Comprehensive Guide to Lighting Calculation Using DIALux 4.13 Software

Comprehensive Guide to Lighting Calculation Using DIALux 4.13 Software

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  Lighting Calculation Using DIALux4.13 Presented By : Swaroop Krishna
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  Contents 1 Introduction toDIALux 4.13 2 Key Concepts in Lighting Calculation 3 Project Setup & Room Definition 4 Luminaire Selection & Placement 5 Running Calculations & Analysis 6 Sample Problem 7 Best Practices 1
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  Introduction to DIALux4.13  DIALux is the world's leading free software for professional lighting design.  Version 4.13 supports indoor, outdoor, and road lighting calculations.  Used by architects, electrical engineers, and lighting designers globally.  Provides accurate photometric calculations using IES/LDT luminaire data.  Generates comprehensive PDF reports with illuminance values and false-color maps. Why DIALux 4.13? Free No license cost Accurate CIE compliant Versatile Indoor & Outdoor Trusted Used in 190+ countries 2
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  Key Concepts inLighting Calculation Lux (lx) Unit of illuminance. 1 lux = 1 lumen per m² Lumen (lm) Total luminous flux emitted by a light source Candela (cd) Luminous intensity in a specific direction Luminous Efficacy Ratio of lumens to watts (lm/W) Uniformity (U₀) Ratio of minimum to average illuminance (Emin/Eavg) Maintenance Factor Accounts for lamp depreciation and dirt accumulation 3
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  Project Setup &Room Definition 1 New Project File → New Project. Enter project name, address and designer details. 2 Interior Scene Select 'Interior' mode. DIALux opens the room editor workspace. 3 Define Room Geometry Set room length, width & height. Use the geometry editor or enter exact dimensions (m). 4 Surface Reflectance Assign reflectance values: Ceiling (70–80%), Walls (50– 60%), Floor (20–30%). 5 Calculation Plane Set the reference calculation plane height (typically 0.85m for work plane). 6 Maintenance Factor Input MF from 0.6–0.8 depending on environment type and cleaning schedule. 4
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  Luminaire Selection &Placement  Import Photometric File Use File → Luminaire Catalogue. Import IES or LDT files from manufacturer.  Luminaire Properties Verify wattage, lumen output, color temperature (CCT) and CRI from datasheet.  Placement Method Use Arrange → Field or Single placement. Specify rows, columns and spacing.  Mounting Height Set luminaire mounting height. Ensure adequate Spacing-to-Height (S/MH) ratio.  Tilt & Orientation Adjust tilt angle if using directional fixtures for accent or task lighting. Typical Spacing Ratios Direct S/MH ≤ 1.5 Semi-direct S/MH ≤ 1.3 Indirect S/MH ≤ 1.2 Downlight S/MH ≤ 1.0 Linear LED S/MH ≤ 1.8 5
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  Running Calculations &Analysis Calculation Setup Go to Calculation → Settings. Choose calculation type: standard (radiosity) or simplified. Set grid size (0.25m–1.0m). Smaller grid = higher accuracy but longer compute time. Calculation Surfaces Add horizontal, vertical, or tilted calculation planes. Mark work plane at 0.85m above floor for office environments. Start & Monitor Press F5 or Calculation → Start. Progress bar shows computation status. Complex scenes may take several minutes. Result Visualization View illuminance as: numeric grid, false-color map, isolux curves, or 3D rendering. Toggle between maintained and initial values. 6
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  Sample problem 7 Asmall assembly shop 15 m long, 9 m wide, and 3 m up to trusses is to be illuminated to a level of 200 lux. The coefficient of utilization is 0.75 maintenance factor is 0.8. Calculate the number of lamps required to illuminate the whole area if the lumen output of the lamp selected is 3000 lumens. Lumen Formula: Number of lamps, Where: E = Illuminance level (lux) = 200 lux A = Area of the room (m²) = 15 m × 9 m = 135 m² Ln = Lumen output of one lamp = 3000 lumens CU = Coefficient of Utilisation = 0.75 MF = Maintenance factor= 0.8
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  Sample problem (Cont.…)8 Substitute values: 15 lamps are required to achieve 200 lux uniformly over the entire area. m Since SHR<1.5, the design is acceptable.
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  Calculation using Dialux4.13 9 Floor Plan 3D-View
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  Summary 10
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  Best Practices Use ManufacturerData Always import actual IES/LDT photometric files from the luminaire manufacturer, not generic models. Correct Maintenance Factor Apply MF per EN 12665. Typical values: clean environment 0.80, normal 0.72, dirty 0.67. Validate Against Standards Compare Em, U₀, and UGR against EN 12464-1 or project-specific specifications. Document Assumptions Record all inputs (lamp data, MF, reflectance) in the report notes for audit trail. 11
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  Thank You