Home-Lighting: Upgrading to LED Made Easy

Assume that I’m someone who is already enlightened about the benefits of LED (Light Emitting Diode) lighting. Very interested, I have made up my mind to upgrade my home lighting to LED soon. I’m prepared to pay for the higher initial costs of LED lighting products. But before I buy, the first question that comes to mind is what power of lighting to choose for the same brightness I have/use now. Then, I begin to wonder whether I can easily retrofit my new LED lights into the existing electrical fixtures in my house. As I’m not sure, I try to find out from the Internet by searching for (maybe) ‘how to migrate to LED lighting’. While I get some useful answers, I also run into a whole lot of new terms that I know little about like ‘diode’, ‘semiconductor’, ‘photon’, ‘lumen’, ‘CRI’, ‘CCT’ and so on. My lack of knowledge makes me unsure of myself, so I begin to wonder, ‘Can I ignore the new terms and proceed safely?’. ‘If I do, will my LED project be successful?’.Not to worry – these are typical roadblocks we all run into. But before you decide to hire a consultant, read the solutions presented in this article. For all you know, after reading through, you may find that you don’t really have to!Problem 1 – DETERMINING EQUIVALENT LED LUMINOSITY BY POWER IN WATTS:Manufacturers are increasingly providing this info on the cartons of LED bulbs and tubes by phrases such as ’40 Watt equal’, ’60 Watt Replacement’ etc. so this problem could be treated as ‘already solved’, in many instances. If not, to decide on the power rating of the LED light to buy that’s equivalent to any of your present non-LED lights, use one of these methods:(A) Rule-of-thumb: Calculate proportionately, using 70W incandescent=50W Halogen=18W CFL=15W LED.CAUTION: This method does not produce accurate enough results to enable you to safely buy/install LED products. It only gives you a fairly correct value; one that should be used in an emergency. It may also help you make an accurate guess, once you get used to it. Here’s an example: You need to replace a 100W incandescent bulb with LED. This rule-of-thumb will point you to a 22W LED bulb (i.e. by the calculation,100/70 * 15, decimals being rounded-up to the next higher whole number). The exact LED power required is 27 W, so that the result is lower by 5W (about -19%). But you can make a good guess at this point because LED power ratings can take only certain standard values like 7W,11W,14W&27W. Since you need to make a guess starting with an approximate value of 22W, its very likely that you will choose 27W rather than 14W, since 22 is closer to 27 than to 14.(B) Switch to thinking in terms of Lumens(lm): This method is easier and highly recommended. However, you might need to change your way of thinking a bit – think in ‘lumens’ (or brightness) instead of ‘watts’When we say ‘an equivalent light source’ we mean a source that produces the same amount of brightness (or luminosity) as the one to be replaced. The unit of measure for brightness of light is the ‘Lumen’ (lm) (Note: To get an idea of Lumen power, remember that a single, burning wax candle produces around 13 lm of light). Quantifying brightness in terms of lm is the straight-forward way to do it, while watts is round-about, from the viewpoint of a light designer. Apart from being indirect, wattage is not a standard measure across different light types since the lm produced by each, for the same no. of watts, is not the same. Hence, the strong recommendation for adopting the practice of thinking in terms of lumens instead of watts for lighting applications in future.The lists below are lm based and you can use them to directly read-off the equivalent watts of LED power you need for a given number of lumens: 450 / 40 (I) /9-13 (CFL)/ 4-5 (LED) 800 / 60 (I)/13-15 (CFL)/ 6-8 (LED)1100 /75 (I)/18-25 (CFL)/ 9-13 (LED)1600 /100 (I)/23-30 (CFL)/ 16-20 (LED)I = Incandescent, CFL = Compact Fluorescent Light, LED = Light-Emitting DiodeNote: The figures above have been taken from the US Govt’s Dept. of Energy website, energy.govProblem 2 – RETROFITTING:Since LED lighting products are standards compliant, retrofitting is usually uncomplicated. However, if (I) the new LED product(s) will not fit into existing sockets OR (ii) the existing sockets are so worn out that they must be replaced OR (iii) you are not sure how to do it, play it safe by buying LED retrofit kits. These kits contain all components, diagrams and step-by-step instructions to help you install your LED lights safely & correctly, by yourself.Problem 3 – REMEMBER TO USE GOOD QUALITY LEDs:The impressive longevity of LED lighting (i.e. of the order of 25,000 hours, that we read about) is one of its most highly valued properties. One of the most important factors responsible for longevity is the quality of LED chips used. So, don’t be lured into buying from little known manufacturers who will, no doubt, offer tempting, low-cost options. Insist on buying from established vendors like Cree, Philips, Feit Electric, GE and so on, even at SIGNIFICANTLY higher price(s), to be assured of longevity.Problem 4 – FIGURE OUT WHAT VALUE OF ‘CRI’ TO USE:CRI is an abbreviation for ‘Color Rendering Index’. It measures the ability of a light source to faithfully render, or light up, objects of all colors equally. Not all light sources are capable of doing this. LEDs are among the worst of contemporary lighting technologies in the matter of color rendering, while incandescent bulbs are good examples of such ideal or ‘perfect’ light sources.CRI can take values between 0 & 100. A ‘perfect’ light source is assigned a CRI of 100.From the foregoing, it’s clear that the higher the CRI value, the better. Hence, when selecting LED light(s), pick up the ones that have the highest CRI values. Also, use a lower cut-off limit of CRI=80.Problem 5 – COLOR TEMPERATURE a.k.a CORRELATED COLOR TEMPERATURE (CCT)How color and temperature are related needs a little introduction. Let me explain it briefly, this way. Suppose we connect an ordinary incandescent bulb to a source of electricity whose voltage can be varied. Let’s start with voltage=zero. As the voltage is progressively increased, at some point, the bulb’s filament will first turn red. Further increase in voltage will cause the filament’s color to change to orange, then yellow, white and so on (to help, memorize the sequence correctly, remember VIBGYOR, in reverse order). We also know that the heat dissipated by the bulb (and hence its temperature) will increase with the changes in color. This is the basis of correlation between color and temperature in lighting applications.We tend to associate the color red with words like ‘glowing’,’fire’,’hot’ etc. Similarly, the color blue is commonly related with words like ‘cool’,’natural’ and ‘bright’. But as we have seen in the example above, red color is produced at low temperature, while blue color, at high temperature. Scientists and engineers always prefer to use degrees Kelvin (deg K), so all ‘correlated color temperatures (CCTs)’ are specified in deg K.To get an idea about the range of color temperatures, note that at 12 noon, when the sun is directly overhead us, its color temperature is 5600 deg K. ‘Warm’ colors have color temperatures in the range 2700-3000 deg K while ‘cool’ colors have color temperatures above 5000 deg K.Problem 6 – DIMMABLE Vs. NON-DIMMABLEMost, though not all LED products are dimmable. If you don’t need dimmable lighting, you will need to find them by specifically sifting through product specifications and/or description.Problem 7 – DIRECTION OF LIGHTAs we are discussing home lighting, choose omni-directional, by default, as lights that spread in all directions are most commonly required for home lighting. If you have specific requirements for uni-directional light, then choose appropriately.ADDITIONAL INFO:1. The mandatory ‘lighting facts label’ (viewable at energy.gov –> energysaver –> articles –> lumens-and-lighting-facts-label) usually pasted on the back of the packing of a lighting product provides you with info such as Brightness in lumens, Estimated Yearly Energy Cost, Life in years, Light Appearance (CCT) in deg K and actual power consumption of the product in watts.2. Detailed info of lighting products can be viewed at the Lighting Facts website (lightingfacts.com)

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Know the Basics of Home Lighting

When we think about lighting in our homes, the first things that come to mind are lighting fixtures such as chandeliers and recessed bulbs. We may have used stylish fixtures in our home yet we always seem to find something lacking in that we have. The dining room may have a beautiful chandelier or the living room is bathed with recessed lighting in all four corners. But, that’s just about it. The room still lacks the warmth that we see in homes shown in the magazines.If we take a closer look at magazines, our fixtures appear more stylish that what they have featured. But what makes them look better than ours at home? Perhaps, there is something more to home lighting than meets the eye. It is important that we as homeowners should be well aware of its basic elements.Providing a light source for the home goes beyond the stylish fixtures. What is important is that there is a right blend of all the different types of lights. Lighted homes featured in the magazines all flawlessly exhibit three basic elements of home lighting. These are ambient lighting, task lighting and accent lighting.Ambient lighting provides general illumination in any part of the home. This is important to ensure safety as well as ease of movement within the said area. Task lighting involved focused lights which are typically used on work stations and desks. Both of these types of lighting are what we usually concentrate on our homes. The last part which is accent lighting is probably one of the things we usually left out. These are used to enhance the decorative elements in the house such as paintings, sculptures, vases and even architectural structures.Knowing all the basics, it is important for us homeowners to create a balance of all these lights in our homes to achieve the perfect home lighting we’ve always wanted that is worthy of gracing the pages of the magazines.

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