Commercial dishwashers in homes (residential kitchens)?
[From information compiled, written, and posted in the Appliances Forum by Colin (GW Member Page: cpovey) on 13-24 July, 2004. Many thanks, Colin!]
A short FAQ on commercial dishwashers in homes (residential kitchens):
While some people think its worth the effort to install a commercial range in their house, its a very different situation for commercial dishwashers.
In general, you should not even think about getting a commercial dishwasher for a home. Heres why:
First, the Pro side:
They are very fast. A typical load takes 2-4 minutes. Yes, thats not a typo: 2-4 minutes.
Some machines are about the same size as a conventional home dishwasher, and will even fit under a counter.
Dishes will be more sanitary than those coming from a home machine, because commercial dishwashers require either very hot water (180 degrees F/82 degrees C) or a chemical sanitizing agent. These include Chlorine, Iodine, or Quaternary Ammonium Compounds (called "Quats" in the trade). Most restaurants use the chemicals, because it is less expensive than heating water. Chlorine is the least expensive, but tears Aluminum pots and pans apart.
Now, the Cons:
First, commercial dishwashers are mostly sanitizers, not washers. They simply are too fast to really get dishes clean. In the catering company I work for, every load of dishes is run through twice to help insure things are clean. By the way, have you ever noticed in restaurants those nifty looking pre-rinse spray gadgets on springs that the dish crew uses on plates before they go into the dishwasher? Well, they are there for a reason. The plates must be pretty clean before going into the washer.
Next, different types of things require different racks. Cup racks, plate racks, utensil racks, glass racks (multiple types needed, because different glasses require different racks), pot racks. Where are you going to store these racks? Four racks take up about the same space as a dishwasher, and you cannot get by with less than three or four different racks.
Commercial dishwashers do not even make an attempt at drying. Everything comes out soaked. And you need a space to put the rack and dishes while they dry.
They have no food grinders, but filters. Again, things must be pretty clean going in or you get floods when the filters clog.
They sound like a jumbo jet taking off. There is zero sound insulation in them.
If you use hot water for sanitizing, most require a separate booster heater to make the 180 F hot water. This will require an additional purchase, whether a gas line or a large 240 VAC electric line, and space. And then there is the matter of all the steam when the dishes come out of the DW.
If you use chemical sanitizing, you will need space for three gallon bottles to hold the chemicals.
Most commercial dishwashers require 240 VAC (as also noted above re booster heaters). Not impossible to provide in a residential kitchen, but another cost.
Most commercial dishwashers do not have drain pumps, though some can have one as an extra-cost option. This means that you need a "gravity drain" in or almost in the floor for the dishwasher to drain into, or the optional pump.
Unlike commercial ranges, which are inexpensive compared to their home versions, even small commercial dishwashers are very expensive when compared to home units.
Lastly, and most importantly, every one I have ever used reuses the rinse water from the first load as the wash water for the second load. This is done to save water. This means that they always have a gallon or so of dirty water in the bottom of them. In a restaurant, it will be used again in a few minutes, so no worry. But at home, it might not be used for days, so there it sits, becoming smellier and smellier. Yes, you can drain them, but then the seals dry out and need to be replaced.
In general, unless you feed a small army three meals a day, a commercial dishwasher is probably not a good idea for a home. Especially given their cost, as you can buy three to six good quality home dishwashers in place of one commercial unit.
[added to Appliances FAQ: 12 August 2004]
[last edited: 12 August 2004]