Led light bulbs: what they are, why are replacing traditional light bulbs and energy saving. What advantages and disadvantages also. Here’s the buying guide for choosing the right led light bulb.
Led bulb: until last year were very expensive, sometimes unreliable and, almost always, with a yield below expectations. Now is no longer the case. The arrival in supermarkets, as well as in specialty stores and online stores, increased greatly the spread (and quality) in our country. So here is the buying guide on new led bulbs. Objects that really, and not only in the advertising slogans, to save on electricity bills. To make it easier to read, the search for topics of interest and regularly updating we decided to write it in the form of questions and answers.
Unlike incandescent bulbs, very hardly LEDs are “shocked”. And if it happens it happens in the first few hours or weeks of use, because it is defective. In this case the manufacturer’s guarantee: read the conditions on the box. Led bulbs usually end their lives by reducing the light intensity until it becomes unacceptable. At least in the place for which were bought: nothing prevents you to unscrew them and put them in a different environment, where they can still be useful.
Led bulbs diffuse the light in the same way as traditional, energy-efficient ones?
Not exactly. Incandescent lamps and energy saving ones project a spherical light, i.e. in all directions. Single dimmable LED light at the LEDBulbBay website, instead, at most project a beam of 120 degrees, which is classified as “directional lamps” that is not suitable to replace an old light bulb because their beam would be too focused in one point or, if you prefer, not quite widespread. To obtain wider beams of light industry brings together in a single bulb led, appropriately positioned to achieve multiple items desired light coverage. The latest additions are the bulbs with micro LEDs that mimic the tungsten filament of incandescent bulbs and diffuse the light almost omnidirectional.
Before reaching its maximum brightness, led bulbs you need to “warm up”?
No. Led bulbs produce instantly their highlights. Exactly like incandescent light bulbs and as opposed to energy-saving light bulbs.
Led bulbs have the same brightness as the traditional ones?
Yes, they may have the same brightness of traditional bulbs but it is not always immediately identify the equivalent-output model. Always, in fact, we are used to evaluate the 60 Watt bulbs to buy 75 Watt second power, etc. To evaluate the brightness of led light bulbs, however, should not be considered the power rating in Watts and even the equivalent power reported by many translation tables. To get an idea of the amount of light emitted is considered the luminous flux of the lamp led, which is expressed in lumens. It is this value that allows us to calculate the equivalence bright with a traditional lamp. In addition at constant rated output expressed in Watts, the amount of light produced by two different brands of led bulbs can be different.
The research of course does not stop and the industry is making significant progress in the field of led bulbs. Philips, for example, has built a prototype high-quality led light giving the beauty of 200 lumens per Watt of energy consumed: practically halving the current consumption led bulbs already great.
What is color rendering index of a led bulb?
On the boxes of led lamps is often number indicated by the initials Cri. CRI is the abbreviation for Color rendering index (in Italian color rendering index: on the boxes of bulbs can be indicated as RA). It is a number placed on a scale from 0 (dark) to 100 (sunlight) and indicates the ability of the bulb to let us see objects that illuminate with natural colors and not yellowish or pale blue. More number Cri is high, the better the performance of the light bulb. Interior led bulb must have, by law, a Cri > 80 ‘s (the old incandescent lamps in this do better because they have a Cri > 95. Energy-saving lamps have a Cri between 80 and 88).
There are only white light led bulbs?
No. The white light led bulbs is produced with the three RGB colors (red, green and blue). By adjusting the intensity of each of the three colored led sources you can get any color led light. It is the principle used by some manufacturers to create innovative lighting systems, such as the Philips Hue, which not only allows to change color, but also to do it over wi-fi using your smartphone or tablet. And also to turn on or turn off the House lights when out.
Led bulbs produce heat?
No, led bulbs are cold, warm very little because they are very efficient: a large percentage of the electricity they receive is transformed into light, not heat as in traditional bulbs. However a part of control circuits led bulbs warm and therefore, higher power models have a part made of metal which is used to dissipate the heat generated during operation.
Turning off and on several times a led lamp you risk breaking it?
Like all industrial products also led bulbs can fail. The law distinguishes between a failure and the normal life of the product. Damage the manufacturer warranty. As regards the duration, the law says that led bulbs should be able to turn on and off without breaking at least 15,000 times (or on/off cycles). In principle, the latest led bulbs reach 25 or more cycles: it would mean switch them on and off 70 times a day for a year, before risking to break them for this reason.
Led bulbs are screwed on the traditional lamp?
Yes: European legislation requires that the attacks led bulbs are the same as those of traditional lamps. However some led lights, despite attack and standard form may be, even if only slightly, longer or wider than the equivalent incandescent or halogen lamps. And this may make it difficult or impossible to put them inside of ceiling or wall light. That said, most common attacks are the classic screw E27 E14 (big) and (small). Moreover, to simplify the lighting of large environments, some ceiling lights and sconces designed for the led lamps have inside two lampholders.