I have heard that there are "commercial" dishwashers which can clean a load of dishes in under 20 minutes. Is that true? Has anyone tried one of them?

More like 90-120s. There's the type that close from the top (expensive) and the conveyor type (more expensive), but they're incredibly fast, mostly because they blast near-boiling water at pressure-washer velocities. They also don't typically have a "drying" cycle -- because the dishes are so superheated they dry themselves in another half minute. Downside is no plastics or anything else meltable. See https://www.cafemutfak.com/en/blog/content/industrial-dishwa...

I worked at a Pizza Hut in college that had one that washed a full load of dishes in just a few minutes. I'm blanking on the exact time, but I'm almost certain it was under 10 minutes. It got extremely hot, so it probably wouldn't work for a lot of dishes people have at home, but it was very efficient! We saved at least a few hours of labor a day from it, and an unquantifiable amount of sanity.

It wasn't designed like a normal home dishwasher, it was open on all sides and you would slide a rack of dishes under the top part of it, pull a lever, and the dishwasher walls would come down around it and start the washing.

I've used the type that are common in bars/pubs/nightclubs in the UK and Denmark. They take 20 minutes or so to heat the water, then each cycle is just 2 minutes or so. The glasses are loaded on trays, so it's best to have a place to load up a tray and another for them to cool down.

This kind of thing: https://www.buzzcateringsupplies.com/classeq-c500-gw-glasswa...

I've also used one three times as wide in a small food factory for cleaning equipment, mixing bowls and so on. This was even more powerful, and could clean greasy pots and bowls quickly. It was hot and steamy while unloading it.

Like this: https://www.buzzcateringsupplies.com/mach-utensil-washer-130...

There's probably something in between for restaurants

Presumably this: https://www.buzzcateringsupplies.com/classeq-pass-through-di...

And something like this for somewhere huge, maybe a large school or office: https://www.buzzcateringsupplies.com/warewashing/commercial-...

Yep, I’ve only volunteered in commercial kitchens for events and stuff before, and the ones I’ve been in have essentially an assembly line for dishes from sinks to a dishwasher box that took 2-3 plastic cubes of dishes, and washed them in like, 5 minutes. No drying though.

Sure, but you'd need to be quite dedicated to install one in a home:

- They're 3-phase, 220-volt.

- They cannot use PVC or other plastics for drainage lines because the water is too hot.

- The high temperature steam can damage surroundings unless designed for it.

- They're very loud.

They'll wash in e.g. 90-seconds, but the dishes are too hot to handle for a bit. Plus some residential kitchenware cannot handle the high heat of a commercial dishwasher.

You'll likely never see a commercial dishwasher in a residential home.

I used a commercial dishwasher in an Airbnb that had the fittings for a catering operation. It had an initial heat up time of like twenty minutes, after that each cycle of dishes took like... two minutes? Maybe five.

But it was much worse at actually cleaning dishes than a regular home dishwasher. I never prerinse at home, but you really had to with this thing. Maybe it was just crap, but some searching around it seems like that's just how they're designed to operate.

Anyway they use a shit-ton of power and energy (wired for 5 KW, 2-3 kWh per cycle), they're loud, it's not something you'd want in your home kitchen.

Yes they're in every restaurant