That means you were consuming something like 250 watts of lighting for
24hours/day for the whole year, seems unlikely to me.
My 'rule of thumb' for electricity costs is that 1 watt continuously
for 1 year costs around £1. (8760 hours in a year, so 1 watt is 8760
watt/hours, 8.76kwH at 12p/unit costs £1.05) It's probably a bit more
now as electricity costs a bit more but even then your figures seem a
bit high unless you have a very big house.
Big house or silly number of lamps will do it...
This place came with a ridiculous number of GLS lamps - most rooms on
the ground floor have multi lamp fittings (tall ceilings etc), so you
get to something around 40 bulbs on the ground floor alone. The
downstairs was even spread over two circuits (old wylex NN type 1
devices), and one of those would trip after about 10 mins with too many
So lots of filament LEDs later, I have probably dropped about 6kWh off
the daily consumption!
 Mate of mine some years back bought a place where the previous owner
had run a furniture sales business from home, and had built a 900 sq ft
showroom extension onto the place. This when converted to domestic use
became a super impressive lounge with three massive patio doors opening
onto the garden. It had loads of recessed ceiling mounted down lighters
- each of which held a conventional GLS lamp - but collimated such that
it just illuminated a relatively small patch of floor directly below it.
There was a massive grid switch at the door, to allow fairly granular
switching of it. He was quite pleased that you could for example
individually switch the lamp cluster that illuminated a large pot plant,
or just the coffee table (one he made from an old double bed frame to
give concept of the scale of the room!) That was until I did the sums
and told him that if he turned all the lights on, they would draw over
6kW for that one room alone.
On Wednesday, 17 January 2018 17:33:26 UTC, charles wrote:
Surely that's a typo 121 !
Are you sure this room isn't a concert hall .
Anyway my proirity is normally to do with the type and amount of light and
not how long it lasts.
I certanly wouldn;t go out and spend over £200 on these lights unless
someone else was paying :)
On Wed, 17 Jan 2018 16:32:12 +0000, charles wrote:
Ye Gods! Just how big a room are you lighting if you're using 121 "40W
equivalent" 470 or 510 lumens lamps? By my reckoning that's something
like a total of 57,000 to 62,000 lumens' worth of lighting.
I'm forced to conclude that you're using the word "room" in the
theatrical sense to refer to a theatre or large hall as "the room".
On Thu, 18 Jan 2018 21:08:20 +0000, charles wrote:
Thanks for the clarification. :-) Mind you, that's still some 6,000 or
so lumens' worth of lighting. It's either a very *large* or *bright* room
in the context of domestic lighting.
It's a sobering thought that a mere 12 quid's worth of those Poundland
5.5W 510Lm LED GLS light bulbs (BC22 or E27) could have been used to
provide the same illumination level for about an extra 20 watts more
consumption over and above the 48 watts consumption of those LED filament
Assuming a price point for those filament type 4W LED "40W GLS
equivalent" lamps of circa 3 quid a pop, that represents a break even
point of some 4 to 5 years of lamp life. That's a long enough time span
to have you thinking of the saying, "I'm damned if I do and damned if I
On Tue, 16 Jan 2018 09:31:25 -0800 (PST), harry wrote:
'Filament' LEDs are, AIUI, COB and are probably the least inefficient LEDs
generally available. Morrisons have (had?) some 6W, 800lm, 'GLS' B22 lamps,
unfortunately ~3000K (I prefer 4000K+) for a fiver each. I have one and it
is good. I've not checked the actual wattage - OK, just for you:
5W is flickering 4 - 5 and is just under %W based on VAxPF
15W, 1500lm is similarly marginally low
60W incandesent shows 60W - surprising as the voltage is ~245.
5 years ago I wouln't go below 80lm/W; 3 years ago I considered only
=>100lm/W, with exception for GU10 for desk and bench lights that don't
spend long on.
Ikea changed to all Led, but those are worse than my benchmark 5 years ago!
BTW, I bought from Ledlam some lamps that have COB on ceramic blades. The
blades are in a triangel and very translucent, with the 'back' of each blade
shining throght th gap between the other two, so near enough 360 deg.
The 3W is 320lm and the 5W is 600lm - this was 3 years ago! How progress
goes - not!
Five years ago (iirc) I thought the 78LPW Asda LED "60 watter" (810Lm at
12 watt rated - actual, 14 watt- consumption) was a worthy replacement
for a 20W CFL of nominally the same lumens output so I bought one to try
out. It proved to have a definite edge in lumen output compared to the CFL
it replaced - instant on for 6 watts less consumption!
That's since been replaced with a "10W" (actually 12 watts) 810Lm lamp
and my most recent LED GLS purchase a few weeks back from Home & Bargain
was a 3 quid 1500Lm 12W (actually a little over 13 watts) "100W
equivalent" E27 LED GLS lamp to replace an actual 100W incandescent light
bulb in the bathroom ceiling fitting (horizontally mounted lamp). Rather
pleasingly, it proved slightly brighter, most likely due to the 5 or 6
year old original bulb having become slightly blackened on its upper
surface as mounted in the luminaire.
I didn't bother comparing it against one of the three spare 100W E27
lamps that I'd purchased with the luminaire but I rather doubt I would've
been disappointed even if I had compared it to a brand new unused 100W
incandescent GLS lamp.
It's only now that we're starting to see 125 and 133 LPW LED GLS lamps
appearing on shop shelves despite one of Cree's CEOs promising that the
303LPW lamp they'd announced almost four years ago (Mar 2014) as a record
breaking laboratory 'Milestone' would be on the shop shelves in a time
frame of 18 to 24 months.
Up until about 6 months ago, I'd been stewing over this 'broken promise'
until I revisited the web page article and spotted, from Cree's very own
progress chart, that the historical reality approximated a lead time of
ten years rather than the 2 years quoted by the CEO who one might have
expected to have checked out his own company's PR materials before
shooting his mouth off with unrealistic promises, D'Oh!
 According to the chart, it's looking more like a 12 year lead time
between laboratory 'Milestones' and shop shelves. The 131LPW 'milestone'
occurred way back in 2006, suggesting that we just might see 150LPW
product materialising in the next two or three years.
On Thu, 18 Jan 2018 19:09:16 +0000, critcher wrote:
By "tube" do you men flourescent tube? Aldi had 5' T8 21 W 2000 lm
LED tubes in before Christmas. Looks like they didn't sell very well
as I picked up two for £4.99 each... They work well, simply take out
old tube, fit LED one and change the starter for the "starter"
I guess there are losses in the ballast that is still in circuit. If
one felt inclined you could wire L and N directly to one of the tube
holders and have done with the ballast and starter. You'd have to put
the LED tube in the right way round and a flory tube wouldn't work.
Not sure if the filament in a florry would object to being
permenantly connected across the mains.
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