in Missouri where the company had to go through the permitting process. They eventually received a letter from the state saying they were exempt from any additional air permitting requirements unless production qualities increased.

Mark S.

on 04/01/2016 at 10:17 AM

Hi Marc. You wrote “…all I need to do is open my front door to create the needed return air.” One worry you didn’t fully touch on. If the return air contains more dust than the vented air, venting outside can cause more problems than it solves. Think about applying some finish and having the outdoor rif-raf of particles end up all over your new piece.One idea is to have a filtered return air vent. In this way you can be assured of particle-free air in the shop. Any thoughts?

Rodger Jordan

on 04/01/2016 at 11:52 AM

I added the same ClearVue Cyclone System to my shop a couple of years ago. The info I got from here and Bill Pentz’s site is what led me to invest in the system. The system works great, however the thing is pretty loud. I have been toying with the idea of building a closet around it or venting outside. Not sure what would produce the best results. So, I was wondering, if there is a noticeable difference in how loud the system is?Thanks for all the great info you provide.

on 04/01/2016 at 12:38 PM

If the return air contains more dust than the vented air, then I’d say it’s a pretty dusty day outside and I’d have my windows and doors open anyway. Also, I can’t think of a reason I’d have the fan on while finishing. I might turn it on prior to finishing to clear out the air, but having any excessive air movement while the finish is wet will certainly invite more dust nibs in the finish. Filtered return air is certainly a nice precaution, but I probably couldn’t justify it in my situation.

on 04/01/2016 at 12:40 PM

But my business is podcasting. My hobby is woodworking. :)

Bob McKenny

on 04/01/2016 at 12:44 PM

whos air filter do you use?

on 04/01/2016 at 12:54 PM

It’s the Powermatic model.

Peter Durand

on 04/01/2016 at 02:32 PM

Hi Marc,Good video. I had a thought about the heating/ac depletion when using that fan. In my house (2700 sq ft) I have an air/air heat exchanger that changes the air completely every 30 minutes with a reported 97% efficiency. Runs continuously. Might work in the shop?But now I just had a duh! moment… the exchange mechanism would get clogged with the wood dust in short order. Oh well, back to the little grey cells drawing board.Cheers,

Dave Stanton

on 04/01/2016 at 04:05 PM

Well said Marc!

Tom moores

on 04/01/2016 at 07:19 PM

How about a heat exchanger ventilation system, they partially condition incoming air using the exhaust air, makes the temperature of the incoming air closer to the room temperature

on 04/01/2016 at 07:20 PM

Now I see Peter already thought of it

Sean McCurdy

on 04/02/2016 at 08:38 AM

To solve the summer HVAC issue, assuming you have not sold the Wynn filters, had you considered using a Y splitter? Normally you could exhaust outside, but when the AC is running flip it over to the filters.

George Woodrum

on 04/02/2016 at 10:22 PM

Hi Marc,Did you ever do any measurements with the Clear-View cyclone running prior to removing the Wynn filters? I would be curious to see the numbers. (I run one with filters currently.)

on 04/03/2016 at 11:05 AM

I considered this in my old shop and in fact, it was part of the original plan. But the reality was I just never bothered setting it up and the AC just wasn’t the issue I thought it would be. While it will be wasteful to run the DC while the AC is on, the reality is that once the interior space is cooled, it doesn’t take long to cool it back down again. Evacuating the air and replacing it with warm air is a very different situation than trying to cool a hot building that’s been sitting with no AC at all.

Lance P Mirrer

on 04/03/2016 at 11:43 AM

Can you recommend any reasonable quality meters that are less expensive than the Dylos?

on 04/03/2016 at 04:07 PM

Nope. This was my first venture into air quality meters and the Dylos was the first product I found.

on 04/04/2016 at 03:29 PM

You can determine when the filters need replaced by installing an air pressure manometer (such as a Dwyer Series Mark II 25 Molded Plastic Manometer or similar) with the tubing intake at the bottom of the filter stack. I use the following suggested by Bill Pentz:“When and how do I clean my filter bag?Knowing when to clean your filter is mostly a matter of feel or buying an air gauge. If the flow is falling you need to clean. When to replace your filter is tougher. You have to monitor particulate count, pressure, or be conservative and do early filter replacement. With particle counters far too expensive for most, it comes down to buying a pressure gauge and carefully tracking the pressure or just regularly replacing filters. When the pressure starts dropping (from the original “new” value) after each cleaning your filter is near if not already needing replaced.Here is how to do that monitoring, at least what works for me. Put an air gauge on your system when you get new bags. For this to work you need a consistent situation. For those with ducting I suggest running with your two closest largest ducts open and all else closed. If you do not have ducting, then test with only a 10′ length of flex hose connected. First record the pressure with no bag then with your bag. The difference is how much resistance your bag adds. Next record the pressure every time you clean your bag by either vacuuming or blowing it down. Don’t use more than 40 PSI to clean your filters or you will kill them early. The pressure should rise rapidly for the first three cleanings then slowly rise for the next six or so. Then the pressure should stabilize after every cleaning. When the pressure fails below its normal after cleaning pressure, it needs attention. If you have a blended poly paper filter like most cartridges, you need to replace the filter. If you have an all poly heavy filter bag or cartridge you need to run the filter through a washer and start over. If the pressure does not quickly build up to the same prior resistance levels, then that poly filter is probably shot and needs replaced.”“Proper exhaust filter pressure for dust collectors ((using a water/radon manometer)):2.5 = you need to clean filter.”I strongly suggest reading Bill Pentz’ website–it has tons of very important info!!!

on 04/04/2016 at 03:35 PM

Sorry, last part did not display correctly–“Proper exhaust filter pressure for dust collectors ((using a water/radon manometer)):2.5 = need to clean filter

on 04/04/2016 at 03:38 PM

Last try–“Proper exhaust filter pressure for dust collectors ((using a water/radon manometer)):less than 1 inch when clean (if higher = not enough filter area)greater than 2.5 inches = need to clean filter”

HIH

on 04/07/2016 at 01:25 PM

it is work good when the outside strong wind?

RL Ron Labrousse

on 04/09/2016 at 12:32 PM

I’ve vented my dust collection to the outside my shop for many years, all of it, without any type of pre-collection. Actually my dust collector sits outside of my shop in an unconditioned space. Makes it really nice for noise,or lack there of. It also makes it great for the pasture outside, in that it grows greener and plusher. It can make it cold during winter months, but as with the AC, it warms back up within a few minutes. What I did was have a return air vent, wlth louvers made, that looks similar to your exhaust fan exterior vent. It simply opens as necessary to replinish the air you’re exhausting. Then the louvers drop back down when the exhaust system shuts off. That way you don’t have to open the door, or a window every time you momentarily turn on the system.As far as air flow is concerned…think about it…there is no filter to restrict airflow, of course the airflow is increased. To a point of almost 1/3 more. I’ve never noticed wind having any effect other than distributing the exhaust better.And as far as particulates in the air…there is far less than simply mowing the lawn, or burning a new EPA approved Woodstove over a long period of time (or especially one that’s not). And it’s not like you’re emiting anything poisonous that would effect someone 300 yards or further away, or even within 30 feet. And…It’s not like you have a cabinet shop with 20 employees producing a truck load of cabinets every day. It’s a great way to exhaust dust, and reduces the risk of fire.I very much enjoy your site and your videos.

Jim Barry

on 04/10/2016 at 08:42 AM

I have a similar approach that I call “Defense in depth”. Collect at the source (using a Clearvue with large mains) , wear personal respirator when needed, augment with air cleaner and use exhaust fan for certain high dust operations. I use a Dylos to define the current DEFCON. When the Dylos numbers are low (DEFCON 1), I don’t use a respirator. But when the particle counter goes into the unsafe zone, we go to DEFCON 2, 3 or 4 and on it goes. Only with the respirator on will I use the air cleaner while in the shop, otherwise it’s for clean-up operations after the war – it drops me back to DEFCON 1 within an hour or so.I don’t have the luxury of venting my Clearvue outside but will occasionally use a large volume window fan to exhaust ambient air, leaving a door or window open to provide air flow.

Ken

on 05/02/2016 at 11:41 AM

What your doing is fine in terms of getting the particles outside. Essentially you’ve taken the whole house fan concept and adapted it to your shop. The problem is that your essentially pumping your nice air-conditioned or heated air outside and replacing it with air sucked in from the outside world. I understand you live in Arizona, Phoenix area I believe, so in July your going to be essentially exchanging air at 75F in your shop with outside air (110F). Bottom-line, your going to run up your power bill doing this and its probably going to be uncomfortably warm while your doing it. Generally those fans can move a lot more air than most air conditioners can keep up with Your case might be a bit different since this is essentially your business. But for most of us hobbyists I think the best (aka cheapest most efficient) way to do this, is to just use the internal cyclone systems we’ve got during the day for most operations and save the high dust generating jobs until the evening/morning. I’m in southern cal, so while it does get hot during the day, the evenings in most cases get down into the 70’s. I just open the garage roll up door and strategically place an ordinary fan so it blows the dust that escapes my vacuum system away from me and out the garage door.

Mark Ross

on 05/05/2016 at 01:27 AM

I had a delta 1 1/2 horse bag type chip collector / dust distributer. So bad I quit using it. Converted it to a cyclone with Onieda’s Super Dust Deputy and 1 micron canister final filter. 50 gallon chip collector. I get about a quart size amount in the plastic bag under the final filter per 50 gallons. Works fantastic. I have a 6 inch main duct about 30 feet. 7 gates to 4 inch. Flex hose from there to my machines. Longest flex is 14 feet to my drum sander and it sucks up virtually all of the dust that beast creates. Average CFM at the 4 in gates is 550 CFM and 5000 ft. per minute. (measured with a Digital Anemometer )

Skip Kessler

on 06/11/2016 at 10:26 AM

Marc – Great videos and solid explanation of alternative approaches to keeping the air clean.Any ideas on how to use an air exchange approach in a basement shop where there is no outside access across from where an exhaust fan would be placed. For example my shop is in the basement and given the design of where my shop is I am surrounded on three sides by concrete and the fourth side is where an exhaust fan (probably a window based unit) would be installed. Short of cutting a hole in a concrete wall, do you see any alternatives to getting fresh air in so that the fan can draw across the work area? Also you comment about knowing your space and the impact “pulling” gas from water heaters and furnaces peaked my curiosity since I have both a gas furnace and water heater in the basement – can you elaborate on how to take this into consideration when ventilating the room?Also would like you opinion on air cleaners. There are a lot of posts out there which suggest that these are nothing more than expensive noise makers.Thank you for you time and again the videos are great.

Peter Lakis

on 07/20/2016 at 07:14 PM

Hi Mark, Question: Any advice for air quality control/dust collection for someone with very limited financial resources and a home garage shop (rental, not own)? I’m just not at a place where I could pay a couple grand for the cyclone you mentioned. Currently, I’m just moving a shop vac around whenever I can, and using a leaf blower to push the dust out open garage doors when it feels like a woodstorm. Frankly, I’m getting tired of the crazy amount of wood dust everywhere, and worried about my respiratory system long term. Last but not least: Thanks for creating a truly amazing educational resource. I’ve been reading your site pretty much non-stop after work since I found it a couple weeks ago.sincerely,Peter

Dave Roy

on 07/22/2016 at 10:35 AM

Mark (et al)To address the wasted air conditioning: Yes you are sending all your conditioned air out the pervrebial window! But in my research for heating my space (looking at a solar heated slab), the energy needed to cool the volume of air in your shop is minimal. So long as you don’t leave it on long enough to heat up all the mass in your shop (think lots of steel, cast iron, and concrete slab!) your recovery time will always be pretty quick. I would worry more about the humidity and condensation. I know, your in AZ.. what humidity; but I say it more for others. My shop stays about 10 degrees cooler than the ambient outdoor noontime temp, just by keeping it closed up as much as possible (and I run a dehumidifier). But If I open the big door for long I can actually watch water bead up on my TS table!So bottom line, Don’t sweat the quick air exchange but make sure it doesn’t make your tools sweat!

Michael Dilday

on 02/18/2017 at 12:08 AM

Now that you are in a cold climate how have your dust collection and venting outside changed? It will be expensive to pull the cold air in during colder months.

on 02/18/2017 at 11:02 AM

I have a more traditional setup with no outside venting. If I want fresh air, I need to open the garage door. :)

Heather McArdle

on 05/17/2017 at 04:15 PM

I live next to a person who runs his dust collection system about 25 plus feet out of his building thru a metal pipe and into a trailer. It is SO incredibly noisy, but he is a local so Im terrified to talk to him. He also has about 4 empty fuel tanks and fuel barrels outside his shop which makes me triple freaked out. My property is literally 15 feet from his shop. The noise is ruining my life and probably bringing the property value down as well. Is this legal to run the tubing out of the shop like this and is there anything to do to make it more quiet? I am going to have to deal with this and want as many ideas as possible from people who have these things. HELP!!!!

George Yetka

on 03/23/2019 at 11:14 AM

How did you adapt the 8″ exhaust on the DC to the 8″ flex? the piece i got with my clearvue said its designed to accept pvc sewer pipe. It looks like yours has 2 pieces

on 03/23/2019 at 01:37 PM

Unfortunately at this point I don’t recall exactly what it was. But looking at the photo, it looks like I just had the 8″ flex clamped directly to the outlet.

on 03/27/2019 at 07:16 AM

Thank you

Kevin Slonecker

on 02/27/2020 at 10:24 AM

Who/what government body did you contact to know if venting outside is legal in your area?

Steve

on 05/21/2020 at 12:36 AM

I was looking at ideas and Nobody mentioned the word swamp cooler. If you live in a dry climate like Colorado they work great in the summer months .winter time is a different storyI can pump 6000 cfm through my basement windows while I am cooling the house down.It is not a total solution but it is a bonus solution plus i already got it paid forIt would even work for a attached garage

Anthony DeChiaro

on 12/02/2020 at 11:03 PM

Hi Marc, based upon some rough math it seems you are doing roughly 15-20 air changes/hour with the 5500 CFM fan (1800 ft^2 * ~10-12 ft ceiling / 5500 CFM =~ 3-4 min/change).I tried searching for OSHA regulations on this number in woodshops without much success (only exposure metrics), but some other sources estimate around 5 changes/hour. Just curious – was there a specific guideline you were following, or just playing it safe? I am trying to calculate what I should use in my garage, thanks for the help! :)

on 12/03/2020 at 09:41 AM

No calculations were done. Just trying to do something more than nothing. :)

on 12/04/2020 at 05:33 PM

Gotcha, thanks for the response and info!

261 – Air Quality Upgrades

Cyclone Exhaust

Exhaust Fan

The Test

Things To Be Concerned About

Comments