Dust Detector Adventures

[Chestnut]

Creating a thread for discussion of my findings from the dust detector i bought a while back. After seeing some experiments from Mattias Wandel, I have a bit more confidence with the detector. The model he is using is similar if not the same the only difference is he has his modified to collect the data with a raspberry pi computer.

I've posted about this in other threads but i can't remember where and it's probably a hijack of the original thread. As other forum users have the meter I figured a thread to discuss findings could be helpful to help people determine what would help improve shop air quality.

I ran the meter a bit in the kitchen as I've read multiple reports that gas stoves are terrible for indoor air quality. What I found was cooking in general is terrible for indoor air quality. After cooking a breakfast for 6, the air quality was very poor. The small particles skyrocketed and reached an absurd number. Leaving the meter in place it took nearly 12 hours for the air to clear up to a level that was below 1,000 and 24 hours to return to a base line value of pretty much zero.

I was curious to see how much just burning gas would add to the particle count. So on a cool day i ran 2 burners on high for 15 min to see if the particle count started to rise.

At the end of 15 min the particle meter had maybe increased slightly but it's pretty clear that food particles are mostly to blame for indoor kitchen air quality. There was some discussion on if the meter can pick up particles from VOCs and other harmful small substances and my answer is a resounding YES. I'll post more information on that below. From my research NOx particles range from 0.05 um to 0.5um which would indicate that this meter would at least be able to pick up some of the emissions from burning natural gas. I'm not saying that it's safe I'm just saying that the emissions from burning the fuel pale in comparison to the food being cooked. I full advocate in installing and using an externally vented range hood regardless of the fuel used to cook.

After the kitchen test i placed the meter around my house with the last spot being right out side my basement shop door. I wanted to see what the impacts of long woodworking sessions would be on air quality in the rest of the house. It turns out that it has had very little impact. When directly outside my open shop door the particle counts bumped up to 500-750 on 0.3um and 100 on 1.0 um. For comparison sake numbers inside my shop have been as high as 5,000-6,000 oddly no where near the kitchen level.

While inside my shop the interesting part of the meter is that the worst thing I can do dust wise is sweep. While sweeping I observed the peak numbers that are above. The other oddity is that dust was NOT visible in the air. The second worst numbers occurred while i was doing hand sanding and brushing the fine dust from 220 grit paper away, or using my mouth to blow it away. Following hand sanding all other options were about equal increasing shop dust levels to 300-500 on the 0.3um level. Interestingly enough just running my dust cyclone I was able to clean the air from a the sweeping level of 6,000 down to 30 in a matter of 15 min.

For reference my shop is 750 square feet and has only 1 furnace vent that I keep closed and 1 air return. Now to the interesting part, VOCs and how i KNOW this meter can detect them. I left the meter running in my shop after I applied coats of Minwax Wipe on Poly to the in-laws dining table. While the finish was curing and you could smell it the 0.3 um number was never below 1,000, it rose to this number after using my dust collector to reduce the particle count to 30. Nothing else was being used in the shop and it held this level for 3 -4 days which was how long it took me to apply finish.

The second VOC occurrence was using spray adhesive to upholster some headline panels for my jeep. When using the spray adhesive in my shop the 0.3 um count jumped to 3,000. That is really near what hand sanding put into the air except these are VOCs and likely more harmful.

If any one else has some interesting observations please share them. This is just interesting from an observation stand point. For piratical sense it's goign to leave me running my dust collector more frequently. I will also start opening the vent in my shop to circulate the clean air into the rest of the house. For comparison sake the baseline is about 100 0.3um for the house vs 0-30 0.3um in my shop. This is all probably pointless and foolish but hey more information is always better than less.

[drzaius]

I was also shocked at how high the particle count can get, yet still see no dust in the air. Sweeping is definitely the worst activity for dust. I've taken to using the vacuum rather than the broom.

I'm going to do some kitchen testing like you did. I want to see how effective the hood exhaust is. It doesn't have the fan in the hood, but on the exterior wall, so it isn't terribly noise, but moves a lot of air.

[legenddc]

Thank you for posting your observations. I'm excited to get mine in and see the results. Mine is somewhere between China and the East Coast. Not sure if it made it out of China before the lockdowns started.

Knowing what you now know about hand sanding what, if anything, are you going to do differently? Also, could you share what Matthias has been doing? I checked his YouTube channel but don't see anything on it.

[drzaius]

I am going to build a sort of exhaust hood above my workbench, where I do almost all sanding, and run an 8" duct to it. After I do that I'll run comparisons and post them. Don't hold your breath on that though  My to do list has many things ahead of that.

[Chestnut]

13 minutes ago, legenddc said:

Knowing what you now know about hand sanding what, if anything, are you going to do differently? Also, could you share what Matthias has been doing? I checked his YouTube channel but don't see anything on it.

For me with hand sanding it's as easy as running my cyclone. My collector has a hepa filter and with 2 gates open can turn over my shop in a small amount of time. The other thing is to remove the saw dust with my hepa CT Vac instead of blasting it around the shop with compressed air.

Matthia's videos.

https://www.youtube.com/watch?v=rDZ9yUdM2wA

https://www.youtube.com/watch?v=4iun3jRUMiA

[legenddc]

Thanks, I didn't think to check to see if he had another channel. Will have to watch them later.

Vacuuming it is probably smarter than blowing it and spreading the dust.

[Ronn W]

On 5/4/2022 at 12:09 PM, drzaius said:

I was also shocked at how high the particle count can get, yet still see no dust in the air. Sweeping is definitely the worst activity for dust. I've taken to using the vacuum rather than the broom.

+1