# Do low voltage 12v DC (not low energy bulbs) use less electricity than standard 240v lights?

Found 18th Mar 2012
Am looking to redo bathroom and down lights are either 12v or 240v. Ignoring the obvious safety argument for 12v which would consume less electricity if 50w bulbs were used in both? I need the room to be as bright as possible and was calculating on 75 lumens/sq ft. Is this enough?
As I understand it, 50w is the energy each lamp consumes. 12v or 240v make no significant difference. Your right 12v is safer, but you need to check the new wiring regulations regarding lighting type and position, in bathrooms, just to be 100% safe.
P = VI. So if the voltage is lower, the charge is higher to consume the same power.
Edited by: "Benjimoron" 18th Mar 2012
50W is the power consumption and that is what (pardon the pun) is consumed ! so voltage makes very little difference.

240V maybe slightly more efficient as you will not have the transformer losses, but it will be marginal.

Also it is in theory illegal now to do your own wiring in a bathroom under Part P of Building Regs, You need to have the lights installed by a "competent person" and certified. You may have to prove this when you come to sell your house

EliTom
elitom

50W is the power consumption and that is what (pardon the pun) is … 50W is the power consumption and that is what (pardon the pun) is consumed ! so voltage makes very little difference.240V maybe slightly more efficient as you will not have the transformer losses, but it will be marginal.Also it is in theory illegal now to do your own wiring in a bathroom under Part P of Building Regs, You need to have the lights installed by a "competent person" and certified. You may have to prove this when you come to sell your houseEliTom

Spot on and quite right too
The work is being done by a qualified electrician, I am just supplying the parts. If they are both comparable in energy consumption and light output is the argument for 12v purely one of safety as they cost more once you've added the transformer.
if you want to use less electric use the greener Wattage bulbs, ie 11W equivalent to 40W. or the LED bulb downlighters, not only do they use less electric they also dont get hot.

garbage456

if you want to use less electric use the greener Wattage bulbs, ie 11W … if you want to use less electric use the greener Wattage bulbs, ie 11W equivalent to 40W. or the LED bulb downlighters, not only do they use less electric they also dont get hot.

The second part of my question was regarding the brightness and whilst I agree with you about the energy consumption of low energy bulbs their light output is too low. I need 75 lumens/sq foot and you won't get that.
garbage456

if you want to use less electric use the greener Wattage bulbs, ie 11W … if you want to use less electric use the greener Wattage bulbs, ie 11W equivalent to 40W. or the LED bulb downlighters, not only do they use less electric they also dont get hot.

..and last a lot longer, although be aware that LED downlighters are a lot more expensive than halogen ones at the moment (at least they were last time I looked at replacing my halogen ones).
LEDs are expensive but I have 12 running in dining / kitchen -total 36w, so less to run than 1 40w lightbulb.
michaelmakro

LEDs are expensive but I have 12 running in dining / kitchen -total 36w, … LEDs are expensive but I have 12 running in dining / kitchen -total 36w, so less to run than 1 40w lightbulb.

They're 3W each?
Are LED down lighters a true cost saving exercise given the initial outlay vs running costs and life?

CBA with the math, anyone?
dga

Are LED down lighters a true cost saving exercise given the initial … Are LED down lighters a true cost saving exercise given the initial outlay vs running costs and life?CBA with the math, anyone?

Yes. Mainly cos they last longer too. Otherwise it would probably be a no.
elitom

50W is the power consumption and that is what (pardon the pun) is … 50W is the power consumption and that is what (pardon the pun) is consumed ! so voltage makes very little difference.240V maybe slightly more efficient as you will not have the transformer losses, but it will be marginal.Also it is in theory illegal now to do your own wiring in a bathroom under Part P of Building Regs, You need to have the lights installed by a "competent person" and certified. You may have to prove this when you come to sell your houseEliTom

This ^^
dga

Are LED down lighters a true cost saving exercise given the initial … Are LED down lighters a true cost saving exercise given the initial outlay vs running costs and life?CBA with the math, anyone?

They are 25 year average life span.
lumoruk

They are 25 year average life span.

Their running costs are very low.