ASDA 100 watt daylight bulbs

sweetgirl2015

thevilla said:

I've had mixed results from supermarket bulbs.  Early failures.  Never had issues from ledhut and I have bulbs from their website which are over 6 years old and working fine.
I have no connection to ledhut.

Did you have any LED bulbs that has ever failed? They say on the box their guaranteed to work 15 years. Not sure how they know because imagine a bulb left on for 15 years? 

vacheron

sweetgirl2015 said:

thevilla said:

I've had mixed results from supermarket bulbs.  Early failures.  Never had issues from ledhut and I have bulbs from their website which are over 6 years old and working fine.
I have no connection to ledhut.

Did you have any LED bulbs that has ever failed? They say on the box their guaranteed to work 15 years. Not sure how they know because imagine a bulb left on for 15 years? 

I’ve had plenty of LED bulbs fail because they are built to a (low) price. Some have failed within 2 years, but the large majority have lasted 5 or more so far.

As a general rule LED’s are rated for about 100,000 hours of continuous operation when driven sympathetically. The manufacturer will have assumed an average number of hours per day and then extrapolated that to the (flawed)  conclusion that it “should” last 15 years.

[Deleted User]

• vacheron said:

As a general rule LED’s are rated for about 100,000 hours of continuous operation when driven sympathetically. The manufacturer will have assumed an average number of hours per day and then extrapolated that to the (flawed)  conclusion that it “should” last 15 years.

This is the interesting thing, an actual LED component itself in practice does last around 100,000 hours which is about 11 years continuous usage - we all know this because we have 10 year old appliances with little red LED power lights / clocks constantly on and they still work at 10 years plus, albeit with a reduced brightness as they age.

The problem is the application of the technology in domestic light bulbs is very different leading to much shorter lifespans - typically most bulbs now quote up to 15,000 hours which is about 2 years continuous usage or about 10 years at 4 hours per day.

The reasons for this short lifespan are:

1. The voltage convertors / regulators: The bulb needs to convert 240v AC into low voltage DC to run the LED, most appliances have lots of space for a well ventilated and large voltage convertor (eg TV's, laptops, white goods) but in a bulb they need to make it tiny to fit in the space available and they get pretty hot without any ventilation. The components in this convertor have a much shorter lifespan than the LED's themselves are most likely to fail before the LED's. Think capacitors failing in TV power supplies - some LED bulbs have them and they get very hot and fail.
   
   
2. The LED's are over-driven:  An LED can be given a range of voltages and currents to produce varying amounts of light. At the lower end, lifespan is enormous, at the upper brightness, lifespan is shorter. For example with a 1000 lumen bulb - manufacturer can choose 10 LED's run at full power or 20 LED's at half power. The 20 LED option will last much longer and cost more - see next point. 
   
   
3. No incentive from manufacturers for long life: As per the above point, a manufacturer can design the bulbs for longer life at a higher cost. They are doing themselves out of a future sale for a replacement bulb meanwhile cheapo manufacturers making short life bulbs are getting all the sales because some customers just buy the cheapest on the shelf and will keep doing it.

See the Phoebus Cartel for real life fixing of bulb lifespans: https://en.wikipedia.org/wiki/Phoebus_cartel

How do we get better at this?

1. Houses should have low voltage DC power say 24v run through to the light bulb circuits from one big and reliable power convertor that can do the job for the whole house and the individuals bulbs won't rely on tiny cheap power convertors.

2. Consumers understanding the lifetime costs of bulbs and making better choices when buying them. 

• Old incandescent bulbs (eg 100w) were about 50p to buy and used around £15 of electricity in their 1,000 hour lifespan. For a 15,000 hour life like an LED, it would cost 15x50p (£7.50) in bulbs and about £225 elec - total cost £232.50
  
  
• New LED's cost as little as £2 per bulb and at 15,000 hours life will use £30 of electricity so total cost is about £32 - saving £200 compared to incandescent.
  
  
• Spending a few extra quid to get a good quality of light and increased lifespan is well worth it especially when you will need to live with that choice for much longer. Especially given the environmental impact of throwing the plastic devices away.

vacheron

Deleted_User said:

• vacheron said:

As a general rule LED’s are rated for about 100,000 hours of continuous operation when driven sympathetically. The manufacturer will have assumed an average number of hours per day and then extrapolated that to the (flawed)  conclusion that it “should” last 15 years.

This is the interesting thing, an actual LED component itself in practice does last around 100,000 hours which is about 11 years continuous usage - we all know this because we have 10 year old appliances with little red LED power lights / clocks constantly on and they still work at 10 years plus, albeit with a reduced brightness as they age.

The problem is the application of the technology in domestic light bulbs is very different leading to much shorter lifespans - typically most bulbs now quote up to 15,000 hours which is about 2 years continuous usage or about 10 years at 4 hours per day.

The reasons for this short lifespan are:

1. The voltage convertors / regulators: The bulb needs to convert 240v AC into low voltage DC to run the LED, most appliances have lots of space for a well ventilated and large voltage convertor (eg TV's, laptops, white goods) but in a bulb they need to make it tiny to fit in the space available and they get pretty hot without any ventilation. The components in this convertor have a much shorter lifespan than the LED's themselves are most likely to fail before the LED's. Think capacitors failing in TV power supplies - some LED bulbs have them and they get very hot and fail.
   
   
2. The LED's are over-driven:  An LED can be given a range of voltages and currents to produce varying amounts of light. At the lower end, lifespan is enormous, at the upper brightness, lifespan is shorter. For example with a 1000 lumen bulb - manufacturer can choose 10 LED's run at full power or 20 LED's at half power. The 20 LED option will last much longer and cost more - see next point. 
   
   
3. No incentive from manufacturers for long life: As per the above point, a manufacturer can design the bulbs for longer life at a higher cost. They are doing themselves out of a future sale for a replacement bulb meanwhile cheapo manufacturers making short life bulbs are getting all the sales because some customers just buy the cheapest on the shelf and will keep doing it.

See the Phoebus Cartel for real life fixing of bulb lifespans: https://en.wikipedia.org/wiki/Phoebus_cartel

How do we get better at this?

1. Houses should have low voltage DC power say 24v run through to the light bulb circuits from one big and reliable power convertor that can do the job for the whole house and the individuals bulbs won't rely on tiny cheap power convertors.

2. Consumers understanding the lifetime costs of bulbs and making better choices when buying them. 

• Old incandescent bulbs (eg 100w) were about 50p to buy and used around £15 of electricity in their 1,000 hour lifespan. For a 15,000 hour life like an LED, it would cost 15x50p (£7.50) in bulbs and about £225 elec - total cost £232.50
  
  
• New LED's cost as little as £2 per bulb and at 15,000 hours life will use £30 of electricity so total cost is about £32 - saving £200 compared to incandescent.
  
  
• Spending a few extra quid to get a good quality of light and increased lifespan is well worth it especially when you will need to live with that choice for much longer. Especially given the environmental impact of throwing the plastic devices away.

Couldn't have put that better!

I completely agree about the benefits of a DC power socket. A decent (ideally redundant) switch mode supply in the loft putting out 24 or 48V would save the cost and inefficiency of having dozens and dozens of cheap, crude and unreliable  "wall wart" rectifiers with mediocre smoothing and load regulation in every bulb and plugged into most the AC electric sockets around the house, each putting out no more than 100-200mA. It would also hugely reduce e-waste and cost.

I seriously considered doing this when I moved in to my new house about 10 years ago, but there simply wasn't the equipment out there that could run from it to make it worthwhile.  

Assuming LED bulbs were used throughout the home, how many appliances (outside of the kitchen) in everyday use actually "need" 230V to the appliance any more?

fenwick458

Deleted_User said:

1. Houses should have low voltage DC power say 24v run through to the light bulb circuits from one big and reliable power convertor that can do the job for the whole house and the individuals bulbs won't rely on tiny cheap power convertors.

interesting thought. I don't disagree, it does sound plausible.
one problem I can see is it would mean a total rewire of the lights for most houses, the extra current would necessitate 1.5mm .
over the last 20 years in the UK at least we have moved to 1mm for lights, now in 2021 where almost every house uses all LED lighting the load on the circuit is probably below 1A, so it makes sense, and the majority of lighting fittings are designed for 1mm