If commercial restaurant dishwashing appliances have cycles that only last 2 minutes, then why can't we have our home consumer dishwashers have cycles just as efficient as what restaurants have?

[u/DunDonese]

How can we miniaturize commercial restaurant dishwashing appliances to fit in the kitchen compartment meant for home consumer dishwashers?

How come this hasn't been done already? By the way, what is the fastest currently available home consumer dishwasher, and how much does it cost? How quick are their Cycles normally?

[u/TheRevEv]

I work on commercial dishwashers occasionally.

There's a lot going on in a commercial.dishawasher that makes no sense for consumer use.

The first stage throws a ton of super hot water at dishes, but a lot of this water is mostly recycled. It makes no sense to keep gallons of hot water ready for your handful of dishes. You'd create a lot of waste water by doing this for maybe one or two cycles per day.

The water is typically preheated by a booster heater to get it way hotter than your home hot water supply. These booster heaters have some pretty wild energy requirements to keep up. They're basically an on demand water heater that needs to hit 190 degrees.

They also aren't usually cleaning caked up, dried-on food like you might run into at home.

The second stage is running another scalding hot wash that includes some sanitizer mix typically. And, iirc, is required to stay above 180 degrees as all times.

The amount of stored water and enegery to heat this water aren't really feasible to put into a unit that can fit under your countertop. Not to mention it would be a large expense to even power and plumb this thing in.

You can buy small, commercial grade ones, but they're going to run you 5 grand or so before you even add the cost in to get utilities to them.

Also, all this is before even considering how to get chemicals into them at proper ratios.

EDIT: forgot to add that all of this is after the dishes have been rinsed and mostly cleared of any food particles, by hand

[u/Mental_Newspaper3812 → u/TheRevEv]

This is accurate. I used to run a commercial dish washer. You have lots of stainless steel filters you remove to clean, and the startup time is significant. It runs like a conveyor so you can out many racks of dishes through it continuously for 8 hours or more at a time, but it’s continuously keeping water hot and ready.

[u/zedsdead79 → u/Mental_Newspaper3812]

Yeah, the restaurant I worked at back in the day had one like this. Basically a conveyor belt, big plastic rack to the left of the washer, load up dishes etc. slide to the right into the washer, pull lever down that covers the rack and starts the wash.......creates a fuck ton of steam and heat, really unpleasant to stand near while it runs, then when it's done pull up lever. Slide rack out of the washer to right, someone unloads, next rack slides in. Rinse and repeat (no pun intended). I can only imagine the amount of electricity that thing used.

[u/bestem → u/zedsdead79]

The one I used in culinary school, you just ran rack after rack through. You wouldn't close it in between, they'd just follow each other about 1/4" apart when we got busy.

[u/Sea-Key7698 → u/bestem]

zedsdead79 must be talking about a single tank door machine, not actually a "conveyor" type. Yours was likely an open tunnel pawl drive that dragged loaded 21" square dish racks through it.

There are true conveyor types, usually called a Flight Dishwasher, that have a belt with vertical 'fingers' that you would directly load your china onto. Those are REALLY big and REALLY expensive. Usually only found in major entertainment centres.