Wrote by kulekat.com/
What You Should Know To Benefit From New Ultra Low Energy Domestic LED Lighting.
Whether you are simply curious about the new LED home lighting solutions starting to appear in mainstream DIY and hardware supply stores, or already know a bit about LED technology and are keen to do your bit to help in the coming struggle against climate change (global warming) or just want to take steps to slash your fuel bills, the fact is that LED lighting is the future.
So you’re going to have to come to grips with this and learn what the future of domestic lighting means to you personally. This article aims to clear up some of the confusion that surrounds the various low energy domestic lighting solutions currently available to consumers, looks at what you need to know about low energy lighting and installing low energy light bulbs and provides a simple guide and helpful LED lighting advice for anyone unfamiliar with evaluating and buying LED home lighting.
If you just want to jump in though then follow these links to check out some of the best LED spot lights and standard globe shaped LED light bulbsavailable these days.
Some Background About Domestic Lighting Solutions
The lighting systems we are most familiar with in a domestic setting are based on GLS (General Lighting Service ) light bulbs – these are incandescent filaments that burn (quite literally) and in so doing convert their input energy into about 98% heat (as you would expect for something that is burning) with the remainder given off as incidental light.
GLS bulbs have a typical lifespan of about 1000 hours, at which point, having converted your these-days-not-very-cheap electricity into vastly more heat than light, they need to be replaced. Put another way, if you started out in life with a single GLS light bulb that you used for just 4 hours per evening, you would need to re-purchase well over 100 replacements during the course of your life.
At approximately $1 per light bulb say, that’s $100. And if you think that’s a high price to pay for having a little light in your life, the cost of running your GLS bulb far exceeds the replacement costs at somewhere above $1000 in electricity bills.
And that’s just ONE measly little light bulb for a few small hours each evening. Now you know why your electricity bill is so much bigger that you would like it to be. There’s more here about calculating lighting costs if you’re interested.
So… regular GLS incandescent light bulbs are economically a poor choice for you directly. But they are also a very bad way to light the world in general. Not only are you (and everyone else) generating a huge amount of waste heat (remember: 2% illumination, 98% heat radiation), there is also the energy and heat required by the lighting manufacturers to make all those replacement light bulbs (we’ll ignore the disposal issue, but that’s yet another concern).
Needless to say, governments around the world are alarmed by this and many governments in the developed world (where frankly the problem is worst) have already enacted legislation to phase out the production and use of standard incandescent lamps, with timescales as short as 2 to 3 years.
Yes, you read that correctly – very soon you will not be able to buy GLS light bulbs anymore.
So What About Low Energy Light Bulbs?
What indeed about conventional low energy (for which read CFL or Compact Fluorescent Lamp) light bulbs? There are many problems with CFL light bulbs compared to GLS and LED lighting, follow the link for further details, but the short answer is that they are bad news on all fronts.
Total cost of ownership of CFLs is poor (the full purchase and running costs taken together); light quality is horrid; they are bulky, ungainly and downright ugly; most are not dimmable; energy efficiency is not all that great; and the cherry on top – CFLs contain toxic mercury vapor and are therefore hazardous waste.
No wonder even the lighting industry itself is keen to get beyond CFLs and into a lighting technology that really can deliver safe, high-quality light that is low-cost, low-energy, low-heat, low-carbon footprint, ultra long life-span.
The lighting industry is at the sharp end of the reality behind global warming and the relentless energy crisis that will accompany oil depletion, and the solution that lighting industry giants such as Philips have put their investment behind is the ultimate in energy saving lighting – LED home lighting.
So when you can no longer find GLS light bulbs at your local store in a couple of years time, guess what you’re going to be buying? So now, time to learn what you need to know and what points to consider when buying LED lights for your home.
How And Where To Use LED Lighting Around Your Own Home
The first thing to understand about LED lamps is that the light they emit is directional – focused on a single spot. So they are an excellent choice for any existing lighting applications that have similar characteristics. We’re talking here about:
tracks and clusters
recessed down lights
decorative & feature lighting
Most people’s homes use this type of lighting in kitchens, bathrooms, hallways and basements. Anywhere really that needs bright ambient light.
A safe choice at the moment to replace halogen spotlights are GU10 LED bulbs such as this Edison 6W GU10 LED which is also available as a MR16 LED spot.
Less obvious uses of halogen lighting are desk lamps and slim cabinet lights, both of which use G4 halogen capsules. These fiendishly hot little lamps are easily and very cost effectively replaced with G4 LED capsules that simply push into the existing fitting.
Domestic LED lighting is also particularly effective in situations that have no natural light at all and can therefore use only artificial light, since LED lights have a light quality that is unique and in many ways more versatile than traditional lighting. Just think of some of the really great basement ideas you could create for example using a mixture of colored LED mood lights and cool LED spots. In fact, when planning any new DIY projects, consider how and where you might incorporate LED lighting to add a new dimension, as well as saving you real money long term and helping the environment. Basements, workshops, garages and the like also often have T8 fluorescent tubes fitted and these are prime candidates to replace with LED T8 tubes that cost far less to run, don’t need replacing anywhere near so often, don’t suffer from headache inducing flicker and give off almost no heat so putting less strain on your air conditioning.
LED lights also work brilliantly in strips, so replacing T5 fluorescent tubes under kitchen units and lighting inside cupboards are both ideal applications, not least because LED kitchen lighting gives off almost no heat, plus their super-bright light is required in a relatively small area rather than spread widely. For the same reason, if you’re looking for walk in closet ideas then simple domestic LED lighting is a great solution.
What they are less good at (at the moment) is all round illumination of the sort you get from say a table lamp with a lamp shade. Though even now there are LED candle and LED GLS replacement globe bulbs available that will outperform general domestic incandescent lighting.
The EvoLux S and EvoLux R globe LED light bulbs are intended as a direct replacement for a regular 100w GLS bulb, with upto 1,000 lumens of brightness (that’s extremely bright by any standard, not just for a low energy light bulb). These come in a variety of regular screw and bayonet fittings and with a choice between warm white down at 3000k (see below for information about LED light color) and cool white at 6000k.
The difference between EvoLux S and EvoLux R globe LED bulbs is that the R series is also dimmable with a built in dimmer capability that allows three preset light levels. It also remembers the previous dimmer setting and automatically returns to the chosen light level when turned off and on. It’s worth noting also that there are also EvoLux Sh and EvoLux Rh variants that have reduced height clearance, for applications where the bulb might otherwise be visible (an all too common problem with CFL bulbs alas, with little sign of a solution from that quarter either).
Given that these EvoLux LED globe replacements for the regular 100w incandescent bulb are powered by a mere 13w LED chip that will last for 50,000 hours and deliver massive savings in electricity costs (not to mention replacement costs), their presently high price still represents excellent value for money.
So, point one: stick initially to what LED home lighting currently does best – directional lighting. But if you do want to try out direct replacement LED bulbs for general lighting, then at the moment both the 13w CREE Evolux series and Ledzworld 6.5W CTA are where it’s at. The latter is from a Dutch outfit that specialize in professional LED applications but also make high quality mass market LED light bulbs. The 6.5W CTA in fact uses Cree LED modules and a patented dimming system (see notes about dimming LEDs).
LED Light Colors
The second area that gets people in a muddle, simply because it’s never been a consideration before when purchasing domestic lighting, is “color”. This is not just color as in green, yellow, red, blue, orange and all the other bright, rich and vibrant colors that are available to home LED lighting systems.
What is mostly meant by color in the context of LEDs is “white color”. LED lamps are available in a range of different “white colors”, meaning the difference between a softer, warmer form of illumination and a sharper, colder effect.
The “color” scale for LEDs is measured in Kelvins and ranges from just below 2000K which has a yellow/orange tinge, through 4000K which is roughly neutral and going up from there to a quite bluish hue. The colors associated with any particular LED product are often described as being one of “warm white”, “white” or “cool white”. Paradoxically, as the temperature goes down the light appears warmer and as it goes up it seems cooler – just one of those weird things, so get used to it.
As a general rule warm white LED lights work best indoors as it is closer to the color we have become accustomed to with GLS bulbs, and cool white is a good choice for outdoors or anywhere where you might want sharper definition and illumination that more approximates daylight.
The in-between white color is a matter of personal taste but would certainly be a suitable candidate for any particularly bright spot or recessed lighting or in say a desk lamp.
To understand the difference between “warm white” and “cool white” take a look at the example above. Although photographs never quite capture how our eyes experience different types of light it’s clear that both very cool and very warm color temperatures can adversely affect vision and generally make a space feel uncomfortable, so it’s worth considering this issue quite carefully and getting a color that suits your own personal needs and tastes.
LED Equivalent Wattages and Power Factors
Next, we get to power ratings. We are used to traditional light bulbs being rated according to their wattage (the amount of energy they consume), so we know that 100w is pretty bright while 40w is comfortable in a lounge for example and 10w is basically a courtesy or night light.
Low energy LED lights don’t conform to this scale for the obvious reason that they don’t consume anywhere close to the same amount of electricity since nearly all their input power is converted to light rather than wasted as heat. So how do we compare the two?
As a rough guide, simply divide an incandescent wattage rating by ten and add a bit. So for example, to replace a 60w halogen lamp (both 12 volt MR16 and GU10 mains fittings are commonly available for LED equivalent replacements) then you would most likely being looking at an LED spot light rated at 7w. Move up to say 12w and your LED is taking on a regular floodlight.
Some manufacturers do state an equivalent conventional wattage for their LED bulbs but experience suggests you take these with a heavy pinch of salt. They do however provide a rough guide to the level of brightness you can expect – for example a GU10 LED spot lamp claiming to be suitable as a replacement for a 50w halogen lamp is in reality like to struggle to match that claim but will almost certainly serve as an extremely effective substitute for a 35w halogen.
However, as always it’s not quite so simple. Your choice of color will make a difference – cooler colors will appear much sharper and effectively brighter than warmer colors, but as noted above this can be harsh on the eye for a typical indoor domestic situation. So mentally adjust the wattage equivalent up or down a bit according to the color chosen.
Also, the angle of the light beam from the lamp has a considerable impact. A narrow angle, say 40 degrees or less will shine all of its light onto a relatively small focused area which will thus appear very bright. A wider angle, anything from 70 to 120 degrees for example, will disperse the illumination over a much wider area but because the light is thus diluted, more will be lit but less brightly.
As an example, consider the GlacialTech LED-BR30 which is a multipurpose 11w LED bulb that has a 120 degree beam, lasts 50,000 hours and delivers 720 lumens illumination (for comparison purposes, a regular 40w incandescent typically outputs 400-500 lumens and a 60w about 850 lumens).
Finally, just when you thought it couldn’t get any more confusing, there is the issue of the power factor. This in fact applies to all forms of lighting (and indeed electrical devices in general) but is disproportionately significant where LEDs are concerned. A power factor is a number between 0 and 1, where 1 is perfect efficiency (no energy loss at all, so in practice somewhat hypothetical) and 0 is beyond terrible.
To apply a power factor simply divide the stated lamps wattage by the stated factor. Assuming of course that this information is available – as a rule you can expect products with a high power factor to mention this, and those with a low factor to keep quiet about it. So for example a 4W LED with a power factor of 0.9 actually consumes 4/0.9 = 4.4444W whereas one with a factor 0f 0.5 in facts draws 4/0.5 = 8W. So even though two bulbs may be rated at the same wattage, one could be drawing twice as much power as the other. What accounts for the difference is often the quality of the built-in electronics that step down and regulate the voltage.
Power factor is without question quite a complicated concept (see how far into this simplified explanation you can get before you realize you didn’t really understand it at all). Its importance is related to the distribution of electricity by utility companies whereby they measure the supply to customers in volt-amperes but calculate the bill using watts. If you recall Ohms Law then you would expect these to be pretty much the same, but they’re often not when, especially when reactive loads (modern electronics typically) are present in the circuit. The point is that electricity suppliers charge more to commercial customers operating with a power factor below 0.9 and although this does not yet apply to domestic supplies, there are dark rumors about what the future may hold.
So remember to take into account power rating (wattage), beam angle and LED light color. And also apply the power factor if this information is available (and you either understand or care about it).
LED Drivers and Dimming LED Lights
Low voltage 12v LED lights need a specialist transformer commonly called an LED driver. These are guaranteed to provide a constant voltage (i.e. 12 volts plus or minus a small variation) since LED light bulbs are susceptible to damage due to too high and/or fluctuating voltage. The problem with using the regular 12v transformers associated with low voltage halogen lights is that these expect quite a heavy load, typically in excess of 30w, and will output rather more than 12 volts if the load is too small.
If you have a large bank of LED spotlights (say 8 or more) then connecting them all to just one of the existing 12v transformers but leaving a single halogen in-situ is a reasonable compromise for many. This simply increases the load on the transformer sufficiently to prevent it increasing it’s voltage output and thereby damaging any LEDs in the circuit. It’s not the best way to go though since you still have an inefficient halogen lamp burning up the electricity bill.
So, if dimming 12v LED lights is not an issue (we’ll get to that next) then either artificially increase the load as described above, or more simply and preferably, install a constant voltage LED driver. You don’t need one per lamp as is common with regular halogen low voltage transformers – a single driver can run a dozen or more LED spots. You could in principle also share a single driver across different areas if the layout of your house permits – have a single master switch to control power to the driver then feed the driver outputs via individual lighting switches to the lights. In practice LED drivers aren’t all that expensive and it’s much better to buy as many as makes the wiring easier.
Using LED lighting with a dimmer switch can be an issue for the reason that they are so low wattage. Conventional dimmer switches invariably require quite large loads (high wattages) otherwise they buzz, hum and generally don’t work. Clearly the tiny wattages associated with low energy LED lamps are nowhere near enough to drive these beasts, and so in general people either opt to install energy saving LED lights for applications where dimming is not required or purchase LED dimmer units designed for this purpose (or purchase items such as the EvoLux R LED globe mentioned above, which has a built in dimmer capability).
There are a number of options however should you want to have normal dimming capability with LED lighting. The approved method for low voltage 12v LED lights is simply to install a dimmable LED driver plus a suitable dimmer switch (these are usually labeled by output voltage (i.e. 1 to 10v) rather than by maximum wattage). Alternatively, if using mains powered GU10 LED spots rather than low voltage MR16, an analog (not electronic) dimmer rated to cope with the very low load will also work. These guys provide a decent write up on the subject of LED dimming:
The whole subject of dimmer switches and transformers in general is a minefield but here are a few key facts to help sort out some of the terminology. First there is the issue of “loads”: a straightforward incandescent lamp is a “resistive” load; a traditional wire-wound transformer (as used to step down the voltage for low voltage lamps) is an electromagnetic or “inductive” load; a modern electronic transformer is a “capacitive” load (these last two both being forms of reactance or a “reactive” load).
Many people assume (reasonably enough) that dimming a light will save money since the light bulb uses less electricity. The truth is that it depends on the type of dimmer being used. Old fashioned dimmer switches simply used resistors (also called rheostats) to decrease the voltage passed to the load; this dissipates power as heat from the dimmer unit (rather than the light bulb) so it’s not actually saving anything much at all.
The heat loss in a resistive dimmer is proportional to the voltage across it multiplied by the current passing through it. But since small drops in voltage result in a much more noticeable drop in illumination for an incandescent lamp (the current is also quite low – about 250mA for a 60W bulb), the actual heat generated is not that great. Note also that the dimmer circuitry absorbs some power, even at full brightness, so there is always overhead involved regardless.
Nearly all modern dimmers however (typically TRIAC or Triode for Alternating Current) work by rapidly switching the electricity off and on as the mains alternating current changes polarity which results in reduced power being sent to the load and hence the appearance of reduced brightness. Normal mains electricity uses an alternating current (AC) that cycles (or switches) at the rate of about 50 times per second. A solid state electronic transformer simply chops the number of “on” states and thus less electricity gets sent to the light which causes it to dim. It also saves some money since power is not simply diverted into heat.
But it’s not quite that simple… there are two ways to achieve this switching effect, known as leading edge and trailing edge dimming. Without going into detail the general rule of thumb is that a leading edge dimmer will work with wire-wound or toroidal transformers (i.e. old style) but not electronic ones and a trailing edge dimmer is suitable for modern electronic transformers but not wire-wound ones. Except where otherwise stated. This site has a great section all about transformers if you want to really get into this subject.
Confused? If you can afford it there is always the option of an adaptive dimmer that as the name suggests dynamically adapts to work with resistive, inductive and capacitive loads. Now you know why so many low voltage light fittings with built-in transformers (ones that use G4 halogen bulbs are a prime example) state “non-dimmable”. They’re just covering their backsides – they often can be dimmed, but you need to establish what type of transformer it is using and purchase a type of dimmer suitable for that transformer.
Finally, be aware that whereas dimming an incandescent lamp will cause its color to shift more towards the red/yellow part of the spectrum, dimming an LED will simply reduce the light intensity without altering the color one iota. LEDs emit light at a particular wavelength according to the energy band gap between the two sides of the diode. A dimmed LED simply emits fewer photons but still at the same wavelength (and hence color). This particular characteristic foxes many people because it’s not what they’re used to.
That said… Dutch based manufacturer Ledzworld has products that incorporate a patented dimming system called Color Temperature Adjusted (CTA) Dimming that fades in an orange LED as the white is faded out and replicates the effect we’ve all come to know and really rather like when dimming incandescent lamps. Sometimes the answer is simplicity itself.
Where To Buy LED Home Lighting
If you are new to low energy LED home lighting then the straightforward answer is: anywhere you can either see an actual example or failing that a decent photograph so you can gauge how a particular LED application will work in your own home before you buy it.
Many specialist lighting shops obviously have displays you can look at (and quite often also catalogs with photographs), and even big DIY and more general stores are now starting to include energy saving LED home lighting in their display items.
The reason for this advice is simple. This new generation of energy saving LED lighting technology is unfamiliar to most people and it will take a while to get used to how the various different bulbs actually perform and what they look like in use.
Also, unlike traditional light bulbs, LED home lighting is a long term investment. It will without doubt save you a great deal of money in the years (decades in fact) ahead but the costs are all upfront.
It is reckoned that most LED lights actually cost less to run than to purchase – and since they last for a very, very long time that is a staggering fact. You do not want to make a mistake you might be stuck with for a significant portion of your life (statistically you are more likely in the USA to keep your LED light bulbs longer than your spouse!).
When it comes to the product itself, find out if possible where both the LED bulb AND the actual LED chip (or “die” as it is sometimes called) within it originate. Although there are many lighting manufacturers selling LED products, there are at present only a handful of chip suppliers – the best of which is arguably Cree whose own products include the highly regarded Cree Evolux LED series of spotlights. Cree chips also pop up in other manufacturer’s products such as the Exergi Hyperbright which currently lays claim to being among the warmest LED spotlights generally available, while others such as Edison use their own for products such as their 6W GU10 LED which is among the brightest and certainly a good replacement for a 50W halogen spotlight.
If you’re looking at say a Philips or Osram LED product that has a reasonable amount of information on the packaging then you are on pretty safe ground and likely to buy a reliable product that performs as you would expect. If on the other hand you are buying the cheapest thing you can find on eBay that ships from China then you will almost certainly get what you deserve and good luck to you.
There is no reason at all why you shouldn’t buy LED light bulbs direct online – but it would be sensible to first get to know which particular types of LED lamp suit you and your requirements and then to stick to buying from reputable web sites that offer warranties.
You tend to get what you pay for and when buying low energy consumption domestic LED lighting the best advice is to buy top quality brands. Anytime you see someone promoting claims such as “cheap LED” or “budget GU10″ then pass on by and look out instead for “quality LED”. You’ll always save money in the long run.