How to choose a bulb

The basic parameters of most light bulbs will be described below.

Power [W]

The wattage of a light bulb determines the current consumption of the light source. It often seems to users that the power is responsible for the brightness of the bulb, and it is indeed so – but only for classic incandescent bulbs. In the case of LED bulbs, the type and quality of the diodes used determine the brightness of the bulb itself. Brightness of a light source is defined by a parameter called luminous flux.

Light flux [lm]

Determines how bright the light source shines. Bulbs with a higher value of luminous flux shine brighter, and those with a lower value – darker. In the case of LED bulbs, the type and quality of the diodes used determine the brightness of the bulb itself.

The table below shows the most commonly used wattage of classic bulbs with the corresponding luminous flux:

Color temperature [K]

Briefly sometimes referred to simply as the color of a bulb – parameter specifying mainly bulbs in LED technology – defines the shade of white light – the light emitted by a light bulb can be:

• Warm (like light bulbs) – 2000K to 3500K – creates a cozy atmosphere, makes it easier to relax, it is best suited, for example, to a bedroom
• Natural(like lighting on a sunny day) – 3500K to 4800K – stimulates action, best suited for the office, shop, kitchen or bathroom
• Cool (blue tending) – 4800K to 6500K – refreshing color that stimulates action even better, it is best suited for production halls, warehouses, etc.

Of course, the above examples are just suggestions, and the color temperature should be selected primarily due to user preferences. The lower the color temperature, the warmer the light, which is best illustrated by the following comparison:

CRI

Determines how well the light bulb reproduces the colors of the illuminated object. The highest possible equal factor is 100 and determines how colors are reproduced in sunlight. The higher the CRI, the more faithful the colors. This is best illustrated by the following comparison:

The lowest CRI is found in lamps typically used for street lighting – sodium, mercury, etc. Low CRI bulbs bad affect well-being. They should not be used in apartments, offices and other rooms.

Medium-quality light (CRI between 70 and 90) have mid-range LED bulbs, fluorescent lamps and metal halide lamps. They are best suited for lighting apartments, schools, offices, etc.

The highest CRI factors (greater than 90) have high-class LED bulbs, modern linear fluorescent lamps and traditional bulbs (incandescent). Sources with such a high factor should be used wherever faithful color reproduction is important – e.g. in a paint shop, photo studios, etc.

Many people wonder if it is worth replacing classic lighting with LED type. The basic differences between classic (incandescent) bulbs and LED sources will be presented below:

1. Power – Classic bulbs with the same power are characterized by lower luminous flux than LED bulbs (LED bulbs are brighter). This is due to the technology and the way the light is generated – classic light bulbs use most of the power consumed for heating, lighting usually accounts for ~10% of the energy consumed. In the case of LEDs, most of the energy is used for lighting.
2. Color Temperature– classic bulbs are characterized by a warm color (approx. 2700K), when selecting sources based on LED technology, the color temperature is practically any.
3. CRI – in the case of classic bulbs, the color rendering index is equal to 100 (this is the maximum value), in the case of LEDs, this value is from 80 upwards.
4. Operating Temperature – the aforementioned differences in construction technology also cause differences in operating temperature. Housings of LED sources (regardless of power) usually do not exceed 60°C, while classic light bulbs can heat up to over 200°C (the temperature of a 100W bulb bulb after five minutes of lighting).
5. Price – LED bulbs are more expensive than classic bulbs, but the exploitation of LED sources is much cheaper.
6. Durability– the service life of classic bulbs is usually approx. 1,000 hours, while the service life of sources based on LED technology – over 50,000h.

Resistance to mechanical damage

LED technology is radically different from standard incandescent bulb technology – there are no glass or moving elements in LEDs, which translates into high mechanical strength – resistance to impacts, shocks, vibrations, etc.