Everything you need to know about LED lightbulbs

  • Funded by a Kickstarter campaign that raised R15 million in six days, LIFX bulbs concoct wild colours that can be controlled via a smartphone app.
  • Thanks to a bluish, neodymium oxide coating that boosts red and green hues, these bulbs have a comparatively high CRI of 93
  • These bulbs look nearly identical to traditional bulbs, but their snowcone design is best-suited for downward-lighting applications.
  • The colour of an incandescent bulb warms as its light dims. The Ultra SE emulates the effect by combining white and yellow LEDs.
  • The LEDs are arranged at the outer edge, helping eliminate the need for a large heat sink while also providing omnidirectional light.
  • Weigh up the differences between Halogen, CFL (Compact Flourescent Light) Halogen Hybrids and LED lighting below.
Date:24 March 2014 Tags:, ,

Feeling lost in the lightbulb aisle? We’re here to help. By David Agrell and Anthony Doman

Incandescent era, RIP. Like it or not, it’s time to move on.

South Africa’s energy policy dictates that, by 2016, all conventional (read incandescent) lightbulbs must be replaced by energy-efficient types. That’s the way the world is moving – most recently in the US, where the Energy Independence and Security Act effectively killed off lower-output incandescents from 1 January simply by requiring them to be about 25 per cent more efficient. That efficiency gain is impossible to achieve without decreasing their luminous flux (brightness), so, instead, manufacturers have shifted to more energy-efficient technologies, such as compact fluorescents (CFLs), halogens, and LEDs.

South Africa is not that far down the road, but we’re headed there.

Already in 2011, this country banned the import of incandescents. The fact that, three years later, these lightbulbs are still freely available on your local supermarket shelves suggests that the importers simply rushed out and brought them in by the shipload before the deadline. In the interim, changes are being phased in. New buildings that exceed a certain energy requirement must incorporate energy-efficient lighting right at the design stage.

Of course, not everyone is embracing these next-gen lightbulbs. Some wonder why we need a mandate to use them, if they’re so great. The fact is, after more than a century of incandescents, we’ve become attached to them. They’re cheap, they dim predictably, and they emit a warm and familiar glow. Weaning ourselves off them won’t be easy: just as the USA’s 40 and 60-watt phaseout went into effect, about half of the country’s 3,2 billion screw-base bulb sockets nationwide still housed incandescent bulbs.

So, what now? According to a survey by switch manufacturer Lutron, two-thirds of American adults are aware of the phaseout, but only one in 10 are “very knowledgeable” about replacement options. Most of us will probably buy halogens without even noticing. They are cheap and they look, feel and function almost exactly like traditional incandescents. But they’re only about 25 per cent more efficient (see “Weighing up the differences”). Meanwhile, CFLs, which are inherently flawed and generally unpopular, are steadily losing market share.

That leaves LEDs, which offer the most sustainable – and exciting – alternative to incandescents. For starters, they’re highly efficient: the average efficacy of an LED bulb is 78 lm/W (lumens per watt), compared with around 13 lm/W for an incandescent and approximately 18 lm/W for a halogen equivalent. Yes, LEDs have their shortcomings: buying an LED bulb doesn’t seem as intuitive as picking up an incandescent from your local convenience store, and the up-front cost is high. But once you get to know the technology and the incomparable versatility that LEDs offer, you’ll see the demise of the incandescent as an opportunity.

Here’s a primer that addresses your concerns and helps you navigate the dazzling array of choices.

Aren’t LEDs expensive?
The days of the R400 LED bulb are over. As demand has increased and manufacturing processes have become more streamlined, costs have plummeted. LED bulbs consume one-sixth the energy of incandescents and last up to 25 times longer. Replacing a 60-watt incandescent with an LED equivalent will save you a fortune in energy costs over the new bulb’s lifetime.

Now you can get a 4 to 5 watt model for anything between R75 and R120. Says Graham Phillips, project consultant for Arora Lights: “Osram has a 5,2 W model for about R150 and a 7,5 W dimmable one for about R250 that will give you the equivalent output of a 50W halogen.”

Going LED need not mean having to compromise on output – or price. “One manufacturer’s 9 W replacement has an output of 810 lumens at a cost of R160.”

Sadly, the fast-weakening exchange rate stabilised prices. “In fact, they have started going up again,” Phillips says. Still, LEDs are being sold in small, but significant, quantities. Phillips says that the branch he operates from sells 1 500 a month. That includes “a bit of both” replacements and new installations.

Even at current prices, though, here’s a statistic to make you sit up and think: “By switching to LED you could amortise your costs within 13 to 14 months. Even less if energy costs continue rising as they are.”

What am I looking at here?
Lightbulb packaging should allow easy comparisons between similar bulbs without relying on watts as the sole indicator of performance. It gives information about the bulb’s brightness (in lumens); yearly cost (based on 3 hours of daily use); life expectancy (in years); light appearance, or colour temperature, measured in Kelvins (K); and energy consumed (in watts). Remember: an LED bulb’s wattage rating doesn’t indicate its brightness; its lumens rating does.

A 60-watt-equivalent LED bulb delivers about 800 lumens, roughly the same as a 60-watt incandescent.

One big selling point of LEDs, besides their energy efficiency, is long life. Whether quoted figures are equal to real-life conditions – one make quotes 25 000 hours for a particular model – time, of course, will tell. “What will happen over time is that your output drops,” Phillips says.

And heat is a killer. “The heat sink is a most important part of the design; that’s another area where the lesser brands fall down.”

I miss my bulb’s warm glow
The higher the bulb’s colour temperature, the cooler its light. A candle glows at a colour temperature of 1 500 K. That CFL you tried but hated because its light was too harsh was probably running at around 4 500 K. LED bulbs marketed as incandescent replacements usually have a colour temperature of 2 700 K, which is equivalent to typical warm white incandescents.

But that’s only part of the story. The quality of a bulb’s light also depends on its colour accuracy, also known as the colour rendering index (CRI). The higher the bulb’s CRI, the more realistically it reveals colours. Incandescent lightbulbs have a CRI of 100, but most CFLs and LED bulbs have CRIs in the 80s. According to a recent study by the US energy department, only a handful of LED bulbs have CRIs in the 90s, though that will improve as efficacy increases. Note that the CRI is not always listed on the packaging, so you may have to search the manufacturer’s website for it.

These bulbs dim, right?
LED bulbs sold as “dimmable” work acceptably with most newer switches. The best dim to about 5 per cent, though at that level some produce a faint buzzing. Make sure you buy a bulb that has been veri­ ed to work properly with your switch; check the manufacturer’s website for a list of compatible dimmers.

If you need to install a new switch, buy something specifically engineered to work with LED bulbs. But be warned: these switches are sometimes larger than older dimmers. In most cases that shouldn’t be a problem, but if you have an overcrowded electrical box, you may need to upgrade it to accommodate the new dimmer.

Where can I use them?
Most household LED bulbs follow dimension guidelines for the familiar A19-shaped bulb. Some have a bulky, space-age-looking heat sink; others incorporate this necessary part more elegantly into the engineering. So-called snow-cone designs have a heat sink that takes up the entire lower half of the bulb. These emit directional light only, which is acceptable in pendant fixtures but throws unwanted shadows when installed in, for example, a table lamp with a shade. For that you’ll need an omnidirectional bulb, so check the packaging before you buy.

Ready for complete adoption? You’ll find LEDs in floodlights, spotlights and recessed-lighting formats, as well as in designer formats such as the ‑ at panels of the Pixi system. It’s not just individual units that are being replaced, either. “We are now replacing 600 x 1 200 fluorescent panels with drop-in LED equivalents,” Phillips says. “I’ve got a 72 W 4 000 lumen panel. But that doesn’t come cheap: it costs R3 800.”

Expensive, yes, but consider this: no maintenance, no ballast and the ability to replace failed LEDS. Even at current prices, many still balk at the high initial outlay. “What I tell people who can’t afford to go full LED now is to think about installing them in passages. That’s a good safety feature if, say, you’ve got kids, because the light can be left on with much less energy cost than a conventional light.”

Okay, now impress me
Wi-Fi-connected LED bulbs, such as those from Connected by TCP, can be operated from a smartphone. Taking it a step further, platforms such as Philips Hue and LIFX combine red, green, blue, and sometimes white LEDs to produce millions of colours, from bright purples to daylight whites. Most offer stand alone, plug-and-play functionality, so you don’t need to buy into a larger connected system.

Integrate them into an IFTTT (if this, then that) recipe and their colours automatically adjust to suit, say, the weather, the time of day, or which sports team is winning.

Weighing up the differences
We asked GE, one of the world’s largest lightbulb manufacturers, to  give us more insight into  your choices.

Halogen: consumes 43 Watts
Like traditional incandescents, halogens instantly produce warm light and are dimmable. That’s because, technically, they are incandescents. The difference is halogens contain a gas that allows them to burn brighter, so they can be made smaller to use less energy. GE expects eight of 10 customers to switch initially to halogens.

Downside: Halogens get very hot, so stay clear of fixtures. That also means it’ll take extra energy to cool your home.

CFL-Halogen Hybrid: consumes 15 Watts
GE’s Bright From the Start bulbs contain both a compact fluorescent lamp (CFL) coil and a miniature halogen lamp. The halogen provides warm, even light until the CFL coil reaches full brightness, at which point the halogen switches off. CFL bulbs last up to 15 times longer than incandescents, so cost savings over time can be significant.

Downside: GE’s hybrid CFLs are not dimmable. All CFLs contain mercury, a pollutant.

LED: consumes 11 Watts
Contrary to popular belief, LEDs are neither ugly nor expensive. Well, they’re not ugly. GE’s Energy Smart LEDs look and feel more like your old incandescents, right down to the shape. Plus, the vast palette of LED colours available allows GE to imitate its traditional Reveal and Soft White hues. LED bulbs can last up to 14 years with typical use.

Downside: Up-front cost is high. However, prices will plummet as demand increases and manufacturing is streamlined.

 

  • Fanandala

    I am still confused in the light bulb aisle. Will the 3 W LED be a replacement for my 14W CFL or my 60 W incandescent? All that would not matter all that much if they were really cheap, but as things are I would love to know before I buy. Because I do not care how efficient they are, but will I have an adequate light level in my rooms.