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Ultra-low-energy consumption ultrasonic clothes dryer

energy.gov

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Re: Ultra-low-energy consumption ultrasonic clothes dryer

#131

Post by kurthr »

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.

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#132

Post by dingo_bat »

somberi wrote: post #130

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.

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

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#133

Post by vitus »

jasonmp85 wrote: post #84
ergothus wrote: post #49

Earlier quoted context omitted.

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.

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.

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_....

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#134

Post by david-given »

willyt wrote: post #105
spodek wrote: post #7

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

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.

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.

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#135

Post by pbhjpbhj »

Nition wrote: post #122
Tharkun wrote: post #97

Earlier quoted context omitted.

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.

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...

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.

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#136

Post by toomanybeersies »

Nition wrote: post #122
Tharkun wrote: post #97

Earlier quoted context omitted.

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.

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...

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

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#137

Post by exprA »

MrFoof wrote: post #16
Scoundreller wrote: post #4

Earlier quoted context omitted.

And the longevity of your clothes.

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 d…

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.)

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#138

Post by kortex »

kurthr wrote: post #131

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 1lit…

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.

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#139

Post by cmdrfred »

StephenConnell wrote: post #26
rosalinekarr wrote: post #10

Earlier quoted context omitted.

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.

Take operating costs into account also.

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

Re: Ultra-low-energy consumption ultrasonic clothes dryer

#140

Post by cmdrfred »

StephenConnell wrote: post #26
rosalinekarr wrote: post #10

Earlier quoted context omitted.

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.

Take operating costs into account also.

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.
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