light bulbs voltage, wattage and heat

[Oumati Asami]

Do a 5W 12 volt light bulb and a 5W 110 volt light bulb (same type) give off same amount of heat? In other words, for same type of bulbs, does voltage affect the amount of heat given off?

[T]

"Theoretically" (watch the weasel word) they should give off the same heat, providing their "efficiency" is the same. A good test of this wold be if they gave of the same lumens.

[Rod Speed]

Oumati Asami [e-mail] wrote

Yep

Nope.

[Bob P]

Cents both light bulbs are 5 whats, dey both produce abut 17 btus/hr.

[Oumati Asami]

Does that mean I would save electricity bill by using 110 v bulbs than

12 v bulbs? I was going to buy 12 12v bulbs but now I may buy 110 v ones. That brings up another question. Why were the 12 v spot lights installed in the first place? They need a transformer to work. So, they are intrinsically more expensive to begin with. It seems to me 110v lights should have been installed in the first place.

[T]

You also have a conversion loss getting the 110v to 12v.

If memory serves me, some halogen bulbs burn better at 12V. That may be why

[trader_4]

But there is also some small loss in the power supply to create the 12 volts.

That would depend on your skills and local code. Low voltage wiring is covered in the NEC. If you don't know what you're doing, you can still create a situation that will burn the house down.