Energy prices.

[daleyd]

I agree it's a low hanging fruit, so why not go for it. Just have to keep in mind that it's a rather small fruit, in the bigger picture!

If your waste heat from lighting is 1kW, if it's within the heated envelope of the house, that's 1kW less heating needed. And, is more than likely lower carbon than a gas boiler's 1kW.

Utterly pointless when you want the house cooler or for outdoor lighting though!

I'm not against LEDs, all but a few random rarely used bulbs here are LED.

Yeah I understand that “wasted” heat from lighting is contributing something, my point is that it’s doing little of any use (in most cases). I don’t think it would ever translate into 1 kw less heating input needed as it’s not warming an area where you need it. I can imagine it making a small difference but I think it would be marginal at best.

The ceiling area is already warm air that has risen from radiators or other heat sources, waste heat from a bulb is simply heating air that is already warm and at a level that no one notices - the air is already at ceiling level. If you were to put 1kw of ceiling lighting on and no other heating source or a 1 kw fan heater at floor level then I bet you would feel warmer with the fan heater.

 

[fizzy]

Of course the bigger things have more of an impact, that’s entirely sensible. It makes sense to make the biggest savings you can but when you can’t do any more then you move on to the next and so on - lighting is an easy win because it’s easy to change as opposed to boilers which come with significant capital cost.

If you replaced, for ease of maths, 10 100w incandescent bulbs with 10 8w led then you have cut a 1kw load down to 80w - a worthwhile saving if that load is going to be on a few hours a day.

I also don’t get the idea that heat from incandescent bulbs is in any way useful either - it’s generally at ceiling level and contributing nothing, or at least very little to the heating of a room.

Think of it as underfloor heating for the room upstairs.
Where do you think the heat goes?
Obviously it is into your house.

 

[daleyd]

Think of it as underfloor heating for the room upstairs.
Where do you think the heat goes?
Obviously it is into your house.

Well - I didn’t say it completely wasted I said it was probably making a very marginal difference (at best) and is heating the wrong area. Why do you think they don’t put radiators on the ceiling . Maybe that’s where the real energy savings are to be made.

And for rooms upstairs - I guess heating the attic might be of some benefit though I don’t know if any of the heat would make it through several inches of insulation. But yeah, whatever makes you feel better I guess

 

[bricol]

Think of it as underfloor heating for the room upstairs.
Where do you think the heat goes?
Obviously it is into your house.

I live in a bungalow . . .

 

[bricol]

Sadly I think LED lights have a lot to answer for. People leave them on all night as they think they are so much cheaper. Defeats the energy saving potential sadly.
Warehouse next to mine replaced his old auto floodlights with new LED manually switched. They are on all weekend even in the day.
His answer was they were so much cheaper to run there was no need to turn them off

15 yrs ago I was heavily into designing a bit of equipment using LEDs for an industrial testing bit of kit, and subscribed to a US LED Magazine. I recall an article where they said exactly this - people removed a lot of older lighting and fitted LEDs.

They either fitted more LEDs, as they had all this "free" capacity to use compared to the previous lighting, or because it was using less power, simply left them on - energy use the same as before.

Me - I have two 10W LEDs in the living room, and one 5W over my work desk - which is considerably less than the two 60W or even 100W I might have had - still got more than enough light.

One thing that does come up - LED lights do give some chronic headaches - they seem more susceptible to the effects of the constant, although mega-faast, switching on/off of the drivers.

 

[Gareth J]

And for rooms upstairs - I guess heating the attic might be of some benefit though I don’t know if any of the heat would make it through several inches of insulation. But yeah, whatever makes you feel better I guess

If only a marginal amount of energy is lost through the attic, because it's appropriately insulated, then the vast majority of our hypothetical 1kW is helping keep the house warm.

Think of it a different way, in order to keep a room comfortable, xkW are needed to balance the energy that moves out via conduction through surfaces and air exchanges. A light bulb will unlikely be enough to achieve this but, even if it only heats the ceiling area a little, that's a little bit less the radiators need to heat the ceiling. Air from your rads will convect back down a little bit more slowly and the boiler will work a little less hard. It's a one for one exchange. However, it'll cost more. As, per kWh, electric costs more.

 

[fizzy]

Well - I didn’t say it completely wasted I said it was probably making a very marginal difference (at best) and is heating the wrong area. Why do you think they don’t put radiators on the ceiling . Maybe that’s where the real energy savings are to be made.

And for rooms upstairs - I guess heating the attic might be of some benefit though I don’t know if any of the heat would make it through several inches of insulation. But yeah, whatever makes you feel better I guess

I was speaking hypothetically of course!
First thing I did when I moved into my current house was replace the 20 GU10 halogens in the kitchen. If anything should have been banned it was those!
The LEDs may use a lot less electric but the light is still awful. A very low ceiling means you have to stand under a spotlight to see anything. 1 or 2 tubes would light the whole kitchen far better and cheaper.
I don't believe in using electric for heating - it used to be 4x the price of gas and oil.
I live down in a valley so not much sun. Always 6C colder than Swansea. Heat from the aga still very welcome even in May. 4C here last night.

 

[finyuk2005]

One thing that does come up - LED lights do give some chronic headaches - they seem more susceptible to the effects of the constant, although mega-faast, switching on/off of the drivers.

Older led lights were awful on the eyes with that 50hz flicker, cheap ones are sometimes still like it,
But generally they seem to have improved that immensely!

 

[Morris]

I was speaking hypothetically of course!
First thing I did when I moved into my current house was replace the 20 GU10 halogens in the kitchen. If anything should have been banned it was those!
The LEDs may use a lot less electric but the light is still awful. A very low ceiling means you have to stand under a spotlight to see anything. 1 or 2 tubes would light the whole kitchen far better and cheaper.
I don't believe in using electric for heating - it used to be 4x the price of gas and oil.
I live down in a valley so not much sun. Always 6C colder than Swansea. Heat from the aga still very welcome even in May. 4C here last night.

If you find the light poor then you have the wrong lamps. I did exactly the same, first time the light was awful. I returned them. The ones I have now have been in for two years or so instead of failing every six months and give just as good illumination as conventional gu10's

 

[reb78]

I still use a paraffin lamp. I have four in the lounge as I type.... . Much nicer light than modern bulbs. I have carbon filament bulbs in the bedroom as they are a nicer light too and nicer to look at as they are candle bulbs (seem easier to get than tungsten now although strictly sold 'for decorative' purposes)

 

[Morrisman]

I live in a bungalow . . .

Me too. I love it, as regards the heating bills.

I had a shock a few minutes ago, my smart meter read out thingamajig is telling me something is running that costs £2.44 an hour. Normal usage is 8p.
Then I remembered, my daughter is home from uni for a few days and is in the shower......

 

[500e]

Throttle the hot side of the shower

 

[Morrisman]

Throttle the hot side of the shower

She doesn't come home very often, so she can use the shower as often as she likes when she is here.

 

[Barking Mat]

Well a couple of years ago I swapped all our tungsten filament bulbs to led.

A lot do stay on 24 hrs a day as landings don't have windows, the utility room, bathrooms.

I concur, it's ovens, hot water tanks and fridge freezer which seems to make the difference, not lighting.

I wonder how much the tv's and 'pooters on standby munch.

 

[500e]

It all adds up Mat

 

[Barking Mat]

It all adds up Mat

Tell me about it.

But the house is huge, and those Bretons didn't put that many windows in.

I've insulated 3/4 of the house, it's wood burners in winter which heat the house, that's another ouch !

 

[finyuk2005]

It all adds up Mat

absolutely! in my folks kitchen there are about 6 million GU10 50w down lighters, its about 1kw if they were all halogen still, the led's are a pretty considerable saving!

 

[Robotstar5]

Well a couple of years ago I swapped all our tungsten filament bulbs to led.

A lot do stay on 24 hrs a day as landings don't have windows, the utility room, bathrooms.

I concur, it's ovens, hot water tanks and fridge freezer which seems to make the difference, not lighting.

I wonder how much the tv's and 'pooters on standby munch.

They are known as Vampire appliances

 

[finyuk2005]

Well a couple of years ago I swapped all our tungsten filament bulbs to led.

A lot do stay on 24 hrs a day as landings don't have windows, the utility room, bathrooms.

I concur, it's ovens, hot water tanks and fridge freezer which seems to make the difference, not lighting.

I wonder how much the tv's and 'pooters on standby munch.

I tried turning everything apart from the computer, printer and all the network gear, (3 ethernet switches, modem, network video recorder box, etc) and it was only about 120watts,
not much, but 24/7 i guess would start to add up

 

[atomant48]

what do folk actually use per day on average ? I always find the “book values” online are way below our usage … we seem to be about 5kW per day just for the house to tick over.