Why won't my "invention" work?

Bingo. This is what I came into say. And I wonder just how big of a load a standard sized combo unit can wash/dry. Since everything is cramed into one unit, I bet it’s quite a bit less.

One problem is that dryers get less efficient if you overfill them - and the user tends to fill the washer to capacity. If you have a washer and a separate dryer, usually the drum of the dryer is larger, so that they both have the same capacity. If you have a machine that served both functions in one drum, you have to be careful not to overfill.

That would be an issue but a scale in the unit could let you know if it’s overfilled. It would have to be a front loader anyway for it to be an effective dryer, and as a result the washer will use a lot less water than top loaders making the drying time pretty good compared to drying clothes out of a top loading washer. You might be able to make an economical double unit that shares a lot of parts, maybe even the motor if you got tricky. So two combined units doing to separate loads at the same time for no more cost than a separate washer and dryer.

A much better solution to the space problem is a stackable washer/dryer combo. My daughter has that in her NYC apartment. My wife has used the other and agrees it just doesn’t work as well.

Had one in a borrowed London flat. Even being a new Bosch unit, it failed at a few light loads of underwear and shirts. Great idea, too limited in practicality unless it’s absolutely the only choice. Kind of like Spider Robinson’s musing about a combo stove and fridge…

Yet they do make those things for tiny efficiency kitchens.

They’re also starting to integrate the washers and dryers somewhat; the GE dryer I got last year has the ability to connect to compatible GE washers, and they’ll basically communicate on the wash and spin cycles and temperatures, and set the dryer accordingly, so that if you washed your jeans using the “Jeans” cycle, but with hot water, it would set the dryer a bit differently than if you did it using the “Perm Press” cycle using “tap-cold” water.

Not sure how useful it is; our washer is about one model too early to actually connect with the dryer. But I can say that matching the settings between washer and dryer does seem to give pretty stellar overall performance.

Physically combined, not functionally. Spi’s got this running thing about his characters musing over or inventing something that couples “a heat maker and a heat waster, side by side.” It’s something that clearly bugs him when he’s, um, musing.

Put the radiator on top of the fridge like the old days and you’re getting there. Going further you’ve got a heat pump that’s always cooling the fridge and somehow storing the heat to use in the stove. Then you use the waste heat from the stove to drive a Sterling engine to power the heat pump. When you’re all done you’ll have an even less efficient stove and refrigerator. Can’t understand why it wasn’t done in the 50s when waste was considered a feature.

We have them in Britain but, yeah they don’t really do what the OP wants and turn out perfectly dry washing at the end. And when I had one you had to reprogramme it to do the drying. I used mine to dry particular bits of washing I needed dry fast or to do things like sheets which are a hassle to hang up. Most people I know who have a dryer at all have a separate one and really it’s only the people with kids who do.

If I were going to opt for a single machine that was both washer and dryer, I would also want it to be a laundry extractor, one of those high-RPM spinners that fling a much higher percent of the water out of your wet clothes than the standard spin cycle on a washing machine does.

That would significantly lower the amount of necessary drying, and people appear to be saying that the existing hybrids are slow to dry the clothes.

It would also remove a lot more of the soapfoam.

It might or might not be more energy-efficient overall, but it seems reasonable that it would be — a well-engineered basket with a good bearing should not require as much energy to accelerate and maintain at high RPM as a dryer requires to dry sopping-wet clothes.

It would require more expensive parts, probably harder metal manufactured to finer tolerances. Don’t know what issues would be involved in designing a washer drum and motor and supports that would be durable for standard laundry agitation behavior and also work well for repeated high-speed extraction spins.

Race you to the patent office. I had this idea a long time ago because I wash clothes then get busy and forget to dry them. Washer on top with a trap door that opens on the bottom to dump the clothes into the dryer. Not only does it simplify things but it saves space.

I remember working on a design for a hypothetical clothes washer/dryer/folding machine when I was in (engineering) grad school as a class project. We came up with some wacky ideas, but in the end decided that it just wasn’t going to be an efficient machine.

It does, because that’s how most washer/dryers work. Most people who choose them because of lack of space for separate units also lack the facility to vent them outside, so that’s the market manufacturers cater to.

But not less than the price of either single unit, because of being necessarily more complex.

So long-term costs will be higher.

So you’re back to two appliances which take up (at least) the same space, at a higher initial cost, with lower reliability meaning more frequent repair or replacement. And both require plumbing and vents, limiting where they can be situated.

I mean, I realise we’re just spitballing this hypothetical idea that Why Child just came up with, rather than a line of appliances that major manufacturers have had in production for decades, but I don’t see why we shouldn’t examine all the practical aspects.

Of course, you can accomplish the task with one standard washer, one standard dryer, and one robotic arm. Those are getting pretty affordable these days.

Well, they had them in Lost in Space.

Remember the “washing machine” there on the alien desert set, that good ol Mom dumped some metallic jerseys into, exchanged two or three motherly lines of dialogue with poor confused Penny, then opened and removed folded, pliofilm-bagged garments from? Sheesh…

I had a little LG all-in-one for a few years. It worked OK. Since it’s ductless, the dry function basically relies on a compressor to cool down the steam and drain the resulting condensate. Heavy stuff like towels often came out slightly damp no matter how much drying, but you could air-dry them for about 5 minutes to finish them off.

My main complaint with the thing is that it took about four hours to run a complete wash/dry cycle, and the drum was quite small. It’s a fine appliance for a bachelor, but would not meet the needs of a family or even a reasonably busy couple. I’ve since upgraded to a separate washer and electric dryer (with larger capacities) and now I have the advantage of processing multiple loads in parallel. And I can actually fit a blanket in the damn thing now.

Reminds me of a Steven Wright joke: “For my birthday, I got a humidifier and a dehumidifier. I put them both in the same room and let them fight it out.”

Yeah, you can run more clothes through the pair, but someone has to babysit it. If I could just throw a load in the combo unit on my way out the door to work, or when I come home for 10 minutes, that would be a bigger time savings for me (and for lots of people, I think). As it is now, doing a load of laundry requires that I be at home and awake for a minimum of an hour, or that I accept having my clothes sitting around wet for many hours. I’d be happy to give up throughput capacity for flexibility in scheduling.

If it actually worked well, of course.

I rarely use the dryer function on mine. The spin is powerful enough to get the washing dry enough to put out on an airing frame overnight to finish drying. Less electricity, fewer (and less entrenched ) creases. But it is useful to have it in reserve, and it would be different for a family with a lot of laundry.