Thursday, November 17, 2011

LED Plate Lights Replace Can Lights

Home Depot has taken the lead, in offering affordable LED lighting affecting my work in attics. I can now replace a crummy can light, where too-hot bulbs pump heat into the attic, for less than $40. Where the can was foolishly non-IC, I can finish the insulation. This will be a lot more satisfying, than just replacing the can. An IC can, with a new LED bulb, is not a better deal than the plate LED.

The 14.5 watt T91 is rated at a fairly low 750 lumens, but will need dimming in many situations. Dimmed to 10%, drawing 1.5 watts, it is a beautiful night light. Somehow, lumens ratings here are not to be trusted. A 23 watt CFL rated 1600 lumens and equal to 100 watt incandescent, gives less light than the full-on T91. Please tell me whether you agree. At December, 2012, amend this post, noting photo demonstration of the equivalence of plate LEDs to light bulbs. A plate, beaming all light from a flat plane, gives twice as much illumination as a bulb. The T91 is found to be equal to a 150 watt incandescent bulb. With this recognized doubling of efficiency, why will anyone still want to use bulbs? 

The Home Depot/ Commercial Electric T91 LED Plate Light will replace 5" and 6" cans. Even this 4" Halogen spot, not as bright, that is pouring heat into an attic. 

Here is Insulation Math, for involved energy costs, where such lights have been baffled, to surround them with insulation:

Example 7: One baffled can light in every 100 sf of an "R38" attic floor. Say, cellulose twelve to fifteen inches depth. Real R38 insulation except for holes. Baffle 12" dia., area 0.8 sf uninsulated or worse, with driven leakage.
100/Reff = 99.2/38 + 0.8/3. Reff = 34.8. As if insulation were less deep by an inch or two. Why would one "waste" all that insulation, to avoid replacing the ugly can light? The baffle, with a cover in a deep insulation bed, must cost as much as the light replacement, say $60 for a T91 LED plate light in a junction box? Correct actions are achieved by prohibiting rebates if wounds and dangers in a house are not fixed.
With math for my home, the uninsulated area at each can light loses $2.4*0.8/3 = $0.64 per year. Bulb local heat is all lost in winter. Countable pennies are lost in heat-driven excess of house fresh air exchange through any can gaps

Please read more, in a Picasa Web Albums Slideshow: 

The preferred installation has replacement of a can, with a 4" junction box.

With Blogger Labels feature, find all of my discussion of these wonderful LED plate lights:

The discussion will include all LED plate lights made by Lighting Sciences Group Company, LSGC, the 6" light sold as T91 at Home Depot, and an even more useful 4" light, not yet available at Home Depot. 

At December, 2012, watch a revolution in the offering of plate LED lighting, with new Home Depot products, and hopeful availability of all LSGC plate LEDs at Lowe's stores. In arguments for new marketing measures, I offer an expansion of associated Insulation Math, above. The difficult swap-out of a can light, in the Picasa Web Album was at cost of $60, installed. With marketing efficiency and training, I suggest a $60 installed cost can be profitable to the contractor.

Typical $1 per year heat loss per can, plus excess cost of electricity. For electricity cost assume a maritime climate with $0.15 per KWH electricity cost. Consider a light that is on 4 hr per day, 1460 hr per year, Cost is $14 per year at 65 watts and $3 per year at 14 watts. Each change-out saves about $12 per year per fixture. Simple payback is in five years if total replacement cost is held at $60 per fixture. This is irreversible repair of a heat bleed, far better than putting a 23 watt CFL in the leaky can, $5 per year electricity cost, only $9 per year  saving of energy. We are looking for fullest easy, painless energy savings, not fastest payback of any investment.

Read more, picking all posts of label LED Plate Lights, on into the future. improving upon the stack nature of a blog. . CLICK HERE,


Lee said...

I know, I have seen all the post out there about dimmer problems with the CE "disk light" T91 for 5 or 6in cans. I just finished installing 2 of them on our bath and have also made 6 trips to HD and Lowes for LED light dimmers and have not been able to get them to dim.

Any pointers would be greatly appreciated.

Phil Norman said...

I'm so happy to have a conversation on a post. I am unaware of any difficulty with dimming T91 lights. I have installed five in the two weeks since discovering the joy of installation without a can, in a RACO 175 ceiling box. Two have dimmers, and dim just as I expect them to. Attractive placement of disk lights tends to be in hallways, where brightness should vary, down to a still-adequate 1.5 watt night light condition, and I expect to add dimmers for most installations.

I have tried Google searches to observe the reported comments. I find nothing with the search of "dimmer problems with the CE "disk light" T91 for 5 or 6in cans". The search of "dimmer problems with commercial electric T91" finds my post.

Please share more about your observations.

Rinbea said...

I also purchased these and we can't get them to dim. What dimmer (specifically) did you use?

Phil Norman said...

I have used any dimmer found at Home Depot, or Lowes: Lutron, Cooper Wiring Devices. The dimming is always as expected. The only complaint is with a confusing variety of vibratory noise.

Easy Victor said...

Can someone please tell me the color output of these CE disc lights? I see the lumens, but can't find the color reference.

Also, do these screw in to existing cans, or is this a hard wired complete replacement?


Phil Norman said...

Hello again to Lee,

I still do not understand this. I have never seen this problem, in about six independent installations, trying everything offered at Home Depot and Lowe's. The only problem is slight buzzing sometimes, bearable to my tinny ears.

Please describe your circuit in detail. If you still blame a dimmer, please let me buy it from you, to try it myself.

Phil Norman said...

Hello to Easy Victor,

Please trust the Lighting Facts label.

The CE T91 is only one Glimpse offering from LSCG, product ordering information:


WW denotes 3000K temperature.

WH calls out the paint color, white.

Other choices of temperature are 2700K (e.g. GLP6 W27 WH), and 4000K (e.g. GLP6 NW WH). I think Home Depot has made a good choice in its low cost 3000K offering. 3000K is warm, not cold, natural light, to my eyes.

The reference for this LSGC information is their Glimpse Spec Sheet:

You ask: Also, do these screw in to existing cans, or is this a hard wired complete replacement?

The easiest installation uses the screw-in connection.

Please follow the link to photos of a preferred installation, with elimination of an energy-wasting non-IC can. This is no more a "hard wiring" than the "screw in" to twist-connected leads.

Easy Victor said...

Hi Phil,

Thank for that information. To me, 3000k is a bit too harsh. I've tried both in my home and I prefer 2700k. I also had no idea that the Glimpse was the same as the Home Depot offering. But outside of HD, the price is out of my ballpark. And it doesn't look like HD offers the 2700k product.

Display name said...

We just bought 6 of these lights and NONE of the dimmers at Home Depot work with these lights! It looks like only Lutron Dimmer LG 600 P or CN 600 P will work, but Lutron doesn't allow you to order them over the phone or online via their website. Lowe's has exclusive rights to sell these dimmers, and unfortunately Lowes is NOT convenient for us. Home Depot shouldn't be selling these lights if they can't also provide dimmers that work with them. The associate told us any of the LED dimmers would work, so they're apparently clueless. And after reading these posts, I'm not even sure the LG 600 P will work after going thru all the trouble of ordering them over the phone with Lowes. Way too much of a hassle. Spare yourself the trouble.

jason said...

I have had this problem with these lights this week. Aproblem with the t91 not dimming..I to made a few trips to home depot and had three differecnt employees tell me the Lutron dimmer switch would work. Well in fact after talking with Lutron tech services they have not tested and do not have a approved dimmer switch for this particular ( t91 ) fixture. They said to contunue to monitor there website for futcher approved dimmer swithches. If someone has found a good dimmer switch please post the manufacture and model #. Thanks Jason

Jeff in MN said...

The T91 lights are very nice and are a great retrofit in 5" fixtures. They are very bright and the 3000K color is a great color for a kitchen. As others have mentioned, dimming them is a different issue as none of the dimmers that I have tried, including the Lutron LED dimmer from Home Depot seem to work. The light stays at full brightness until just near the end of the adjustment when some of them start to pulse or flicker. Please post a model number and brand of dimmer that will work.

Unknown said...

I contacted Lutron support at 800-523-9466. The tech said that the Lutron LG-600P or CN-600P will work well with up to four T91's.

Orton said...

I am also having issues with dimming the T91 lights, Conventional dimmers will will dim then but will cause them to burn out, I have replaced two already. I have 11 in one room and 6 in another and I would love to have a Dimmer that could handle them. i was going to replace all the lights in my house with them but I am thinking i will hold off now.

Phil Norman said...

I don't want to believe this. Of my dozen installations since T91 lights came onto the market in late September, 2011, I have no reports of dimmer or luminaire failure.

Please identify dimmers tried. Could there be errors in 3-way wiring? Do you have failures in single-pole switched circuits?

josuar said...

I have incredibly loud BUZZING from the T91! The lights work well when in the maximum setting of the dimmer, but as soon as I start dimming there is this really annoying buzzing sound comming from all lights. I have 5 lights in that room. I have used 7 different dimmers, all of which dimmed the lights (and were listed as compatible with the glimpse, which is very similar to t91) but they all initiate the same problem.

IF YOU BUY THESE LIGHTS AND WANT TO DIM, EXPECT AN ANNOYING BUZZ!!!! Im considering returning these lights (after going through the mess of installing them using a junction box).


Alan said...

I think I might have a solution to the discrepancy here. Phil, have you done any installations with more than one T91 on the same dimmer? It seems to be that the people complaining are doing just that.

I just installed 5 of these: 4 on one switch and 1 on a separate switch. I found the same trouble with the 4 on a single dimmer. First, I used a basic $4 knob style dimmer: nothing fancy. That produced the same pulsing mentioned above. I replaced it with a Lutron TGCL-153PH-WH (regular looking switch with tiny slider next to it; $20) because it specifically says "works with DIMMABLE CFL & LED bulbs" on the package. It behaved the same as the cheepo.

So, I googled and found this discussion. After reading it, I decided to try the TGCL on my sink light which has a dedicated switch. It works as desired except for a slight buzz from the bulb.

Others could test this theory by disconnecting all but one lamp. Mine were a bit of a hack job to install since my cans don't have tabs, so it is a pain to disconnect individual lamps. Please let me know if you find this confirmed my hypothesis.

Has anyone has tried the Lutron LG-600P or CN-600P on a circuit with multiple T91 lamps? I'd like to know if that solved the problem before bothering to find one on-line or trekking to Lowes (over an hour to nearest) to get one.

Alan Johnson
Hartford (VT) Energy Commission

Alan said...

I'm also having a problem getting the lights to turn on. I have to hold the switches up for a few seconds to get them to come on and stay on. This is both for the cheap standard one and the TGCL Dimmer. It is like they are not putting enough pressure on the contacts to get the electrons flowing, but I never had trouble with the CFLs they are replacing, in any any other switch in the house which are all the same brand. Any thoughts would be welcome.

Alan said...

I corrected the hold-the-switch problem by replacing the switch with a new heady-duty, 20A switch that clicks on an off much more solidly.

I'd still like to know if anyone has tried the Lutron LG-600P or CN-600P dimmers with multiple T91s connected. Anyone?

Ryan G said...

I just read this today while having these issues with the CFL/LED Lutron dimmers

I tried the LG-600P from Lowes(was LG-600PH-WH at store I believe) on one circuit with 4 of the T91 LED lights. Worked perfectly.

No buzzing, pulsing, or annoying adjustment knobs to calibrate.

Only dims to about 25-30% but that was all I needed.

What a relief. Im putting in 14 of the T91s total. 4-4-4-2. I will be buying 3 more of these dimmers tomorrow. Just hope I can return the ones that didn't work...

Thanks for all the help!

Alan said...
This comment has been removed by the author.
Alan said...

I bought an LG-600PH-DK (dual knob? one white and one off-white: almond or something) online and installed it this weekend. (The CN has a light that is on when the switch is off: great "energy saving feature", right? Otherwise, I prefer that look.) The LG works better than my other attempts, but I still get pulsing toward the lower end and the lights go off well before the dimmer is at the lowest setting. Still, I'm able dim it enough for our purposes before it gets low enough to pulse. I don't need mood lighting in our kitchen, just wanted to take the edge off and save a few more watts. So, my efforts are done.

Ryan, please report on how your other installs go. Thanks!

Joe said...

I too had problems with the dimmers so I purchased a Lutron CFL/LED dimmer (probably a Model TGCL-153PH-WH) and used it on a single circuit with 4 of the Home Depot lights. It worked, and as I dimmed the light the lights would begin to flicker in the lower end.

The LED dimmer has an adjustment so you can "trim" the switch so that the lights won't flicker within the full range of the slide, which is a nice feature of that dimmer but it comes at a higher price.

What bothered me was the limited dimming I could attain. It seemed like I was only dimming the light about 20% and I wanted a much lower setting. I suspect that these dimmers act differently depending on how many lights are on the circuit...How much the current draw is. I want to dim a batch of 4 lights and 6.

If anyone has been successful in dimming a batch of these lights with a decent dimming range I'd like to know what dimmer was used. Repeatedly buying and returning dimmers gets old fast.

Joe said...

I just installed a TG-600P dimmer on a circuit with 4 lights and it worked great. I also tried it in a chandelier that has 15 9w led bulbs and it worked with that as well. Now I want to find a 3-way dimmer that works.

Joe said...

And the winner for the 3 way dimmer is the Lutron TG-603PGH at Lowes for $14.97.

Robert Anthony said...

this is an old post but the hum/buzz problem still persists on most led lighting fixtures the t47/t67/t65 and many other units must be controlled by a Electronic Low Voltage Dimmer (ELVD). Most units have a low voltage circuit built into them for the LEDs to light. Home Depot for some reason does not carry the proper dimmers. Go on line or write to home Depot and Lowe,s. What work in most installations is the Lutron Diva model DVELV-300 or 600. Hope this helps.