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Students invent quieter leaf blower

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Re: Students invent quieter leaf blower

#381

Post by raddan »

jasomill wrote: post #377
kylebenzle wrote: post #363

Earlier quoted context omitted.

I guess I'm glad we don't use your ear as a way to measure sound levels then because we would all be way off. Gas-powered leaf blowers typically operate around 90-100 decibels (dB), while electric leaf blowers usually range from 60-70 dB.

To put this into perspective, per Wikipedia[1]: 60 dB SPL: TV (set at home level) 100 dB SPL: Jackhammer [1] https://en.wikipedia.org/wiki/Sound_pressure#Examples_of_sou...

Also, crucially, dB is a logarithmic scale. So 100 dB is MUCH louder than 70 dB.

Re: Students invent quieter leaf blower

#382

Post by grecy »

xkqd wrote: post #354
adrianmonk wrote: post #331

Earlier quoted context omitted.

That is exactly the kind of situation where regulations are needed. Sometimes the market can take care of things, and regulation isn't needed. But these workers don't have lots of leverage. If conditions are bad, they can't tell the boss "I have other options" and quit. So the market won't solve this case.

In all fairness, we’re not wrangling in a megacorp or small company / bad actor type. These are usually tiny businesses where the owner is busting their ass in the hot sun alongside their crew. These are usually the smallest of small biz, and oftentimes just a young guy and a single helper. I don’t believe we can expect lawncare prices to 4x, but this is a perfect example of targeting those who we should be supportin…

But by that logic we should let a 20 year old kid start as asbestos mine with hand tools next to a drinking water source, or let them operate heavy machinery on a highway with no training of any kind.

Clearly, just because doing is a path to making money, it absolutely does not mean we should automatically reduce all barriers and allow it to happen.

"More jobs" should absolutely NOT be the goal, and anyone that says it is clearly hasn't thought to hard about it.

Quality jobs are clearly much, much more important.

Re: Students invent quieter leaf blower

#383

Post by moribvndvs »

I welcome even quieter electric, but the two stroke engine on most blowers (particularly the pack blowers) is the real problem and they are EVERYWHERE. Every day from sun up to sun down from March until December my neighborhood has a nearly constant drone and reeks of two stroke gas. It has gotten so much worse over the past 7 years I’ve lived here, and sharply worse since pandemic. I dunno if it’s attributed to more affordable pack models becoming more popular with homeowners or increased usage of landscapers, but it has become an extreme nuisance.

I have a handheld electric to help with a couple of hard to reach spots. While it’s not as quiet as I wish, you can’t (well, least I can’t, from my testing) really hear it after about 75 to 100 feet. The surrounding neighbors’ blowers can be heard over a quarter mile away when I’m walking around the block.

It has ruined enjoying time out in the backyard, especially during the fall which is my favorite season.

Re: Students invent quieter leaf blower

#384

Post by Kirby64 »

SoftTalker wrote: post #278
foobarian wrote: post #158

I got an electric leaf blower mostly to avoid the noise and partly to avoid gasoline engine issues (a Kobalt 80V blower). What baffles me is that here the designers had a chance to make something truly quiet but instead they blew it and used a super-high-RPM motor-powered narrow turbine placed inside the pipe. It sounds like a dental drill amplified through a set of loudspeakers. I would kill to get a commercially de…

They are made. Of course a hand-held blower that has enough air velocity to do its job is going to make some noise, but I walked by a landscape maintenance guy outside work yesterday, he had a battery-electric blower and it was much quieter than the old two-stroke gas blowers they were using last year. I didn't note the brand but the casing was green. Maybe Deere, but it wasn't quite the Deere shade of green so I don…

Likely Ego. Ego makes probably the most premium electric only power tools.

Re: Students invent quieter leaf blower

#385

Post by modeless »

datahack wrote: post #372
modeless wrote: post #296

We don't need quieter electric leaf blowers. We need to ban the gas ones, with no grandfather clause. Not just for the noise pollution but the local air pollution. It's crazy the volume of air that can be ruined by a single gas leaf blower, far worse than modern cars, and they are inescapable in cities.

They are already banned in California. The rest of you need to catch up. I for one am stoked to have a quieter electric one though of course I’m behind your sentiment! But for Calfironians, it’s already better for the environment with all these small engines phasing out, and now it’s quieter too? Slick.

I'm in California and the ban is only on sales, not use. There has been no difference in practice, yet. And my city also has a citywide ban on use, but there's no enforcement, so it's pretty much a joke all around.

Re: Students invent quieter leaf blower

#386

Post by datahack »

modeless wrote: post #385
datahack wrote: post #372

Earlier quoted context omitted.

They are already banned in California. The rest of you need to catch up. I for one am stoked to have a quieter electric one though of course I’m behind your sentiment! But for Calfironians, it’s already better for the environment with all these small engines phasing out, and now it’s quieter too? Slick.

I'm in California and the ban is only on sales, not use. There has been no difference in practice, yet. And my city also has a citywide ban on use, but there's no enforcement, so it's pretty much a joke all around.

I’ve noticed a drastic reduction here where I live already.

Use will take care of itself if you ban the sale, which is what happened.

Why the pessimistic take? Don’t you want to live in a quieter environment? Transitions take time — but we are well on our way. Most places can only dream about not having a gas powered leaf blower going on and on for hours while they try to work: here it’s already transitioning. So why be anything but positive about it?

Re: Students invent quieter leaf blower

#387

Post by gwbas1c »

planb wrote: post #10
xxs wrote: post #6

Unfortunately the article is very poor on details. The sound from the video is insufficient to tell. Personally, I'd be quite excited to see what are the changes engineering wise. I bet it'd make a proper addition to BOLTR. I still can't see how it'd be much quieter, as lots of the noise is just the air moving (and making sound waves), perhaps less vibrations, different frequencies due to different rpm?

"Our product takes in a full blow of air and separates it," said team member Leen Alfaoury. "Some of that air comes out as it is, and part of it comes out shifted. The combination of these two sections of the air makes the blower less noisy." Sounds like they created a noise cancellation air channel.

Basically, by splitting the airflow into a shorter and longer channel, the slight delay in the longer channel cancels out the most annoying frequency.

It would be interesting if they stacked two or three together to muffle even more noise.

Re: Students invent quieter leaf blower

#388

Post by ssl-3 »

duped wrote: post #352
SOLAR_FIELDS wrote: post #308

Earlier quoted context omitted.

And the other underlying problem implied there is that electric leaf blowers are only viable for household use. They are just so completely impractical for commercial use that no one will ever use them.

So use a rake and broom, it's what I do when I clear my yard and driveway. Edit: and for that matter we probably need to stop clearing so much yard waste. My village has crazy expensive yard waste tags (with free pickup on select weeks of the year, usually fall) and everyone agrees it's not worth it to bag grass and leaves for the better part of the year. Unsurprisingly we have tons of pollinators, healthy firefly po…

It seems that the value of clearing yard waste depends on the local conditions.

Some climates produce layers of thatch from simple lawn clippings, for instance, which can be problematic. And for some people, fallen tree leaves can be a real concern.

My lawns (all of which have been in Ohio) have never had these issues. I just mow the grass. Stuff (leaves, grass, whatever other stuff is growing or present) gets chopped up, either with a "mulching" mower or a side-discharge mower (and it'd probably work about the same with a reel mower). It degrades quickly-enough in-situ that neither lawn clippings nor tree leaves are ever things that are a concern. (The biggest lawn-oriented issue I ever had was that of having a large number of black walnut trees; the walnuts themselves were unseen ankle-killing traps and/or projectiles in the fall, and the abundance of food lead to an abundance of squirrels and thus fleas.)

But as I understand it, some others are not so lucky. I'm not familiar enough with the problems because I've never had any problems, but I understand that they do exist in some areas.

(Heavily-manicured deliberately-monoculture lawns are a different thing that I'm not even attempting to address here.)

Re: Students invent quieter leaf blower

#389

Post by actionfromafar »

travisb wrote: post #375
actionfromafar wrote: post #26

Earlier quoted context omitted.

It will get there I suspect, the tools and batteries can charge in the truck en route. Easier to just fuel up the truck once instead of filling up little gas tanks all the time.

Charging using the truck would require running the truck all day -- probably not an acceptable alternative. Consuming 2-10 Kw from a 200 Kw engine would be so inefficient that it'd be too expensive anyways. Instead you'd need to run a generator all day charging batteries. A fast charging, high capacity tool battery takes at least 60 minutes to charge. In high power applications (lawn mower, leaf blower, chainsaw, etc…

Hybrid truck?

Re: Students invent quieter leaf blower

#390

Post by ssl-3 »

raddan wrote: post #381
jasomill wrote: post #377

Earlier quoted context omitted.

To put this into perspective, per Wikipedia[1]: 60 dB SPL: TV (set at home level) 100 dB SPL: Jackhammer [1] https://en.wikipedia.org/wiki/Sound_pressure#Examples_of_sou...

Also, crucially, dB is a logarithmic scale. So 100 dB is MUCH louder than 70 dB.

Also, crucially: dB is a measure of sound pressure level at a point in space. It is not at all a measure of total sound output. And it tends to fall off at a rate of 6dB per doubling of distance.

So by halving the measurement distance and changing nothing else, a thing reads as being about 6dB louder. And by doubling the measurement distance and changing nothing else, a thing reads as being about 6dB quieter.

So stating that a jackhammer is 100dB and a television is 60dB is rather meaningless by itself.

If the jackhammer is measured at 0.5 meters (the distance of the operator's ears, say) and the television is measured at 2 meters (the distance of the viewer's ears, say), then there is a measurement delta of 12dB, which is a difference more than an order of magnitude in energy intensity.

And all we did to produce that massive delta was vary the distance where we've placed the meter.

(And, no, there is no standard measurement distance. Loudspeakers are often [but not always!] measured at a distance of 1 meter, and generators are often [but not always!] measured at a distance of 20 feet. It needs to be explicitly stated.

In all cases, if the only parameter relayed is "dB" then it doesn't really mean very much.

And this isn't even getting into other important factors, like if the measurement is performed in a half-space or anechoic or whatever environment.)

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