e-watt LED light bulbs - what has been your experience

[Aren_Hill]

Kinda made over 4k on these guys so far....

[rsisk]

Originally Posted by Aren_Hill

Kinda made over 4k on these guys so far....

Suhweet! Any tips on how you are selling them?

[Katie_UPS]

Originally Posted by rsisk

Suhweet! Any tips on how you are selling them?

I heard a rumor that their local itty-bitty airport uses them to line the runways. I wonder if I can get MKE's airport to do the same...

[hocman22]

My team, team 358 is looking for another fundraiser, to replace our main fundraiser we cant do anymore. I was wondering how much it cost to buy the light bulbs and how much you guys sell them for. Also how successful are you in selling and making profit with them? Thanks



Team 358

[KarenH]

One of my concerns with the FIRST light is that we don't use 40-watt bulbs much in our house; mostly we use 60-watt bulbs. This bulb is supposed to have light output equivalent to a 40-watt bulb. Our team leader tried one out and said it's as bright as a 60-watt bulb, but he used two different types of light fixtures to display them. While they both nearly blinded me, I didn't think that was a "scientific" enough test, so I devised a somewhat more "scientific" test, using the bulb my husband bought from the team. (If we like it, we'll probably buy more.)

We have a ceiling fixture in our house that had two CFLs and two soft white 60-watt incandescent bulbs. One of the CFLs was burned out. (CFLs do NOT last as long as traditional bulbs.) So I replaced the bum bulb with one of the e-watt LED lights, and turned on the switch. Cameras tend to be pretty objective about things, so I also took pictures. Here is one picture, taken from directly below the fixture. Can you tell which bulbs are brighter or dimmer? Can you tell which is the CFL and which is the LED light?

By the way, if you would like to use a larger version of this picture in your sales pitch, feel free to PM me.

[Ether]

Originally Posted by KarenH

One of my concerns with the FIRST light is that we don't use 40-watt bulbs much in our house; mostly we use 60-watt bulbs. This bulb is supposed to have light output equivalent to a 40-watt bulb.

I thought the FRC LED was rated as equivalent to 60Watt incandescent.

[pfreivald]

Originally Posted by Ether

I thought the FRC LED was rated as equivalent to 60Watt incandescent.

The problem is that the light is much more directed, which is why the literature says that in downlight and spotlight applications it apes a 60W bulb, but in 'most other applications' it apes a 40W. I have one that I bought from our team to try in various applications around my house, and I find this to be almost exactly true.

In a standard lamp (where the bulb is upright), it's a bit dim -- the ceiling above the lamp is plenty bright, but it doesn't do that much for the room. In a light fixture where the bulb is at the ceiling and directed downward, it's great...

...and I think it's important to emphasize this distinction to customers when you're trying to sell the bulb if you want them to be happy with their purchase.

[Ether]

FWIW:


60 watt incandescent 840 lumens

40 watt incandescent 490 lumens


LED T-67004M (Cool White 5000K) 560 lumens

LED T-67004S (Warm White 2700K) 450 lumens

[KarenH]

In the picture I posted--
--the bulbs are horizontal
--the frosted glass shade is below them
--there is no shade above them
--the ceiling is moderately dark (main reason why this room is hard to light)

So maybe my "test" should include a situation such as in a table lamp, where the bulb is upright and lights up the ceiling and walls. One thing I haven't done is to try it at night, when there is no outside light. To be truly "scientific," though, I would have to remove all the furniture and somehow take a picture of the floor, but how could I do that without blocking the light with my camera? Oh, well. I guess the main thing is whether we decide we like it in our house.

[pfreivald]

Originally Posted by Ether

FWIW:


60 watt incandescent 840 lumens

40 watt incandescent 490 lumens

I know, but all that really tells me is that a lumen rating is a poor indicator of how a bulb 'looks' in a room...

[Brandon Holley]

Originally Posted by pfreivald

I know, but all that really tells me is that a lumen rating is a poor indicator of how a bulb 'looks' in a room...

This is an extremely true statement. While lumens are an important metric when evaluating light, there are often many other factors to consider.

When dealing with LED bulbs in particular, higher CCTs (color temperatures) result in a higher light output (for the same drive current). Essentially, higher CCT LEDs are more efficient than lower CCT LEDs because the phosphor conversion of blue light to white light is less dramatic.

Many companies will try and squeak a few more LPW (lumens per watt; essentially how efficient the bulb is) out of their fixtures and bulbs by bumping the CCT up a little bit and essentially gaining free light.

CRI (color rendering index) is another very important measure, albeit a controversial one at times. CRI basically tells you how well the light coming out of the bulb/fixture renders colors. The higher the CRI (max=100) the closer it is to natural sunlight in terms of color rendering. You can read more about CRI here: http://en.wikipedia.org/wiki/Color_rendering_index

One last measure which has a lot of play in LED lighting is lux. Lux is a measure of ILLUMINANCE, not LUMINANCE. Lux takes into account how much light is being emitted over a certain area. In situations which are a direct replacement for incandescent or flourescent bulbs (such as the FIRST bulb) it is not as useful, but for other LED retrofitting applications it is extremely useful. One example of where lux is extremely important is in streetlighting. Streetlighting has very specific requirements for lamps to meet so roads/sidewalks/parking lots are lit correctly. Just putting a big light source in a fixture will not necessarily give you the correct light output. To ensure the beam is being spread and shaped correctly, measuring lux at specific areas of illuminance will tell a better story of how well the light fixture is working.

These are some more metrics that can be useful when evaluating light, and LED lights in particular. As with most things, there are direct tradeoffs between things like cost and efficiency, CRI and output, etc. It is our job as engineers to find a balance that consumers will enjoy!

-Brando

[Ether]

Originally Posted by Brandon Holley

Many companies will try and squeak a few more LPW (lumens per watt; essentially how efficient the bulb is) out of their fixtures and bulbs by bumping the CCT up a little bit and essentially gaining free light.

... and they do the opposite (lower the color temperature) with incandescents to create "long life" bulbs.

60 watt standard 840 lumens

60 watt "long life" 770 lumens


Don't forget that the user can easily lower the color temperature and/or change the lighting pattern by selecting a different lamp. A different lamp can completely change the look and feel of the same bulb in a given room. A glass bowl or reflector which directs the light upwards to reflect off the ceiling produces a completely different lighting pattern than a lampshade that is narrow at the top and wide at the bottom to direct the light downward. And a white lampshade produces a different "feel" in a room than a dark color.

[Brandon Holley]

Originally Posted by Ether

... and they do the opposite (lower the color temperature) with incandescents to create "long life" bulbs.

60 watt standard 840 lumens

60 watt "long life" 770 lumens


Don't forget that the user can easily lower the color temperature and/or change the lighting pattern by selecting a different lamp. A different lamp can completely change the look and feel of the same bulb in a given room. A glass bowl or reflector which directs the light upwards to reflect off the ceiling produces a completely different lighting pattern than a lampshade that is narrow at the top and wide at the bottom to direct the light downward. And a white lampshade produces a different "feel" in a room than a dark color.

I have way less of an understanding of how incandescents work so I cannot speak to them as well as LED, but how do you tune the CCT of an incandescent bulb? Just curious, it seems like a pretty interesting thing to do.

Lighting is all about "feel" as you have said. Unfortunately its extremely difficult to put measurable metrics on feel, which is why lighting is sometimes a very tough market to penetrate. As you said, options must be available for users to make their own choices of what feels right to them.

I do have to say however, since I began working on LED lighting around 3 and a half years ago, I now prefer cooler feel temperatures (higher CCT). Nothing in the 4500K+ range, but a 2700K temp actually feels wrong to me now.

-Brando

[Ether]

Originally Posted by Brandon Holley

I have way less of an understanding of how incandescents work so I cannot speak to them as well as LED, but how do you tune the CCT of an incandescent bulb?

The user can change the color temperature of an incandescent bulb by dimming it.

The manufacturer makes long-life incandescents by changing the filament slightly so it doesn't burn as hot. That gives a yellower light, and the filament lasts longer. And the bulb is less efficient (fewer lumens per watt).

[Molten]

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