Energy efficiency of these bulbs?

[Jupiter01]

My folk have a number of light fitting in the house that have these bulbs. Some of the lights take 3 bulbs. They thought these were the energy efficient LEDs but I’m not too sure.

Can you please advise on whether these are energy efficient or should I replace with something else.

I think they are an eBay special!

 

[winston1]

It is a compact florescent. Generally about 5 times more efficient than traditional filament light bulbs so would be classed as energy efficient. LED may be slightly better but you will not recoup the cost over its life. So don’t bother to replace until it fails.

 

[ericmark]

The compact fluorescent was no where near as efficient as the straight tube, however the LED also varies a lot, I have two boxes for smart GU10 bulbs on my desk, one 5.5 watt with 345 lumen, the other 5 watt with 500 lumen, odd the latter is colour changing so would have expected to have been the worst of two.

But the first one at 63 lumen per watt is likely worse than the compact fluorescent. I have a 7 watt GU10 compact fluorescent but no lumen marked on the bulb. Have found advert for 9 watt CFL GU10 with 200 lumen which is very poor at 23 lumen per watt, so clearly not good but the quartz version 50 watt at 500 lumen down to 10 lumen per watt, I have kept to GU10 so you can compare.

The problem with fluorescent is over time the output falls off, the one GU10 CFL still works, but more like a toc H candle. But as to if worth replacing, hard to say, we had some really poor Philips E14 golf ball CFL 8 watt each, now replaced with 5 watt LED, but although now room is brighter, saving between 5 and 8 watt is not very much, and the life of a bulb seems to be so variable it is impossible to calculate costs.

Looking at adverts 5.5 watt LED = 9 watt CFL approx. Hardly worth worrying about.

 

[big-all]

just put the leds in the most used fittings to get the maximum value
i still have 2 100w bulbs in my attic as i only ever go up there for perhaps 5 mins a year

 

[RandomGrinch]

i still have 2 100w bulbs in my attic as i only ever go up there for perhaps 5 mins a year

....but imagine if you forgot to turn the light off before you closed the hatch - your annual loft visit could have cost you nearly £500 at today's costs!

 

[Jupiter01]

Is the mA reading significant?
My research suggests that modern LED bulbs are much lower in the mA they draw.

 

[big-all]

....but imagine if you forgot to turn the light off before you closed the hatch - your annual loft visit could have cost you nearly £500 at today's costs!

indeed but i read my meter every week and at 4 units a week i would notice the extra 34 units

 

[davelx]

Is the mA reading significant?
My research suggests that modern LED bulbs are much lower in the mA they draw.

mA is a unit of current - 1/1000 of an Amp.
Voltage (Volts) * Current (Amps) = Power (Watts)

 

[winston1]

....but imagine if you forgot to turn the light off before you closed the hatch - your annual loft visit could have cost you nearly £500 at today's costs!

err, no. The bulbs would fail after around 1000 hours or six weeks leaving the costs at around £50. Still worth remembering to turn the light off though. LED equivalents say 2 by 10watts would also cost around £50 over a year 24/7.

 

[RandomGrinch]

err, no. The bulbs would fail after around 1000 hours or six weeks leaving the costs at around £50. Still worth remembering to turn the light off though. LED equivalents say 2 by 10watts would also cost around £50 over a year 24/7.

Yes, I was being facetious - and big-all hadn't stated they were incandescent bulbs!
Although interestingly, long life incandescent seem to have been popular in the US, with claimed lifespan of up to 20'000 hours!

 

[bernardgreen]

Although interestingly, long life incandescent seem to have been popular in the US, with claimed lifespan of up to 20'000 hours!

this is apparently the longest living lamp

Centennial Light - Wikipedia

en.wikipedia.org

 

[flameport]

Is the mA reading significant?

Up to a point - less mA is less power (watts). However there is the issue of power factor, so it's not necessarily a direct conversion.

In terms of power:
Compact fluorescents typically 20% of an incandescent
LEDs typically 50% of a compact fluorescent, or 10% of an incandescent.
100W incandescent = 20W CFL = 10W LED.

LED and incandescent are full brightness immediately.
CFL take anywhere from one to several minutes to reach full brightness, and are therefore not suitable for applications where they are only used intermittently for short periods.

 

[winston1]

mA is a unit of current - 1/1000 of an Amp.
Voltage (Volts) * Current (Amps) = Power (Watts)

Bit more to it than that. There is something called power factor which has values between zero and one.
Volts x amps x power factor = watts. Power factor for lamps is never quoted but old CFLs and some LEDs are quite low.

Edit Flameport beat me to it.

 

[davelx]

Yes, I know. I also knew someone would pop up and mention it. But I didn't want to make it too complex

An electricity meter measures true power, so it is the wattage that you should be comparing when comparing lamps' power consumption, rather than the current, and there is also the efficiency and optics to consider. Even for lamps of the same wattage the effective or perceived level of illumination will vary depending on a number of other factors.

 

[Munroast]

err, no. The bulbs would fail after around 1000 hours or six weeks leaving the costs at around £50. Still worth remembering to turn the light off though. LED equivalents say 2 by 10watts would also cost around £50 over a year 24/7.

A permanently on incandescent - without the considerable heating up / cooling down it would not surprise me if they lasted a good few years permanently on.