I’m remodeling the kitchen and am planning on using a mix of recessed cans and pendants. I’ve been looking at low voltage for energy conservation (thinking green) and somewhat to keep the load on the circuit down.
Good side, as I’ve been able to discern, is energy cost
Bad side is fixture cost. Cans appear to be about 2.5x more. Pendants are 3-4x more. I have a ’37 house and want to keep the look traditional. Most of the suppliers make contemporary fixtures and the only one I could find with nice styles was Wilmette. I don’t want to go with track lights.
So here’s a couple of questions:
-Good vs bad? Am I right? Is LV worth the cost?
-Can spacing? Lighting designer wants them to be no more than 36″. That’s a lot of cans!
Do you have LV in your house or have you installed them?
Replies
Ken,
There is no energy conservation advantage to low-voltage fixtures; in fact, exactly the opposite is true. Stepping the voltage down wastes energy (more if a magnetic transformer is used, but even switched-mode power supplies consume energy).
The efficiency of the lamps (lightbulbs) is no different for low-v and line -v.
If the length of the runs from transformer to fixtures is long at all, the resistence (impedance) losses for the higher current lead to greater voltage drop, and may require upsizing the wire gage.
In my opinion, the only time to use low-voltage fixtures is when the fixture style you want is available only for low-voltage lamps. If you are interested in a more traditional look, you're not going to get it in low-voltage fixtures.
If you do go low-voltage, keep in mind that power (watts) is (for incandescent lights) the product of volts and amps. So if you have, say, 600 watts of lamps on a circuit, at 120 volts, that's 5 amps, and 14 gage wire is suitable (if it's a 15-amp breaker that's protecting the circuit) . At 12 volts, 600 watts of load translate to 50 amps. So you have to run AWG 6 copper wire (assuming it's in non-metallic cable AKA romex) between the transformer and all the lights. Even if you have a system running on 24 volts, current is still 30 amps and so it's AWG 10 copper. Not a lot of fun to work with, and not cheap, either.
Go with line voltage.
Cliff
Low voltage doesn't conserve energy. Small, task-oriented lights may conserve energy if they permit you to reduce overall lighting.
The only substantial reduction in energy costs you get is by using fluorescent (or, in a few special cases, LED) vs incandescent lighting.
Kent, all of the above :-).
The main reason to use one or the other is for lighting design.
LV fixtures are used usually because 1) they are able to use small bulbs that still put out a lot of lumens...........like those cut-glass pendants on steel cable that are so popular right now (I have 2 in my kitchen) or
2) because of the tiny filament they are able to focus the light in a tight beam and light up something a good distance from the fixture (artwork for example).
If you don't need small, tightly focussed bright light overhead then you don't need LV recessed cans, unless you have very high ceilings. You can put in a small 3" or 4" can and use a 50W 120v PAR16 or PAR20 bulb that gives bright halogen light without paying the expense of low-volt. And the incandescent dimmers are significantly cheaper that LV dimmers.
Ed
Edited 9/14/2007 8:04 am ET by edlee
Wow, you all just blew my idea out of the water! I really appreciate the good, constructive feedback.
Looks like I should change my plans and save some money by using line voltage cans and fixtures with lower wattage bulbs. I'm not a fan of using CFL. I'm in and out of the kitchen and turn off the lights when not there. I don't like the time that CFLs need time to warm up.
Use CFLs exclusively for a month and you'll no longer notice. Be sure to use the cheap multi-pack CFLs, not the expensive name-brand ones. The cheap ones are better. (Don't ask me why.)
If your view never changes you're following the wrong leader
I'll bet that as time goes on we'll see alot more styles of LED lamps so if as you say, you don't like CFLs I'd still install regular fixtures for 120VAC and use regular lamps now but be on the lookout for LED lamps in the future.
They should be very efficient and last almost forever.
I've seen the LEDs advertised. They look nice (online).