Hacker News new | ask | show | jobs
by spijdar 1760 days ago
I haven't watched this video in a while so apologies if it's not specifically elaborated on, but I believe it's covered here: https://youtu.be/_rBO8neWw04

From memory yes, it's partially about water usage, but dishwashers are in general just pretty good overall about efficiently using energy to maximize "food grime removed" per unit of resources fed in. Even if you're careful with water usage while hand washing, I think a decent dishwasher will beat you.

Another advantage is the dishwasher heats its own water, whereas with hand washing either you need to use a house-wide water heater or preheat water in a kettle or something, which will have its own energy wastes. This of course depends also on how your house's water is heated.

One page I found googling elaborates on these ideas, concluding that you could potentially be more efficient hand washing, but only with a lot of effort: https://www.treehugger.com/built-in-dishwashers-vs-hand-wash...

4 comments

>Even if you're careful with water usage while hand washing, I think a decent dishwasher will beat you.

I once ran the dishwasher with the outlet hose in a bucket because the drain pump was on its way out. I expected to have to empty it several times, but at the end of the cycle there was less water in it than I would use to fill a washing-up bowl to do the dishes by hand (and the amount of dishes it cleaned might have required more than one bowl).

And it's disgusting and water where I live is cheap and plentiful. Hate water austerity imposed on everyone because of megacities and people living where people shouldn't live.
Large human population is an issue. But if you accept that as a premise, Megacities are more efficient in terms of resource usage than equally-sized but geographically dispersed populations.

As for water usage, think first of agriculture, then industry. Only after that do cities come into play. Cities are relatively small water consumers.

A city may be more efficient than lower population density on a per-capita basis but that is only tangential to the problem. A city in the California desert is not a good reason someone in NYC should have to endure a washing machine and dishwasher that are so stingy about water usage they are frequently ineffective at their primary task.

>As for water usage, think first of agriculture, then industry. Only after that do cities come into play. Cities are relatively small water consumers.

Where do those agricultural products get sold and eaten?

<insert screeching about "taxing muh negative externalities" here>

See my other post: agriculture water is not heated or treated. Thus cities use as much energy for their water despite only using a fraction. In all of the above water itself is not the issue as it isn't lost, just moved downstream until the water cycle (rain - which has always been non-uniform) brings it back.
Typically even within residential areas the issues isn't people per se, it's lawns and golf courses. And those are absolutely not evenly distributed or used.
IF this was about water I agree with you. However it isn't actually about water it is about water heating. Hot water cleans better than cold, but it takes energy to heat water and that affects everyone (global warming). Thus less water is better.

There are also some water pumping and treatment costs (more energy), but they can be ignored as insignificant.

Thanks. I read the treehugger link—pretty convincing overall. Not sure why my question was downvoted tho. (Not accusing you)
I didn't downvote -- it's fair to be skeptical that a machine that spends hours making loud whirring noises would be more efficient than just scrubbing some dishes in the sink. And I don't want to careful about making unequivocal statements like "dishwashers are always more efficient", I've just heard some convincing reasons why dishwashers in particular are pretty cool and (unintuitively) efficient.
In my observation unfair downvotes come, when people are angry at something and looking at anything that looks like a scapegoat to direct that anger, which can be anyone not expressing the same mindset they have. Which was you by asking that question that apparently was enough to mentally puts you in the "stupid treehugger camp". I would not worry about it too much and try to not take it personal.

Their rational explanation is probably "how you can be so stupid for not knowing that common knowledge".

And well, even though I am indeed a treehugger, I also knew about the efficency of dishwashers before and also assumed it to be common knowledge, but I would never downvote someone because of a genuine question adding to the conversation.

You have to heat water to wash your dishes ? What kind of gravy sauce are you cooking in your pot.