Understanding lighting conditions is paramount in creating environments that are both functional and comfortable. Lux charts, also referred to as illuminance charts or light level charts, play a pivotal role in this endeavor.
These charts offer a visual representation of illuminance levels across various spaces, providing valuable insights into recommended lighting levels for different activities or applications.
By delving into the intricacies of lux charts and exploring how lux is calculated
, we gain a deeper understanding of how lighting design influences our daily lives and environments.
What is lux chart?
A lux chart, also known as an illuminance chart or light level chart, is a graphical representation of illuminance levels across different areas or spaces. It typically displays the illuminance values in lux (lx) for various activities or applications, helping users understand the recommended lighting levels for different tasks or environments.
Lux charts are often used in lighting design, architecture, workplace safety, and other fields where precise control of lighting conditions is essential.
They serve as practical references for professionals to ensure that lighting installations meet specific requirements and standards.
Lux charts may include:
Recommended Illuminance Levels: These charts often provide recommended illuminance levels for different activities or tasks, such as reading, computer work, or manufacturing processes. For example, the recommended illuminance for office workstations might be higher than that for corridors or storage areas.
Occupancy Types: Lux charts may categorize spaces based on their occupancy types, such as residential, commercial, industrial, or outdoor environments. Each category may have different lighting requirements based on the activities typically performed in those spaces and the needs of occupants.
Lighting Zones: Some lux charts divide spaces into different lighting zones, such as task, ambient, and accent lighting zones. Each zone may have specific illuminance targets to achieve the desired lighting effects and functionality.
Regulatory Standards: Lux charts may reference regulatory standards and guidelines related to lighting design and workplace safety. These standards, such as those set by organizations like the Illuminating Engineering Society (IES) or Occupational Safety and Health Administration (OSHA), provide benchmarks for illuminance levels to ensure compliance and mitigate risks.
Overall, lux charts serve as valuable tools for designers, architects, engineers, and facility managers to make informed decisions about lighting design, optimize energy efficiency, enhance visual comfort, and promote safety in various settings. By consulting lux charts, professionals can create lighting environments that meet the needs and preferences of occupants while achieving desired aesthetic and functional outcomes.
Lux Chart
| Activity/Space | Recommended Illuminance (lux) |
|---|---|
| Residential | |
| - Living Room | 100 - 200 |
| - Bedroom | 50 - 100 |
| - Kitchen | 300 - 500 |
| Commercial/Office | |
| - General Office | 300 - 500 |
| - Conference Room | 300 - 500 |
| - Reception Area | 200 - 300 |
| Industrial | |
| - Manufacturing Floor | 300 - 1000 |
| - Warehouse | 100 - 300 |
| Retail | |
| - Retail Store | 750 - 1500 |
| - Showroom | 500 - 1000 |
| Education | |
| - Classroom | 300 - 500 |
| - Library | 300 - 500 |
| Healthcare | |
| - Hospital Ward | 100 - 200 |
| - Operating Room | 1000 - 2000 |
| Outdoor | |
| - Sidewalk | 5 - 10 |
| - Parking Lot | 10 - 20 |
| - Sports Field | 200 - 1000 |
Why do we use lux?
We use lux as a unit of measurement for illuminance, which quantifies the amount of light falling onto a surface per unit area. Lux is widely used for several reasons:
Standardization: Lux provides a standardized unit of measurement for illuminance, allowing for consistent comparisons and assessments of lighting conditions across different settings and applications. This standardization facilitates communication among professionals in fields such as architecture, engineering, lighting design, and workplace safety.
Accuracy and Precision: Lux offers a precise and quantitative measure of illuminance, enabling accurate assessments of lighting levels in various environments. This precision is essential for ensuring optimal lighting conditions that meet specific requirements and standards, such as those related to visual comfort, safety, and productivity.
Versatility: Lux can be applied to a wide range of settings and activities, from residential and commercial spaces to industrial facilities, outdoor areas, and specialized applications such as photography, horticulture, and healthcare. Its versatility makes it a valuable tool for addressing diverse lighting needs and objectives across different industries and disciplines.
Accessibility: Lux meters, devices used to measure illuminance in lux, are readily available and relatively easy to use, making them accessible to professionals and individuals alike. Lux meters come in various forms, ranging from handheld devices for on-site measurements to sophisticated instruments used in laboratory settings, catering to different needs and budgets.
Regulatory Compliance: Many regulatory agencies and standards organizations specify minimum illuminance requirements for various settings, such as workplaces, educational facilities, and healthcare environments. Lux measurements allow stakeholders to assess compliance with these regulations and ensure that lighting installations meet legal and safety standards.
Overall, the use of lux as a unit of measurement for illuminance enables precise, standardized, and versatile assessments of lighting conditions, supporting the design, evaluation, and optimization of lighting systems to enhance visual comfort, safety, and well-being in diverse settings
How is lux calculated?
Lux is calculated by measuring the luminous flux (light energy) incident on a surface and dividing it by the area of that surface. Here’s the formula for calculating lux:
Lux (lx) = Luminous Flux (lm) / Area (m²)
In simpler terms, to calculate lux, you divide the total amount of light energy (measured in lumens) by the area over which that light is distributed (measured in square meters). This formula gives you the illuminance, or brightness, of the surface in lux.
Here’s a step-by-step explanation of how to calculate lux:
Measure Luminous Flux (lm): Luminous flux is the total amount of visible light emitted by a light source, measured in lumens (lm). You can measure luminous flux using a device called a photometer, which captures the light emitted by the source and quantifies it in lumens.
Determine Surface Area (m²): The next step is to measure or determine the area of the surface onto which the light is falling. This could be the floor, desk, or any other surface where you want to calculate the illuminance. The area is measured in square meters (m²).
Calculate Lux (lx): Once you have the values for luminous flux (lm) and surface area (m²), you can use the formula mentioned above to calculate lux (lx). Simply divide the luminous flux (lm) by the surface area (m²), and you’ll get the illuminance in lux.
For example, let’s say you have a light source emitting 1000 lumens of luminous flux, and the light falls onto a surface with an area of 10 square meters. To calculate the lux:
Lux (lx) = 1000 lm / 10 m²
Lux (lx) = 100 lx
So, the illuminance on the surface would be 100 lux. This means that there are 100 lumens of light energy distributed over each square meter of the surface.
Conclusion:
In essence, lux charts serve as indispensable tools for professionals in fields such as lighting design, architecture, and workplace safety, enabling them to make informed decisions that enhance visual comfort, productivity, and safety.
By adhering to recommended illuminance levels and regulatory standards, designers and facility managers can create lighting environments that not only meet functional requirements but also contribute to the overall well-being of occupants.
As technology advances and our understanding of lighting continues to evolve, lux charts will remain invaluable references, guiding us towards creating brighter, safer, and more comfortable spaces for generations to come.