I love to swim! As much as I don't really like fish, I feel like I am slowly becoming one. My YMCA has a lovely spin dyer to use so that my swimsuit isn't dripping wet in my bag. These aren't conventional at every pool and thus was a novelty when I first saw one but didn't really take time to see how it worked. It seems pretty obvious that by the name, this dryer uses a spinning motion as a mechanism to drying my swimsuit. Basically the drum inside spins fast enough so that the water separates from the clothes and you hear that dripping noise as it exits through the center of the drum. The swimsuit isn't completely dry but in that 10 seconds most of the water has been removed. This got me thinking about how much more efficient this system was to a normal heat dryer.
When I went to read about how tumble dry system works I found out they are even less efficient than I thought (since heating air takes a lot of energy). In your normal dryer, air is heated before it enters the drum and then exhausted to maintain dry heat in the drum. So the air is continually cycled through to make sure that your clothes are in constant contact with dry heat to remove the water. There are other dryers which cool the air and drain the water vapor instead of simply venting the hot air. I was also told by a washer/dryer professional that since tumble dryers do not rely on the mechanical motion to remove the water, the spin cycle in the washers are very important. The front loading washers must use a fast spin cycle at the end of the wash as compared to a top loading washer in order to remove more of the water content. All of these systems still use more mechanical or electrical energy to do something that the sun is already doing but of course there is nothing quite like the warm and toasty feeling of clothes just out of the dryer!