1600 W maximum on vacuum cleaners from from Sept!

[Top_gun]

11 pages on a thread that was started about vacuum cleaner power inputs!

I think there's more mileage in this debate to go.

[scaryjim]

I think there's more mileage in this debate to go.

You'd need a long power cord to get more than a few metres on a vacuum cleaner 1600W should get you to quite a good speed though!

[kalniel]

Maybe we're missing a trick regarding mileage - they should add pedometers (or zombie-app enabled GPS) so you can record your fitness while doing the cleaning

Or pac-man. Yes. AR pac-man where you have to hoover up the dots while avoiding the monsters.

[DanceswithUnix]

You'd need a long power cord to get more than a few metres on a vacuum cleaner 1600W should get you to quite a good speed though!

Sinclair C5 was only 250W, so with that much power you might be popping wheelies

[peterb]

I think there's more mileage in this debate to go.

Well it certainly shouldn't be brushed under the carpet.

[kalniel]

Well it certainly shouldn't be brushed under the carpet.

That pun sucks.

[Agent]

http://www.telegraph.co.uk/news/worl...d-kettles.html

And so it begins.

The kettle one is interesting....

[watercooled]

Oh. Wow.

I checked out the source and started with the kettle bit.

A manufacturer of thick film elements estimates that up to 20% energy saving may be achievable

How convenient! Says it all really...

[Agent]

"up to"....I'd be amazed if a 20% increase in efficiency could happen from just the element.

[Noxvayl]

I wonder if they will make the new and improved kettle out of polystyrene due to its really good insulation properties...

Seriously though, "up to 20%" seems optimistic to me even if innovations are stacked on top of one another. I would guesstimate that 4 or more changes would be needed to achieve something close to 20% improvement in efficiency; I would start with insulation and move onto thermostat like control to turn off the kettle at the perfect time, no idea how the element will be improved.

Power generation seems like a much simpler task to tackle which could create energy abundance and thus drive the price so low that energy use is no longer a concern... don't mind me, I'll be chasing this pie in the sky for some time

[kalniel]

Well it's rather simple - lack of efficiency means more heat.. but if that's what you're going for in the first place then you can't increase efficiency except loss outside of the system.. which should have nothing to do with the element.

[DanceswithUnix]

Well it's rather simple - lack of efficiency means more heat.. but if that's what you're going for in the first place then you can't increase efficiency except loss outside of the system.. which should have nothing to do with the element.

Absolutely.

It is the old comment, if you are cold then an incandescent light bulb is 100% efficient as you want the waste heat.

The base of my kettle doesn't get all that hot, so looks like most heat goes upwards.

My wife did choose a kettle with a metal upper body which is wasteful compared to plastic, not sure how much that loses though.

[Noxvayl]

I would imagine the waste is minimal with a metal vs plastic body for kettles. The metal does get hot but that energy would be transferred to the "cooler" water because it is a better store of energy than air. I would think that the evaporation and condensation mechanism, which causes the steam coming out the top, would be a larger factor of heat loss than the metal enclosure vs plastic.

I think the best way to use the transfer of heat with metals would be to have the inside metal and attach an insulating cover (plastic maybe or even another metal one with insulation material in between) to that to prevent heat escaping. In our house we use a metal ketal because we find it more aesthetically pleasing and have a plastic one in the loft that has been with us for over a decade now; both have an element inside that is directly exposed to the water which seems to be the standard for kettle designs.

Perhaps the improvement in the element design is not changing the way it works but rather making the bottom portion of the kettle the element. It would increase possible surface area needed for heat transfer and could help keep the water hot even if you forget to make your cup of tea right away. Might not be a cheap option though so doubt consumers would be happy with that.

[DanceswithUnix]

More I think about it, the more I think the only way you can improve on a kettle is to make it an on demand water boiler.

Then I remembered seeing one years ago. I was tempted, the wife vetoed buying it for some reason I can't remember but probably purchase cost.

Seems you can still get them, called "instant heat kettle".

http://www.coopersofstortford.co.uk/...e/ST09619i.jpg

The water in the jug stays cold. Just one cup of water heated. Job done. So why are they a flop? I come from a family where the blood group is probably "Tea", yet I have never even seen one in the wild.

[Noxvayl]

That is a brilliant example of good efficiency, only heat exactly what you need to.

A friend of mine got a new boiler installed that gave almost instant hot water, it is really good. Perhaps in the future we'd have a bunch of tanks connected to a "smart" boiler that automatically fills them with hot water when low; can have one massive one for bathing at say 40 degrees or close to, a small 2-3 litre one for making tea that is the hottest, and has the best insulation, and then a mildly warm one in the loft for use as the supply to the hot water taps giving you warm water rather than ridiculously hot water that is of little use when washing hands.

When I get my own place I will see if a plumber will build a system like this for me. Sounds far more useful than everything being separate.

[Zak33]

Long long long ago a famous lesson was learned in the large houses of Britain's landed gentry

A metal tea pot....although potentially very conductive, held the tea hotter for longer without j tea cosy than a large pottery teapot

The reason is that a shiny surface, highly polished, radiates less heat than a dark coloured pot of any other material

This was then proven in physics labs across our countries schools and lives with me to this day

So potentially a shiny metal kettle, while deadly to touch, will hold lots of heat for you

And if you want a really efficient radiator in one of your rooms at home.... Paint it matt black!