The indoor powered clothes line.
 

If I put clothes on the clothes line in the summer during the day with a breeze shirts dry in like 20 minutes.
During fall/winter and at night not so much.
I told my wife would wash and dry her shirt for work.
But I didn't.
It was washed, but still wet.
So I took the shirt hung it over my kids little trampoline. Just hanging there wasn't doing anything.
Then I tuned on the high volume air filter, that just made the fabric cold.
Then I took the 10,000btu propane heater and 40lb tank and had the radiance from the heater pointed to the shirt and the high volume air filter blowing over the propane heater directing the heat rising off the heater also on the shirt. That was working.
Setup and testing had the shirt dry in about 20 minutes.

No dryer there?

My natural gas dryer can get it done in 20 minutes and costs beans to operate.

I was thinking a vacuum chamber.

Just an electric dryer.
I have a natural gas dryer but I would need to swith over to propane.

Now I'm wondering what a bag and a vacuum would do. I could test that with my shop vac.

There's a reason why dryers tumble, and why the blower doesn't make an insane amount of noise.

I do like the idea of creating a vacuum to evaporate the water. I wonder if that would be more energy efficient? Should be I suspect, and detecting "dry" would be more reliable. When water stops converting to gas and ruining the vacuum, that's when it's dry.

I wonder if the vacuum method would eliminate the problem of shrinking wool sweaters too?

The best solution depending on your local electricity and natural gas prices is a clothes line for the summer and an electric dryer with one of these for the winter.
https://www.amazon.com/dp/B07MQYPG34...roduct_details
Surprisingly I just got mine today and just hooked it up with mesh filter on the staight end out of the laundry room to just below the central air pickup, and it worked great. I didn't have any lent problems and the water all evaporated pretty well.
Clothes lines are cool but even in the summer i have to dry them for the last 20 minutes in the dryer or they look and smell bad. In the winter clothes lines just don't work.
Suprisingly for me the diverter with the electric dryer comes out just ever so slightly cheaper than a natural gas dryer here since the unit price on natty vs electric is a lot cheaper.
Cool part though is im saving money and i have also solved my total home humidity problem in the winter lol. I usually get a 20% rise in humidty to around 50% when i do laundry. lol

$25 flapper valve?

When the thread title came up, this popped into my head:

https://secure.img1-ag.wfcdn.com/im/...lothesline.jpg
https://secure.img1-ag.wfcdn.com/im/...lothesline.jpg

Put one of these on a rotating Christmas tree stand.

Don't think freebeard can generate enough vacuum with the shop vac to get significant drying. Also the best dry you can ever get is slightly above ambient humidity which is why dryers are hotter than ambient. Theoretically I can put clothes into my convection oven and get them dry fairly fast but at 3kw the electric dryer is cheaper to run.

When I lived on Maine and was poor our clothes dryer broke and so were we so we used the clothes line in the middle of Maine winter. The clothes froze and the ice eventually phased to vapor after about 24hr. Seemed like the colder it was the faster they dried.
I like the electric dryer because I vent it inside during the winter, learned to do that living in Maine also, laundry day was about the only time the house got above 60 degrees F during the winter.
Probably why I have a dryer, a back up dryer and a heater, secondary heat and a third emergency backup, no batteries or electricity required.