Tuesday, January 28, 2014

Review Lithonia 7" LED Versi Lite FMML 7 840 M6. AC-Powered LED, No Converter Block!

Who else missed this announcement of June 28, 2013?

Acuity Brands Introduces New LED Flush Mount Luminaire From Lithonia Lighting  

Flush Mount? I suggest this should be called a surface-mount fixture. It is installed fully proud of a ceiling junction box. It is a plate LED luminaire, where beam angle is large, greater than 130°. Might "flush mount" describe a light whose body must penetrate the junction box to set the lens closer to the ceiling? A terminology debate is important. I found this displayed and shelved with surface-mount fluorescent fixtures, while so-similar lights that may retrofit a can light are in that row of cut-in disasters. Let all LED plate lights be called down lights or surface-mount. Never called "recessed." Not stocked with stupid can lights. Not displayed as can light retrofits. This will help to teach shoppers to not buy can lights. Let all manufacturers of LED Plate Lights learn to avoid structure that must penetrate a junction box, adding to volume needs and voiding the label "surface mount."

This light, at 4000°K only, is sold at and in my nearby Home Depot store. I bought this for examination, but will recommend that with 3000°K phosphors. Three offerings are:

The three manufacturer offerings of the Lithonia light are summarized in Lighting Facts labels, here copied from the second page of the Specification sheet, listed at this web page: 

The 4000°K product is sold in-store at Home Depot. I have purchased this product only for evaluation. I dislike the blue color, though a bit brighter, as unnatural indoors. It alters the color of walls and furnishings. 3000°K lights at the same price are offered online , with free shipping to my home if I buy two, and those, I will happily keep and will offer to customers. They will be needed where a customer with an over-full shallow junction box will not permit its replacement with a deep junction box. Anyone can install this light, even onto crummy wires, and stop baking those wires.

The packaging is compact and beautifully recyclable.

In comparison photos that follow, the VersLite is from a box with labeling of Model No. FMML 7 840, 740 lumens, 10 watts. Newer packaging states Model No. FMML 7 840 M6, 660 lumens, 9.4 watts.

Contents are identical. Accept the lower lumens and wattage numbers, which agree with the Lighting Facts labels above.

In the box, only the luminaire and connecting hardware. No waste.

Further study the packaging in comparison to that of a Lighting Science 4" Glimpse.

Compare 4000°K versions of the Lithonia Versi Lite, 9.4 watts, 660 lumens, and a 4” Glimpse, 9.5 watts, 475 lumens. Note poorer Glimpse packaging, bigger for a smaller light.

Compare luminaire beauty and size.

Both are recommended for hallways and corridors, utility closets, and bathrooms. The brighter Lithonia will also serve work areas. I think the Lithonia is too bright for many of the claimed applications; the 4” Glimpse is just right. 

Look under the lenses.

Both key onto junction box cover screws, with removal of a simple lens.

By lumens ratio, the FMML 7 840 is brighter than a 4" Glimpse, by 39%. If 4" Glimpse is Brightness Number B4, then FMML 7 840 is B5.6.

I find equal illumination from a 450 lumens, 3000°K, 4” Glimpse, and a 100 watt incandescent point-source light bulb. Assign both a Brightness Number of four, B4. Here compare brightness from 4000°K sources, still calling the 4” Glimpse, B4. The Lithonia FMML 7 840 M6 is then brightness 4*660/475 = B5.6, 39% brighter. The FMML 7 840 M6 equates to a 140 watt incandescent, not to the package-claimed 60 watts. The package claim may be nearer true if the incandescent is a well-reflected downlight, but the buyer will see comparison to a simple bulb in the surface mount holder that is being replaced, and will be misled. He may want to buy a dimmer, too.

See unnatural color of this light-tan wall with 4000°K illumination.

Vs. a 100 watt incandescent bulb, the FMML 7 840 M6 should still be brighter by 39%. The photo comparison is indeterminate.

The FMML 7 840 diodes are beautiful, at fully dimmed, and they are still quite bright, not an ideal night light.  The Cooper DAL06P dimming here has the black wheel nudged up a wee bit, else there is low-amplitude rapid flickering.

A 100 watt bulb at the same fully dimmed position is rather ugly, and dark.

The FMML7 840 at full bright, is dazzling. Everything surrounding the 3" outer diameter of the hexagonal circuit board is heat sink and packaging.

How has Lithonia made the circuits so simple? This has no hum on a dimmer. No delay in startup.

I wish for a 4" version, 3000°K, with at least 50% less metal.

This weighs 501 grams including 51 gram acrylic lens. Compare to 340 grams for a 4" Glimpse, where the AC adapter block, converting to DC, might be half the weight.

Here is a close-up of the LED array:

I see similarity to Seoul Semiconductor Chip On Board . (This is not a Seoul Semiconductor board.) 

AC powered LEDs ! This has seemed extreme, chopping up the AC waves. But, it works as my eyes can see it, with pretty-good efficacy (>70 lumens per watt). Worry about stroboscopic effects, unhappiness in slowed-down/ stop motion video. This Lithonia light is rated for total harmonic distortion , something new with LEDs, not explained where stated as :

Low THD of less than 20. 

How good is this? How hard have they worked to give a good number. This isn't mentioned. We have lived with similar harmonic distortion in fluorescent lighting , controlled in the ballast design. 32% is a poor number. 20% is good, and common. 5% is expensive.

Addition 2/24/2014:
A new post will present observations and installation details, where two 3000°K Versi Lites are installed in place of 60 watt bare bulbs in a garage. Brightness is increased times 2.4.
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