Which is better? LED fixture replacement or LED retrofit?

[Besoeker]

But unless the CFL or LED was designed to be in an enclosed luminaire, what heat it does produce may be enough to effect it's performance and shorten it's useful life. Yes it will still run much cooler overall then the equivalent incandescent that it replaced, but that 50,000 hour expected life may be shortened if it operates above the temperature it was rated for.

Those in my kitchen are enclosed. At a guess, they have already done 30,000 hours which is about 30 times as long as an incandesecent life expectancy. And, possibly more to the point, using less than 10% 0f the energy.

 

[ramsy]

Those in my kitchen are enclosed. At a guess, they have already done 30,000 hours which is about 30 times as long as an incandesecent life expectancy. And, possibly more to the point, using less than 10% 0f the energy.

If year-round climate in the UK is a bit cooler than some of US in relative deserts & swamps, your delicate LED drivers may be cooler. Most package WARNINGS of LED-recess kits, LED-retro kits, and screw-in LED bulbs list 45°c as ambient limit.

Here in Southern California the common A-Frame attic construction can exceed 113°F half the year, not good for LED-recessed kits exposed to attic ambients, much less when insulation, or enclosed fixtures prevent driver-heat dissipation by Circulation, Conduction, Convection, or Radiation.

 

[Besoeker]

If year-round climate in the UK is a bit cooler than some of US in relative deserts & swamps, your delicate LED drivers may be cooler. Most package WARNINGS of LED-recess kits, LED-retro kits, and screw-in LED bulbs list 45°c as ambient limit.

Here in Southern California the common A-Frame attic construction can exceed 113°F half the year, not good for LED-recessed kits exposed to attic ambients, much less when insulation, or enclosed fixtures prevent driver-heat dissipation by Circulation, Conduction, Convection, or Radiation.

I don't think the LED drivers are all that delicate. We have been using LED indicators for more that 20 years.on panels in places like papermills. Processes that run 24/7. As I said, not one single failure has been reported. And they are a form and fit replacement for the filament lamps we used to use - and they used to fail regularly.

 

[kwired]

I don't think the LED drivers are all that delicate. We have been using LED indicators for more that 20 years.on panels in places like papermills. Processes that run 24/7. As I said, not one single failure has been reported. And they are a form and fit replacement for the filament lamps we used to use - and they used to fail regularly.

an indicator is not going to have the watt density as a comparable replacement cluster for a 100 watt incandescent lamp or for a 400 watt metal halide lamp. How well it will last? depends on if they considered it being suitable for an enclosed luminaire. You are seeing more design variety these days then you used to, and costs are coming down as well. Still lowest cost unit with nearly all the same specifications may not work as well if installed where heat can build up compared to one designed to operate in that condition.

 

[Ragin Cajun]

I don't think the LED drivers are all that delicate. We have been using LED indicators for more that 20 years.on panels in places like papermills. Processes that run 24/7. As I said, not one single failure has been reported. And they are a form and fit replacement for the filament lamps we used to use - and they used to fail regularly.

I have used LED indicator replacements as well. HOWEVER, the lumen output is quite low and so it the wattage. No comparison to a LED fixture for area lighting.

RC

 

[Ragin Cajun]

MY COMMENTS IN CAPS (NOT YELLING!)

But, why is the old fixtures a generic "400W MH" while the replacement is brand specific?

Please know that such success story is hugely dependent on the poor performance of the old one. Builder grade "one size fits all" MH downward pointing socket with textured plastic ring yard light that replaces the outlawed mercury vapor of the same type is not the benchmark of premium HID lighting system. It would be great if you have before and after daytime photo of the two.

THE EXISTING FIXTURES WERE QUALITY SHOE BOXES. SORRY I TRASHED THEM AFTER WE TOOK THEM DOWN. LAMP WAS IN THE HORIZONTAL POSITION.


Personal experience is an important parameter that complements measurable and objective parameters and it would be really helpful if you can provide the latter.

AGREE, BUT i DON'T HAVE MEASUREMENTS OF BEFORE. MY WIFE WAS IMPRESSED AND THOUGHT THEY GAVE OUT MORE LIGHT THAN BEFORE. THAT'S ALL THAT MATTERS!


Guarantee is only as good as the guarantor and the devil is in the details. A lot of warranty conditions on products marketed to homeowners and SMBs are designed to close a sale and collect profit upfront with so many bailout terms to protect themselves from liability of the very things they claim to save you from. FULLY AGREE. THE NEW FIXTURES ARE HUBBELL. I AM VERY PICKY ON MANUFACTURER SELECTION.

Exclusions that exclude failures from normal harsh conditions due to design engineers' failure to consider real world conditions is another thing to watch out for. If I'm sold a glass walls for a batting cage, I can't expect it to withstand a car driving into it, but I expect breakage from balls hitting it covered under warranty. A LOT of electronic ballasts failed from normal power surge in 1990s and household CFL ballasts from overheating. The real world was much harsher than engineers expected. I expect ballasting components of LEDs to be more reliable than older electronic ballasts simply because it's essentially the same design. I BOUGHT THE OPTION FOR SURGE PROTECTION WHICH ACTUALLY SHUTS THE FIXTURE OFF UPON IT'S END OF LIFE.

Everyone raced into LED retrofit sales game targeting SMBs, because LEDs have been EXTREMELY expensive and it offered high margin upfront and leaving gullible customers with 99% of the risk. It's still a high risk investment with a low return potential. They don't target large businesses since their purchasing team is not that stupid. The ones that do realize it's a gamble. Green, sustainable, renewable power are buzz words. Corporations spend money on something that might not actually save on operation expenses so they can brag about using recycled toilet paper and LED bulbs in locale. They want to earn the business of shoppers who feel those thing are dope. Grocery stores would have significant edge over competitors if they know what people will buy and avoid shortages as well as spoilage losses. It would be a dumb thing to give away if they figure out how. I HAVE ENGINEERED NUMEROUS PROJECTS WITH LED LIGHTING IN THE LAST FEW YEARS. I WAS A SERIOUS SKEPTIC FOR MANY YEARS BECAUSE OF MANY OF THE ISSUES ABOVE. I WAS NOT GOING TO PUT MY REPUTATION ON THE LINE FOR FLY-BY-NIGHT LED FIXTURE SUPPLIERS OR BLOATED SPECIFICATIONS - SEEN TOO MANY OF THOSE! I TELL MY CLIENTS MY LIGHTING DESIGN IS FOR LOWEST LIFE CYCLE COST. FIRST COST IS NOT MY WAY. MOST HAVE GONE WITH MY RECOMMENDATIONS. THOSE THAT DIDN'T WILL PAY THE PRICE IN THE END!

I HAVE BROUGHT GE LED SCREW IN LAMPS BACK BECAUSE THEY FLASHED WHEN DIMMED. THEY ARE NOT THE ONLY ONES THAT DO THAT. I AM ALSO HOLDING OFF ON CONSUMER SCREW IN LED LAMPS BECAUSE THERE IS WAY TOO MUCH JUNK OUT THERE AND THE PRICES ARE ALL OVER THE MAP. AND THE PHYSICAL SHAPES AND LIGHTING PATTERNS ARE ATROCIOUS.

IMHO.
RC

 

[Besoeker]

I have used LED indicator replacements as well. HOWEVER, the lumen output is quite low and so it the wattage. No comparison to a LED fixture for area lighting.

RC

I've already pointed out that our kitchen has enclosed fixtiures. And no failures.

 

[JFletcher]

We are having more and more customers ask for complete LED fixtures. The HPS/MH/Mercury ones they are replacing are frequently old, with damaged glass, globes, corroded, etc. We did 3 streetlights at a commercial job today; just 3 bulbs. But the plastic globes are melted thru on the top. Crap design long past its prime. I wont miss changing those boat anchor ballasts either.

We do not recommend drop in replacements that run off the original ballasts as they are probably past their prime, and a second service call a year or three down the road is going to cost way more than rewiring and converting to line voltage when the LED is installed, especially if we have to rent a bucket truck or do other high work.

 

[romex jockey]

We've done one retrofit after another, usually based on some entities 'ROI math'

Out of sheer curiousity, i've retro'd my entire farm ,over time of course.

Quite frankly some of us have lived through T12 to T8's to T5's to HID's to LED's ,along with the same repackaged market hyperbole.

It all makes me wonder what the next market shtick will be....

~RJ~

 

[JFletcher]

We've done one retrofit after another, usually based on some entities 'ROI math'

Out of sheer curiousity, i've retro'd my entire farm ,over time of course.

Quite frankly some of us have lived through T12 to T8's to T5's to HID's to LED's ,along with the same repackaged market hyperbole.

It all makes me wonder what the next market shtick will be....

~RJ~

I actually have love for the old T12 ballasts, many of which have lived longer than I. But 45 years ago, parts were cheap, well made, and labor was next to nothing (in modern terms). T5s, I know they are efficient, but they are also junk. Every time I remove one I'm convinced that thin, small diameter bulb is going to bust sending shards of razor glass thru my gloved hand. Im sure if they had the build quality of the old T12s, ballasts might last 75 years; bulbs a good 10.

HID, like G4 base? Those things will be legacy equipment before I hit 50.

I'd bet serious money that LEDs are here to stay, even tho there is supposedly research on incandescents that makes them as efficient as current LEDs... to me, it's like trying to replicate dinosaurs. LCD might be the next thing, or cameras that project surroundings (read: invisibility), but for now, LEDs are it.

 

[kwired]

I actually have love for the old T12 ballasts, many of which have lived longer than I. But 45 years ago, parts were cheap, well made, and labor was next to nothing (in modern terms). T5s, I know they are efficient, but they are also junk. Every time I remove one I'm convinced that thin, small diameter bulb is going to bust sending shards of razor glass thru my gloved hand. Im sure if they had the build quality of the old T12s, ballasts might last 75 years; bulbs a good 10.

HID, like G4 base? Those things will be legacy equipment before I hit 50.

I'd bet serious money that LEDs are here to stay, even tho there is supposedly research on incandescents that makes them as efficient as current LEDs... to me, it's like trying to replicate dinosaurs. LCD might be the next thing, or cameras that project surroundings (read: invisibility), but for now, LEDs are it.

Seemed like the tail end of production years of the T12 magnetic ballasts weren't making that great of products. I had replaced many newer ballasts in a two ballast fixture while the second ballast in there was still the original.

 

[Electric-Light]

Hugely less energy is consumed by a LED bulb than an incandescent.
But it's a portion of a much smaller amount.

Concerning cooling, we can ignore lumens. We just have to look at how much of the input power is not radiated.

Given a covered mug full of water at 100C at room temperature of 40C, the drop in temperature in degrees C per minute gets lower and lower.
If you submerge a 20W heater inside the mug with an ambient temperature of 40C, it will get to some point above 40C and stabilize.

Let's say size A gets you to reach +40C above, or 80C. If you want it to change it to stabilize at +10 above or 50C you'll need to make the mug a lot bigger.

Given the same wattage dissipation, you have a fairly constant x + y rise where x is the ambient and y is the rise, but x+y can't be more than the upper limit.

The difficulty with LED and other electronic devices is that the upper limit is quite low and the ambient temperature for high bay fixture should be designed for 55C. Electronic ballasts are limited to 90C case temperature while coil & core ballast can handle 150C or so. This is why you seldom find 1,000W HID electronic ballast for high bay use. You need a fan or a whale sized heat sink.

Higher power switch mode power converters like pot growers' 1,000w ballast and computer power units have a fan, because you can't just let them get up to the same temperature as a core and coil ballast without frying.

Commercially feasible LED solid state fluorescent lamps use plastic optics in direct contact with the chip. Phosphor mixture and plastic lens can degrade faster at high temperature unlike glass.

http://forums.mikeholt.com/showthread.php?t=167281

This source estimates only 12% is removed by conduction and convection or only 12W by action of air movement around the bulb.
http://www.posterus.sk/?p=9400

An A19 bulb has quite a bit of surface area and the bulb can spread the heat evenly across the entire envelope.
AND it can run the envelope over 150C allowing it shed off heat as long wave IR radiation. So, a 100W bulb makes maybe 5W in visible light, 83W radiated away and 12W "heatsunk" and that's while running at 150C.

So, it's quite a struggle to get rid of 12W of localized heat.

This is the basis for figuring out how much heat must be conducted away rather than radiated away.

A coffee mug at 180F surface temperature can reject about twice the heat compared to a 130F surface temperature

With the greatest respect, that's a bit of a silly analogy. I'm comparing one bulb with another. Not a swimming pool with a car park puddle.

It is actually like that. With the exception of some new exotic LED filament tower bulbs that operate in a helium atmosphere (cost about $12-15). Helium has much better thermal properties and carry heat to glass bulb by convection and use the entire glass bulb as a heat sink.

Normal screw-in LEDs have minimal area available for non transparent sections. The popular LED trim installs like a retrofit, but the decorative brim is not decorative. I would call those 75% of a compete fixture given that all the optics, ballast and cooling are built into the lamp.

I can cover the illuminated LED bulb with my hand an feel little heat. I would advise against trying that with an incandescent.

Not so for A21 CREE 18W SSFL. The heat sink fin can actually get hot enough to sizzle if you splash water on it. The thermal resistance between LED elements and the heat sink is good enough that the temperature difference between the two points are low enough allowing the heat sink to run that hot. Make that thing run at two watts and you can manage to keep the whole thing cool to the touch.

We have been using LEDs on PCBs since before the Dead Sea reported in sick. Of the many thousands fitted we have not had a single failure. Not one. And have never used heatsinks on them.

Those things run at 5-10mA at 2-3v or about a few hundredth the power of a current lighting LED. Also, white LEDs of that design degrade very rapidly and not practical for lighting applications. Some of the earliest LED bulbs sold were a bunch of them gobbled up together into a tower.

When three people huddle up in a blizzard, you have triple the heat output, but perhaps 1.5 people's worth of surface area which cuts down the heat loss of each person to half. Same thing happens with electronic devices.

But my Q is, why do LED dimmers have a completely different rating ? One would think a watt is a watt is a watt....?
~RJ~

http://www.lrc.rpi.edu/programs/solidstate/assist/pdf/assist-TechNote-Dimming-InrushCurrent.pdf

Forward phase controls power duration by dropping the clutch against a moving power source. Reverse phase control couples while stopped, then chooses when to decouple. It stops and starts 120 times a second, but slow it down a couple tens of thousands of times and you can see the idea.
The singing from bulb is caused by the abrupt current rise. The capacitive input of LED ballasts grabs even harder.

If you had a carbon fibre propeller and brass propeller of the exact same shape, you can see that the stress on drive train is much harder with the brass propeller when you drop the clutch even though they'll draw the exact same shaft horsepower at full speed.

 

[iwire]

Concerning cooling, we can ignore lumens. We just have to look at how much of the input power is not radiated.

Wow, what a wall of text and it can be answered simply.

The LED fixtures I am putting in take about 1/3 the current of the fixtures they replace and the customers feel they are brighter.

End of story.

 

[Besoeker]

Concerning cooling, we can ignore lumens. We just have to look at how much of the input power is not radiated.

Given a covered mug full of water at 100C at room temperature of 40C, the drop in temperature in degrees C per minute gets lower and lower.
If you submerge a 20W heater inside the mug with an ambient temperature of 40C, it will get to some point above 40C and stabilize.

Let's say size A gets you to reach +40C above, or 80C. If you want it to change it to stabilize at +10 above or 50C you'll need to make the mug a lot bigger.

Given the same wattage dissipation, you have a fairly constant x + y rise where x is the ambient and y is the rise, but x+y can't be more than the upper limit.

The difficulty with LED and other electronic devices is that the upper limit is quite low and the ambient temperature for high bay fixture should be designed for 55C. Electronic ballasts are limited to 90C case temperature while coil & core ballast can handle 150C or so. This is why you seldom find 1,000W HID electronic ballast for high bay use. You need a fan or a whale sized heat sink.

Higher power switch mode power converters like pot growers' 1,000w ballast and computer power units have a fan, because you can't just let them get up to the same temperature as a core and coil ballast without frying.

Commercially feasible LED solid state fluorescent lamps use plastic optics in direct contact with the chip. Phosphor mixture and plastic lens can degrade faster at high temperature unlike glass.

http://forums.mikeholt.com/showthread.php?t=167281

This source estimates only 12% is removed by conduction and convection or only 12W by action of air movement around the bulb.
http://www.posterus.sk/?p=9400

An A19 bulb has quite a bit of surface area and the bulb can spread the heat evenly across the entire envelope.
AND it can run the envelope over 150C allowing it shed off heat as long wave IR radiation. So, a 100W bulb makes maybe 5W in visible light, 83W radiated away and 12W "heatsunk" and that's while running at 150C.

So, it's quite a struggle to get rid of 12W of localized heat.

This is the basis for figuring out how much heat must be conducted away rather than radiated away.

A coffee mug at 180F surface temperature can reject about twice the heat compared to a 130F surface temperature



It is actually like that. With the exception of some new exotic LED filament tower bulbs that operate in a helium atmosphere (cost about $12-15). Helium has much better thermal properties and carry heat to glass bulb by convection and use the entire glass bulb as a heat sink.

Normal screw-in LEDs have minimal area available for non transparent sections. The popular LED trim installs like a retrofit, but the decorative brim is not decorative. I would call those 75% of a compete fixture given that all the optics, ballast and cooling are built into the lamp.


Not so for A21 CREE 18W SSFL. The heat sink fin can actually get hot enough to sizzle if you splash water on it. The thermal resistance between LED elements and the heat sink is good enough that the temperature difference between the two points are low enough allowing the heat sink to run that hot. Make that thing run at two watts and you can manage to keep the whole thing cool to the touch.



Those things run at 5-10mA at 2-3v or about a few hundredth the power of a current lighting LED. Also, white LEDs of that design degrade very rapidly and not practical for lighting applications. Some of the earliest LED bulbs sold were a bunch of them gobbled up together into a tower.

When three people huddle up in a blizzard, you have triple the heat output, but perhaps 1.5 people's worth of surface area which cuts down the heat loss of each person to half. Same thing happens with electronic devices.


http://www.lrc.rpi.edu/programs/solidstate/assist/pdf/assist-TechNote-Dimming-InrushCurrent.pdf

Forward phase controls power duration by dropping the clutch against a moving power source. Reverse phase control couples while stopped, then chooses when to decouple. It stops and starts 120 times a second, but slow it down a couple tens of thousands of times and you can see the idea.
The singing from bulb is caused by the abrupt current rise. The capacitive input of LED ballasts grabs even harder.

If you had a carbon fibre propeller and brass propeller of the exact s
ame shape, you can see that the stress on drive train is much harder with the brass propeller when you drop the clutch even though they'll draw the exact same shaft horsepower at full speed.

I understand the exponential drop off in temperature of your mug of water. And having been a designer of power electronics for about half a century, I think I might reasonably claim to know something about how heatsinks work. So, I'm not quite sure what you are trying to tell me or teach me.

For me, the advantages of LEDs compared to incandescents are fairly simple.

They run cooler.
Use far less energy.
Have hugely longer life expectancy.

 

[Electric-Light]

I understand the exponential drop off in temperature of your mug of water. And having been a designer of power electronics for about half a century, I think I might reasonably claim to know something about how heatsinks work. So, I'm not quite sure what you are trying to tell me or teach me.

For me, the advantages of LEDs compared to incandescents are fairly simple.

You STRUGGLED with grasping the concept of power density as you did not understand why dissipating 12W in the shape of a A19 standard light bulb shape WHILE keeping the LED junctions and LED ballast within their long lasting temperature limit in a lighting environment is a huge challenge.

They run cooler.

And you still don't and you didn't understand how a 1,000w water bed is "cool running". Those that run cool have a huge sq.in/watt ratio!
You should know that Tj on those 5mm LEDs running at 20mA is quite scorching hot even though you can't feel it thanks to the package's huge thermal resistance.

 

[kwired]

I understand the exponential drop off in temperature of your mug of water. And having been a designer of power electronics for about half a century, I think I might reasonably claim to know something about how heatsinks work. So, I'm not quite sure what you are trying to tell me or teach me.

For me, the advantages of LEDs compared to incandescents are fairly simple.

They run cooler.
Use far less energy.
Have hugely longer life expectancy.

If you build a VFD and design it to operate in a 100 degF ambient, doesn't using it in a 140 degF ambient potentially shorten it's life, or at very least allow for other operational issues like thermal protective devices causing intermittent operation?

An LED replacement lamp not designed for an enclosed luminaire will have more difficulty operating at/below it's maximum design temp if operating in an enclosed luminaire, now if it is inside a cooler/freezer that may help some.

 

[electricguy61]

We are having more and more customers ask for complete LED fixtures. The HPS/MH/Mercury ones they are replacing are frequently old, with damaged glass, globes, corroded, etc. We did 3 streetlights at a commercial job today; just 3 bulbs. But the plastic globes are melted thru on the top. Crap design long past its prime. I wont miss changing those boat anchor ballasts either.

We do not recommend drop in replacements that run off the original ballasts as they are probably past their prime, and a second service call a year or three down the road is going to cost way more than rewiring and converting to line voltage when the LED is installed, especially if we have to rent a bucket truck or do other high work.

I just quoted a parking lot job; here are my comments to the customer:

Per our phone discussion and my visit to the site, here two options for repair/replacement of the parking lot lighting at the above address:

1. Install LED retrofit kits in (58) pole light fixtures (LED Trail model PH49150 LTR Retro Kit)

60 month manufacturers warranty. No labor warranty due to the age of the fixtures. Not responsible for damage to old fixtures

My issue with the above option is that we would be putting new parts into an aluminum fixture that is @ 25 years old. The lenses are in poor condition, which blocks a significant amount of light. Many are already broken. The aluminum degrades, especially over 25 years, becoming extremely brittle. When we open them up, many may just fall apart. My analogy: putting a new engine into a 1991 Dodge Colt. It’s certainly the cheaper alternative, but does it make economic sense in the long run?

Customer is going with new fixtures

 

[Besoeker]

Wow, what a wall of text and it can be answered simply.

The LED fixtures I am putting in take about 1/3 the current of the fixtures they replace and the customers feel they are brighter.

End of story.

Different colour spectrum. Street lighting where I live used to be high pressure sodium vapor. These give out a yellowish light. When they come to the end of their life, they are being replaced by LED street lights. These look about the colour of a shining moon. Very white. They are also more directional, downwards, so there is less scattering of the light so lower levels of light pollution.

 

[Electric-Light]

LED Trail model PH49150 LTR Retro Kit)

ugh. You might as well buy some stuff from the Home Depot. Energy sales retrofit fit have a lot of smaller sales reps working on substantial commission meaning that things have to be extra super duper cheap to cover those costs in addition to profit for the company. I googled this company and it looks pretty obvious to me that they're just yet another import-reseller and the spec sheet is ambiguous, classic Alibaba stuff.
It is the functional equivalent of an outdoor light sold at the Home Depot claimed around the pole and abandoning the existing head and powering it with an extension cord. There's a reason HID luminaires come in so many different models and SKUs for the same wattage. They are supposed to be used as a part of an engineered solution. Not a shower head peppered with LEDs and voila, retrofit.

The problem is that the vendor is a four year old start-up like a lot of other Energy Service Retrofit sector. Who says they'll even be around a few years later?

The bar has been lowered quite a bit in this LED days. I've reviewed the lab reports for Philips T8 LED bulb. The testing was done in China. I've seen some errors and model to model lab procedure inconsistencies and numbers that don't quite add up right in those reports.

So, what about the actual LED fixtures you have in mind rather than the retrofit?

 

[Besoeker]

If you build a VFD and design it to operate in a 100 degF ambient, doesn't using it in a 140 degF ambient potentially shorten it's life, or at very least allow for other operational issues like thermal protective devices causing intermittent operation?

Yes unless you derate it.

An LED replacement lamp not designed for an enclosed luminaire will have more difficulty operating at/below it's maximum design temp if operating in an enclosed luminaire, now if it is inside a cooler/freezer that may help some.

We are using LED replacement lamps in our kitchen luminaires which are totally enclosed. Thousands of hours of operation. No failures.
We have LED table lamps in our lounge. They run very cool.