What to consider when buying LED bulbs

What do we need to know before purchasing an LED?

Watt

The amount of energy consumed by a light source.

Lumen

"A unit of luminous flux, a measure of the total quantity of visible light emitted by a source."

The total amount of visible light. The higher the lumen output, the greater the amount of light spread over a larger area.

Incandescent - LED - Lumen Output

25W - 3W - 250 lm

40W - 5W - 450 lm

50W - 7W - 500 lm

60W - 9W - 800 lm

75W - 12W - 1100lm

100W - 20W - 1600 lm

Candela

"A unit of luminous intensity, luminous power per unit solid angle emitted by a point light source in a particular direction."

The light intensity from any point in a single direction from the light source. Compared to lumens, candelas focus in single directions, points, and beam.

LM/W

Refers to the energy efficiency of the bulb. The higher the lumen output per watt, the more efficient the bulb is.

Life-span

LED bulbs have longer life-spans compared to traditional light bulbs. They last up to 50.000 hours.

CRI

Color rendering index, measures the ability of a light source to reveal the colors of objects in comparison with an ideal or natural light source or the sun. This is measured in a scale from 0-100, 100 indicating that the colors under that bulb appear the same as they would appear under direct sunlight.

CRI>90 is recommended for retail applications.

CCT

Is the color temperature measured in Kelvin. Bulbs offer a range of colors, the lower the Kelvin, the warmer (yellower) the light will be.

Warm white 2700-3000K - Most similar to incandescents, offers a relaxing and warm light

Neutral white 3500-4100K - Energetic, good for retail applications

Day - cool white 5000-6500K - Refreshing light, enhances the blue color. Ideal for office, school, hospitals

IP

Ingress Protection. This classification tells against what lamps & luminaires are protected.

IP20 - Dust proof

IP21 - Dripping water

IP23 - Spraying water

IP44 - Splashing water

IP54 - Dust + splashing water

IP65 - Powerful water jets

IP67 - Dust proof + immersion for 30 min.

IP68 - Dust proof + long periods of immersion

Dimmable or non-dimmable?

Non dimmable bulbs can not work with dimmers. Dimmable bulbs on the other hand, can be adjusted and dimmed. You can control the light.