How to choose a led bulb
It was easy to select from usual incandescent bulbs because they differed only in capacity and in shape of the cap; led bulbs which replaced them have much more characteristics.
Characteristics of LED lamps
Luminous flux
The brightness of a led bulb is characterized by a luminous flux which is measured in lumens (lm). You can choose how bright you want to light your office or room. But try to stick to the recommendations of Building regulations.
| Type of a room | Norm of illumination (lm/m^2) |
| Bedroom, kitchen | 150 |
| Kid’s room | 200 |
| Bathroom, toilet | 50 |
| Office for a general purpose | 300 |
| Office for drawing works | 500 |
Use the spreadsheet to understand what number of bulbs and what wattage of bulbs you need. It also shows compliance of the usual incandescent bulbs with the led bulbs which replaced them.
| Luminous flux (lm) | Led bulb (W) | Incandescent bulb (W) |
| 250 | 3 | 25 |
| 400 | 5 | 40 |
| 650 | 8 | 60 |
| 1300 | 14 | 100 |
| 2100 | 22 | 150 |
It’s possible to see in the spreadsheet that led bulbs use less energy. That’s one of the main reasons of their popularity.
Color spectrum
The color of the emitted flux is also an important thing when you select a bulb. It is measured in Kelvin degrees (K). The smaller this parameter is – the warmer the light will be.
| Color temperature (К) | Shade of the light |
| 2700–2800 | Warm yellow |
| 3000 | Warm white |
| 4000 | Neutral white |
| 6000 | Cool white |
The most comfortable shades for home are yellow ones: they help to relax and to have a rest. Warm white light is recommended if you work in an office environment. It is believed that it increases efficiency. Bulbs with cool white light are designed only for non-residential utility rooms.
The voltage range and the color rendering index
Usual incandescent bulbs were working at a voltage of 120 V (220 V non US) with no loss of brightness, but for the led bulbs it is possible to have lower indicators to radiate stable. So the owners of these bulbs will not even notice the drops of voltage in the electric system.
Try to choose the voltage range with the biggest spread of indicators when you’re buying it.
The color rendering index determines how natural will colors of objects look in the light of the particular bulb. It is denoted by parameter CRI (color rendering index) or Ra. The higher the CRI is – the more natural illuminated objects will look.
It is recommended to use bulbs with an index of not less than 80 CRI or Ra in dwellings.
Dispersion angle
The LEDs are arranged so that they are able to only shine in front of themselves: a very small part of light deviates to the other side. So pay attention not only on their quantity but also on how they are located. This will directly depend on the dispersion angle. For different models of bulbs it can be from 30 to 360 degrees.
Pulsation of light
The light of defective bulbs often pulsates. It is invisible for the human eye, but it can make a negative effect on the nervous system and the vision can deteriorate because of it.
Purchase bulbs with a range of pulsation not more than 5-15%.
Durability and manufacturer
Led lamps have average durability from 10000 to 50000 hours. It is very difficult to know the real durability, because technologies are improving from day to day, the durability is calculated only in theory.
The warranty on these lamps is given for 1-5 years depending on the manufacturer. The duty of the store is to replace the lamp if it breaks during the warranty period.
There a lot of manufacturers of led technology today. And not all of them indicate reliable information about a bulb on the packaging, we suggest to buy only from Amazon 4+ stars reviewed items.
How to choose a right led bulb
To select a bulb that will create a comfortable lighting, will last for a long time, will not do harm to the health and will save electricity, use the following tips.
- The color spectrum of the bulb for an apartment should not exceed 3000 K. If you need a bulb for an office, select a temperature of 4000 K. The bulbs of 6000 K and above should only be used in the utility rooms.
- Choose bulbs with 110-230 V variation of the voltage.
- The color rendering index should be no less than 80 CRI.
- The pulsation of a bulb should not exceed 15%. It is easy to check in the shop: screw the bulb into the base and bring a smartphone camera to it. If the pulsation is high, the image on the screen will blink.
- Be sure to check operability of a bulb. Almost all electrical shops have this possibility. In case you buy from Amazon be carefull to buy from Prime offers so in case you have any problem they offer free return and refund.
