Would this really save electricity?

[Mark]

[george (dicegeorge)]

it would mean my kettle and toaster would take longer, and wouldnt cut my electric heating costs would it? (whereas more insulation would)

The lights would be a bit dimmer so I'd get higher power lightbulbs!

If the fridge pump gets less volts would it have to be on for longer to pump out a certain amount of heat (like when that salesman opened the fridge door?)

[g]

[Andrew Gabriel]

significant energy savings]

There's a tiny bit of truth, but mostly you're listening to a journalist who doesn't seem to understand the issues, probably egged on by the manufacturer. The claims won't be realised.

I think most current fridge/freezer compressors contain energy management circuits, so they're already doing this much better internally than any external device can. Most TV's for the last

25 years have switched mode PSU's and hence have a constant power draw irrespective of the supply voltage. A cordless phone (or any other rechargable battery device) simply takes longer to charge if you reduce the supply, assuming a crude linear PSU, so you will be looking at 30% lower power consumption for 30% longer, although the losses once charged are likely to be less too. Lighting - filament lighting will become much less efficient, requiring higher total power consumption to achieve the same lighting levels, and it would be much more effective to reduce the wattage of the bulbs fitted if you are happy to manage with less light. CFLs - depends on the quality of the ballast circuitry, but they will either run at constant power (defeating the device), or reduce power and light output proportionally.

[Tim S]

george (dicegeorge) coughed up some electrons that declared:

Exactly. Ditto switched mode PSUs for electronic appliances.

More snake oil.

[Harry Stottle]

250v, but my supply seems to range between 230v and 240v, and usually more nearer to the 230v mark than 240v, so reducing the voltage to 220v would mean less savings in my case, and if proportionate, any saving would be reduced by 33% at 240v and 66% at 230v, so more like a 3% to 6% saving than the 10% quoted. To also quote that this device is similar to loft insulation is misleading in my opinion, loft insulation is very cost effective, but £250 for this device (plus installation?) for a potential 3% saving would seem not to be the case, and as the device seems to be a transformer, I would imagine that there would be losses through the transformer itself, but it does not say if these losses had been taken into account when calculating any savings. In theory, like most of these money saving devices, it looks good on paper, but some careful calculations and cost comparisons need to be made on the claims made before committing.

[Owain]

used on lower-power circuits, not cooking or heating, so there is a need to split circuits within the CU to those controlled by Vphase and those not controlled by Vphase. (This is in addition to any splitting required by RCD discrimination.) The Vphase also needs its own 50A MCB to supply it and its downstream load.

In many cases installing this is going to need a whole new CU because the old one won't be splittable.

Owain

[RubberBiker]

The item mentions this type of device has been in use for some time in commercial settings.

The only application I can think of that is power heavy and where this sort of device would offer real savings - are places where there's lots of large ac motors.

Which ain't most people's homes.

That clip is more like a (misleading) infomercial - does anyone regulate this sort of thing?

[Mark]

Pretty much what I suspected. I would imagine that their "savings" conveniently neglected to include losses in the transformer and allied components.

I am also unsure whether it has a fixed step-down ratio or if it is variable dynamically.

[John Rumm]

And I can see the install costs exceeding the purchase cost in the majority of cases!

[Michael Shergold]

and there's the power the thing itself consumes as well as the £250 plus installation charge...

[Harry Bloomfield]

on 29/07/2009, Andrew Gabriel supposed :

All agreed with. Mostly smoke and mirrors.

I would though like to know what method they use to reducing the voltage, That toroid doesn't look capable of delivering more than about 300w.

[Andrew Gabriel]

If it's an auto-transformer, then for a 30V buck, it will handle a load of about 8 times its VA rating, but that's still not much (say, 2,500VA). What it could do is reduce the buck voltage as the load increases above 2,500VA, e.g. to 10V max at 7,500VA, but that would somewhat mitigate the object of having the device.

No idea if this is what it actually does.

[Alan]

In message , Andrew Gabriel wrote

Slightly more if you cool it in a bath of snake oil.

[Harry Bloomfield]

Andrew Gabriel formulated on Wednesday :

It seems to have one pair (for mains input?) and what looks like around four or five tappings from the top right of the toroid.

[Andrew Gabriel]

What picture are you looking at?

[Harry Bloomfield]

Andrew Gabriel formulated the question :

stopping the video somewhere in the middle, where it shows a close up of the toroid and pans across to the PCB. Two windings go to the lower + middle part of the PCB close to what looks like a PCB mount fuse, then the four or five go to upper LH corner of the PCB via a multi way nylon molding.

[Dave Liquorice]

A lot more Snake Oil has a higher heat capacity than Hydrogen.

[T i m]

'anti-phase voltage' apparently.

Whilst I'm generally in the snake oil camp on this one (as far as real returns are concerned) I think I can see a little logic to some of it.

I think the key to this device working is if we are to agree that most domestic electric devices were designed to run at (say) 220V or not. If so then running them at a higher voltage isn't necessarily going to yield any further performance (which is what I think the presenter was trying to put over).

If you are used to an incandescent lamp giving off say 65W worth of light (I know that's not how you measure the light output but you get the idea) rather than it's designed 60 then you may need a brighter lamp to compensate (not really the fault of the 'Magic box' though).

An electric kettle for example may boil the water that little bit quicker with 240 over 220V but it may not be the same ratio quicker. ie, The 'sweet spot' in the design for transferring the energy from element to water may have been done at 220V?

Similar with the fridge / freezer. Once the pump is spinning the extra torque available (it wouldn't pump faster would it as it's a synchronous motor) isn't necessarily going to make the fridge cool down faster? Wouldn't the 'extra' voltage simply be consumed by producing more waste heat from the pump? (Aside: Aren't there already add-on products that capitalise on this, providing sufficient starting torque then backing the current (power) off once running?)

Anything thermostatic or temperature adjustable (like a hob) would be less effected as it would generally turn off when up to temperature (but may still get to that point less efficiently [1], depending on the thermal mass and element to object conductivity etc).

Like trying to boil an egg faster by turning the gas up on the already boiling water.

T i m

[1] I guess there is a balance with energy input for much of this where you have to apply the energy fast enough to minimise any losses over not forcing the load to absorb energy too fast.

[Harry Bloomfield]

Modern tech devices are made to work over a range of voltages. As the voltage rises to maximum, the current demand falls.

These types of lamps need to run at very close to their rated voltage. It is a careful balance between efficient conversion of current into light versus lamp life. Decrease the voltage and their light output becomes much less. Increase the voltage and light output rises disproportionaly, but the life decreases. I accidently bought some 230v

500w TH's for flood lights and they lasted just a few weeks instead of the couple of years or so I would expect on our 240v supply.

Within wide margins, I would not expect it to make much difference to the Kwh consumed. Decrease the voltage sufficiently and time to boil will increase due to heat loss.

That feature is included I believe in all modern units.

As per above, the kettle loosing heat through its surface. Longer to get hot, more heat radiated or lost into the room while you wait for it to attain temperature.

Not quite, all (almost all) the energy from electricity is delivered into where it is needed.

[Harry Bloomfield]

Harry Bloomfield pretended :

I meant to point out that dimmers, can reduce the light output of a lamp down to around say 5%, yet that light will still be consuming say

75% of the wattage.