Low voltage lighting

haha..soon u will hav B-1 bombers flyin over your house dude..and even tanks at your garage

Maybe some kind of nuke plant???? 😀
Our officials tell us that’s it’s not dangereous , so I assume that you can have one in your basement.

well if that’s what you want…

should’ve say so earlier…get a heat lamp…it’s purpose is to generate heat…not light.

use candles.. gives a room much more character

Doesn’t help with downlighters but we’ve just fitted low energy bulbs in a couple of rooms. Kitchen has gone from 100W to 15W. Once the light has been switched on it tends to stay on for a good few hours so there’s a good saving over time. After a few minutes to warm up, the new bulb is probably slightly brighter than before.

Ahhhhh … another solution / suggestion … put them on a timer! 😀

Better yet … take your wife out to dinner more often. :rolleyes:

Or, install skylights!

Me … I hardly ever enter my kitchen! :p

Flylady 🙂

Thank you everybody. Great answers from both the electrical perspective and the point of view of obtaining the best lighting effects.

Just to let you know why I posted this question – I currently have 8 40W mains voltage spotlights in my kitchen totalling 320W. My wife (who has no interest in the electricity bill) seems to think that she can heat the house using these bulbs (ie she never thinks to turn them off) so I was wondering if I could lower my electricity bill (below that of Manchester United’s floodlight bill) by going over to a low voltage system. Obviously this is not the solution!

…

the answer you gave still don’t give the right answer. Why? Because we all agree that the higher voltage one should be better. But, you didn’t even do a comparison of the transformer loss versus the line loss. All you said was transformer isn’t 100% efficient so, it must mean it’s worse. Yes, that’s most likely true, but you didn’t factor in the loss in the line. For example, if the tranformer is 90% efficient (i believe it’s to be much much higher than that). at 20W final means you lost ~2W. But, due to contact loss (most significant part of the “line” loss in general) a double in the current directly means the loss is doubled(or roughly). So, you might be losing more than 2W in addition to the transformer! The problem with this is most people underestimates line losses and have no working “feelings” for it, until a building burns down due to electrical fire. This is why most high end high current devices (say a high torque RC powered car) shows dramatic differences when the gauge of the wire is decreased and the conectors are changed from tinned iron contacts to gold plated ones….big differences! but, back to the light bulb…ok, 20W may be somewhat low on the scale of whole thing….but 20Volts DC at 1Amps is 20W!

WARNING!! By the way, if you happens to have cuts on your body or holding somewhat ionic water (say salt water) and electricity happens to pass through you, DO NOT say 20Volts won’t kill you…IT WILL. Again, i need to stress this or you’ll end up on the JackASS movie Part duh…it’s the current that kill you not the voltage…ask any electrician or engineering person. And…no, even current as low as a few milliamps can kill you if you’re unlucky…but yes, i believe cardiac arrests starts at around 15-20mA while above that…..depends on where the current loop pass through.

Your dad is perfectly correct 🙂

The word from my dad… who incidentally happens to be a sparkie is… They’ll use exactly the same amount of electricity, in fact, due to losses through the transofrmer, the transformer option will use slightly more electricity.

Re: ..

Originally posted by Vortex
20W is 20W, actually transformers are usually pretty efficient…so what’s the difference? Because lower voltage means higher current to get the same power as the higher voltage ones you’ll end up with the result that as hand said (answer is correct, but reasoning was wrong) the lower voltage one is not as good (assuming both 20W electrical loss light bulbs generate the same amount of lumens at visual). Back to why it’s not as good, because higher current in any system means higher “line” loses. That’s why our phone line is relatively high voltage. But as always, the lower the current, irregardless of loss, the better for all sorts of reasons. Voltage you get a shock, Current is what kills you.

what’s was wrong in the raisoning.

Let’s get back to basics.
P=U*I*cos(Phi) right?
As you said if one assumes that both voltages lead to 20w.
If U=220 V I=100mA roughly (If one assumes cos(phi) =1
If U=22V I=1A roughly
What’s the difference :.

1) Loss in line in case of the low voltage and hight current (means bigger wires)
2) Need of a transfomer to bring the voltage from 220v to 22v
This kind of transfomer never give a 100% efficency.

Bottom line : low current = higher cost : loss in line and in the transformer+ bigger wires.

However low voltage = high security since 22V is not dangereous for the human body.

Max current allowed in human body = 30mA.

..

20W is 20W, actually transformers are usually pretty efficient…so what’s the difference? Because lower voltage means higher current to get the same power as the higher voltage ones you’ll end up with the result that as hand said (answer is correct, but reasoning was wrong) the lower voltage one is not as good (assuming both 20W electrical loss light bulbs generate the same amount of lumens at visual). Back to why it’s not as good, because higher current in any system means higher “line” loses. That’s why our phone line is relatively high voltage. But as always, the lower the current, irregardless of loss, the better for all sorts of reasons. Voltage you get a shock, Current is what kills you.

I have a solution for that! Double tracking/wiring or double inset … lights in both directions, it gives you the illusion of the same lighting you get at fancy diamond jewelry stores. Ever wonder why lighting looks so good there, that’s why.

If you use the three lights on the wires, turn the middle one facing a different direction. Or, add more to the wires and have every other face a different direction.

I just designed a home with such lighting, the room was designed with an elegant feeling and mood lighting was a must without bright blinding lights which provide good results for objects and people to be lit. Amazing results.

So, using low halogen lighting is effective and affordable too.

Don’t forget to clean bulbs with alcohol and don’t touch with fingers.

Good luck!

Flylady

And i will add that, with such spotlights, you will have bright places where the bulb is directed, and the rest will stay much darker… So, think twice…

Thanks Hand, that is exactly what I thought. Despite the rubbish some people tell you, due to inefficiency in the transformer your electricity bill would be higher using low voltage lighting compared to the equivalent conventional lighting.

I’m not sure that I understandand your question properly but …

If you consider 20W , whatever the voltage is , the consumption is always …. 20W right ?

The only difference is the transformer. The yield of the low voltage transformer is never =1 .Some energy will be loss in the transformer. Therefore the efficency will be a bit worse in the case of a low voltage bulb.

However the safety is much better.

Does it make sense ?