Low voltage recess lights

[bobbyho]

Customer asked me tonight where is the energy savings on a lv recess light if the lamp is 50watts. I told him 50 watts at 12 volts as opposed to 50watts at 120volts. He said "Watts is watts, we are billed by the watt". Told him that it is 50watts on the secondary side of the transformer (I was starting to squirm, I had never pondered this before and now I was being questioned by an electrical engineer) He let it drop (thankfully) and so did I but now I am asking you guys, am I over thinking this or was I off on my answer of where the energy savings is?

 

[mdshunk]

They'll be less efficient because you'll have losses in the transformer(s). They're also less "green" because you use a lot more copper to wire them up.

 

[peter d]

He said "Watts is watts, we are billed by the watt".

Yup, that's right, plus the x-former loss as Marc said.

 

[infinity]

He would save energy by using a 120 volt 50 lamp to get rid of the losses associated with the transformer. However he would likely also get less light. Although the wattage of the lamps may be the same it's likely that the 12 volt lamp will provide a higher light output.

 

[raberding]

Watts is watts...but a 120v 50PAR20 is one of the least efficient sources on the market. A 50W 12v MR16 would provide More Light.

The energy efficiency comes when you realize that you could probably use a 35W MR 16 to get the same light output as a 50PAR20.