Bulb life not in hours, but y.m.d before bin.

oldwiring

ISTM that estimates of bulb life in any case are wide, one site saying 750 to 2000 hours. I guess this is based on the pattern of use, so would take a mid point average.

BUT what is 1000 hours life? How many hours per day is the supposed use of a domestic bulb? Then one could guesstimate a reasonable life in y.m.d.

How do any of you convert bulb life to y.m.d?

JohnB47

oldwiring wrote: »

ISTM that estimates of bulb life in any case are wide, one site saying 750 to 2000 hours. I guess this is based on the pattern of use, so would take a mid point average.

BUT what is 1000 hours life? How many hours per day is the supposed use of a domestic bulb? Then one could guesstimate a reasonable life in y.m.d.

How do any of you convert bulb life to y.m.d?

How long is a piece of string?

You need to estimate how long you have a particular light on in any 24 hours, then you can produce your own guess as to how long a bulb will last.

But then, this will be based on the manufacturers claimed life and this is an estimate too, so you are double guessing.

Not a fruitful exercise.

elsien

I have one bulb that is going strong since I moved in 20 years ago because it only gets turned on every couple of months. Others have been changed multiple times since then. Life is too short to worry about vague averages.

MWT

oldwiring wrote: »

How do any of you convert bulb life to y.m.d?

I don't.


... but if you are working with 750-2000 hours that sounds a lot like incandescent bulbs so certainly not worth trying to estimate the lifespan of those.


We replaced all our incandescent bulbs more than 10 years ago, initially with CFL.


About 1/3 of those had to be replaced over the last 10 years or so and more recently the replacements have been LED.


We proactively removed the surviving CFL bulbs a couple of months ago, along with 10 halogen bulbs that just wouldn't die, and replaced them all with LED..


The halogens have been in use as the main lighting in our lounge for over 20 years without a single failure, but they just use too much energy so they had to go.

Gerry1

Unless used with an open fitting or shade (e.g. a table lamp) LED GLS type bulbs won't reach anything approaching their claimed lifetimes.

Use them cap upwards and you'll reduce their lifetime by a factor of about five. Use them in a closed or semi-enclosed fitting and there's another five-fold reduction, so they may not even outlast a conventional incandescent bulb. The Osram 1521 lm bulb (11W = 100W) is especially unreliable.


The good news is that the falling prices of LED bulbs means that they're still cost effective even if they don't last longer.

oldwiring

Thanks all, even those critical.:)