1. What is the Average Daylight Factor?

The Average Daylight Factor (ADF) is a metric used to quantify the amount of natural light available in an interior space. It represents the ratio of indoor illuminance to outdoor illuminance, expressed as a percentage, and is particularly important for adult-oriented spaces where adequate daylighting is crucial for visual comfort and well-being.

2. How Does the Calculator Work?

The calculator uses the ADF equation:

Where:

• Total Area of Windows — Combined area of all glazed surfaces (m²)
• Transmittance — Light transmittance factor of the glazing (0-1)
• Maintenance Factor — Accounts for dirt accumulation and maintenance (0-1)
• Total Floor Area — Area of the space being evaluated (m²)

Explanation: The equation calculates the percentage of available outdoor light that reaches the interior space, considering window properties and maintenance conditions.

3. Importance of ADF Calculation

Details: Adequate daylighting is essential for adult workspaces and living environments. Proper ADF values contribute to visual comfort, reduce eye strain, improve mood and productivity, and can significantly reduce energy consumption by minimizing the need for artificial lighting during daytime hours.

4. Using the Calculator

Tips: Enter all values in appropriate units. Window area and floor area should be in square meters. Transmittance and maintenance factor values range from 0 to 1 (e.g., 0.8 for 80% transmittance). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good ADF value for adult workspaces?
A: Generally, an ADF of 2-5% is considered adequate for most adult-oriented spaces, with higher values preferred for tasks requiring detailed visual work.

Q2: How does ADF differ from other daylight metrics?
A: ADF provides an average value for the entire space, while other metrics like Daylight Autonomy or Useful Daylight Illuminance provide more detailed temporal and spatial analysis of daylight availability.

Q3: What factors affect transmittance values?
A: Transmittance depends on glass type, number of panes, coatings, and any obstructions like window screens or external shading devices.

Q4: How often should maintenance factor be updated?
A: Maintenance factor should be reassessed periodically, typically annually, as it accounts for dirt accumulation on windows and any changes in cleaning schedules or environmental conditions.

Q5: Can ADF be used for residential spaces?
A: While ADF is primarily used for commercial and institutional buildings, the same principles apply to residential spaces, though target values may differ based on room function and user preferences.