How to save electricity?

[limlim]

Oh, by the way, if your place is air-con…


By generating less heat, your air con no need to "work so hard", and that could explain for the "huge" savings… not just bills relating to lighting alone. If fact, if you replace with F bulbs of similar wattage, there would be no saving in lamp bills at all… just brighter illumination.

[verykiasu2010]

florescent tubes used to be more energy efficient than bulbs


then came the energy saving bulbs (made from twsited / spiral florescent tubes)

now the "in" thing is LED lighting which is truly energy saving - and more durable than the flourescent tubes

[Nebbermind]

Spoke to some LED industry people a couple of yrs ago n they told me although LED uses less energy than fluorescent, the saving is not that significant, and led is relatively much more expensive now.

[verykiasu2010]

Nebbermind:

Spoke to some LED industry people a couple of yrs ago n they told me although LED uses less energy than fluorescent, the saving is not that significant, and led is relatively much more expensive now.

that was a few years ago in terms of pricing, now is totally different; and most LED last more than 10 years

for energy consumption, it depends which salesmen talk to you. better do some own research first

[Nebbermind]

Spoke to manufacturer…they found it difficult to sell coz justification not enough, unless pushing towards ‘environment’ cause.


Another thing, LED light work as a cluster so a single failure can affect part or whole of the light assembly. Eg, I think the traffic is made of 3 or4 block so a single led failure will knock out 1/3 or 1/4 of the display.

Also, led may last but the electronics (if any) in the assembly may not. The soldering joints too…coz u not getting MIL GRADE…plus many is MIC, u shd be wary of the quality.

[limlim]

Right… LED operating voltage is ard 5V. It makes sense to put them in series, about 48 of them, to consume 220V ~ 240V. So, just need to rectify w/o stepping down.


To step it down to 5V or other voltages would induce losses at the transformer… doesn’t make sense to do so (Energy losses).

So, a single failure could knock out 48 bulbs… and I wonder how they identify the problem LED if there is no obvious physical signs… test 1 by 1?

Anyway, This is my speculation based on theory… not sure how the industry does it. But I believe in series for a block is correct.

[Way2GO]

verykiasu2010:

Nebbermind:

Spoke to some LED industry people a couple of yrs ago n they told me although LED uses less energy than fluorescent, the saving is not that significant, and led is relatively much more expensive now.

that was a few years ago in terms of pricing, now is totally different; and most LED last more than 10 years

for energy consumption, it depends which salesmen talk to you. better do some own research first

I received d same info as Nebbermind also about 2 years ago,
not fr any salesman but fr a friend who is in d business.
IIRC, LED pricing then for domestic use was between 20 -30 x F tubes.
Has d pricing changed significantly?
No arguments on d advantages u mentioned.

[Nebbermind]

Perhaps there’s more advantage for commercial bldg than domestic use.

Commercial bldg would have greater volume n usage per day is longer so the savings is greater n can be recovered in shorter time. Also, since bldg r aircon, op temp is lower n that may increase effective lifespan.

[Imami]

Wta- which scenario will consume more electricity:


A) to boil 500ml of water using an electric kettle which has a capacity of 1litre.
B) to boil 500ml of water using an electric kettle which has a capacity of 4litres.

Anyone?

[limlim]

The bigger one, assuming similar construction (same brand etc…), coz the kettle is bigger (more mass).


To heat the water inside to boiling the inside of the container need to reach boiling temperature too. A bigger container will need more energy to reach boiling temp.

Also, a bigger kettle will have a larger surface area hence more heat lost (again, assuming same construction/material/insulation etc…) as it heats the water to boiling temp. If you touch the surface and it is very hot, means, insulation is not very good and a lot of energy wastage, and a bigger surface lost significantly more heat…

If compare a VE 4l kettle with a normal 1l kettle, then different story already, bcoz the VE kettle have very good insulation which result in much lower heat loss.