Sweet Spot

Okay, this one is a bit far afield for me. I’m no mechanical engineer. But clothes dryers have to be the most inefficient way to dry clothes. What I’m thinking is that the current model is:

1. heat some air to make it better able to absorb moisture
2. briefly allow that air contact with the clothing
3. blow all that energy outdoors and start over

There has to be a better way.

Here are some dumb ideas (remember I’m no engineer):

Microwaves. Microwave ovens very efficiently heat water, and not much else. I’ve heard tell of experiments done with microwave clothes dryers, but the problems include non-microwaveable buttons or zippers, and overheating parts of the clothes.

So why not get the water out of the clothes through other means, and evaporate/heat the water elsewhere? One idea I had was some sort of wicking material–imagine those cloth handtowel loops in bathrooms. Some sort of wicking microfiber that was in contact with the clothes, then allowed moving the water to evaporate it elsewhere with microwaves.

Vacuum. PV=nRT. If I lower the pressure, I increase evaporation. What about a clothes dryer that has a vacuum seal, sucks most of the air out of the chamber, allowing water to evaporate. This will consume energy making your clothes colder but drier. Then you could move the air to some compartment where it gets microwaved (see above) and the heat could be exchanged back into the dryer chamber to help with the evaporation. If I keep a strong heat differential between portions of the main chamber, I might be able to continuously evaporate in one place and condense in another. Maybe even freeze dry the clothes

Recycle the heat. At the bare minimum, it would be helpful to recycle the heat from a traditional hot air dryer. If your heated air is just pumped outside, you lose all that energy. But if, for instance, the air intake was a long metal tube with radiator fins inside the wider plastic exhaust tube, you would recapture some of the heat without recapturing any of the moisture. Now, you’d have to worry about condensation on the intake pipe, but I assume this could be set up to just drip out somewhere.