Saturday, September 19, 2015

Review, GreenCreative LED 4" Downlight, Product 40834

This is a new LED 4" Downlight imagined and sold by GreenCreative, as UPC 28672 40834. their Product: 40834/ Model: 10SMDL4GDIM/930.

10 watts, 625 lumens, 3000°K
It is a prominent addition in my Pinterest collection of LED lights that advance my vision of our Residential LED Lighting future. I act responsibly toward followers of my Pinterest collection and LED lighting vision, in offering this product and concepts review.

Begin with discussion of concepts, and start in that, with Brightness Numbers .

The package graphic almost-correctly indicates similarity to a 50 watt incandescent BR20 flood, perhaps this current offering at amazon  .

An E26 bulb which might be housed in a can is rated 500 lumens, and is 20% less bright (by the lumens ratio, 500/625 = *0.8). If this bulb is set deep within the can and under an obscuring lens, it will deliver even less than the well-revealed LED with its broad 110° beam angle .

Here is naive advice from Green Creative , that gives further understatement of the task illumination achieved with this light. The comparisons are with point-source bare bulbs.

The table implies that a useless 50 watt bulb corresponds to a 625 lumens LED downlight. In fact, a 625 lumens LED downlight corresponds to a 140 watt point source light bulb.

I offer Brightness Numbers to allow comparison of LED downlights with point-source incandescents. Directional 3000°K light of 450 lumens gives a good match in task illumination, to the well-understood 100-watt good old light bulb some won't surrender. I assign that task illumination a Brightness Number, B4, based on side-by-side comparison with human vision, my own.

Here is one of my several demonstrations of luminaire match at B4, as sensed by my eyes and by sensors of a commonplace Canon Digital Rebel, a good DSLR camera. The available 450 lumens LED standard is a now-antique Lighting Science 4" Glimpse LED downlight  .

Apr 12, 2014
I'm looking for a 450 lumens dot, better than 4" Glimpse . A 450 lumens directional down light gives illumination below equivalent to a 100 watt point-source light bulb. I assign this illumination a Brightness Number B4, and ...

The GreenCreative Product 40834 light is too bright to be the replacement of 4" Glimpse lights. It has Brightness Number, 4*625/450 =  B5.6. If you are replacing a dangerous, hot 100-watt bulb at last dead, this light will give about 40% better light. That is a lot. Perhaps in your closet, hallway, or over your shower, you will be displeased enough to also install a dimmer. In many hallways, you will be grateful to have more brightness than that of a 100 watt bulb.

Unpackage a GreenCreative LED 4" Downlight, Product 40834.

I want to put the luminaire on my test stand, mounted to a junction box. Employ a quick-connector male end from my loose-parts inventory.

The flush side of a three-pointed bracket will be set against the ceiling of course, for junction-box mounting. This is the reverse of orientation in all installation drawings.

Box labeling includes the word CLICK. Here a  luminaire is Clicked to the bracket as it would be assembled for can light mounting. The deep side of the click slot is set upward.

Mount the GreenCreative downlight at Stage Left in my test stand. The bracket and quick connect do quite a bit to occupy and obstruct a junction box.

At Stage Right, mount a Nicor DLS4 3000°K LED downlight, my light most similar to the GreenCreative 40834.

At Stage Right on my test stand I employ two RACO 175 junction boxes. That fully visible here is at the same elevation as a junction box at Stage Left. Fit the upper Stage Right junction box with a porcelain lampholder for test of various light bulbs vs. GreenCreative 40834 at Stage Left.

At full power, illumination of Nicor DLS4 and GreenCreative 40834 is identical. The DLS4 is 671 lumens. The GreenCreative 40834 might be more than 625 lumens. The color temperature of 3000°K is a remarkably good match.

The GreenCreative 40834 dims smoothly, to a lesser light level (better) than Nicor DLS4. Both luminaires buzz as energized through a very-good Cooper DAL06P dimmer. 

The buzzing of the GreenCreative 40834 is about twice as loud, but might not offend you.

Here are photos of the lights on the test stand, upper at full power, and lower with full dimming.

Review now, one more labeling of the package front, the claim Estimated Energy Cost: $1.20 per year. This is 3 hr/day*365 days/yr*10/1000 kilowatts*$0.11 per KWH. The number does not inspire. Better, calculate the money this light will save you over its lifespan of at least 40,000 hours. Consider replacement of 100 wall bulbs on a dangerous porcelain fixture, and replacement of incandescent of fluorescent BR20 flood bulbs in a 4" can light. I have offered unique math for this, until now treating the cost of electricity as fixed forever at current 11 cents/kwh.

Philips 455444 65 Watt Equivalent SlimStyle BR30 LED Soft White Light Bulb, Dimmable, High CRI, $15.86 and free shipping. 

GreenCreative BR30 7.5W Cloud,avalable somewhere as Soft White 3000°K.

A BR30 "65-watts equivalent," 650 lumens, $15, 25,000 hours life is included in the savings table below. One of these will be the least-cost conversion from an incandescent or CFL bulb in a 4" can light. The lighted surface is probably adjustable to the face of the can and ceiling plane.

The above YouTube video states that a GE Reveal BR30 is best. I don't accept that. Perhaps it is only a little less likely to be ruined in a drop-to-be-expected. Poorer efficacy, lumens per watt, makes this less desirable.

GE Lighting 83574 LED 12-watt 650-Lumen BR30 Spotlight Bulb with Medium Base

BR30? A19? Expect up to 14 watts in your purchase, less-pretty 2850°K, and unsure survival of a drop.

Add one more choice in a savings-comparison table, Lithonia LED Versilite :

If you would retain a 4" can for your light, an inexpensive LED bulb achieves the savings, with least effort and installed cost.

If you start with a safe but jam-packed ceiling junction box, and can't replace that box, choose a Lithonia LED Versilite or GreenCreative 40834 dependent on your style preference. Many people will prefer the GreenCreative 40834 for appearance.

There are many adequate choices. Just be sure to stay with LED and someday OLED, from now on.  There was no joy in the jungle of incandescent, halogen and fluorescent bulbs now past. 

A menagerie of twelve light bulbs at the higher position Stage Right on my test stand, is compared with GreenCreative 40834. Note the ordering as for the cluster of four bulbs below. Two similar 65 watt incandescent spots at left give less-pretty light perhaps a bit brighter than GreenCreative 40834, but in unintelligent cones, concentrated with 60° beam angle. Light for general illumination, not upon some object, serves best with maximum beam angle.  At lower right see awful illumination from a "65 watt" CFL spot. At upper right, see that GreenCreative 40834 is much brighter than a 100 watt incandescent bulb. All comparisons are in a dimmer circuit at full power.

Of twelve lights in these photos, only the Cree 60-watt LED bulb, lower-right below, is dimmable. A 300 watt incandescent bulb, upper right below, is brighter than GreenCreative 40834, fragile and very hot.

Good riddance to all of these bulbs. Good riddance too, to the awful fruit of the L-Prize, among LEDs tricked to act as point-source and very poor in directional application.

GreenCreative LED 4" Downlight, Product 40834, at stage left again, is very superior to an 800-lumens Utilitech response to Philips L-Prize bulb , dead end beaming as it would, placed overhead to light a room. An LED bulb, tricked to act as a point source is uncompetitive for efficiency in practical illumination. We shall wish that the US Department of Energy would do something useful in the advancement of residential LED lighting.

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