3 ms·

I hope you know that energy efficients often means using motors with less Watt so that e.g. your washing machine will take longer to complete the washing cycle

by frik 11y ago

I hope you know that energy efficients often means using motors with less Watt so that e.g. your washing machine will take longer to complete the washing cycle and with less hot water. The same with vacuum cleaners, eletronic kettles, etc. Eletro motors aren't a new invention, even brushless motors are there for some decades. Not every energy saving idea is a good idea. Often it's better to buy a few photovoltaic panels yourself and buy high quality brands that last decades (e.g. Miele washing machines). I would buy a 2000W vacuum cleaner that can clean my house in 30min than a 1000W vacuum cleaner that is less efficient in cleaning the floor so it takes at least twice as long to really clean the floor. In the end you often trade time for peak power usage. Sure, power grid operators like that.

xorcist 11y ago
In published tests, cleaning ability is not correlated at all to power over a certain level. Most 2000W cleaners are older models, since research and development has focused on energy efficiency for the past decade, so they are even likely to be worse. I could easily construct a 10 kW model for you, and it's going to run very hot. (There was this EU introduced power cap for domestic vacuum cleaners the other year, accompanied with articles how you should hurry up and buy one of the powerful ones before they were forbidden. I was in the market for one, and scoured every independent test I could find where I understood the language, and the result were the same: the modern ones using less power picked up small particles better. As soon as you have a powerful enough engine other things start to matter. That's when I sighed deeply about journalistic integrity and bought one of the newer models.) You describe an important problem. Consumers keep buying older models, which are objectively worse, because they want a scalar value for "betterness". It's just like megapixels, where you stuff a 20 megapixel sensor behind a plastic lens and consumers buy it because big numbers are good.
- frik 11y ago
  Some devices like a electric kettle are incredibly simple in how the works and you can't beat the real world physics, less Watt means more waiting time. You can only improve the design of vacuum cleaner and washing machines so much, a half as powerful device (Watt) won't make up the loss by a far superior design. Don't get me wrong I am for energy efficient devices, but I have an engineering degree and know a lot of the little tricks, and the average Joe falls for every marketing trick. These recent laws that were introduced by lobby-orgs aren't that great.
  - xorcist 11y ago
    Don't let your engineering degree stand in the way of finding out the facts. You claimed a 2 kW vacuum cleaner would clean in half the time, and there's plenty of data that suggests otherwise. The claim that cleaning time is linear to motor effect is unrealistic at best. There is an optimum effect for the nozzle. A 10 kW engine wouldn't clear your floors any faster than a 1 kW one, and definitively not ten times faster. The best (household, not for garages or anything like that) vacuum cleaner commercially available on the market is likely closer to 1 kW than 2 kW. You think only "average" people falls for marketing tricks, but this superficial knowledge of the engineering involved actually makes you an easier prey for the marketing trick that more powerful motors makes for a better product. That bigger numbers are better is one of the easiest marketing schemes ever.

by frik 11y ago

xorcist 11y ago

In published tests, cleaning ability is not correlated at all to power over a certain level. Most 2000W cleaners are older models, since research and development has focused on energy efficiency for the past decade, so they are even likely to be worse. I could easily construct a 10 kW model for you, and it's going to run very hot. (There was this EU introduced power cap for domestic vacuum cleaners the other year, accompanied with articles how you should hurry up and buy one of the powerful ones before they were forbidden. I was in the market for one, and scoured every independent test I could find where I understood the language, and the result were the same: the modern ones using less power picked up small particles better. As soon as you have a powerful enough engine other things start to matter. That's when I sighed deeply about journalistic integrity and bought one of the newer models.) You describe an important problem. Consumers keep buying older models, which are objectively worse, because they want a scalar value for "betterness". It's just like megapixels, where you stuff a 20 megapixel sensor behind a plastic lens and consumers buy it because big numbers are good.

frik 11y ago
Some devices like a electric kettle are incredibly simple in how the works and you can't beat the real world physics, less Watt means more waiting time. You can only improve the design of vacuum cleaner and washing machines so much, a half as powerful device (Watt) won't make up the loss by a far superior design. Don't get me wrong I am for energy efficient devices, but I have an engineering degree and know a lot of the little tricks, and the average Joe falls for every marketing trick. These recent laws that were introduced by lobby-orgs aren't that great.
- xorcist 11y ago
  Don't let your engineering degree stand in the way of finding out the facts. You claimed a 2 kW vacuum cleaner would clean in half the time, and there's plenty of data that suggests otherwise. The claim that cleaning time is linear to motor effect is unrealistic at best. There is an optimum effect for the nozzle. A 10 kW engine wouldn't clear your floors any faster than a 1 kW one, and definitively not ten times faster. The best (household, not for garages or anything like that) vacuum cleaner commercially available on the market is likely closer to 1 kW than 2 kW. You think only "average" people falls for marketing tricks, but this superficial knowledge of the engineering involved actually makes you an easier prey for the marketing trick that more powerful motors makes for a better product. That bigger numbers are better is one of the easiest marketing schemes ever.