Landscaping Lighting

[Steve]

Has anyone run into any heat issues? The superbright site mentions this. Most of these fixtures in fact are sealed units and I wonder how bad they heat up and potentially shorten the lifespan of the LEDs?

 

[pete_c]

The Cree I've been testing outside heatsink is warped / melted a bit; but still works. I'll take a picture of it. Never mounted the LED on anything though. The new LED MR 16's appear to have a metal base and part of the casing looks like a heatsink.

 

[oberkc]

Has anyone run into any heat issues?

Many of my fixtures are open. My path lights all tend to be those down-light, open-air types. So far, I have not had any failures for any reason.

My floods are all "sealed". Though not entirely watertight, most are closed off with glass lens. Again, so far, no failures. I have not taken a lot of time to feel the fixtures for temperature. Perhaps I should.

My oldest LEDs are about three years.

 

[sic0048]

I was a little surprised to see these big heat sinks on the LED lights. Doesn't heat generally mean lost energy? I guess they put out so much more light than an equivalent light bulb in another form that even with the energy lost to heat, they are more efficient?

I just haven't looked into LEDs before, but always assumed they ran fairly cool. I guess I was wrong in my assumption.

 

[pete_c]

The Cree lamps get very hot. You can get burned touching one. A few of these in a room would heat it. Read some where they get hot when overdriven.

 

[pete_c]

Yesterday recieved a couple of MR-16 5 Watt LED lamps from China. I also noticed that they too sell MR-11 LED lamps. Mine are split between both the MR16 and MR11. I also purchased a couple of put together kits. These include LED, Lens, transformer and heat sink. I purchased these to test a bit.

 

[Dave X10]

I was a little surprised to see these big heat sinks on the LED lights. Doesn't heat generally mean lost energy? I guess they put out so much more light than an equivalent light bulb in another form that even with the energy lost to heat, they are more efficient?

I just haven't looked into LEDs before, but always assumed they ran fairly cool. I guess I was wrong in my assumption.

The lower wattage bulbs... use such tiny amounts of power... they of course produce no noticeable heat. As we use brighter and brighter LED bulbs the heat becomes more noticeable. The cheap-o LEDs have too little heat sink... and much shorter life-spans.

I am a big advocate of LEDs (but not an expert on them or their use). My landscape light conversion... is my first LED venture that will actually have a chance to save me money. My other tests and trials have cost me for the privilege of being on the cutting edge.

I am old enough to remember the 1950's when even new homes were under-wired and poorly lighted. People's (DIY) solutions were huge wattage bulbs (150W) and rheostats to dim the brightness down for night usage. It took decades for people to realize that a couple 60W lamps made for a more pleasant environment than one 150W. My findings with newer technology bulbs... seem to expand on that same theme. I find... that a couple 10W CFLs and a 3 to 5 Watt LED.. can brighten a room better than any one fixture of any wattage. Hence I am more prone to add fixtures.. than I am to add higher wattage lamps.

I am sure that 8, 9, or 10 individual LED 1W (or smaller) bulbs... could light a large room very nicely. But we may never see any home wired for this kind of lighting.

 

[pete_c]

I currently utilize "top of cabinets/bookshelves" indirect halogen lighting using mostly hockey puck style 20 watt Halogen lights. I had some issues with one set (in the study) and switched to a Xenon type 20 watt lamp (6 of them). Only three sets on bookshelves at this time - one in the study, living room and dining room. I am testing "under" the counter multiLED 120VAC dimmable hockey puck lighting and it works fine, color and brightness are OK. Most likely will be switching the over the bookshelf indirect lighting to LED's this year. The halogen hockey puck lights are still much hotter than the 1-5 Watt LED lights that I am using. In FL had custom incandescent lighting put into built in wall and glass shelving. I will most likely replace this lighting with LED 120VAC lamps. The kitchen cans currently turn the kitchen into daylight and my wife likes that when cooking; so will leave those alone for now. When no one is in the kitchen two lights are left on. One is the over the sink can light and the other one is the over the stove light (bulbs though keep burning out). When remodeling kitchen will change this scenario to LED's.

With the landscaping going to move a bit slower because of the four main lighting transformers / subzones will do a small section at a time. The easiest will be to convert the deck lighting (only about 10 sconce mini lights) first. Its only one feed right now. Its very indirect style lighting providing an illumination on the deck and stairs but only just enough to see where you are walking. Years ago put a 120VAC halogen lamp over the grill which provides ample lighting for cooking at night.

I saw this bit of news today.

SSL Funding

 

[nick_l]

I, too, like the forum over at Lawnsite. Check it out if you have not already. Also, at DIY.net there is a forum for landscape lighting.

Some good info and links, thanks. Im glad to see someone has had dealings with superbrightleds because I am considering some of their products when I move and was curious about quality, etc.

Qestion: Did you really mean diy.net? I don't see anything regarding forums on the site. I basically appears to be a gateway site for links to other places, but of course I might just have missed the link.

Nick

 

[pete_c]

Purchased MR16's for my initial testing. 3 from a national company and three from China. The builds look similiar.

Also purchasing MR11's & replacement's for the 7 watt incandescent lamps.

I also purchased a "kit" which comprised of the 3 watt lamp, 12 VDC/AC transformer, lens and heat sink. My test lamp failed yesterday. It was connected to one of the 12VAC transformers. Gonna have a look at it today.

 

[oberkc]

Qestion: Did you really mean diy.net?

You are correct, and I apologize. Try:

http://www.diychatroom.com/

 

[pete_c]

I took apart my "experiment". I had mounted the whole assembly (transfomer, heat sink and LED) and an underwater pond Halogen landscaping light housing. The transfomer and housing were the only things which survived. The 3 watt LED and lens burnt to a crisp. Previously my testing was with 1 Watt LEDs which get hot but not as hot as this one. The house with the clear plastic lens though did not melt. It was outside but none the less looks like it was a small fire. The new 3 watt MR16's housing is an entire heatsink so I guess they would have survived the testing.

 

[BraveSirRobbin]

Hi Pete;

Is there anything in the literature that states to current limit those LED's?

 

[pete_c]

Not much other than the LED runs off of about 3.4VDC on the Ebay site and that the transformer has an input of 12VDC/AC and puts out the 3.4 VDC required by the LED. In addition the company sells other voltage transformers (from 85VAC to 220VAC) - very small (1" X .5")

I set up a new one today. This one using the same transformer which survived last experiement and a new heat sink with a fan. The light is so bright you can't look at it directly. The heat sink (which the same company sent me) appears to be a CPU style heat sink with two leads and a connector.

Very little documentation on the sale site. The odd thing was that the lens appeared to be custom made for covering the LED. The whole assembly with the lens and LED melted. Nothing else was affected.

Its a blue LED. Here are the specs:

1:Intensity Type:70-90Lm
2:Forward Voltage (V) : 3.4V-3.6V
3:Forward Current:700mA
4:Lens Color : Water Clear
5ower:3W
6:Color Temperature:470000
7:Viewing Angle: 120 Deg

Here are the specs for the driver:
1 - Input Voltage: 12V
2 - Output Voltage: 3.0V~4.0V
3 - Current: 620mA~1050mA
4 - Operating Temperature: -20~80 ℃
5 - Storage Temperature: -20~80 ℃
6 - Function: Open circuit, Short circuit and Over loading

60 degree lens.

 

[pete_c]

I left the assembled LED/driver and heat sink outside last night connected to the deck 12VAC. I glued the LED to the back of the heat sink. This morning it looks fine not showing any signs of excessive heat. It was powered on for about 5 hours or so.