Suppose I already understand the benefits of LED (Light Emitting Diode) lighting. Very interested, I have decided to upgrade my home lighting to LED as soon as possible. I’m going to pay the higher initial cost of LED lighting products. But before buying anything, the first question that comes to my mind is what kind of lighting power should I choose for the same brightness I currently own/use. Then I started to wonder if I could easily retrofit my new LED lights into my existing electrical installations at home. Since I’m not sure, I’ve tried to find the answer on the internet by (maybe) searching for “how to migrate to LED lighting”. While I got some helpful answers, I also came across a lot of new terms that I don’t know much about, such as “diode”, “semiconductor”, “photon”, “lumen”, “CRI”, “CCT” and so on. My lack of knowledge made me feel insecure about myself, so I started to wonder, “Can I ignore the new terms and move on safely?”. “If I do this, will my LED project succeed?”.
Don’t worry, these are typical obstacles we all face. But before you decide to hire a consultant, read the solutions in this article. For all you know, you may find after reading that you really don’t have to!
Question 1- Determine the equivalent LED brightness per watt of power:
Manufacturers increasingly provide this information on the boxes of LED bulbs and tubes by means of phrases such as “40 watts equals”, “60 watts replacement”, etc. Therefore, in many cases, this problem can be considered “solved” . If not, you can use one of the following methods to decide that the rated power of the LED bulb you buy is equal to any non-LED bulb you have:
(A) Rule of thumb: use proportional 70W incandescent lamp=50W halogen lamp=18W CFL=15W LED.
Note: This method may not provide sufficiently accurate results to safely purchase/install LED products. It only gives you a fairly correct value; a value to be used in emergency situations. Once you get used to it, it can also help you make accurate guesses. Here’s an example: you need to replace a 100W light bulb with an LED. This rule of thumb points to a 22W LED bulb (that is, by calculation 100/70 * 15, the decimal point is rounded to the next higher integer). The exact LED power needed is 27 W, so the result is a reduction of 5 W (about -19%). But you can make a good guess at this point, as the LED power can only use certain default values, such as 7W, 11W, 14W, and 27W. Since you have to start guessing from an approximation of 22W, you will most likely choose 27W instead of 14W because 22 is closer to 27 than 14.
(B) Switch to the Lumens(lm) way of thinking: this method is simpler and highly recommended. However, you may need to change your mindset a bit – think in terms of “lumens” (or brightness) rather than “watts”
When we say “equivalent light source”, we mean a light source that produces the same brightness (or luminous intensity) as the light source to be replaced. The unit of measure for brightness is “lumen” (lm) (note: to understand lumen power, remember that a lit candle will produce approximately 13 lm of light). From a lighting designer’s point of view, quantifying brightness with lm is a simple method, while watts is cumbersome. In addition to indirectness, wattage is not a standard measure across different types of light sources, as each light source produces the same lm. Watts are not the same. Therefore, it is highly recommended to use lumens instead of watts in future lighting applications.
The following list is based on lm, you can use them to directly read the equivalent LED power wattage required 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 lamp, CFL = compact fluorescent lamp, LED = light emitting diode
Note: The data is from the US Department of Energy website energy.gov.
Question 2-Retrofit:
Because LED lighting meets product standards, retrofitting is usually not complicated. However, if (i) the new LED product is not suitable for the current fitting or (ii) the existing fitting is very worn and needs to be replaced or (iii) you do not know what to do then the LED Buy a retrofit kit. To ensure safety, these kits include all components, schematics and step-by-step instructions so you can install LED lighting yourself safely and correctly.
Question 3 – Remember to use standard LEDs:
The impressive lifespan of LED lighting (approximately 25,000 hours as we read) is one of its most valuable features. One of the major factors affecting longevity is the quality of LED chips. So, don’t be tempted to buy from lesser known manufacturers, who will definitely offer attractive cheap options. Insist on buying from leading suppliers like Curry, Philips, Fat Electric, GE, etc., even if the price increases significantly to ensure longevity.
Question 4 Determine the value of “CRI” to use:
CRI stands for “Color Rendering Index”. It measures the ability of a light source to honestly reproduce or illuminate objects of all colors. Not all light sources can do that. In terms of color rendering, LEDs are the worst in today’s lighting technology, and incandescent bulbs are a good example of this ideal or “perfect” light source.
CRI can cost between 0 and 100. The “perfect” light source is CRI 100.
In short, the higher the value of CRI, the better. Therefore, when choosing LED lighting, choose the light with the highest CRI value. Also, use the lower limit of CRI = 80.
Question 5 – Color temperature, also called mutual color temperature (CCT)
The relationship between color and temperature needs some introduction. I will explain it briefly, like this. Suppose we connect a typical light bulb to a power source whose voltage may vary. Let’s start with voltage = zero. As the voltage slowly rises, at some point the lamp’s stem turns red first. Further increase in voltage will change the color of the fiber to orange, then yellow, white, etc. (to correctly remember the order, remember VIBGYOR in reverse order). We also know that the heat emitted from the lamp (and its temperature) increases with the change of color. It is the basis of the relationship between color and temperature in lighting applications.
We associate red with words like “luminescence”, “fire” and “hot”. Similarly, blue is often associated with words such as “cool”, “natural” and “bright”. But as we saw in the example above, red is produced at low temperatures and blue is produced at high temperatures. Scientists and engineers always like to use degree calculus (degrees), so all “correlated color temperatures (CCT)” are specific to degrees K.
To understand the color temperature range, keep in mind that at noon, when the sun is directly overhead, the color temperature is 5600 degrees K. The color range of “warm colors” is 2700-3000 degrees K, while the color temperature of “cool colors” is more than 5000 degrees.
Question 6- Dimmable vs. not adjustable.
Most (but not all) LED products are dim. If you don’t need dim light, you’ll need to find it by screening specific product specifications and / or instructions.
Question 7- Direction of light.
When it comes to home lighting, the choice of each side is made by default, as home lighting usually requires light that spreads in all directions. If you have specific needs for One Way Light, please choose the right one.
Additional information:
1. The mandatory “Lighting Fact Label” is usually affixed to the back of the lighting product packaging (available at energy.gov-> energysaver-> articles-> lumen-and-lighting-facts-label) to provide you the lumen Does-and-lighting-facts-label information such as brightness in units, annual energy costs, age in years, the appearance of light in degrees K (CCT), and actual power consumption (in watts) of the product.
