What is light intensity? “The key” for your living space

What is lighting intensity?

Concept of light intensity

Light intensity represents the energy that the light source emits in a specific direction. It indicates how strong or weak the light is from that light source. When the light intensity is high, the emitted light will be stronger and vice versa.

Lux light intensity

Lux is a unit of measurement for light intensity, expressing light power per unit area (m²), also known as illuminance.

Unit for measuring light intensity

The unit of measurement for light intensity is Candela (cd). One candela is the luminous intensity of a source emitting 1 lumen in a specified direction within a solid angle.

Formula for calculating light intensity and how to measure it

Formula to calculate light intensity

To determine light intensity, we use the following formulas:

- Illuminance (Lux) = Luminous flux (lumen) / Area (m²)

- Light intensity (I) = Luminous flux (Lumen) / Solid angle (steradian)

For example:

Suppose you have a lamp with a luminous flux of 1 lumen. When the emitted light is adjusted to focus in a beam with a solid angle of 1 steradian, the beam's luminous intensity will be 1 candela. If the solid angle is adjusted to 1/2, the light intensity will increase by 2 candela, making the beam narrower but brighter.

How to measure light intensity

There are two common methods for measuring light intensity:

1. Use a specialized light intensity meter

2. Use a light intensity measurement app on your smartphone.

Factory lighting standards

Factory lighting requirements: Light intensity in the production area needs to meet standards to ensure labor productivity. The lighting design must be sufficient, with not too high glare to ensure eye comfort.

Standard light intensity for housing

Similar to the factory area, families need to calculate appropriate lighting to ensure it does not harm vision and save electricity. 

Ensuring proper lighting standards also helps protect health. 

Some typical illuminance levels for each room are: bedroom 150 lux, living room 400 lux, and bathroom 400 lux. Super bright LED lights are a popular choice for home lighting.

Corridor lighting standards

Corridor areas are often rarely used and do not require high lighting. Light intensity should range from 100 lux - 200 lux, suitable for lamps such as ceiling lights and spotlights.

The light in the classroom reaches standard light intensity

Classrooms need good lighting for easy reading and note-taking. Light intensity ranges from 700 lux - 750 lux, ensuring the light on the study desk is strong enough to not cause eye strain or eye pain.

Kitchen lighting standards

Kitchen lighting: The kitchen area needs quality lighting to serve cooking well. The standard light intensity for the kitchen is 400 lux.

Hotel lighting standards

Each area in the hotel requires different light intensity. Installing the correct number of light bulbs and ensuring light intensity for each area is very important. 

For example, reception and reception need 200 lux, conference room 300 lux, bedroom 100 lux, restaurant 200 lux, kitchen 500 lux, hallway 200 lux, bathroom 300 lux, and parking area 75 lux. 

Designing a standard lighting system will help the hotel operate effectively and create a good impression on customers.

Toilet lighting standards

Toilets do not require high quality of light. Light intensity should range from 200 lux - 250 lux, enough to ensure lighting for necessary activities.

Conclude:

So you understand what light intensity is and what the lighting standards are for spaces. Hopefully this information will help you better understand the lighting requirements of each area, thereby easily choosing the appropriate lamp that meets current lighting standards.