Indoor lighting is not just a matter of aesthetics; it affects human health, safety, and productivity. Many people ignore the specific technical requirements of lighting, which results in eyestrain, high energy consumption, and even safety hazards. To solve these problems, the first step is to understand the relevant standards and data requirements for indoor lighting, from the choice of light source to the distribution of brightness, everything has a scientific basis.
In order to achieve the best lighting effect, different rooms, uses, and functional areas need to follow specific lighting standards. Understanding these standards not only makes a space more livable but also dramatically improves energy efficiency and reduces long-term maintenance costs.
Next, we’ll explain interior lighting standards in detail, providing you with a professional guide that will help you master all aspects of interior lighting requirements, from basic concepts to technical details.
1. What is the basic definition of indoor lighting?
Indoor lighting refers to the enhancement or supplementation of natural light in a room by means of an artificial light source to meet the functional as well as aesthetic needs of the space. It usually includes main lighting (e.g. ceiling lights), auxiliary lighting (e.g. wall lamps, table lamps) and decorative lighting (e.g. spotlights, ambient lighting). Different combinations of lamps and luminaires determine the brightness, ambience, and practicality of the space.
2. International standards for indoor lighting
The core objective of indoor lighting is to provide sufficient light to the indoor environment through light sources to ensure the functionality and comfort of the space. According to CIE (International Commission on Illumination) standards, indoor lighting must consider the brightness, color temperature, color rendering, light distribution, and efficiency of the light source and other indicators. In addition, a number of EU and U.S. standards (such as EN 12464-1, ISO 8995) specify the illuminance, color temperature, and color rendering index requirements for different indoor places.
3. Lighting requirements and brightness standards for different spaces
Lighting standards for different spaces are different, please refer to the following values:
- Living room: the general requirements of 300 to 500 lux illuminance, brightness is recommended for 2000 to 4000 lumens.
- Kitchen: work area illuminance standard of 500 to 750 lux, recommended brightness of 4000 to 6000 lumens, especially need to pay attention to the worktable area of the strong light exposure.
- Bedroom: relaxation-oriented environment, recommended illuminance of 100 to 300 lux, lumens range from 1500 to 3000.
- Bathroom: requires a higher illuminance than 300 lux, with 500 lux in the area in front of the mirror, and waterproof fixtures are recommended for protection levels IP44 and above.
Lux (Lux, symbol lx) is the unit of illumination, used to measure the brightness or intensity of light on a surface. 1 lux is equal to the luminous flux of 1 lumen per square meter, i.e. 1 lx = 1 lm/m².
4. Selection basis for functional lighting fixtures
Functional lighting needs to be based on the use of the room and the needs of the work area to choose different equipment. The following are common selection criteria:
- Main lighting: Use chandeliers, ceiling lights, ceiling fan lights with a brightness of >1000 lumens. Applicable to large spaces, such as living rooms and kitchens, need to meet the main illumination requirements.
- Auxiliary lighting: such as table lamps, wall lamps, floor lamps, for local work or reading, it is recommended that the brightness of 300 lumens or more, color rendering index (CRI) in 80 and above.
- Decorative lighting: light strips or small spotlights, mainly used to create the atmosphere, the brightness can be moderately reduced between 100-200 lm, but the color temperature needs to be consistent with the main lighting, in order to maintain a harmonious visual effect.
5. The color temperature standard of indoor lighting and its impact on vision
Color temperature is expressed in Kelvin (K), which affects the visual perception and experience of the space. The following are the recommended color temperature standards for common indoor settings:
- Warm white light (2700K-3000K): suitable for bedrooms, dining rooms and other casual spaces, providing a soft, relaxing environment.
- Neutral light (3000K-4500K): suitable for living room, office and other occasions, clearer light for work and activities.
- Cool white light (4500K-6500K): Suitable for kitchens, bathrooms or workspaces, providing high-contrast light that helps concentration.
6. Internationally Recommended Illumination Levels and Applicable Scenarios
According to ISO 8995 and EN 12464-1, the minimum illuminance requirements for different spaces are as follows:
- Office space: 500 lux
- Living room: 300 lux
- Bedroom: 100-300 lux
- Kitchen worktops: 500 lux
- Bathroom mirror front: 750 lux
Achieve illuminance level value that meets the standard, to ensure that people in different environments, can get enough light support, to avoid eye fatigue or work efficiency decline.
7. Color Rendering Index (CRI) standard and its impact on indoor lighting efficiency
Color Rendering Index (CRI) is a measure of the ability of a light source to reproduce the true color of an object, with a value ranging from 0 to 100. Simply put, the higher the CRI, the closer the color of an object under such a light source will appear to be to the color it would have in natural light. A light source with a low color rendering index will distort the color of an object, making it appear dull or unnatural. According to the standard:
- CRI > 80: Suitable for most living spaces, such as living rooms and bedrooms.
- CRI > 90: Suitable for spaces that require high color reproduction, such as kitchens, powder rooms or art studios.
Imagine you are preparing ingredients in a kitchen. With a CRI of 60, red tomatoes may look gray, green vegetables look yellowish, and fresh fish may even look shapeless. In this case, even if the ingredients are fresh, your visual perception will make you think they look bad. But under CRI > 90 lighting, red tomatoes will appear bright red, green vegetables look bright green and attractive, and fish looks to have a natural luster.
This is the significance of high color rendering index lamps – it makes objects look as real and vivid in indoor light as in natural light, especially in occasions where accurate color identification is required, such as kitchens, dressing rooms, etc.
8. Safety standards and protection levels of lighting equipment
Safety standards and protection levels for lighting equipment are important factors in ensuring safe operation in various environments. These standards and ratings are not only concerned with electrical safety and heat dissipation of the lighting equipment, but also with protection against external environmental factors (e.g. water, dust).
8.1 Safety standards for lighting equipment
Different countries and regions have standards and certifications for the safety of lighting equipment. Common safety standards include:
- IEC 60598 (International): This is a standard developed by the International Electrotechnical Commission (IEC) covering safety requirements for lighting equipment, including structural, electrical and mechanical safety.
- UL Certification (U.S.): Underwriters Laboratories certification in the U.S. ensures that equipment meets U.S. safety and performance requirements.
- CE marking (Europe): European safety certification that ensures equipment meets EU health, safety and environmental standards.
- CCC Certification (China): Compulsory product certification in China, ensuring that products comply with national mandatory safety standards.
- RoHS Standards (EU): Restrictions on the use of hazardous substances in electrical and electronic equipment to ensure that lighting equipment is not harmful to the environment and human health.
These standards usually cover electrical safety, mechanical safety, thermal performance, structural design and requirements for materials to ensure the safety of lighting equipment in normal use.Read this article to learn more about certificates-Rechargeable Table Lamp Certification Guide (2024)
8.2 Protection class (IP rating)
The Ingress Protection (IP) rating is used to assess the protection of lighting equipment against solid substances and liquids, especially for lighting equipment used outdoors and in harsh environments. This is a rating code consisting of two numbers. Common IP ratings are explained below:
- First digit (0-6): Rating for protection against entry of solid substances
- Second number (0-8): Rating for protection against the ingress of liquids
Example:
- IP20: Can only prevent fingers and other solid substances larger than 12.5mm, not waterproof, suitable for indoor dry environments.
- IP44: Protects against solids larger than 1mm in diameter and water splashing from all directions, suitable for wet indoor environments or outdoor applications with some shade.
- IP65: Dustproof and protected against low-pressure water jets, suitable for outdoor luminaires.
- IP68: Completely dustproof and can be used underwater for a long time, applicable to underwater lighting equipment.
9. What are the installation and maintenance standards for indoor lighting?
The installation and maintenance standards for indoor lighting are an important basis for ensuring the safe operation of the lighting system, providing the best lighting effect, and extending the life of the equipment. Different types of lighting equipment and application environments may require different standards to be followed. The following are common indoor lighting installation and maintenance standards:
9.1 Installation Standards
- Electrical Wiring Code: All lighting equipment should be wired in accordance with local electrical codes (e.g., IEC, NEC, GB, etc.). Cables should use insulated wires that meet the specifications, and ensure that the terminals are fastened securely to avoid loosening.
- Protection against electric shock: Usually divided into Class I, Class II and Class III protection. Class Ⅰ lighting equipment must be reliably grounded to prevent leakage of electric shock. Class Ⅱ equipment ensures safety through double insulation, and Class Ⅲ equipment uses safe low voltage power supply.
- Lighting uniformity: The distribution of lamps and lanterns should be uniform to ensure that there are no obvious shadow areas or overly bright or dark places in indoor lighting. A combination of direct and indirect lighting is usually considered when designing the lighting layout.
- Protection class: In luminaire installations in wet or special environments (e.g. bathrooms, kitchens), the protection class (IP) of the lighting equipment must be adapted to the environmental requirements. For example, bathroom luminaires require at least IP44 protection.
- Height and angle: Depending on the function of the space, the height and mounting angle of the luminaire vary. For example, chandeliers should be installed at a suitable height to avoid obstructing the view or interfering with the activities in the space.
9.2 Maintenance Standards
- Lamp surface cleaning: Dust and dirt will reduce the luminous efficiency of the lamps and lanterns. Regularly cleaning the surface of the lampshade and light source can improve the lighting effect. Use non-corrosive cleaners, especially for plastic, glass or metal housings.
- Light source replacement: Although LED lamps and lanterns have a long life, they should also be replaced in time if there is a significant decrease in brightness or flickering problems.
- Electrical safety check: Regularly check the electrical connections of the lamps and lanterns to ensure that the lines are not damaged and the connections are tight and not loose. Especially for high-frequency utilization of lamps and lanterns, electrical safety should be checked once a year.
- Heat dissipation problems: For high-power lamps and lanterns (especially LED lamps and lanterns), regularly check its heat dissipation performance. If the luminaire shell is overheated, it should be dealt with or replaced in time.
10. Conclusion
Indoor lighting standards cover a wide range of aspects from illuminance, color temperature, color rendering index to energy efficiency and safety. Understanding these standards helps to create a comfortable lighting environment. Whether you are decorating your home or designing for business, adhering to the lighting standards will ensure that you get the ideal light efficiency and experience.
