I bought one of those damned eco dishwashers, and it takes about 2 hours to get the dishes sort of clean. The only thing worse is the damn eco-clothes-washer that also takes two hours and twists your clothes into something that looks like it came from a cable factory. They are quiet, at least. What do you want for two grand?
I absolutely do NOT believe that a dishwasher is more efficient with water than handwashing (appropriately). Find here the original research article.The problems I have with this research article and the resulting conclusions are:1) The water consumption for the dishwasher is taken from the manual, it isn't even measured.2) No pre-washing of dishwasher dishes is performed. I don't know about everybody else, but my dishwasher is terrible (I rent an apartment). So I must remove most of the food before I put it in the dishwasher.3) The water consumption via hand-washing is extrapolated. That is, they take the water consumption of a 2-place setting and then multiply it by 6 to determine the total water consumed to compare it to dishwashing.4) The study is performed in Europe. American dishwashing habits are certainly different both for handwashing and using dishwashers.5) The study is paid for by manufacturers of dishwashers. If we really wanted to answer this question we would do a paired comparison test where we would measure actual real-life water consumption for handwashing and dishwashing households and then have these households use the opposite approach. My personal belief is that handwashing by filling up the kitchen sink with soapy water in one side and non-soapy in the other is much more water efficient than the average dishwasher. Certainly I could see dishwashers being more efficient with water if you have the tap on constantly throughout the washing and rinsing process.
Jarad,Thanks for the PDF on the dishwashing study. I do agree with much of your criticisms of the study, particularly its methodology, the fact that there is pre-washing before dishwasher filling, and the washing habits of Americans vs. Europeans, the former being much heavier water users (guaranteed).What it comes down to for me is this: People, especially Americans (and Canadians), will almost always use more water when available than is necessary. That said, unless water use is (self-)restricted, the utilization of a fully filled dishwasher applying a standardized volumeof water is more likely to impose those restrictions. To wit, many will keep the tap open the entire time they wash dishes.I'm sure that there are those that are able to restrict their water use (and dishwashing) habits, and their ranks are growing, but until an internalized conservation ethic appears in much of the American population, the proper and sensible use of a dishwasher will, on average, lower water use.
You can even one better the sink of soapy water; my method:Fill a quart container with soapy warm or hot water. Wash a sink load of dishes. (I can pretty much do a dishwasher load with this quart if not too greasy). Rinse with cold water from low-flow (1gpm) tap, closed when not in use. No dishwasher can beat that, I think. Of course, when I'm camping I've been known to use sand, or not wash, or use cold water sans soap, so the above is a compromise to normal clean dish expectations, not to health needs per se.
Great comments! Jarad -- we need a study like the one you are looking for. Where are the "scientific" dishwashers when you need 'em?
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