A dryer that uses half the energy and may become Energy Star certified?

I know.  Sounds crazy!  But here's an article from EcoGeek that makes it look like it's not too far off in the future:

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Generally when people offer up miracle devices from backyard and basement tinkering, we're pretty skeptical. But it's hard to argue with Michael Brown. Especially when he hooks his "Dryer Miser" up to a Whirlpool dryer, turns it on, and pulls out dry clothes using half as much energy as the exact same dryer without his device.

The device, really, is fairly simple. Instead of using a traditional air-in-contact-with-heating-coils heater, it uses an oil as the heat-transfer medium. The oil needs less energy to heat, and, once heated, holds onto the heat better. That oil is then used to heat the air that gets blown into the drying drum.

The device is so much more efficient that it can be plugged into a regular 110 V plug (instead of 220s now required by dryers.) Considering how simple this is, it's a marvel (or perhaps a travesty) that GE or Whirlpool didn't think of it first. Additionally, the heating unit only ever reaches about 150 F, since the heat-transfer is so much more efficient. Traditional dryers have to heat their elements up to 1000 F in order to reach optimal efficiency, resulting in about 15,000 household fires each year.

The device can be installed by a technician in 30 minutes at a total cost of around $300, which would be recouped in less then four years. A quick calculation based on the number of households with electric dryers (around 80 million) and the average amount spent on electricity for drying clothes a year ($85 per household) shows that this device could indeed save several billion dollars per year just in America.

Already Brown is in talks with a major European manufacturer to integrate the device into new units, and he's raised several million dollars in angel funding. He's also talking to the EPA about getting his dryers Energy Star rated. Up until now, dryers have been so inefficient that not a single one on the market has been awarded with the Energy Star label.

While it would have been easy to call his dryers the most efficient on Earth. Brown always qualifies the statement with "aside from the sun." And that's a touch of modesty that, to me anyway, is very welcome.

(Hank Green, EcoGeek, Feb. 15, 2008)

Honestly, how do teams of well-compensated engineers not make these types of innovations? Is there a side effect or some sort of half truth in here? I hope not - sounds incredible.

Perhaps if he did not decorate the device with hippies it would get more mainstream acceptance?

Actually, right now they do retrofits of existing dyers with their Hydronic Dryer technology.  Here are some photos (from GizMag) of what the system actually looks like:

Booyah Amit! Nice work Stins, haha

The cycle time may be longer; while heat transfer efficiency might be improved, it would take longer to heat the oil etc. 

It would be interesting to see a calculation comparing the longer cycle time to the less efficient (but faster) electric coil heating dryers. 

I'd be interested to know who that European manufacturer is.

I checked the website and they haven't released any of that information yet.  But hopefully soon there will be an update!

Sorry - but this is hype and doesn't make much sense from an engineering standpoint. 

Pretty much all electric dryers have the same efficiency of removing moisture from clothes -- it takes about 0.5 kWh per pound of moisture removed.  if you check the basic physics, it requires 0.3 kWh just to provide the heat of vaporization to the water.  Therefore, existing electric clothes dryers are about 60% efficient.  The 40% lost energy is mostly neeeded to make sure that the exhaust air doesn't condense inside the vent hose (the air leaving the dryer can't be at 100% humidity, it must be superheated).  So, if it's a dryer that spins a drum and exhausts moist hot air (like this invention seems to involve), you can't really get much better than the current approach.  That is why there are no Energy Star dryers.  

 You can achieve higher efficiency by perhaps using an entirely different approach for getting rid of the moisture, but you couldn't save 50%.  Of course, you could save 100% by  hanging the clothes to dry otdoors.  But, the system they describe can't work as claimed. 

Why don't you just get one of these things: http://greenhome.huddler.com/products/the-laundry-alternative-inc-centrifugal-spin-dryer

It removes a majority of the moisture from your clothes with centrifugal force rather than evaporation and then you just finish them off in the regular dryer for 10-15 minutes or just hang them.

I have one and it works great.

This is what many call a "sustaining" innovation, meaning something that can sustain profitable growth for the established companies in a market.

What would be a "disruptive" innovation is to create something that dries clothes without the need for a bulky and power hungry piece of equipment. Remember, people don't buy dryers because they love dryers; they just need their clothes dried.