How to save electricity?

[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.

[iRabbit]

I'm so glad I started this thread ... at least nobody throws bricks in my thread

[Imami]

Thank you Limlim!

[Imami]

FQW:

I'm so glad I started this thread ... at least nobody throws bricks in my thread

Absolutely (glad that this thread was started)! Even more happy that we have some \"in house consultants\" like Limlim to help with the answers.

[peterch]

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?

It is not the capacity of the kettle, but the power of the kettle used. See the label then you will find out the watt usage. So if same power with different capacity, it would be the same if you boil same volume of water.

[Way2GO]

I concur capacity of kettle is not a factor.

d amount of power u consumed to boil d same quantity of water is only a function of d power rating times d time it takes to boil d water.
Using a higher power rated kettle would take a shorter time to boil.
My sense, without doing d actual experiments on timings, wld be d difference in power usage for 1L vs 4L kettles is not significant.