A word about low-energy light bulbs.

mute_posting

iltisman wrote: »

I think we overlook why tungsten filament bulbs use more power, the energy is released as light and heat.In the UK it is fairly cool for 9 months and the heat given off from several tungsten bulbs is useful in warming the house.
I feel that operators of low energy bulbs will burn more energy in their heating systems.

Is not really the most efficient way to heat a room lol (from the top) - but, IMHO, it is a valid point - especially for people with with lots of downlighters and spots, they may well have to heat slightly more by other means.

However, I reckon for the average household they are still better of replacing the bulbs with something that fullfils it's primary function efficiently instead of performing 2 functions (very) innefficiently.

MP

iltisman

I think another solution to lighting is to have two seperate lighting systems in rooms
one producing a good light for working reading etc , and another using a couple of LEDs for basic illumination which would only use fractions of a watt.

geordie_joe

iltisman wrote: »

I think we overlook why tungsten filament bulbs use more power, the energy is released as light and heat.In the UK it is fairly cool for 9 months and the heat given off from several tungsten bulbs is useful in warming the house.
I feel that operators of low energy bulbs will burn more energy in their heating systems.

I too have "Never having sat round a 60 watt bulb", but I have tried to change quit a few just ofter they have popped, and I can tell you they get bl**dy hot!

iltisman wrote: »

I feel that operators of low energy bulbs will burn more energy in their heating systems.

I think you may have a point there. You may be right and you may be wrong, but I think it is definitely worth discussing.

Mikeyorks

0rsen wrote: »

These 60 Led types give of an extremely bright, pure white light.

Are they the same size / shape as the GU10, please?

My fittings have a glass cowl over the bulb and the GU10 is a really snug fit. Bought some Megaman ones a while back in a bid to reduce the OH's consumption in the kitchen (electricity .. not the cooking sherry). They were the only ones at the time that promised similar output to 50w. But the 'direct replacement for GU10' blurb ... kind of omitted they were 1" longer and much fatter at the base. Not a chance of getting them in the cowl. So I'd postponed looking for a while until the LED technology improved a bit.

But size matters in this case?

geordie_joe

0rsen wrote: »

but if you enter 60 led GU10 in ebay search, you should bring them up.

Does anyone want to post a guide to these bulbs?


Then sound interesting, but can I fit the in my ceiling light fittings?

I don't care how big they are, the day I look at my light bulbs and want the tom look pretty is the day I will lose the will to live.

But I would like to know if they will fit ordinary bayonet type fittings, and if they light the whole room and are not just spot lights.

I did a search on ebay as per another post, and came up with this.

• Material: High Quality Toughened Glass
• Colour: DAY WHITE (not blue colour)
• Specs: 60 super bright LEDs, 240v AC Suitable for use with recessed downlighters/uplighters.
• Fitting: GU10
• Output: = 30w Halogen
• Diameter: 50mm

What does Output: = 30w Halogen mean? Please don't say it means it gives off the same light as a 30w Halogen bulb, I don't have one of those to compare it too. I do have a Halogen heater, but that gives off more light than it does heat.

mute_posting

geordie_joe wrote: »

Does anyone want to post a guide to these bulbs?


Then sound interesting, but can I fit the in my ceiling light fittings?

I don't care how big they are, the day I look at my light bulbs and want the tom look pretty is the day I will lose the will to live.

But I would like to know if they will fit ordinary bayonet type fittings, and if they light the whole room and are not just spot lights.

I did a search on ebay as per another post, and came up with this.

• Material: High Quality Toughened Glass
• Colour: DAY WHITE (not blue colour)
• Specs: 60 super bright LEDs, 240v AC Suitable for use with recessed downlighters/uplighters.
• Fitting: GU10
• Output: = 30w Halogen
• Diameter: 50mm

What does Output: = 30w Halogen mean? Please don't say it means it gives off the same light as a 30w Halogen bulb, I don't have one of those to compare it too. I do have a Halogen heater, but that gives off more light than it does heat.

http://www.lightbulbs-direct.com/article_view.asp?ArticleID=10

may help with the 30w part, basically a 60w halogen gives out about the same light as a 75w tungsten

gu10 is a mains halogen type fitting.

http://www.lightbulbs-direct.com/article_view.asp?ArticleID=12

will help identify the different bases

I would imagine your ceiling lights are Bayonet Cap (BC) or Eddison Screw (ES) types.

MP

geordie_joe

Thanks MP, that's a big help.

0rsen

Mikeyorks wrote: »

Are they the same size / shape as the GU10, please?

My fittings have a glass cowl over the bulb and the GU10 is a really snug fit. Bought some Megaman ones a while back in a bid to reduce the OH's consumption in the kitchen (electricity .. not the cooking sherry). They were the only ones at the time that promised similar output to 50w. But the 'direct replacement for GU10' blurb ... kind of omitted they were 1" longer and much fatter at the base. Not a chance of getting them in the cowl. So I'd postponed looking for a while until the LED technology improved a bit.

But size matters in this case?

The bulb dimensions are the same as the halogen fittings. They are certainly no larger.

mech_2

iltisman wrote: »

I think we overlook why tungsten filament bulbs use more power, the energy is released as light and heat.In the UK it is fairly cool for 9 months and the heat given off from several tungsten bulbs is useful in warming the house.
I feel that operators of low energy bulbs will burn more energy in their heating systems.

If you use electricity to heat your home, that would be true. You would only save money for 25% of the year.


If you heat your home with gas it gets much more complicated:

Let's assume a 20 watt compact fluorescent bulb is equivalent to a 60 watt incandescent bulb. The saving from 60 watts to 20 is 67%. For 3 months of the year we assume the house doesn't need heating, so 25% of 67% is a saving straight away. That's 16.75%.

For the other 75% of the year, the electricity turned into waste heat by the 60 watt bulb would help heat the house. Lets assume gas costs 2.7p per unit and is burnt in a 65% efficient boiler. That means each kWh of useful heat energy from gas is actually 4.15p due to the boiler being inefficient. Lets use an electricity cost of 9.5p per unit for comparison. 4.15p is about 43.7% of 9.5p, so it's 56.3% cheaper to heat the house with gas rather than the waste electricity. So 56.3% of our 67% electricity saving is a real cost saving, making 37.7%.

So for the whole 12 months of the year it's 75% of 37.7% plus the 16.75% from earlier. A total saving of 45%. Phew.

Of course, with a 90% efficient boiler the saving is greater.

Ben84

Lighting seems to be getting less and less efficient. Not so many years ago a house would have a single bulb hung in the middle of each room (perhaps two in a big room) and a few table lamps in sitting rooms and bedrooms. You wouldn't normally use the ceiling light and table lamps at the same time, so one or two bulbs lit the entire room. Lighting the whole room would consume around 60w-200w maximum. Now everyone wants ceilings full of mini-halogens and multi-spotlight fittings, plus wall lights, none of which seem to provide more useful light, but certainly use a lot more electric.

Energy saving bulbs are a good idea, we use them in almost all the fixtures in our house, but I still suspect that lighting the average house consumes far more lumens than it did 20 years ago, and while some sources emit more lumens per watt, wasting lumens still means wasting energy. If a single 12w energy saver can light a room properly, that's the best use of energy. Huge numbers of bulbs that don't cast their light efficiently, regardless of the type, are just wasting electric.

We got rid of the halogen fixtures that came with our house. With ordinary halogen bulbs they use lots of electric, plus they burn out frequently which means more bulbs to buy. Replacing the bulbs with low energy bulbs seems to improve them, but they're so expensive in large numbers that it makes better economic sense to replace the whole fixture and use a normal energy saver bulb. It will also use less energy still, partly by casting the light more usefully in the room, and also by eradicating the wasteful transformer used in many 12v halogens. An ordinary pendant fixture and low energy bulb is less than £5.