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by ams6110 3352 days ago
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.

4 comments

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).
> 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.

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

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... ;)

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.
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.

how much did the rover cost?
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.

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

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.)

You said the difference was "/initially/ amazing"; did something change later?
No. After 10 years of using them I've just been acclimated to not having my shirt collars and cuffs destroyed in the dryer.
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".
Possibly so; it just seemed like a conspicuously odd thing to add given they seemed to have no other complaints about it.
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.
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?
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.
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.

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

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.
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.

"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.

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...
If you put it by the road someone should pick it up promptly for free (or list it for free on craigslist).
Don't forget delivery and installation fees too. They don't deliver them to your house for free.
Who cares about delivery fees? it's the total cost that matters.
How much are these new dryers? I didn't see the cost.

also, where did they state the longevity?

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.

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

Must every appliance become "disposable"?
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.
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...

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