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I'm interested in installing LED lights in my home, and I'm having a dilemma between buying LED bulbs and rolling my own solution. I have some questions on how to DIY:

How efficient is it? Single 1W led can yield about 90lm which sounds impressive, but when coupled with rectifier losses, dimmer, and resistors, what lm/W should I expect for 8 * 3 leds on 12V transformer?

Quality of light? How comparable the warm white is to fluorescent light-bulbs? Would mixing few yellow LEDs yield nicer color?

Other things to consider?

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Many issues here. Let me go over in as much detail as possible: Background: I love energy efficiency, and when doing my kitchen researched this LED Vs CFL vs incandescent lights extensively. Notice there are also permit (legal) implications, depending on which state you leave (CA has Title 24 for example).

Connector types: There are several connectors that make the decision of which light you can use tricky. the main ones are

Edison: The screw type, accepts CFL, Incandescent and some LED bulbs

Pins (2 or 4): Accepts florescent. Was invented mostly so that for permits purposes, they can make sure you are installing an efficient light and will not go and replace the CFL bulb with an incandescent one after you pass the permit.

GU10: mostly used for high voltage halogen

GU5.3 Bi- Pin: mostly used for low voltage halogen

High level rules:

  • You never go with incandescent when it is incandescent Vs CFL (Edison, screw system). LEDs are getting there, but not enough to justify the price and their light output is very low.

  • You can only go with pin florescent if you have a florescent "hw". that is the only thing that you can plug there by design.

  • Never use Halogen. If it is a GU10 (line voltage), get a $20-$30 LED (MR16). you get 4W Vs 35W. Light output is lower, but you can get HW with simply more heads. Replace 3 halogen with 5 LEDs and you are fine in terms of light and energy savings

  • If the halogen is a low voltage, things get tricky. You can just replace the head with a 3-5W bi-pin LED. they run $10-$20. They problem is that you need to make sure your low voltage converter will work. converters have what's called "minimal load". For most of them, they expect a 35-50W halogen so they have a minimal load of 10-20. That means that when you plug a 3W LED, they may not kick in. you solve it by either using a remote transformer that feeds "enough" LED bulbs, or get a transformer that is "led" designed, but really all it means is that it has a minimal load of 3w and goes all the way up to something (I have a 3-60W for mono-points).

Lat general tip: do not mess with dimmers. Just on/off.

My personal choices: For kitchen recessed light I got LED LR6-GU24. It is 12W, think that the florescent way would suggest I put a 23W bulb for each of these (I have 7). That means 50% saving. Same light output (they say it is 65W equivalent, but it feels like closer to 90W). No one can tell it is LED BTW, it is bright and even (not a "pin" of light, and well spread). Cost efficient: great! less energy, and upfront cost was the same as getting a florescent can combination. (you may get cheaper florescent if it is not for a permit and you do the Edison type)

For a bat lights I went with 3 mono points. Each has a transformer built in. I did not (suggest you never) buy "LED" lamps since you pay a huge premium for getting the LED HW. I just got the transformer with minimal load of 3W. I then threw away the GU5.3 Bi- Pin halogen and got Maxxima LED MR16. They are very good price (value) company. I compared the light to a $30 GE and these one are just as good. Notice that at 3W it is indeed just ambient light. good for over the bar in addition to some other light in the room. If you need more power, get 4 or 5W bulbs. see maxxima site

For spotlight lights in the center of medium size room, I went with much cheaper "line voltage" fixture from Lowes. These fixtures expect GU10 halogen (25-50W). I got in this case a the more expensive $30 LED GU10 bulbs (GE, at home depot). They are great, but I hope you can do better on the price. I have 5 and for medium size dining room, correctly targeted, it is nice light to use while eating.

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    +1 for suggested types. My concern over LEDs (at least those readily available in the UK) is that give a light just like a Bulgarian chip-shop. Anyone got any UK sources for GU10 LED bulbs with a decent colour temperature? Jul 22, 2010 at 19:23
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Mix in a few other colors as well, then use a microcontroller to mix a suitable color based on time of day, mood, and the music that is currently playing.

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Consider LED light casts sharp shadows. While the light output of an LED is high, the effect is bright light and dark shadows (as cast by your hand or whatever). In addition the LED's themselves appear very bright on the ceiling and catch your eye.

The fluorescent bulbs do a much better job atm of imitating the warmth of incandescent or halogen bulbs in terms of both scattering and color.

I'm not sure what it would look like if you mixed yellow LED's in, but the white LED's I've seen have been very "cold" (almost vaguely blue-ish tinged).

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I would agree with csmba that the Cree LR6 lights are great. I put 8 of them in my living room a few weeks ago (no ceiling lighting before, just a couple of floor lamps.) Great lighting. The LR6's have mulitple colors of LED with a microcontroller that keeps the light the appropriate color (2700K in my case). Highly recommended.

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