Commercial vs Consumer Dishwashers - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: April 20, 2022, 03:00:57 am
content: I know this is not strictly cooking-related... I've been looking at dishwashers and kind of like the idea of commercial under-bench models (the ones where you load up the rack then just shove it in the machine and it comes out clean (and hygienic) minutes later. But I'm curious to hear from those who know more about these appliances... What makes them so different?For example, my current Siemens/Bosch unit takes about 2.5 hours to run through it's most intensive cycle (or about 1.5 hours in the "speed" mode). It will heat the water to 70°C.By comparison, commercial washers have much shorter wash cycles, we're talking anywhere from 45 seconds to 6 or 7 minutes and heat to roughly the same temperature (some models go to 90-100°C during a "hygiene" cycle"). Although they do seem to pre-heat the water first and hold it in a tank before any cycle, which can take up to 20 minutes.Why the huge difference in wash times? Is it a difference in the chemical detergents used? Higher pressure spray arms? Are plates and cutlery soaked and/or manually rinsed off first (as opposed to just being "scraped clean")?The dishwasher is one appliance I use just about every day or even multiple times per day on weekends or if I have guests over. Aside from when I'm washing plastics, I almost always use the intensive/hottest cycle and at 2.5 hours per load, this adds up considerably.

author: bill_c
author_rank: Regular Contributor
timestamp: April 20, 2022, 04:24:55 am
content: The few I seen (not under bench style) had a 5gal. container of soap and another 5gal. of sanitizer, they also required 150F+ water. There are "test strips" for daily verification of sanitizer presence. It seems like they use it only for plates, cups, and such but not stuff like pots and pans that need a real scrubbing. They are much louder than the consumer version. The few I seen had more space between items compared to consumer version and only one level unlike the 2 level consumer version. Simple box of cams and limit switches instead of a few special control boards with flat touch panel that will be unavailable or cost $600 each when they do break. Last I seen, most consumer models focused on having it play a short tune when starting or complete and less focused on durability and function.

author: Halcyon
author_rank: Unknown
timestamp: April 20, 2022, 04:35:03 am
content: Yeh I couldn't care less about the noises it makes. It has one job and it should do that job well (and at the same time, keep itself relatively clean between monthly "deep cleans").I do like my current unit. It washes well, but it could be a bit quicker in my opinion at the expense of some additional pump/sprayer noise.

author: John B
author_rank: Frequent Contributor
timestamp: April 20, 2022, 04:35:17 am
content: Most that I've seen in a cafe/bakery etc also ran on a 32A plug, probably 3 phase.

author: jpanhalt
author_rank: Super Contributor
timestamp: April 20, 2022, 05:13:01 am
content: My Maytag (one of Whirlpool-owned brands) higher end domestic washer works fine, and a full cycle with sainitize is about 1 hour. I can open the door to let the seam and out and facilitate drying. Otherwise, it is about 1-1/2 hours until cool. It is labeled "steam" and includes various service cycles for which one can choose heated dry and/or sanitize. I usually choose both. It is also quiet. I always rinse my dishes, but that washer also includes a drain for garbage from unrinsed dishes and a water pre-heater.One suggestion for installing under counter, particularly if the counter is wood or particle board is to apply laminate (e.g., formica) under the counter. That has prevented the steam from the washer from causing it to roughen/warp.The biggest difference I have found in use is choice of detergent. For years (>40 at 3 homes) , I used Cascade powder and not only got lime buildup in the washer, but it etched the dishes. I switched to Finish about 8 years ago. Ran one cycle of its de-limer and the washer looked like new. Also, no more etching of my dishes.

author: Halcyon
author_rank: Unknown
timestamp: April 20, 2022, 05:17:27 am
content: My bench-tops are all stone so no issues there. In relation to detergent, I've always used Finish. The powder fully dissolves and there are no harsh fillers that scratch glassware. Sure, you pay a bit more for it, but extra few cents per wash is worth it. I also don't use tablets, they are a waste of money and do a poorer job (in my experience). Finish powder and keeping the rinse aid container filled up is more than enough for a decent clean. For really stubborn or oily items, I'll throw a little Trisodium Phosphate into the bottom of the machine during the pre-wash.

author: jpanhalt
author_rank: Super Contributor
timestamp: April 20, 2022, 05:36:25 am
content: I used to throw a tablespoon of real TSP (not "substitute" TSP) into the dishwasher for heavy loads. With Finish, that didn't seem to help at all. I am sure TSP is fine with most things, including pots, but it will contribute to etching china.I am still in the habit of pre-washing everything and rarely put pots and pans in the dishwasher. One of my daughter's screams at me about doing that, but I ignore her.

author: david77
author_rank: Frequent Contributor
timestamp: April 20, 2022, 06:06:36 am
content: There are also half-commercial dish washers. They look and work mostly like consumer machines but are connected to hot & cold water supply and usually need three phase power. We had one of those at work, it took about 15 min. to clean a full load of dishes.I suspect the time advantage is mostly due to the machine being hooked up to the hot water supply. If I remember correctly it also had 3 heating elements in the bottom, that's probably why it was hooked up to 3 phase power.Our newest Miele dish washer (bought in January) could be hooked up to hot water instead of cold too. Maybe I should try it but I hate plumbing, the "wires" are too stiff for my liking.

author: beanflying
author_rank: Super Contributor
timestamp: April 20, 2022, 09:14:39 am
content: Quote from: Halcyon on April 20, 2022, 04:35:03 amGot an under Bench mount one currently out of service and in storage with trays to suit. 20A single phase from memory (4500W I think?) without looking at the plate. The pass through ones are maybe a little OTT for homeAs to function good for general Cafe work but pots and pans still went through the sink and elbow grease.

author: tooki
author_rank: Super Contributor
timestamp: April 23, 2022, 12:38:34 pm
content: Quote from: Halcyon on April 20, 2022, 03:00:57 am1. Commercial machines are designed to do lots of loads throughout the day on short notice, so they heat their water in advance, so it’s always ready to go once preheated. Domestic machines aren’t used that frequently so preheating would be wasteful. (Modern domestic machines even use heat exchangers to recapture heat from the outgoing wash water to warm up the incoming rinse water. Efficient but slow.)2. Commercial machines prioritize speed over energy efficiency, primarily by using hotter water. Domestic machines are subject to energy efficiency rules that have gotten stricter over time, with the consequence of cycle times getting longer.3. Commercial machines are designed, in essence, for easily washed items: freshly-soiled, pre-rinsed glasses and dishes (and soaked, if anything was baked on). Domestic machines are designed to do all the soaking and rinsing so that they produce good results even as you collect a load of dishesand pots and pansover a few days. If you put that load into a commercial machine it’d come out dirty. For restaurants, they make special “pot washer” machines to do pots and pans. A domestic machine has to handle them all.4. Commercial machines do not dry the dishes at all. “High temperature” commercial machines use water so hot that the dishes flash-dry quickly.5. Different chemistry using a) a main detergent/degreasing agent for the wash water; and then in the rinse water either: b) in high-temperature machines, a rinse aid so that the dishes flash-dry without spots; or c) in low-temp machines, a sanitizing rinse.

author: rsjsouza
author_rank: Super Contributor
timestamp: April 23, 2022, 02:26:24 pm
content: The higher temperatures involved would also be fatal for plastics - very common in households but not in commercial venues.

author: tooki
author_rank: Super Contributor
timestamp: April 23, 2022, 02:33:34 pm
content: Nonsense.Plastic items melt in household dishwashers that use strong radiant heat during thedryingphase. Commercial dishwashers don’t dry the dishes at all — all the heat comes from hot water, which is heated in a tank outside the washer cavity. So the maximum temperature possible is 100°C, which most plastic kitchen items can handle without difficulty.Furthermore, plastic is common in commercial kitchens. Plastic cutting boards are nearly universal (and are expressly required in many jurisdictions), as are plastic storage tubs, plastic-handled knives, plastic utensils like salad tongs, and plastic cups.

author: Halcyon
author_rank: Unknown
timestamp: April 23, 2022, 10:59:02 pm
content: I believe most consumer washers dry by heating water as well (at least, the ones sold in this market). I've never seen a unit with an exposed element in this country. I use the hottest wash setting and have never had plastic melt. There are warnings on some products which say to use the low temperature cycle on some plastic items, but that's more to do with weakening of the plastic over time leading to cracking, such as the "hard" plastics used on my food processor parts.

author: beanflying
author_rank: Super Contributor
timestamp: April 24, 2022, 01:15:36 am
content: The Boards for a start are HDPE (generally modified polymers from this) which is fine in boiling water. The Wash Trays going into the washers are also Plastic and never have an issue. Commercial kitchens with Dishwashers still wash some things manually so don't conflate the all in one lazy home solution with commercial kitchens. Plastic tubs in use in commercial kitchens vary a lot in composition and we hand washed those and a lot of our cookware.

author: Halcyon
author_rank: Unknown
timestamp: April 24, 2022, 07:42:25 am
content: Great advice as always beanflying. Thanks.

author: tooki
author_rank: Super Contributor
timestamp: April 24, 2022, 03:37:33 pm
content: Quote from: Halcyon on April 23, 2022, 10:59:02 pmI've never seen a model with an exposed heating element here in Switzerland, either. They have it in hidden in the sump and rely on the thermal mass of the dishes to dry.In USA, dishwashers with exposed heating elements are common, and many dishwashers use them to actually heat the air inside the dishwasher while drying. Unsurprisingly, this isn't very even heating, so hot spots can melt some plastics.