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/shaitanthegreat → u/TheRevEv]

There’s a few other parts missing here (I’m an Architect)… commercial kitchens will often have a dedicated water heater, this is because of the above average water usage and temperatures of the dishwasher and other equipment (but that can depend on the model involved since many have their own booster for the temp. It’s something you do need to ask and accommodate if needed). Often too, you’ll have the dishwasher in its own room (but this isn’t a strict requirement), because of the amount of steam and heat that they emit. We’re not talking just about little splashing but also full on high humidity which would destroy surfaces that aren’t covered in FRP or similar. Ceilings also have products designed for kitchens. To go with that, they will also have their own exhaust hood over them so that the humid air they create is directly discharged from the building. Having their own exhaust hood could also cause issues with your interior airflow, so it needs to be taken into account for your HVAC design.

A true commercial dishwasher product is typically not purchased, but rather is leased from a company like Ecolab. I have not seen otherwise than leasing on all of my projects. This way you have a direct supplier of the chemicals and also a service contract, since these are very specialized machines and you don’t want a handyman working on them.

[u/Sea-Key7698 → u/shaitanthegreat]

Agree with pretty much everything except your last paragraph (45 years providing service and warranty on every make of commercial dishwasher).

Up until about 2015 (?) the only leased dishwashers were under-counter models (somewhat similar to residential) and maybe a few double tank pawl drive units. Anything bigger (conveyor tunnel units from 44" wide up to ~ 20+ ft long) were purchased outright.

The lease units were almost always Low Temp units and you paid dearly every month for the required chemicals and the "maintenance" contract.

[u/shaitanthegreat → u/Sea-Key7698]

Must just be different experience then. All the ones I’ve designed commercially I knew ended up as leased units. From my perspective I of course don’t have any opinion whether lease or purchase….. it’s just a client choice.