ohms law

[wulluff]

well sort of..

I have 9x60w mains powered spots n my kitchen on 2x dimmers. My question (triggered after a £1308 duel fuel bill) is whether using a dimmer reduces the chargeable amount?

My concern is that the resistor in the dimmer switch is dissipating the energy but I am still paying the full kwh amount as it's on the consumer side of the meter.

I will be checking this out asap but the property is tenanted...

btw I worked out I'm paying £12/month just to keep a very low dimmer on the landing

[singlecoil]

AFAIK modern dimmers work by cutting part of the waveform electronically, so I don't think that is where the problem is

Just noticed the bit about tenants- it will be their elecric fires that are causing the bills.

Edited by singlecoil on Friday 29th January 20:26

[voyds9]

I would worry more about the 5 bar electric fire that you seem to have left running.

£1300 thats about 5 times our spend and I can't get my wife to turn anything off. I regularly come home to all the lights on and wife at work for 8 hours.

[VxDuncan]

singlecoil said:

AFAIK modern dimmers work by cutting part of the waveform electronically, so I don't think that is where the problem is

Just noticed the bit about tenants- it will be their elecric fires that are causing the bills.

Edited by singlecoil on Friday 29th January 20:26

Yup, the sine wave is chopped to dim the light, which is pretty efficient way of doing it. There will be some loss through the dimmer (it probably buzzes a bit and gets slightly warm), but only uses a few watts max. Compare the heat given off by your 60 watt bulb, then the heat given off by the dimmer switch, it uses very little power.

Having over half a kilowatt of lighting in your kitchen is pretty impressive though

[Parrot of Doom]

For the dimmer to be using the same amount of energy as a light bulb, it would have to be as hot as that light bulb.

[Jasandjules]

I wonder if the mod's head are doing this

trying to decide if this should this be in the lounge, home, (do we have an electrics section yet?) etc...

[wackojacko]

singlecoil said:

AFAIK modern dimmers work by cutting part of the waveform electronically, so I don't think that is where the problem is

Just noticed the bit about tenants- it will be their elecric fires that are causing the bills.
Spot on fella I read this thread a little late ( busy Electrician ) lol

Edited by singlecoil on Friday 29th January 20:26

[big dub]

Are they halogen? AFAIK you shouldn't use dimmers with halogen?

though I may be wrong

[TooLateForAName]

Tell the tenants that the cannabis farm has to go.

[eliot]

I've got dimmers on nearly all my lights and one of those clamp on meters which reads out electricity consumption in real time and can confirm that consumption is proportional to brightness.

[Lord Flathead]

If they are GU20 etc standard downlighters then change them for LED's! They use 3 Watts per fitting and can be dimmed if you buy the right dimmers (which retrofit through the same holes as the fittings). Also they produce virtually no heat and last for 50,000 hours.

I am about to go LED crazy at home and replace every light I can find (including the outside 500w floodlights) with LED's.

They are the future

[stuttgartmetal]

^^^ +1
Switch everything off, and see if the little wheel is whizzing round !

[finlo]

Lord Flathead said:

If they are GU20 etc standard downlighters then change them for LED's! They use 3 Watts per fitting and can be dimmed if you buy the right dimmers (which retrofit through the same holes as the fittings). Also they produce virtually no heat and last for 50,000 hours.

I am about to go LED crazy at home and replace every light I can find (including the outside 500w floodlights) with LED's.

They are the future

They may be the future but right now they're ste.

[Simpo Two]

And once you've changed the whole lot to LED, it will suddenly be revealed that they contain some unforseen hazard, so you will have to buy OLEs. And then ZCTs and so on... and hopefully in 50 years we'll be back to tungsten!

[ctdctd]

If you have 9 x 60w bulbs, then you are using 540w per hour at most.
If your 'leccy costs 10p/KwHr then your bulbs cost 5.4p per hour to run.
If you left them on 24/7 for a month, that would be about £40

I would guess they are not the main reason for your huge bill!