Heat in the wrong place (which you get with lighting) is wasted, particularly since you are paying 3p for heat for each 1p of light.
And heat in the summer (which you also get with lighting) is also wasted
You are now talking about a derivative of a derivative.
Take a few drops from the teaspoon that you filled from the bucket.
Irrelevant. During the summer months much less on-time for lighting is needed because the sun helps out with longer daylight hours. During the winter, the heat is wanted anyway
On Tue, 13 Nov 2007 08:21:24 +0000 someone who may be Andy Hall wrote this:-
Fascinating.
To buy. They cost a lot to run though.
Ah, a swerve. A little while ago the claim was of energy savings lamps being sold on their "alleged" money savings.
Anyway information on the expected lifetime of GLS lamps is written on the sales material in much the same way as it is on energy saving lamps.
Only the negligible amount which passes through the ceiling and floor and only then where the arrangement you specify is in use. The amount of heat getting through the floorboards and carpet in such an upstairs room is I imagine difficult to measure and makes little if any difference to heating of that room.
On Tue, 13 Nov 2007 15:02:30 +0000 someone who may be John Rumm wrote this:-
I suspect many people on this group will have experience of how far the heating effect of a GLS lamp extends. It isn't very far.
On Tue, 13 Nov 2007 09:23:39 +0000 someone who may be Terry Fields wrote this:-
The usual suspects may accuse you of lying for saying something so at variance with their assertions.
I wouldn't say that. It starts more quickly, reaches full output a lot more quickly and is less bulky/heavy. It is too early to see how well it will last, but I have some more modern ones which are now something like 15 years old and still working fine.
On Tue, 13 Nov 2007 09:07:54 +0000 someone who may be Mike Barnes wrote this:-
How many GLS bulbs do you think would have failed over that time, assuming you can recall a more accurate period than "seemed like about once a week" and GLS bulbs now are as robust as they were then?
A few years ago stayed in a holiday cottage where the kitchen had reflector bulbs in downlighters for general lighting. Dreadful, but presumably it looked pretty. On the first day I replaced the lamps which had failed, so they were all working. Within a few days one more had failed so I replaced it. Near the end of the week I replaced some more which had failed. At the end of the week I couldn't be bothered to replace any more. These lamps had failed, not become unscrewed due to heating/cooling cycles.
My experience is that GLS-replacement CFLs generally last pretty well, though when one does go and I replace it I realise how dim and slow to warm up it had become. However the GU10s I've tried have been pretty awful: very slow warm up and short lives. They've been ones I initially bought from Toolstation and some from Maplin, both with a narrow cylindrical neck widening out abruptly to a wider housing for the tube. I'm now onto a couple of Toolstation's current supply, which have a more gradual conical flare from the base to the business end (which have required me to remove decorative skirts off the fitting which was designed for halogens). They've only been in a few weeks so lifetime remains to be seen.
Roll on metal halides or some technology which really gives us light that's not a by-product of an electric heating element, but that hopefully doesn't have to contain toxic stuff like Hg.
Aesthetically I prefer the light from most CFLs, and like having light fittings that don't get cooked in use.
'Largely wasted' would perhaps be more accurate since heating up ceilings isn't particularly useful and in top floor installations where the heat escapes into the unheated roofspace it is almost entirely wasted.
I can't tell you with any more accuracy than I already have done ("seemed like about once a week"). I do know that bulb replacement was a continual PITA, and it's that that prompted me to change over to CFLs, at least as much as it was for saving money or energy.
It might be that I had a lot of duff GLS bulbs; there might be something screwy about the mains here; etc. I don't speculate about the reasons for the difference in failure rate before the change to CFLs and after, but there is no doubt that the difference was dramatic.
The CFLs haven't been without their little problems, but on the other hand I've never once thought that the change might have been a mistake.
I find it uncomfortable on the hairless bit on the top of my bonce.
Seems the concept of lumen depreciation has quite passed you by....
Adam
The heat from ground floor lights will find its way to the first floor where it is gainfully employed - it doesn't evaporate. Heat from first floor lamps really doesn't matter because in most households the downstairs ones are used considerably more.
The discussion either way is about a few tens of watts. In the meantime one can make a difference of high hundreds of watts or even kilowatts through the walls.
The energy saving from a few bilious lightbulbs just isn't worth having.
Do you have pointed ears?
Tungsten lamps last for a period and at a certain point fail. They are replaceable for pence, not pounds
No they don't. If you consider the context, the issue is a drop in the bucket.
Irrelevant. Both claims are untrue.
Except that people don't care about GLS bulb lifetime because the replacement cost is bugger all. They can simply enjoy the quality of the light
If the amount involved is little, it's because the amount emitted is also little. The heat doesn't disappear into thin air.
Where does this heat go, if it doesn't go into the room above or the room below?
Andy
On Wed, 14 Nov 2007 16:50:36 -0000 someone who may be Adam Aglionby wrote this:-
On Wed, 14 Nov 2007 09:43:49 +0000 someone who may be Mike Barnes wrote this:-
That was one of the reasons for their wide introduction in commercial buildings. Lamp replacement is expensive and the cost of the lamp is a relatively small part of the total cost, no matter whether it is a GLS or CFL.
On Wed, 14 Nov 2007 08:40:43 GMT someone who may be John Stumbles wrote this:-
I suspect it is the size. I avoid the things, but I do now have an SES reflector CFL which is of similar size, so time will tell. According to the usual suspects it should have died by now, it is about six months old, but it is still working.
You didn't warn the usual suspects to cover their ears:-) They may never recover from this statement.
years ago if the now current light level is sufficient ;-)
Adam
I never did get to like the light from GLS lamps, too yellow. I much preferred the gas mantles. I have used CFLs almost exclusively for nigh on 20 years. I would prefer a higher colour temperature to the almost ubiquitous
2700K version, 3500, at least, which is what I use in the kitchen (2Ds).
Correct. It is indeed less of a problem.
1) They are not promoted on the basis of their alleged lifetime. CFL's are. Filament lamps with a longer life than GLS (General Lighting Service) are available but I don't know anyone who's ever bought one. 2) A 60w GLS lamp is 16p from Tesco. It must be possible to better that price.All the heat has to go somewhere, the temperature will increase until a steady state equilibrium exists. A lot of it heats the floor above, a useful contribution to reducing condensation / dampness in bedrooms ceiling voids and roofspaces enabling the contribution from other forms of heating to be reduced.
DG
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