Hi! In this video we'll take a look at
bulbs. The market is interesting at the The market is interesting at the
moment – at least in Denmark where the opportunities are more
than I ever remember seeing. This is caused by new efficient technology
and banning of old inefficient technology. And some solutions in between… I'll explain why LEDs are so efficient
compared to incandescent lights. And check the bulbs advertised
wattage – which isn't always correct. I may also find time to just… [oink]
goof around… But first let's look at the
difference between incandescent and LED.
Here we have two large decoration bulbs.
One of them is at full power drawing close to 40 watts. The other one is
dimmed. If I crank it up, it still only draws around 7.5 watts but
gives off much more light. Why is the LED so much more efficient? Well, there's a clear difference.
The incandescent bulb is hot to the touch. The LED is not. Incandescent light actually works
by heating up a small metal wire until it glows white-hot from thermal radiation. We may not think about it every day
but the hotter things get – the more they radiate. If hot enough it's a visible glow to us.
For example a flame or a wire heated by a flame. The heat in the wire excites the electrons pushing them to higher energy
orbits around the atomic nuclei. When the electrons fall back
to a lower energy orbit again their energy is converted to a photon – light.
The metal wire in an incandescent bulb is
typically heated to thousands of degrees. It is therefore made of tungsten. Most other metals would melt at this temperature. But where does the heat come from? There's no flame inside the bulb? Tungsten isn't the best conductor
and the wire is also very thin. So it has the highest
resistance in the electrical circuit.
The filament wire is therefore a resistor and its resistance causes friction
for the electrons passing through it. This friction generates heat. Like when
you rub your hands against each other. LEDs on the other hand
do not work by heating up a wire. Instead of incandescence
LEDs emit light by electroluminescence. The Light Emitting Diode is a semiconductor which has a negative side with electrons in excess and a positive side with holes – missing electrons. When the right voltage is applied to the semiconductor, electrons
flow from the negative side and fills the holes on the positive side. This releases energy as light photons.
No heat is needed but even an LED will warm up in use. The operating temperature inside
the semiconductor is usually 60-80 Celsius. Way less than the wire in the incandescent bulb. And this explains why LEDs are much more efficient. It takes A LOT of energy to heat
anything to thousands of degrees. Only around 2-3% of the electricity is
converted to light in the old-fashioned bulbs. The rest is lost into heat. Therefore incandescent bulbs for
house lighting are banned or being banned in many countries. The incandescent bulb
to the left is illegal to sell in Denmark. I generally hate bans but looking at the specs
I have to admit it makes sense. There is a problem though…
I recently had a brunch at a local restaurant and noticed that
the lunch meats looked undelicious. It was lit by LED-bulbs with a bad color rendering index. CRI is a measurement of how well
colors look when only lit by the bulb.
Not all bulbs give off light that
will make all colors look natural to you. 100 is the perfect score and
incandescent bulbs are very close. But many LEDs struggle with
color rendering. Let me try to show it. I will use the Danish lunch meat called 'rullepølse'. – "Repeat after me: Rullepølse" And test with these three bulbs that are
fairly similar except for the color rendering. This LED has a rendering index above 80. This other LED is above 90 and the incandescent bulb is close to 100. I filmed each bulb with the camera
locked to the exact same settings so the difference in the three
recordings is only the bulb.
Here's the side-by-side comparison.
Notice the color difference. On my monitor the middle one
is an ugly yellow-greenish. The left one is way better but the right one has the best
meat-look and a white plate. I'll leave it up to you which one
looks the most delicious – if any – but over a dinner table I highly recommend
bulbs with a high color rendering index. LEDs also need electronics built into the bulb to work.
The semiconductors need DC
and not the AC from the mains electricity. If the electronics are poorly designed
LEDs can flicker badly. It's not easy to film but hopefully you can tell
which of these two is flickering the most. In real life
– not chopped into 25 frames a second – the one on the right has an
annoying stroboscopic effect. And the electronics don't like excessive heat
so LEDs aren't suitable for oven lights. This incandescent bulb is rated
to 300 C – no electronics to melt… Speaking of speciality bulbs…
Sometimes heat is exactly what you want. Heat radiation is infrared radiation and this
bulb is meant for keeping baby animals warm Like chickens and piglets. The bulb is
tuned to emit a lot of heat and this pig will soon feel it and start… venting… [hissing noise of air escaping under pressure] [oink…] Did… did I mention that these infrared
bulbs are also excellent over a buffet for keeping the food warm.
Like bacon… and… pork chops…
[disapproving pig squeal and oink] Are uh… Are you okay, piggy? [long, deep, sighing oink…] He's fine. Let's move on. I think it's time to show and quickly test
some of the more special bulbs I've found. These are the big decoration bulbs from earlier. They are advertised at 7.5 – 40 watts. Let's test it. The silvery gadget is a wattmeter
and the top number shows the wattage. The 40-watt incandescent draws
37 watts – a little low but that's okay. The two LEDs are closer to spec
and draws around 7.5 watts. It takes a little time for them to warm up so
let's jump to the spec-sheet with the final readings. Here you really can see
the differences in the two technologies. I've marked the not-so-good specs
with a red color for a fast overview because we are gonna expand with more bulbs.
These two take decoration bulbs to
a new level with a complicated glass shape. I know it's upside down but this is just a test rig 🙂 Apparently 40W incandescent bulbs use
close to 10% less than advertised. How about a 40W LED? This is mostly for industrial use
because at 3200 non-dimmable lumens it isn't…. cozy. But it surely is a 40-watt bulb. Just for reference I'll show a comparison with
a 40-watt incandescent decoration bulb. Yup! That looks like a normal cozy
lighting. Let's try the other one… Wh… well it's cozy… in the…
lying-on-the-beach-with-sunglasses-on way… Let's carry on… This is an example of a bulb that
will be hard to find in the future. An incandescent bulb with clear glass. Apparently tinted glass models will
be permitted for longer in the EU. While clear glass incandescents are banned. Halogen bulbs were also
supposed to be phased out by now but so far the ban has been delayed.
At close to 70W each they are a little
power hungry but halogens are still more efficient than the endless
choices of decoration bulbs. Alright, this is the summary so far.
Only a few more to test now. The next bulb is a fluorescent one
I use in my soft boxes for video lighting. It is a big one – advertised at
125 watts and a CRI over 90. However the specs may not be very
accurate because it is only using around 50W. Hmm… I guess that's one way of saving energy…
Letting the bulb use less watts than advertised. Now this is a real energy saver.
Its energy rating is A++, since it is
only using 6W to generate over 800 lumens. And the wattage is very
precise – even from a cold start. This bulb was a little different because
it was the only one which started at a higher wattage than advertised
and only dropped after a long warm up. The final bulb is the very
popular 400W halogen work light. It may use a lot of electricity
but puts out close to 9000 lumens. This one is a little below spec at 368 watts. So here is the final summary. I hope you liked this video and liked it enough to click the thumbs up button. That would make me very happy 🙂 My next video will be something different. I visit a fellow Danish youtuber and…
mess up some of his stuff…
– I can't say safety first because
then we shouldn't do this at all. – It is a little dangerous and actually
I'm a little nervous because… – We're not gonna ground him.
His not gonna be wearing a… Here's a little bonus for hanging on to the end. Look at the advertising on this one.
On the front it clearly says anti-insect and insect repelling. On the back it says it attracts less than white light English is not my first language but
'repel' and 'attract less' isn't quite the same, right? Thanks for watching!.
