Yeah that could be a concern depending where you live. Where I live, water is cheap and abundant. And I've never measured, but I would guess I use maybe 10 gallons to wash a car. 2 gallons in the bucket, and just a light wetting followed by soapy sponge and then a rinse, using a nozzle to create a high velocity spray. The water doesn't run at all unless I'm spraying it on the car.
Water is cheap and abundant where I live, too. If we have a problem with water in any normal year, it is usually that we have to deal with a surplus of it. (We put drainage tiles under our farm fields to get rid of excess water and generally don't even bother with irrigation systems at all.)
But car washes are interesting systems and one of the things that makes them interesting is that the water they use is (often) recycled. The same water gets reclaimed and re-used to wash cars over and over again.
I didn't look very deep at all, but one car wash chain suggests[1] a reclamation rate of 70%. Not perfect, but way better than 0.
You can probably match that efficiency at home by using an electric pressure washer. Mine does 1.2 GPM, which means an entire car wash is only a few gallons.
That's surprising. I once tried an automated car wash just to see what all the hullabaloo was about and I think the rain actually does a better job. Worst $5 I've ever spent...
Yes. In the same way that dishwashers are an order of magnitude more water-efficient than washing by hand. (But consume a kilowatt of electricity heating the water and running the pump, which is the part that everyone always leaves out.)
You heat the water when you wash dishes by hand too, don't you? It's not very hygenic to do dishes with just cold water.
Given that by hand you use much more hot water than the dishwasher would, you're using more electricity (or gas). Since a little pump doesn't use much at all, it's mainly just the drying heat that matters. Though nobody is forced to use the drying cycle - if one enjoys drying dishes by hand, they can still use the dishwasher to do the washing.
You're assuming an absence of solar hot water heaters - the world isn't homogenous.
eg. Our household conserves water (we track every litre we bring up to the tanks and filter) and we don't have a dishwasher - hot water is heated by the sun and run-off goes to the grey water tank for the garden.
No I'm not. I don't care how you heat your water. I'm saying you (should) heat it either way, and you use more of it when hand-washing so if you do pay to heat it, you pay more by handwashing.
And in your case, you use more water because you hand-wash, than you would if you used a dishwasher. You use slightly less energy because of the pump but also a lot more of your time, so... obviously how you relatively value those different things is up to you.
Our concern here, and that of many people in the area, is total water usage per household - and to a large degree water usage for washing, showers, and toilets is a small fraction of the total usage - and one that can be ignored as most people have grey water capture (as do well planned and infrastructured cities).
Water used inside the house runs out to water food, shade, animals, etc. and that use can be deducted from the water that is required for those uses.
Energy is no great cost, it comes from the sun - both as electricity via panels and directly as heat via solar hot water systems.
In my house you don't heat the water but it's been sitting in a metal water tank at equitorial latitude for hours so is generally quite warm for evening dishes.
Is it safe? Not for a restaurant where the temps need to get to parasite killing temps to pass muster.. but if I had to guess, the odds of getting killed by a bad-tempered cow outweigh it by 10x.
When my water heating was electric, switching to a dishwasher consistently led to lower electric bills compared to a year prior (confirmed for 12 whole months).
Yeah that could be a concern depending where you live. Where I live, water is cheap and abundant. And I've never measured, but I would guess I use maybe 10 gallons to wash a car. 2 gallons in the bucket, and just a light wetting followed by soapy sponge and then a rinse, using a nozzle to create a high velocity spray. The water doesn't run at all unless I'm spraying it on the car.
Water is cheap and abundant where I live, too. If we have a problem with water in any normal year, it is usually that we have to deal with a surplus of it. (We put drainage tiles under our farm fields to get rid of excess water and generally don't even bother with irrigation systems at all.)
But car washes are interesting systems and one of the things that makes them interesting is that the water they use is (often) recycled. The same water gets reclaimed and re-used to wash cars over and over again.
I didn't look very deep at all, but one car wash chain suggests[1] a reclamation rate of 70%. Not perfect, but way better than 0.
[1]: https://www.tsunamiexpress.com/our-washes/
You can probably match that efficiency at home by using an electric pressure washer. Mine does 1.2 GPM, which means an entire car wash is only a few gallons.
That's surprising. I once tried an automated car wash just to see what all the hullabaloo was about and I think the rain actually does a better job. Worst $5 I've ever spent...
Yes. In the same way that dishwashers are an order of magnitude more water-efficient than washing by hand. (But consume a kilowatt of electricity heating the water and running the pump, which is the part that everyone always leaves out.)
You heat the water when you wash dishes by hand too, don't you? It's not very hygenic to do dishes with just cold water.
Given that by hand you use much more hot water than the dishwasher would, you're using more electricity (or gas). Since a little pump doesn't use much at all, it's mainly just the drying heat that matters. Though nobody is forced to use the drying cycle - if one enjoys drying dishes by hand, they can still use the dishwasher to do the washing.
You're assuming an absence of solar hot water heaters - the world isn't homogenous.
eg. Our household conserves water (we track every litre we bring up to the tanks and filter) and we don't have a dishwasher - hot water is heated by the sun and run-off goes to the grey water tank for the garden.
No I'm not. I don't care how you heat your water. I'm saying you (should) heat it either way, and you use more of it when hand-washing so if you do pay to heat it, you pay more by handwashing.
And in your case, you use more water because you hand-wash, than you would if you used a dishwasher. You use slightly less energy because of the pump but also a lot more of your time, so... obviously how you relatively value those different things is up to you.
You're a bit all over the shop in that answer.
Our concern here, and that of many people in the area, is total water usage per household - and to a large degree water usage for washing, showers, and toilets is a small fraction of the total usage - and one that can be ignored as most people have grey water capture (as do well planned and infrastructured cities).
Water used inside the house runs out to water food, shade, animals, etc. and that use can be deducted from the water that is required for those uses.
Energy is no great cost, it comes from the sun - both as electricity via panels and directly as heat via solar hot water systems.
In my house you don't heat the water but it's been sitting in a metal water tank at equitorial latitude for hours so is generally quite warm for evening dishes.
Is it safe? Not for a restaurant where the temps need to get to parasite killing temps to pass muster.. but if I had to guess, the odds of getting killed by a bad-tempered cow outweigh it by 10x.
When my water heating was electric, switching to a dishwasher consistently led to lower electric bills compared to a year prior (confirmed for 12 whole months).
You save water and electricity.
But can you put dishes with food on them in the dish washer?
Yes.