Note: This is a “classic” Interesting Thing of the Day article from over 10 years ago. It has not been edited recently, so it may contain broken links, outdated information, or other infelicities. We plan to eventually update or retire most classic articles, as time permits.

Nearly two years ago, my wife and I decided to move out of our trendy loft apartment and find a quieter, friendlier, and less expensive place to live. One of the criteria on our list was laundry facilities. Here in San Francisco, this is not a trivial issue. There may be plenty of beautiful Victorian and Edwardian buildings, but it’s relatively rare to find an apartment with a washer and dryer in the unit, and even shared laundry facilities in the basement or garage are not the norm. Although many thousands of people make their way to the neighborhood laundromat each week with a basket of clothes and a roll of quarters, that’s something we hoped to avoid. Years of experience have shown us that there is a positive correlation between convenience of laundry facilities and marital bliss. So we were most drawn to homes that had their own washer and dryer.

At a certain point in our search, we came across an otherwise suitable apartment that included a small extra room with hookups for a washing machine, but no space for a dryer—nor any way to vent one. That sounded to me like a problem that ought to have a technological solution, so I began searching the Web. Sure enough, I found a class of machines that used a single chamber for both washing and drying—put clothes in dirty, push a button, wait an hour or two, and take them out clean and dry. That by itself was interesting, but what really got my attention was the fact that these devices could dry clothes without any sort of vent. I had always assumed that hot, moist, linty air has to come out of a clothes dryer one way or another—it seemed like one of those cosmic truths you just couldn’t get around. But you can get around it, and surprisingly enough, one way to do so is to use water to dry your clothes.

Small Change

We eventually found a home with a conventional washer and dryer, and I forgot all about the combination devices until I went over to a friend’s apartment and saw one of the combo washer/dryer machines in the corner humming merrily along. After it washed his clothes, a different light came on and it started drying them. It didn’t give off any heat, which was actually slightly disappointing because that room was a bit chilly. He said it worked extremely well, the only minor drawback being that it had a relatively small capacity. According to the sticker on top of the machine, it was expected to consume about US$12 worth of electricity in a year—or about as much as a typical San Franciscan spends on coin-operated washers and dryers in a month.

But it wasn’t the compactness or energy efficiency of this machine that intrigued me, it was the way it got the clothes dry. Ordinary dryers suck in cool, dry air from the room, heat it, blow it through the clothes, and then discharge the damp, hot air outside through a vent. This dryer, on the other hand, runs the exhaust through a heat-exchange system to cool it. Cold water flows through the heat exchanger, absorbing heat from the air. As the air cools, the moisture in it condenses and runs down the drain (along with the used cooling water); the dry air is then heated again, sent back through the clothes, and the cycle continues. The upshot of this is that drying your clothes with a ventless dryer requires a few extra gallons of water, but eliminates the need for a vent and keeps your laundry room from overheating.

Air Apparent

Not all ventless dryers (or condenser dryers, as they are sometimes called) have built-in washing machines, and not all of them use water to condense the moisture from the air. Another design—frequently seen in Europe but hard to find in North America—has heat exchangers that use cool air from the room to absorb the heat. This means that hot (but dry) air is discharged into the room; the condensed water drains away just as it does in the combination units.

Now that you can wash and dry your clothes with the push of a single button—while keeping your apartment cool and dry—it’s time for the world’s engineers to tackle the final frontier of laundry automation: folding. I remember an old “Lost in Space” episode in which Mrs. Robinson put the family’s dirty clothes into a box, pressed a button, and then pulled out clean, dry, folded, and plastic-wrapped garments a few seconds later. That’s what I want. Then my wife will be happy to do the laundry while I replicate dinner. —Joe Kissell

More Information

For a good discussion of how condenser dryers work, see What is a condenser dryer? by Tom at GardenWeb.

Some of the major brands of combination washer-ventless dryer machines are:

Compact Appliance, Inc. or AJ Madison Superstore, or even at cover art

You can find these devices at large appliance stores, online at stores such as Compact Appliance, Inc. or AJ Madison Superstore, or even at