replacing halogen lamps

Halogen lamps are inefficient for lighting, but I like the spotlight effect very much (especially the smaller ones). Is there any way to recreate that with more efficient types of lighting? I've doubts about it, at least for the small sizes.

Seb

Reply to
silicono2
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They are not inefficient at all.

It depends on your criteria and scale of values.

If you measure efficiency as being light out vs. electricity in then that may well be a factor.

If you measure it in terms of aesthetic benefit vs. cost employed then they are highly efficient.

Reply to
Andy Hall

On Wed, 23 Aug 2006 21:19:43 +0100 someone who may be Andy Hall wrote this:-

Yet you then go on to contradict this assertion.

Everything does.

In other words they are inefficient.

Beauty is indeed in the eye of the beholder, but that is nothing to do with efficiency.

Reply to
David Hansen

around 4% istr

No. The nearest one can get is to use lower power halogen downlighters/whatever and make up the difference with more discreet fl or cfl lighting. Power can drop to 1/2 to 1/3 this way, so it makes a fair difference.

Yes technically... there are other ways too.

NT

Reply to
meow2222

No I don't

No they aren't. It depends on your criteria for efficiency. If something is completely worthless because it doesn't meet the basic criteria of acceptability, then it is inefficient. It can't possibly ever achieve any greater status than that.

Nothing to do with beauty.

If something doesn't meet basic acceptability requirements, it is inefficient. To be precise, efficiency is zero.

Reply to
Andy Hall

At the moment, no. LEDs may in the future.

Reply to
Dave Plowman (News)

Yes I remember something--but so far the advice is that if you don't need light in a specific colour other than white (which LEDs do), other forms of lighting are more efficient. Well I guess related to a post I made ages ago--incandescent lighting is not completely inefficient in a heated building--some of the 'waste' heat is 'recycled' to heat the building.

Seb

Reply to
silicono2

On 23 Aug 2006 16:42:32 -0700 someone who may be snipped-for-privacy@yahoo.com wrote this:-

Only when heating is necessary. Even then it is a very expensive way of providing heat.

Reply to
David Hansen

|On 23 Aug 2006 16:42:32 -0700 someone who may be snipped-for-privacy@yahoo.com |wrote this:- | |>Well I guess related to a post I made ages ago--incandescent lighting |>is not completely inefficient in a heated building--some of the 'waste' |>heat is 'recycled' to heat the building. | |Only when heating is necessary. Even then it is a very expensive way |of providing heat.

For at least six to nine months each year, at least where I live 750 ft above sea level in Yorkshire.

Reply to
Dave Fawthrop

A couple of points:

Low voltage halogens are ~twice as efficient as mains voltage, so start there. Also Osram do a range of so called IRC bulbs which are more efficient again. As a guide to relative efficiency the best measure is lumens out per W of electricity. Things can get confusing with halogens as often the makers quote outputs in Candela not lumens. The problem is that Candelas is a brightness measurement not a light output so you can get a bigger number by making the light more focused, i.e. a 38degree flood will have less candelas than a 6degree spot although the total light output is the same. As a rough guide:

Mains halogen ~10 lumens/W Incandescent ~13 lumens/W Low voltage halogen ~20 lumens/W High efficiency low voltage halogen ~25 lumens/W Compact fluorescent ~40-60 lumens/W (depends on colour rendering properties) Tube fluorescent ~60-70 lumens/W (depends on colour again)

The colour of white light is measured in terms of a CRI (Colour Rendering Index) where 100 represents the colour of a pure tungsten filament. The CRI is a measure of the ability of a light source to accurately represent colour. For example sodium lamps have very high efficiency (approaching 200 lumens/W) but diabolical CRI which is why everything appears as shades of orange. Halogens have very good CRI so the colours of objects appear to be the same as in daylight. Fluorescents vary greatly depending on manufacturer, price and efficiency, generally better CRI means lower efficiency.

This makes halogens a good choice for kitchens and places where you want colours to be vibrant i.e. red peppers to be red rather than orange.

You shouldn't get CRI mixed up with colour temperature as this is something else entirely and describes what the light itself is like to look at rather than the colour properties of illumination by it. You can have two lamps with the same colour temperature but very different CRI. Colour temperature relates to the colour of light that would be emitted from an object at that temperature. So while we would generally desribe blue-ish white as being 'cool' in fact it has a higher colour temperature than say a candle which we would describe as 'warm'.

The terminology is on the whole bloody confusing, but anyway fit halogens, but just make sure they are low voltage not crappy mains ones, which have shorter bulb life as well.

Fash

Reply to
Fash

Clearly, inefficient was intended in its scientific sense, i.e. that of providing the maximum useful energy out for the minimum energy in.

But very environmentally unfriendly. Bulbs should immediately have a scale of taxes applied in relation to their energy efficiency rating. They are already rated A-G and it works well enough with cars. I would say no additional tax for Band A, rising to about 10 pounds a bulb for Band G.

Then all those wastrels who insist on needless polluting the environment just because they whine on about liking inefficient lightbulbs can at least pay more than proportionally extra for the priviledge of destroying the planet.

Christian.

Reply to
Christian McArdle

Very much not the case. A huge proportion of CO2 emissions are from vanity lightbulbs.

No. That would be proportional. I'm all in favour of making the charge disproportionate. This allows the measure to not affect those (including less wealthy people) who choose to use efficient methods, whilst providing a significant tax burden to those who wish to make a display of environmental destruction beyond that which is reasonable.

Christian.

Reply to
Christian McArdle

But they do anyway.

Through increased electricity bills.

The fact that electricity bills (here) are something like 1/10th of the oil bill needed to heat the place, shows that bulbs are not the biggest source of carbon dioxide pollution in the average house. The fact that the CFL's cost about ten times what the ordinary bulb does indicates SOMETHING about its energy of manufacture, too.

Reply to
The Natural Philosopher

I can assue you that you don't have the average house.

Energy of manufacture of bulbs is tiny compared with the energy they emit during their lifetimes, but you are right to indicate that this should always be included in any comparison. Although not affecting the bottom line in bulb comparisons, they because very significant in comparing electric and hybrid cars, which do not cut the mustard, IMO.

Christian.

Reply to
Christian McArdle

In the context of all the other uses of energy, a drop in the bucket.

That's already done, by implication, via VAT on the electricity used, if the energy use really is that significant.

Reply to
Andy Hall

Indeed I do not, but I do think before you sharpen that axe some more, you should at least do the sums on your own house.

Lighting is probably the least of my domestic expenditures of the electrical flavour. I would say that fridges and freezers run to more than that.

And the other 'permanently on' stuff is not insignificant either..PABX, router, printers, TV head amp, etc...

I do use CFLS where I can, more because they last longer though, and cost less to buy when amortized over the life span.

Well I won;t disagree there.

However I still think that the largest single places to tackle domestic energy expenditure are heating and the domestic car.

Here those two together can amount to a shatteringly high figure.

We simply don't drive when we can shop online...and try to modulate heating..which leads me to another post I am about to make.

Reply to
The Natural Philosopher

You would be surprised. When I first swapped all our incandescent bulbs for CFLs, in about 1996, I measured the electricity usage before and after. The electricity usage went down to 60% of its previous value. Therefore, we concluded that lighting was about 50% of our electrical usage. The gas bill was about the same as the electric, so I suspect, making a guess that gas provides more CO2 emissions than electricity on a cost basis), that wasteful lighting was emitting a good sixth of the house CO2 emissions. If everyone changed, that would be an extremely substantial benefit.

You should note that our house had no multiple halogen fittings or such like. Every room was lit by a single incandescent bulb in the middle. A halogen equiped house is likely to spend well over half the electricity bill on lighting. A fridge probably only draws about 100W over a continuous period. Little electronic devices probably only a couple of watts each. Nothing compared to lightbulbs, which are often continuously lit throughout the day, especially in winter.

Christian.

Reply to
Christian McArdle

And should be tackled also. I'm not one to pick and choose. However, lighting IS a very significant use of CO2. OK, the bulbs don't use as much as many appliances, but they are on for hours at a time. At least a third and possibly more than a half of electricty use in a house goes on lighting when using incandescent bulbs. When people have obscene halogen room lighting throughout, often in excess of 500W per room, lighting can absolutely dwarf the other electrical usages. Often these are the same houses that get so hot in summer from the lighting, that people insist on installing air conditioning to take away the heat!

There is no need for wasteful lighting as low energy alternatives exist. Therefore, punitive taxation should be applied for wasteful methods. I would like to see this principle consistently applied to all energy usage, where it can be practically applied and where low energy alternatives exist.

Christian.

Reply to
Christian McArdle

Hello,

At tp24 we don't yet have a low energy alternative for small halogen capsule lamps but there is a low energy downlight product available. It's designed to replace standard mains voltage 50w halogen downlights.

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technology involved in making CFL lamps is improving, and they are getting smaller, so other halogen replacements will become available in the future.

LED lamps might get there first. We don't think that they are suitable yet for 'whole room lighting' - there just isn't enough light.

Andrew tp24

Reply to
Andrew Davis

Figures?

It might be if it were unreasonable use of electricity, but it isn't. Other uses are far more significant.

Reply to
Andy Hall

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