Don't mind comments as long as you don't mind anything.

Yea I legitimately trust Matthias to be impartial and to provide actual data. This is among the many reasons why I think I would trust sponsored videos from him more because I trust him to tell the truth.

It is a fact that UFPs (Ultra Fine Particulates) are emitted by the FFF/FDM 3D printing process with thermoplastics. There’s plenty of data proving the harmful nature of long term exposure to UFPs, especially in significant quantities. This is one of the reasons for the significant ventilation requirements for commercial kitchens. What is lacking is enough study in particular of the quantities of UFPs generated in the FFF/FDM printing process with various materials. If you’re running a print farm with multiple printers running 24/7, you likely have an air quality issue you should be addressing. If you have employees working in that environment, you DEFINITELY need to take this seriously. The questions come in with a consumer using 1 or 2 printers on a lower duty cycle - does this present a hazard to the occupants of the home? One significant issue however is that HEPA filters aren’t fine enough for UFPs. This is why solutions designed for the application often have 3 filter stages. A cheaper one to protect the more expensive filters from larger particulate. Then a HEPA filter, followed by an even finer stage filter. Dental office units can fill the criteria. But you may want to avoid any running UV light. As these can create ozone (sometimes sneakily referred to as “activated oxygen”) which some believe could be as harmful or worse than UFPs. The air filtration market is full of a lot of conflicting and confusing claims. Much of which is not backed up well by peer reviewed scientific study.

@@barrettdent405 This unit that sponsored him has 3 stages, with the 3rd being a carbon filter.

Dyson air purifiers are complete garbage

That's actually a good point, to see the rate at which the particles naturally settle out.

This is what I wanted to see. Science needs a control.

It is important, but my guess is over the time scale of these experiments, the slope of the curve on the log graph would be within experimental error of zero. For the smallest particles anyway.

@@alans1816 Matthias did say that some of the particles can stay in the air for days.

@@SuperDavidEF True, but that would be the control aspect of the experiment. Without it you don't know exactly how much quicker something works

Oh that's a good point I hope he addresses that.

I was wondering the same. I guess it would friend on whether the particles would land on the floor… as I typed this he said that smoke can hang in the air for days, so that answers that

The decay rate with no filter would be dependent on the building construction, available windows to open and everyone's setup is different. We always open the garage door in the shop I work in during the summer and with a fans running that seems quite effective in clearing paint fumes quick. Would be good to know his natural decay rate for this video though as that is a large space and I assume those small air filters are not performing that well on their own. He says 165 sq ft and it was roughly 40 minutes for the dreo on high to clean it and the box fan was not much longer. I've seen testing on KZfaq in a smaller 100 sq ft bedroom take an hour to clean to that level with the box fan filter.

That's my thoughts as well, this test is not really worth much, without a baseline

I was about to say, we didn't get a control test to see what happens when the particles are left to settle, I'd like to see that. It could turn out the box fan is just a placebo

You need to remember that if he showed a product that makes the sponsored product look bad he wouldn't be paid, that's what a sponsored video means. The Dyson is absurdly under-performing compared to almost any air purifier, and the other competitor is a furnace filter taped to a fan..

@@diego1694 that depends on the contract they agreed on. I'm pretty sure that Matthias negotiated being able to do a full non-biased test against the filters he already had. Cause that's the type of person he is. He will not take sponsoships if he cannot show that it's what it claims to be. Though if he had a better commercial air filter the story might be a bit different.

​@@ratchet1freak Matthias isn't lying about anything, I am sure that everything that is said in the video is completely true. I am also sure that if there was a similar product for half the price that obtained similar results, the sponsor would never agree to allow Matthias to include it in the video. You can find other replies here where Matthias essentially admits to choosing the Dyson because he know it is not very good..

Dyson once more proving that, at best, they make adequate products that are comically overpriced.

@@IstasPumaNevada Dyson makes decent products that look outstanding and are priced accordingly.

@@IstasPumaNevada i have one of the dyson fans with the same filter but with fan/heater mode(it was a gift so i have no bias), its "nice", has a cool display that shows if it's detecting i think 4 different harmful particles in the air as it runs. it works really well as a room heater. i'd say it's the Apple of fans. only those who have money to spare will spend it on such an appliance, even if it isn't the best, but is the best looking and feeling

Dyson is the Apple of appliances, and it makes me happy when they lose.

@@IstasPumaNevada I never liked Dyson because of their pricing, and really got tweaked by their "bladeless fan". Hiding a fan blade behind a grill doesn't make it bladeless!

Indeed, I was thinking that was missing.

He kind of did it with the ineffective filter, but didnt show us the result.

Correct. Dust settles, even with a fan blowing, in about 30 minutes anyway. The smoke makes a good example because it stays airborne so long. If you have ever burned bacon, popcorn, or something, you know the smell lingers for like a day or two.

Ngl, that wouldnt just be scientific, i think its necessary as a measuring tool of "how much is natural decay and how much is the filter's doing"

@@atatdotdot scientific*

Yeah, I was also going to ask what MERV filtrete filter that was - there's all different levels

Yeah; you’d have to think a 4” Merv13 filter on the box fan might clobber everything… or burn the fan up, one.

@@jasonm.7358 The part that I don't really have the equipment to test is where the point is where a higher MERV rating is actually worse because of how much it restricts airflow. I'm in wildfire country (who isn't these days) and I have been running some low-end MERV13 filters on several box fans when it's really smoky out. It makes a noticeable difference but the noise gets old.

If sticking with 1" filters, the 3M Filtrete 1900 which is a MERV-13, shown in this video, is the optimal one. It has the lowest pressure drop of the entire line (hard to believe, but true, you can see why in the design with high pleat density). Otherwise most 2" MERV-13 are a good option.

If you're going to use the box fan, rather than placing a single filter on the back, I would take five filters, and make a box. That will give 4 or 5 times the filter area, reducing air flow restriction. With that, you can use the HEPA style high MERV filters, without restricting the air flow from the box fan. (If you place the apparatus on the floor, the bottom filter won't get much air)

And CHEAP! Even the sponsor seems a bit price to me compared to the $20 box fan special from Wal-mart.

@@jandrewmore Or a pedestal fan from the side of the road.

@@user2C47 You've got better luck (or richer neighbors) than I do. I'm happy if I can find some plywood, and that was before lumber prices went nuts.

@@jandrewmore I will admit that furniture is not a common find even where I live, and it was several miles away from home. I only mentioned it because a lot of things used on this channel are found in the trash.

It tweaks me when I hear people say "a dirty filter doesn't filter" when in fact they filter better, just slower. No 2. was *perfectly* stated!

Lol. Me too. Thinking of putting one in every room actually. Maybe rig up something that runs it x minutes per day

I did exactly that during wildfire season a few years ago. It really helps, and was comparatively very cheap. I set up multiple fans to try to swirl the air around the larger rooms. Only issue was the noise level - I'd run them during the day if it was really bad, but otherwise I tried to run them overnight (while I was in a different part of the house) or while I was out.

"No problem"? Openly-discussed sponsorships should be the norm for sponsorships. Are people expressing concern about how open Matthias is with his sponsorships? That's actually one of the reasons I respect him.

@@PBTophie I think what they mean is this is the right way to do them, in contrast with sponsorships they do have a problem with where they are just "product placement" or, even worse, "product praise" videos.

Any odor a product causes is technically airborne pollution, whether particles or VOC caused.

@@mlindholm Yeah, that makes sense... I guess I'm not clear on where the line between molecule and particle is, in terms of health impact from particles lodging in the lungs, or whether it's even a particularly relevant distinction; I just assumed that whatever off-gasses from glue guns wouldn't be detected by the particulate sensor he was using or have the potential to be harmful aside from whatever immediate/acute impact it had. Like, I know I shouldn't breath acetone vapors, but I don't think of them as particulate pollution, and my impression of the sensor he is using is that it's detecting the latter, and I would have assumed that glue guns would be the former...

Very helpful. I have a $170 one on the way, and I am re-thinking to doing this. Plus to REPLACE the filter in the new one is 50bucks! These are about 10 bucks each!

@@Davethreshold The cheap filters are cheap, but if you want a furnace filter to clean smoke out of the air (MERV 11 or better) too ... mine cost $36 Canadian. But I don't have to change it often because the cheap filter catches all the big stuff.

Yes, I knew the dyson would underperform :)

@@matthiasrandomstuff2221 Pimp out with a higher MERV rated filter and/or 2" and 4" thick filters. Then compare to this video and your previous referenced as well. Seems silly not comparing to the 4 or 5 filter versions while at it. That'd be awesome. Wondering about other filters like maybe an electrostatic pre-filter and/or carbon filters maybe?

yes, that can work quite well, but noisy and big. but it’s what I’d recommend if you just need to know if an air purifier will improve your situation.

Not available in Canada?

Question: how good is a old/new t-shirt over a table fan on low?

@@jstreutker it's available in Canada at 339.42 and free shipping what a deal

Ain't I happy that you did a video like this. I needed a small air purifier for my place. Shit, I think the sponsored videos are getting to me.

@@MrHack4never probably just as bad as the useless old style furnace filters that only keep the chunks out.

That filter shouldn't run while doing woodworking, a HEPA filter would be ruined in no time. Leave, let the dust settle 5-10 minutes, then come back and turn it on for nice clean air. You probably know that, so take it for what it's worth.

small correction, when you block/restrict the airflow it reduces the load on the motor not increase

This may be a good point for viewers. But Matthias knows all this stuff. He has a long history of building air cleaners for the shop. Just FYI.

True, would have been even better.

Exactly!

Very slowly!

My guess is that with the particle sizes under investigation, Brownian motion is going to keep a lot of the smoke in the air for quite a while until it sticks to a surface as opposed to settling out. Heck, on those time scales, unless the room is hermetically sealed, diffusion out of the room might start to affect the result.

I suspect that no air purifier would be a close 3rd. As it was not tested, we will not know.

I was waiting to see that tested too.