[–] kortex link

And with the air mostly removed, you can spin the drum really really fast! I think you're on to something here. :P Maybe not.

I've done hundreds of solvent evaporations under vacuum (rotovap). The problem is you need a trap, or else solvents condense in the pump which causes your efficiency to go down. So now you need a heat pump or similar, now you're talking about a really complicated dryer. But it'd be efficient.

reply

[–] kurthr link

Yeah, thanks for the comment on the condensation.

The output pump would really need to mostly pump water and vapor at the input and liquid at the output, but not to very low pressure... even a peristaltic might be doable (no rotary vane/blower needed). It was just a thought, I used to rotovap too so running through the calculations seemed like a fun idea.

reply

[–] kurthr link

Why not just use a vacuum pump and pull the water vapor out at a constant temperature. You can flow 33C dry air (use a condenser before expanding and heating, if you like) across the clothes as they tumble to keep them from freezing.

You wouldn't have to pump below a 10% of an atmosphere to quickly dry your clothes (vapor pressure of water is 5% of an atmosphere at that temp).

To give an idea of how fast: With a 1liter/sec STP air intake, you would extract ~1gram/sec of water so in 15min you would remove ~1kg of water.

reply

[–] ergothus link

For apartment goers (or those that live in uncooperative climates) the reliability of such a system is a bigger problem than the speed.

But for those that can use it, it is indeed a great system.

reply

[–] Nition link

One day we'll invent a technology device to answer the age old question: "Still wet or just cold?"

reply

[–] Nition link

Perfect, of course this exists. It even has a FUN button for when waiting for the clothes to dry gets too boring.

reply

[–] obituary_latte link

What really struck me as remarkable was this bit: "Digital display with back light gives exact and clearly reading although you stay at the somber conditions"

I wish my TV could do that...

reply

[–] hugodahl link

4.47$ shipping, and it's not even next day? Pass! /s

reply

[–] seanp2k2 link

Yeah I'll wait for the ETEKCITY version for $16 with prime shipping.

reply

[–] Tharkun link

I press it to my face to answer that question. Somehow my face is much more reliable at telling the difference between cold and wet than my hands.

reply

[–] Nition link

I just mentioned the "wet or cold" problem to someone else and they said "just use your face"! So it's not just you. Something to try this winter...

reply

[–] pbhjpbhj link

Lips or tongue are even more sensitive for this IME. I test vitrification of pottery by putting my tongue on it. I use my lips to test washing for cold vs. damp, but we sparsely use an eco friendly washing liquid, YMMV.

reply

[–] toomanybeersies link

Doesn't work so well if you have a beard.

reply

[–] celticninja link

Doesn't using your tongue, which is usually wet, increase the chance of a false positive?

reply

[–] Quequau link

I live in a tiny flat in Austria. The vast majority of my washing dries overnight provided I actually get it done around lunch time... even when it's raining. I don't even put it outside most of the time.

If I'm in a major hurry, mostly due to self inflicted procrastination, I'll point a regular fan at the rack as it dries.

reply

[–] jp555 link

I used to hang my clothes indoors when I was living in Europe (some apartments had clever retractable hangers built above the bathtub), and even when raining they would dry in less than a day.

reply

[–] jdavis703 link

Can you put your clothes on a fire escape? Or in your bathroom (works great if you have a bathroom with a window).

reply

[–] ergothus link

Every apartment complex I've lived in has had rules banning hanging clothes (no idea about enforcement). Also, for any group larger than 2 I imagine the clothes would not dry fast enough to keep up.

And most bathrooms are small and often without a window.

Not a complaint, just pointing out that sun-drying is often not a real choice. Often it is.

reply

[–] jasonmp85 link

Many management types will attempt to tell you that you can't hang clothes on a line. In nineteen states, such rules are explicitly prohibited by state law: http://www.sightline.org/2012/02/21/clothesline-bans-void-in... . They have the cheeky name of "right to dry states".

A related thing often banned is external over-the-air antennas, protected by US federal law.

reply

[–] vitus link

Well, the focus in that particular article is on HOA bans, not apartment ones. For instance, the Hawaii law (the first one I clicked on that seemed particularly cut-and-dried) is restricted to single-family homes and townhomes.

"The purpose of this Act is to prohibit real estate contracts, agreements, and rules from precluding or rendering ineffective the use of clotheslines on the premises of [b]single-family dwellings or townhouses[/b]." [0] http://www.capitol.hawaii.gov/session2009/bills/SB1338_CD1_....

reply

[–] seanmcdirmid link

Living in Beijing, we never dried our clothes outside the apartment. We had racks in the kitchen for that. I don't think management companies can ban drying inside! It sounds unenforceable.

reply

[–] FullMtlAlcoholc link

Alternatively, a clothes rack on a balcony or receiving direct sunlight through a window or glass sliding door, with both slightly ajar works well.

One benefit of this is that your clothes last much longer.

reply

[–] _delirium link

In the winter, I find they dry quite quickly if I just put the clothes rack indoors near a radiator.

reply

[–] celticninja link

However never hang clothes on a radiator to dry, this is the least efficient method of using your radiators.

reply

[–] seanmcdirmid link

If you have city central radiated heating, then making the radiators less effective is just a bonus of getting your clothes to dry a bit faster.

reply

[–] celticninja link

I'm not sure how common that is, the only place I have heard of it is in some Scandinavian countries but if you know otherwise i would love to hear about it.

reply

[–] seanmcdirmid link

All of northern china is like this. I'm sure much of Russia is also, its a pretty common thing spread by the soviets (socialized heating....).

reply

[–] sambe link

It's considered reasonable to endanger lives to dry washing? (I don't live in the US).

reply

[–] jdavis703 link

Well obviously don't be stupid where you put the clothes, (I.e. don't block egress).

reply

[–] comicjk link

Hanging clothes in direct sunlight is overkill, and probably reduces their useful life due to the UV. All you need is sufficient moving air. I hang mine under the deck or just on racks indoors.

reply

[–] nnain link

Sunlight isn't an overkill. It's a great germ killer (You have to be cautious not to leave them out for too long, lest the UV/Heat damages the colours).

You can use a lot of detergent to remove the last bacteria; but household detergents are a big source of water pollution.

reply

[–] amelius link

Or you could throw your clothes into a geyser [1] :)

> (...) The group put their soiled clothes in a pillowcase and threw it into the geyser’s cone. When it erupted, the clothes were sent flying over a hundred feet into the air. When they collected them, the churning, heated water had indeed cleaned them.

[1] https://news.ycombinator.com/item?id=14146482

reply

[–] fpoling link

Hm, I thought the best way to kill germs is to wash clothes at 60C/140F or higher.

reply

[–] riffraff link

it is a good way, but it's also a good way to ruin some more delicate clothing.

reply

[–] jo909 link

Not sure why everybody assumes fusion powered implies direct sunlight.

Drying clothes in the shade is also powered by the sun, because the air only has "unused" moisture capacity because it was heated at some point. To repeat the cycle forever it will need to cool down and then be heated again.

reply

[–] undefined link
[deleted]

reply

[–] willyt link

Once both my kids wet the bed every night for a week. 3 loads a day. Even on a sunny day in Scotland a duvet won't dry on the line in 1 day.

reply

[–] david-given link

Years ago (on Mull), I saw someone selling drying tents: basically, a large tent with open ends and clotheslines inside. The shape apparently draws air through the tent. They said that even on cold, wet days, clothes dried quickly because of the air movement, and of course, no energy consumption.

Never, ever seen one since, and a quick web search for 'drying tent' shows up nothing but kit for pot growers.

reply

[–] robert_tweed link

This would also solve the other problem that stopped me drying things outside in Scotland: the garden tended to attract a lot of birds. I won't go into details, suffice to say the results were less spectacular than I had been led to believe.

reply

[–] Cerium link

I've seen indoor ones with fans. Looked like a fabric armoire with a box fan underneath. It blows air through the clothes to dry them faster.

reply

[–] seanp2k2 link

Bed-wetting children get cheap blankets and mattress protectors (plastic sheets), not duvets!

reply

[–] test1235 link

I'm at the top end of Scotland - we can barely dry towels and trousers, nevermind duvets.

reply

[–] johnny_reilly link

I feel you.

reply

[–] ComputerGuru link

Lucky you. Try doing that in Chicago or Miami and your clothes will stink like holy hell thanks to the humidity.

reply

[–] Cerium link

If you use an air conditioner, you can do it the Chinese way. In humid cities people hang their clothes near the AC exhaust, since it is "free" hot air. In a super humid city I've seen clothes dry that way in only a few hours.

reply

[–] sten link

Is this really free? Doesn't it just lower the efficiency of the AC unit?

reply

[–] detaro link

Why would it lower AC efficiency? It doesn't use the exhaust air for anything. (Obviously you shouldn't block it)

reply

[–] Cerium link

No, the fans are quite strong and have an effect up to a couple meters away. I think it is more like a cat sleeping on the hood of a car. The waste heat needs to go somewhere, might as well put it in my clothes.

reply

[–] eximius link

They hang it near, not on top of the vent. And if the exhaust is outside the unit (balcony, etc), it would have basically no effect.

reply

[–] sargun link

I've heard it has anti bacterial properties as well. Unfortunately, they come at a pigment destroying cost.

reply

[–] yummybear link

Wasn't space fusion established as carcinogenic?

reply

[–] hugodahl link

Oh really? I thought those were just little balls of lint and fabric. Now I feel like a jerk.

reply

[–] mozumder link

Doesn't the UV end up fading the colors?

reply

[–] chrischen link

Probably about the same as wearing your clothes outside I'd imagine.

reply

[–] taberiand link

You go outside?

reply

[–] r00fus link

Hang inside out.

reply

[–] nnain link

A big (practical) problem is that you might not be around to take the clothes of the clothline in time and they end up 'roasting' for extra hours/days. Sunlight definitely does fade the colors.

reply

[–] hughes link

Beamed energy is here!

reply

[–] kyriakos link

Star based clothes drying is always better

reply

[–] undefined link
[deleted]

reply

[–] duncan_bayne link

We did that, right up until we had three kids and full-time jobs :)

reply

[–] prawn link

We dry ours (2A+2C) inside on hanging racks, but it takes up a fair bit of space. In a smaller house, we'd have no chance.

reply

[–] seanp2k2 link

You also need adequate cubic footage to absorb the moisture dependent upon the humidity inside. If you run the AC, that helps keep the humidity lower, but it's probably more expensive than just running the dryer.

reply

[–] mason240 link

Why on earth is this being downvoted?

reply

[–] spodek link

It's not the fastest clothes dryer, but I often use one that runs on fusion in outer space.

reply

[–] briandon link

It's also a shame that the US DOE has partnered with and is funding R&D for a fully-owned subsidiary (as of 2016 iirc) of a Chinese state-owned company (Haier, which bought GE Appliances).

reply

[–] zkms link

> The idea sounds pretty neat but I wonder about longevity of the piezeoelectric transducers.

If they'll wear out fast it's entirely feasible to design the dryer around user-replaceable piezos.

It may end up like with inkjet printers -- where the dryer itself is just a boring spinning drum with a fan and a moisture collector and a powerful piezo driver, and you end up buying consumable cassettes with the actual transducers inside.

reply

[–] lt_kernel_panic link

But then you won't be able to dry your white clothes because your color piezo needs replacement.

reply

[–] nickpeterson link

You know what I want? A lemon law that states that major appliances need to run forever. Literally something that says, "This device must run without professional service for 25 years." Forget energy star stuff, 100Kwh saved a year is meaningless because we can always optimize powerplants. Stop building disposable 100LB metal boxes that have to get scrapped and thrown in a landfill. If the device fails earlier than that, the company has to replace it and pay a large fine for producing faulty equipment (larger than the profit from the device by an order of magnitude).

Then just allow people to rent the devices (which would obviously cost more) rather that have to buy them outright.

reply

[–] DKnoll link

First you need engineers that can design appliances that, even if warrantied, do not need service within 25 years 100% of the time.

Perhaps they can be legislated into existence... ;)

reply

[–] nickpeterson link

There is a rover on Mars that had been running by itself for quite a bit and it contends with far more than a dryer.

reply

[–] DKnoll link

I assume you don't mean Beagle 2.

A Mars rover is a bad example here because it's not an item that is, or will ever be, mass-produced.

reply

[–] blibble link

how much did the rover cost?

reply

[–] nickpeterson link

Hard to know, looking at the 600 page NASA PDF, but Google says 400 million. But that's for a object that had to be transported to mars first. I bet transporting a dishwasher to mars intact to sit and not work is a similar amount of money.

Guess I just need to start an appliance company and fail to become enlightened as to why my desire of quality and serviceability are unattainable ideals.

Incidentally, your comment on price is a weak argument, because the product doesn't even exist. Even the luxury appliances have tremendously low longevity now. So luxury at this point basically means it looks really good while it works and you can afford to buy another when it doesn't.

reply

[–] chemmail link

Or just buy my grandmas fridge from the 60s that still running strong.

reply

[–] Scoundreller link

And the longevity of your clothes.

reply

[–] MrFoof link

This is the main reason.

The difference in the longevity of my clothes -- same exact articles, same brand, same material, thickness, size and stitching -- from switching from a "hotbox" dryer to condensation dryer was initially amazing. No more did cuffs and collars start to crack and fail, nor did my shirts slowly develop small tears.

The latest (2014 is when they really started to hit the market) heat pump dryers dry clothes even cooler still, albeit since they're new tech they're quite a bit more expensive right now.

In Europe, a "condensation dryer" is so common, they're just called a "dryer", with no differentiating term. Additionally some countries (Switzerland I think) I believe don't even allow hotbox dryers anymore (and their needed conduit and vents) as part of fire/building code. Condensation dryers simply have a high quality lint filter (that truly does trap it all) and vent to atmosphere, since they just use a heat exchanger.

All while using far less electricity than simply heating things resistively.

reply

[–] exprA link

TIL.

I don't think I've ever seen one of these hotbox driers in person, but gathered somewhere that those had existed earlier and saw them as fully obsolete technology used only in some industrial settings. The fact that they are still sold and installed (with all the requirements) in ordinary homes is very surprising.

(Hint: if you buy a condensation dryer, buy one with a drainage hose, if at all possible. Unless you are a very punctual person, you probably won't learn to empty the water storage after every cycle despite that all the manuals tell you to do so, because it can hold water from several cycles – but you will find yourself having unexpectedly wet laundry from time to time when you start drying with an almost full water tank and are not near when the machine tells it can't continue the program.)

reply

[–] pimlottc link

You said the difference was "/initially/ amazing"; did something change later?

reply

[–] MrFoof link

No. After 10 years of using them I've just been acclimated to not having my shirt collars and cuffs destroyed in the dryer.

reply

[–] MBCook link

Could simply be habituation; where, like with HDTV, it's amazing at first but you get used to it and it simply becomes "the normal".

reply

[–] pimlottc link

Possibly so; it just seemed like a conspicuously odd thing to add given they seemed to have no other complaints about it.

reply

[–] sambe link

It varies by country. I'd think most in the UK consider "dryer" to mean heated dryer. I've found condensation dryers do a sub-par job and heated ones are fine on the low setting.

reply

[–] sargun link

Do they use the cold side of the heat exchanger to drop the moisture out of the air prior to passing it back through for heating?

reply

[–] yetihehe link

Yes, it works exactly this way. I don't have a clothes dryer, but I have condensing air demoisturizer (for places with too much moisture). Works fine when you need to dry some clothes in one room. Also costs MUCH less than full dryer. Air coming out is only a little hotter than room, but sometimes room gets colder due to evaporation from all textiles.

reply

[–] sargun link

I've thought about buying an old 200mm or 230mm fan, and hooking it up to a Peltier cooler -- First pass the air over the "cold" side to drop out the moisture, then through some rechargeable desiccant, and then through the hot side to my clothes.

I wonder why dryers don't work this way, other than I think that it'd be much slower to dry as compared to a traditional dryer, and I'm not sure if you'd be able to wick the moisture out of ever fabric.

reply

[–] yetihehe link

Why rechargeable dessicant when moisture just condenses on cold side? Then it drops into container. Also peltier cooler is too inefficient to do this. It uses about half of energy just for resistive heating. Typical european dryer works just like this but doesn't use dessicant.

reply

[–] sargun link

Unless you drop the air temperature down to below 0, all the moisture won't drop out on the cold side.

reply

[–] awqrre link

Batteries don't last this long, why does a dryer have to? it's not all about longevity ...

reply

[–] bicubic link

What to batteries have to do with clothes dryers...? You're comparing a consumable good to a household appliance. Household appliances are expected to last 5 years. 7-10 is pretty normal.

reply

[–] awqrre link

If a dryer is not a consumable, shouldn't it last forever?

If a battery is a consumable, shouldn't it last only one charging cycle?

reply

[–] awqrre link

so according to these links, a battery that lasts 2 years is a consumable good but a fridge that last 3 years is a durable good..... I think I get it.

reply

[–] function_seven link

Batteries not lasting long is considered a limitation of our current battery technology. This limitation doesn’t currently exist for typical clothes dryers.

There’s no reason to introduce a new limitation unless the technology makes up for it in other ways. Having to replace a clothes dryer every two years would require the technology to be very good to justify such a burdensome task.

reply

[–] tunap link

"Having to replace a clothes dryer every two years would require the technology to be very good to justify such a burdensome task."

Or, a cost cutting measure of replacing a long-lasting ball bearing assembly with a shaft rotating in a vinyl cup which wears down to metal-on-metal like mine did after 3 years. Which is the sort of accelerated deprecation the OP was alluding to. Granted, the battery metaphor isn't great as energy storage tech is far from mature.

reply

[–] rosalinekarr link

Because dryers are expensive appliances. If they're going to make one that only lasts one tenth as long, it better cost one tenth of the price too.

reply

[–] StephenConnell link

Take operating costs into account also.

reply

[–] cmdrfred link

And time lost waiting for a new one to be delivered, disposal fees...

reply

[–] awqrre link

If you put it by the road someone should pick it up promptly for free (or list it for free on craigslist).

reply

[–] Arizhel link

Don't forget delivery and installation fees too. They don't deliver them to your house for free.

reply

[–] awqrre link

Who cares about delivery fees? it's the total cost that matters.

reply

[–] Arizhel link

The delivery fee is a significant fraction of the total cost of a modern dryer in the US. Saving a little money by getting crappier dryers will likely have a larger total cost because of the delivery fees, and also the cost of your time in taking time off from work to accept delivery.

reply

[–] awqrre link

that dryer costing $180 at Home Depot has free shipping, by the way... http://www.homedepot.com/p/Magic-Chef-Compact-1-5-cu-ft-Elec... .... and by the way, you are paying for shipping even if you by at the store (it is just included)

reply

[–] Arizhel link

WTF? We're talking about real dryers here, not dorm-sized dryers that you can dry maybe 2 shirts in.

However, if you select the Samsung 7.5cf dryer, it also has free delivery. Of course, this is built into the price, and $550 for an appliance isn't pocket change.

reply

[–] awqrre link

here is a pocket change dryer that is slightly larger: http://www.homedepot.com/p/Amana-6-5-cu-ft-Electric-Dryer-in... and of course it also has free shipping.

reply

[–] cmdrfred link

And time lost waiting for a new one to be delivered, disposal fees for the old unit, laundromat fees and time spent there while the system is down.

reply

[–] awqrre link

How much are these new dryers? I didn't see the cost.

also, where did they state the longevity?

reply

[–] DanBC link

This device is supposed to be eco-friendlier than a hot air dryer.

The benefit reduces if you have a consumable component that needs changing, especially with the amount of e-waste that goes to landfill.

reply

[–] awqrre link

eco friendly? right... they are only trying to get the cost down for the consumer.

reply

[–] majormajor link

Arranging large appliance delivery and disposal is a pain in the ass when you've got full time jobs to deal with. Don't want to do that any more than needed.

reply

[–] ergothus link

Batteries are also (relatively) cheap and easy to replace.

If my dryer was $50-$200 and could be carried in one hand, I'd be (grumpily) okay with it only lasting 2 years.

reply

[–] arthulia link

Must every appliance become "disposable"?

reply

[–] ergothus link

No - I'd really love it if they didn't become disposable. Sustainability, however, isn't why people have different expectations of batteries vs dryers. I didn't mean to imply a cheap, portable, but flimsy dryer would be a good thing.

reply

[–] awqrre link

How much does it cost for you to get an iphone battery replaced by Apple ($79)? a basic dryer costs $180 at home depot...

http://www.homedepot.com/p/Magic-Chef-Compact-1-5-cu-ft-Elec...

reply

[–] tempestn link

Do you own a dryer? If so, would you want to go out and replace it every two years?

reply

[–] undefined link
[deleted]

reply

[–] ams6110 link

A bit puzzled why GE needs government funding to do research -- they make a lot of money already.

The idea sounds pretty neat but I wonder about longevity of the piezeoelectric transducers. A clothes dryer needs to last at least 7-10 years, minimum. A resistive heating element is about as simple as you can get, and it's cheap to replace if it does burn out.

reply

[–] oniony link

Can't you stick them in the microwave?

reply

[–] ftio link

Bring em to your neighborhood pizza shop. They've got nice, hot ovens. Just don't burn your socks.

reply

[–] kaosjester link

Does this mean the socks won't come out of the dryer warm? That's sort of a deal breaker for me.

reply

[–] s0rce link

The career advancement of the scientists and engineers working on the project depend on publications and outreach like this. Source: I was a post-doc at a DOE lab.

reply

[–] seren link

GE appliances is already a Chinese company so pretty sure they have some chance to be the first to actually commercialize it. So no need to worry about China copying it..

reply

[–] seanmcdirmid link

As if I could ever find a clothes dryer in china.

reply

[–] pasta link

Well I found this design from 2012: http://www.yankodesign.com/2012/03/01/ultrasonic-drying/

Looks Chinese to me.

reply

[–] demarq link

even if they found out about it on the day of release they'd still out manoeuvre their American counterparts because.. cost.

reply

[–] smaili link

> At the end of the project, appliance manufacturers including GEA will be ready to invest in this technology and commercialize it. This will result in the U.S. becoming the leader in the clothes drying industry and generate new jobs and innovative applications of the technology.

Pretty sure as soon as China is aware of this idea (if not already), they will have something in production and out the door faster and at a much larger scale than the US. Could someone explain why innovative ideas like this have to be published before they're actually built?

reply

[–] blarghh link

What's the effect on the clothes themselves? I won't let anything but underwear, gym clothes, socks, and tees in a dryer because it's generally considered bad for them. I hang dry all of my wovens.

reply

[–] undefined link
[deleted]

reply

[–] yourapostasy link

They likely will sonically baffle any outlet for humidity to avoid this issue.

I'm curious if the ultraound causes increased wear of the fabric at the thread ends, for example.

reply

[–] sandworm101 link

>> sonically baffle any outlet

Good point! The water vapour needs a way out. That means a direct air path between the fabric and the outside world. They cannot seal the entire thing in a vacuum bottle to deaden the sound. I see a 50' pipe full of baffles, a giant truck muffler, between this thing and anyone with eardrums.

reply

[–] averagewall link

It seems to produce droplets of cold liquid water, not vapor, so it should be much easier to collect that into a container in a closed system.

There are ultrasonic mist generators for cooling yourself down which probably work on the same principle:

https://www.amazon.com/Ultrasonic-Cool-Mist-Humidifier-Whisp...

reply

[–] s0rce link

Conventional driers also cause significant wear to clothes.

reply

[–] yourapostasy link

Right, so the question is if the ultrasonic causes more than hotbox dryers, or condensation dryers, or the heat pump dryers.

reply

[–] bpicolo link

Looks like they calculated the optimum as ~500-600 Hz? That's in human hearing range too.

reply

[–] sandworm101 link

Give it a try: "600 Hz Sine Wave Sound Frequency Tone" https://www.youtube.com/watch?v=ERHcqYNLHyg

and 500: https://www.youtube.com/watch?v=GlEfshsoyZk

If that really is the range they are targeting, this product is doomed. That will be one heck of a noise to cancel. "Soundproof box" is right up there with perpetual motion, zero-point energy, and spherical chickens in vacuums.

reply

[–] derefr link

A 'soundproof box' is hard because most of those boxed things we want to quiet down (say, pets) still need to be a part of our environment, breathing air and the like.

A clothes dryer, meanwhile, is a near-ideal case for vacuum isolation + elastic dampening. Build a box with a door; hang an airtight motorized barrel in the box from a bungee cord, with a second door, and electrical connection; and then, whenever both doors are sealed at the same time, [slowly] evacuate the air from the box.

reply

[–] sandworm101 link

If you are going to go through all the effort to create a proper vacuum, and then isolate all the little penetrations needed to maintain whatever is inside, just throw the wet clothes into the vacuum and call the thing a freeze dryer. No sonic required. A heat lamp inside a vacuum chamber would probably dry stuff using much less energy than either sonic of hot air.

reply

[–] derefr link

I'm not sure whether organic materials would be very happy with all their water content getting sublimated out of them due to the sudden drop in pressure. The result would probably look more like cotton jerky than fluffy towels. (If anyone has a Youtube link of such a reaction, though, I'd love to be proven wrong!)

reply

[–] phonon link

That (the 600 Hz) is the modulation of the ultrasonic signal from the transducer...I am not sure if modulating the underlying signal at that frequency has a similar auditory effect as a simple 600 Hz sine wave.

reply

[–] TD-Linux link

Indeed that's what it says. That's neither ultrasonic nor easy to block with reasonable quantities of sound dampening materials.

They also directly mechanically couple the transducers to the fabric. You need as much area of transducer as fabric you need to dry, unless you have some automated way to place the fabric on the transducers sequentially.

reply

[–] Kubuxu link

To get the effect they want they have to use high frequency 30-40kHz (as in name, ultrasound). They modulate it with lower frequency (which probably splits off bigger water globs) for better efficiency or something. You won't be able to hear the modulating signal as you are not able to hear the carrier frequency.

reply

[–] tgb link

That's definitionally not ultrasonic, so I don't think that's the relevant frequency.

reply

[–] bpicolo link

You're right that it's not, it's just what the paper says :)

reply

[–] tgb link

Yeah, maybe it's the frequency that some component runs at but not the produced sounds? Or maybe they forgot a "k" in "kHz"? Eyeballing a chart in their presentation seems to show 100kHz piezotronics. [Page 8 of https://energy.gov/sites/prod/files/2016/04/f30/31297_Momen_... ]

reply

[–] Smushman link

This video actually has audio included of the action on a small piece of cloth (~1 inch circle) - I could not hear anything when it was drying.

https://www.youtube.com/watch?v=mCmXzdz6qGQ

reply

[–] zxcmx link

I'm not sure that we can make an accurate judgement based on that because it's going to depend on the mic they used, audio codec, (and less relevantly), speaker setup and hearing of listener.

reply

[–] undefined link
[deleted]

reply

[–] bpicolo link

Not to mention warm clothes is like 80% of the benefit of the dryer ;)

reply

[–] vinceguidry link

I don't understand why this is such a valued aspect of dryers. All clothes coming out of the dryer for me go right into my drawers / hanging. They don't get worn at the very earliest the next day. I rotate everything so I'm not just wearing the same socks and undies over and over again, so the vast majority of the time they don't even get worn then.

Is the psychological effect of folding warm clothes rather than cold really that powerful?

reply

[–] sandworm101 link

Hanging hot fabric can sometimes flattens out wrinkles almost as well as an iron.

reply

[–] vinceguidry link

Well, if you're using a hotbox dryer, it's not the hanging up while hot, but rather the fact that you just steamed and tumbled them. That gets wrinkles out of anything. Hanging up just keeps new wrinkles from forming.

reply

[–] Endama link

I didn't realize this, but yes, this is absolutely true. I wonder how many people would actually be willing to pay a premium on having their clothes warm when coming out of a dryer.

reply

[–] giarc link

Fancy models will have a "warm" cycle that heats the clothes for the last 10 minutes.

reply

[–] zkms link

Most of the energy consumption in a dryer is from the actual drying cycle -- once the clothes are totally dry, the high-temperature cycle to get them all hot doesn't consume much power.

reply

[–] dawnerd link

Wonder if they could add a quick warm cycle at the very end. Still use a lot less energy but still get warm clothes.

reply

[–] ergothus link

...This is a great comment I'd not have thought of.

reply

[–] sandworm101 link

And how will my cat react to this thing? Something with enough sonic energy to vaporize a significant volume of water is probably loud enough to wake every animal in the area.

reply

[–] scarlac link

The demonstration seems to assume that physical contact is possible. For layered clothes it may not work that well, if at all. But! Even if we assume there's no progress in that area, I can still see this being used in an industrial laundry. I've worked in one and there are machines specialized for different types of garments. With automation, it may actually make economic sense. So while use in a consumer market may seem far out, industrial applications are still possible.

reply

[–] iplaw link

This is how I dry all of my cycling kits, gloves, socks, warmers, etc. I have a four hanging drying racks [1] that I hang on the four ceiling fans in my home gym. The lycra dries in only an hour or two since there is airflow on all sides of the items. It makes for very efficient drying and it wholly prevents heat degradation of the lycra.

[1]: https://www.containerstore.com/s/stainless-steel-lingerie-dr...

reply

[–] dingo_bat link

But you cannot dump your clothes into the room and expect them to dry.

reply

[–] somberi link

Electric ceiling fan in a small room dries a stand full of clothes in 4-5 hours in a 70%RH climate and costs a LOT less than drum dryers and is safer for the garments.

reply

[–] tim333 link

The video showed a small bit of fabric touching the transducer. I'm not sure how well it's going to work with a big heap of jeans, jumpers and the like.

reply

[–] beagle3 link

Depending on the ultrasonic frequency used, and the spacing of seams/tailoring of the clothes, it's possible that some clothes will come out of the dryer in pieces, and you will have to sew them back together... Although I suspect wide availability of these dryer will quickly eliminate that kind of sewing, much like the prevalence of dishwashers has almost eliminated non-dishwasher-safe kitchen stuff.

reply

[–] Tharkun link

So this project ran from 2014-2016. Any word on whether anything was accomplished?

reply

[–] s0rce link

This is an interesting idea and probably would be useful but would only address people in single-family dwellings that don't share driers. I'm guessing that there is a reasonable use of clothes driers in commercial settings (laundry services) and shared driers in multi-family/large residential complexes (although many modern upscale projects have in-unit driers) where driers are shared.

Probably the best solution is a cultural shift to air drying. I was very surprised that when I was in the UK, a place not known for sunshine, many air dried their clothes, while when I lived in the desert of Eastern WA nearly everyone used a drier.

reply

[–] duncan_bayne link

In Australia, that's very hard to achieve because the residential energy market is heavily regulated specifically to _avoid_ exposing low-end consumers to spot pricing.

reply

[–] caf link

In at least WA, NSW, QLD and ACT you can go on time-of-use residential tariffs.

And driers (and washing machines - which use a considerable amount of energy particularly if they heat the water internally) typically already have timer-start functions.

reply

[–] duncan_bayne link

Sure but time of use is _far_ less volatile than actual spot pricing. Hell, in WA and QLD it's not unknown for AEMO to post _negative_ energy prices.

reply

[–] undefined link
[deleted]

reply

[–] Scoundreller link

> DOE’s Building Technologies Office is seeking new clothes dryer technologies that can increase the energy factor (EF) from 3.7 to 5.43 lb/kWh without increasing drying time by more than 20% over baseline units.

They're concentrating too much on kWh. One could use the same technology and focus on variable electricity pricing. I want a dryer that I turn at night, and it dynamically turns on-and-off as electricity rates go up and down. It ends at a smooth tumble in the morning so I can put on my day's clothes and fold the rest at it's lowest wrinkle-point.

reply

[–] undefined link
[deleted]

reply

[–] marak830 link

I saw something like this demoed on Australian TV about 15 years ago. I was always wondering what happened to it!

reply

[–] zubat link

Will it kill bug infestations?

reply

[–] djrogers link

Probably the same ultrasonics hat are used in humidifiers. Hint, they don't travel far.

reply

[–] iamatworknow link

They mention that in the video.

It also mentions that they're thinking of creating a tumble/drum dryer with these piezoelectrics. As opposed to a traditional tumble dryer that spins to aerate the cloths, I think the spinning motion would instead be required to pin the clothing against the piezoelectric lined drum (though I imagine it would need to stop and change direction periodically in order to expose different areas of the fabric to the drum wall).

reply

[–] jostmey link

I want to see a study done on such a devices safety. The sound waves it emit are able to desiccate clothing. What is the effect of these sound waves escaping the device? Would it desiccate living tissue?

reply

[–] gravypod link

If these go mainstream it would be thousands of times more handy to the small shop then for cloths. Vibratory cleaners with that kind of volume are crazy expensive!

reply

[–] didsomeonesay link

I sincerely hope this is no vaporware...

reply

[–] jdhendrickson link

As but the difference is in the amount of energy expended vibrating them no? It sounds to me more like vigorously shaking the water off the cloth fibers and then hoovering them up, which is much more energy efficient than heating said water until it turns into a vapor and hoovering it up.

reply

[–] basicplus2 link

Vibration of molecules... sounds alot like heat energy

reply

[–] chroem- link

The whole point of cooking food is to denature proteins and kill pathogens. Denatured proteins have exactly the same nutritional content as functional proteins: they're just not folded into their original and potentially dangerous shape anymore.

reply

[–] uncensored link

"denaturing" does sound scary and bad -- It's a dumb way to describe what happens in any cooking process.... it sounds like turning food into plastic before eating it (take the nature our of it) LOL.

Anyway, there are real health risks according to the World Health Organization:

"Food safety: Food safety is an important health issue. In a microwave oven, the rate of heating depends on the power rating of the oven and on the water content, density and amount of food being heated. Microwave energy does not penetrate well in thicker pieces of food, and may produce uneven cooking. This can lead to a health risk if parts of the food are not heated sufficiently to kill potentially dangerous micro-organisms. Because of the potential for uneven distribution of cooking, food heated in a microwave oven should rest for several minutes after cooking is completed to allow the heat to distribute throughout the food."

That sounds like nuking the surface of the food then waiting for it to cook after it has ben microwaved which may or may not fully achieve thorough cooking.

http://www.who.int/peh-emf/publications/facts/info_microwave...

reply

[–] db48x link

That's why your microwave oven has a power setting. It toggles the magnetron on and off during cooking, so that your food cooks more evenly.

reply

[–] uncensored link

Yet it never does, unless maybe you have a $2000 microwave oven?

reply

[–] db48x link

Yours doesn't toggle on and off when you use the power level controls? Maybe it's broken; this is a feature that all microwaves have, because it's so cheap to implement. Note that the lights and fans and things keep going; it's only the magnetron that turns on and off. You might hear a difference in the sound of the microwave, or a relay clicking when it toggles, but that's all.

reply

[–] uncensored link

I meant the food always comes out unevenly cooked. End result is usually super dry (almost dry burnt) on outside and not cooked enough on inside.

reply

[–] uncensored link

The logical next leap is to cook food with ultrasound which will hopefully be somewhat faster than conventional cooking and less harmful (no protein denaturing [1]) than microwave cooking

1. https://www.ncbi.nlm.nih.gov/pubmed/11088227

reply

[–] peterwwillis link

Advanced clothesline technology, now available with WiFi.

reply

[–] rotten link

Maybe it will keep mice and bugs away while it is running.

reply

[–] tiatia link

Ultrasonic Dryer? Who needs this? And DOE dropped nearly a million on it? Was it an SBIR grant with nice kickbacks? :-)

I found a washing machine with ultrasonic much more interesting:

http://www.tovatech.com/blog/3759/ultrasonic-cleaner/ultraso...

http://www.huffingtonpost.com/2015/01/21/dolfi-washing-devic...

Would be a little worried about stress on your clothes AND/OR Ears. http://www.sciencemag.org/news/2014/09/sounds-you-cant-hear-...

reply