Today, I washed my hands at the kitchen sink while making lunch, and was unexpectedly chastised by my partner because she had just started the dishwasher. Apparently, she has recently come across something that has convinced her that running the hot water in your sink means the water that enters your dishwasher will be hotter (checks out), and thus the dishes will be cleaner. I tried searching startpage to see if this is real, but I couldn’t make it through even one llm-slop-ticle about it before my eyes rolled back into my head, so here I am asking y’all: chat, is this real? Doesn’t my dishwasher have a heating element? Is there any meaningful difference between heating the water with a hot water heater vs a dishwasher, other than I can’t use my sink while the dishwasher is filling and I have to pour a bunch of cool water down the drain?
Yes, hot water cleans better, and results in dryer dishes due to condensation drying.
The heating element in a dishwasher is weak. It can’t heat water up that well since it’s limited to 120v and probably not even 20A. The first rinse cycle will effectively be cold water.
Your tank water heater is 240v and has a dedicated circuit, probably 30A. It can heat a lot of water, fast.
If you’re concerned about wasting water you can get a small tank or tankless hot water heater under the sink. Your water will then be hot nearly always.
Some wash cycles will both purge more water and heat it up longer to compensate.
The water heater tank is also insulated better than your dishwasher because it doesn’t have a big door on it. Even if the heating elements were the same, the water heater would be more efficient at heating water and keeping it hot due to less energy loss.
They are both 100% efficient, although 240v has less loss over the same amount of length.
Insulation doesn’t matter too much if you’re just dumping the water down the drain.
But you’re right a dishwasher doesn’t have nearly as much insulating properties. The heat element in one is basically there to counter act the heat loss.
Different country and all, but both are 240v in my neck of the woods, and since I live on tank water with mains water supply as a back up. Coupled with what I believe may be the most circuitous route from hot water cylinder to kitchen tap on earth (3 meters point to point yet seeming out to the local post office and back based on how long it takes to get hot water out of the tap) we use the Dishwasher to heat our water.
Which is all a very verbose way of saying “It depends on your circumstance…”
US doesn’t get 240v at most outlets unfortunately. My hot water to the kitchen is 50-60 ft as it goes up to the 2nd floor attic, across maybe 45 ft, then back down.
Takes a couple of litres of water before we get hot water. I have filled the kettle twice before the water was too hot to hold my hand under before. That’s roughly 3.5 litres of water just to get to the hot stuff. Luckily boiling water was a key consideration in our voltage level (actually that’s something I made up on the spot 😜) but more power equals good so… Its weird that this is a field that the US apparently just decided to let a large portion of the world be more “powerful” almost expect that if there were parts of the world settling on 240v the US would arbitarily decide they needed 500v.
Are you going to pay to change the entire electrical grid, rewire every house, replace every appliance, etc.
It would be an unimaginably massive undertaking for very little gain.
The US electrical system was well-established when Europe had to rebuild post-WWII.
I always thought the decision was made a lot earlier than that. Wasn’t it largely due to Westinghouse that America settled on 60hz 110v? Where AEG pushed 50hz 220v in Europe? That was late 1800s early 1900s from memory. World war 2 may have resulted in some rebuilding but they rebuilt along lines that were already established, the bump up to 230-240v with time and gained efficiencies is mirrored in the US with the move towards 120v at least that’s what I recall, but I must admit that outside of some Technology Connections videos I haven’t delved too deeply in recent years (and yes I know Alec would say the US technically already sends 240v but that’s not what your general appliances are rated to).
The US uses many smaller circuits. I have two appliance circuits, a lighting circuit, a dedicated refrigerator circuit, and a 240V range circuit. Five separate electrical circuits, just for my kitchen.
Rebuilding after WWII, the UK standard was to run a single ring circuit for each floor of the home. They ran as few household circuits as possible, because they needed the copper.
If you look at the amperage/wattage ratings of UK circuits, they are considerably higher than other 220v/240v countries, because their circuits are intended to be shared among many more devices.
You know how they warn you not to plug in too many devices into a single circuit? The UK electrical system took the exact opposite approach, because they needed to. This is why they have a fancy plug that nobody else in the world uses: it is an essential safety component that serves the same purpose that the household circuit breaker performs for the rest of the world.