This is not a flashlight question but I though that I would ask since there are a few of you here that are quite knowledgeable with home type LED lighting.
Has anybody here tried replacing their MR16 20W (Base GUS5.3) Halogen bulb with an LED equivalent? My preference would be a single LED that is as close to the original Halogen bulb as possible in tint, which means that it would be have to warm white. Brightness should be similar to the 20W Halogen too if possible and this will be used outdoors for landscape lighting.
I don't know what made me think that a 1W LED is equivalent to a 20W Halogen but you are definitely right. I will need at least an equivalent of a 3W LED or possible more.
Currently I am using a Philips BC20MRC16/FL36/LAND/TP. It is rated at 200 lumens on http://www.lightbulbemporium.com/philips_155283_bc20mrc16_fl36.asp. I don't know if the lumens can be compared but if so, then I will narrow my search for LEDs between 180 to 240 lumens.
Your question was about what Wattage for the LED and if the bulb would have a similar “tint”, or color of light. (As a landscape contractor I can answer exactly what you are looking for)
Answer:
Most LED’s with equivalent lumens (the brightness/amount of light) will be in the 4-5 watt range. (in an equivalent temperature)
The color, or tint, or temperature, is measured in “Kelvin”, abbreviated as “K”. A halogen bulb is the the temperature range of 2800K to 3000K. Most of what I see are in the 2800K range, but 3000K is very close. The lower the number, the warmer the light.
If you want an LED to replace a halogen you will want one in the 2800 to 3000K range and equivalent Lumens to your bulb/wattage, for this range typically 4-5 Watts
Most LED bulbs are in a much higher Kelvin range, making them appear blue. It has taken technology awhile to get this right, and the 2800 or 3000K bulbs are usually much more expensive, though the prices are coming down. I usually find wholesale prices to be in the $16-35 range, as of may 2013. Retail much more. Cheaper bulbs probably have a higher Kelvin range (bluer color)
I bought some Sylvania’s from Lowe’s last year they are pretty close to the Halogens I replaced. The Sylvania’s are rated at 3000K and uses 6W, so they are a little brighter than the Halogens. However the tint is just perfect and I don’t think anybody can tell that I am using LEDs unless they are looking right at the bulbs. I don’t remember exactly how much I paid for them anymore but I believe that there were around $20 each.
I have tested a LOT of MR16 bulbs. All the Chinese ones were crap. Less than half their rated output, crappy looking color. Don’t expect more than 40 lumens per watt (some were around 20 lumens per watt). Several died after a few hours.
Another thing to be aware of is most landscape fixtures are totally sealed, and all the LED MR16 bulbs that I have seen are not rated for use in sealed fixtures. They pack a lot of heat into a small form factor/heatsink and get toasty in open air. In a sealed fixture, all bets are off.
Fortunately the landscape fixtures I use are not sealed and the Sylvania bulbs can be used for damp locations. I have not had to test out the replacement policy at Lowe’s or Sylvania yet.
I have been swapping these out in remote off the grid cabins…replacing incandescent, fluorescent 12v units. I was not that unhappy w what I was getting for early adopter prices (mostly USA sourced from TMart) and the drain on the batteries/solar systems is significant.
Now we are back to E27 edison base LED bulbs as they are way down in price, up in power and tint and much easier to plug and play w wiring wise.
I’ve always wondered why it’s so hard to find a decent LED MR16. A 20w halogen outputs 300 lumens at 3000K
I mean how hard would it be to have on XM-L2 warm white led it’ll be about 3000k? Run it at one amp and you’ll equal the output at 300 lumens on the dot. You wouldn’t have much heat running it at only about 3 watts because of the better than 100 lumens per watt efficiency. I know running my flashlights at one amp certainly never has them heating up even if constantly on.
The only caveat is you really want a separate regulator. Building the regulator into the bulb costs money and cramming extra electronics into the bulb only increases heat and the likelihood of failure as well as increasing the cost.
I mean it’s pretty much the equivalent of having a 12v transformer in each halogen MR16. It makes no sense. The transformer is always outside the bulb. It should be the same way with led’s. The regulator should be separate.
I didn't make the board, just stumbled across it right after reading this
I would make a separate transformer/regulator board in the base/neck of the light, then make the emitter separate...but I don't know how to run Eagle CAD to design a board
And that 100 lumens/watt number people quote is pretty much fantasy. It ignores driver and optical losses. A GOOD MR16 bulb barely makes 50 lumens per watt. The 10 watt/500 lumen Philips bulbs that I use actually have a tiny fan in them. MR16 bulbs have virtually no room for heatsinking and tend to be mounted in rather poorly ventilated fixtures.
Oh, and a 20 watt MR16 halogen doesn’t even make it to 200 USABLE lumens out… despite their published specs, you can assume an incandescent/halogen bulb is doing 10 lumens/watt.
The point I’m trying to make is in order to equal the light output of halogen with led is actually quite easy. Halogens are only about 15 lumens per watt. A good led like an XM-L is easily 100 lumens/watt at 1 watt it’s already 186 lumens/watt for the cool white, trouncing the industry best average of 60-70 lumens/watt or worse and that 100 lumens/watt is already including sag due to thermal increase and loss due to warm white tints.
Considering you’re packaging both the led and halogen in the MR16 package, both will equal each other in lost light output. So you’re still making an apples to apples comparison.
As far as thermal problems. At 1 amp the led will at most be outputting 2 watts of heat, that’s almost nothing and can easily be conducted out through a metal case. The fact that Philips is severely trailing Cree in terms of led efficiency does mean needing a fan or other forced cooling. But Cree has such an efficient led I’m just surprised nobody is making any decent MR16 modules with them.
It might just be a matter of time though since Cree developes so many different products and packages it’s hard for companies to keep up right now.
But the SiC technology seems to be stabilized so I’m hopeful something will finally materialize in the consumer lighting market.
The 10 watt PAR16 Sylvania bulbs that I have use 4 Cree XML’s… they also put out 500 lumens. They are the most efficient/highest output PAR16 bulbs on the market.
The raw emitter lumens numbers in data sheets have little to do with what you get out-the-front of an LED bulb. Driver/optical/thermal effects rule in this world. 50 lumens/watt is still the rule in smaller bulbs. Larger ones struggle to reach 70 lumens/watt.