Calculo de flujo luminoso, Indice de local, coeficiente de utilización, numero de luminarias.

Calculating Illuminance in a Room

Introduction to Illuminance Calculation

• The speaker introduces the topic of calculating illuminance and luminous flux required for a room, emphasizing the importance of electrical installations for lighting.

Standards for Illuminance Requirements

• Reference is made to standard EM010, which specifies that bedrooms require an illuminance level of 50 lux.

Steps to Calculate Illuminance

• The speaker outlines the need to understand how to calculate illuminance, indicating that specific formulas will be used based on different types of lighting (direct, semi-direct, indirect).

Gathering Necessary Data

• To perform calculations, dimensions such as width, length, and working height of the room are essential. These measurements form the basis for further calculations.

Local Index Calculation

• The local index (k) is introduced as a critical factor in determining lighting requirements. Formulas vary depending on whether the lighting is direct or indirect.

Factors Influencing Lighting Design

Reflection Factors

• Discussion on reflection factors from ceilings, walls, and floors is presented. These factors depend on surface colors and significantly affect overall illumination.

Utilization Factor Calculation

• The utilization factor is derived from the previously calculated local index. This factor helps determine how effectively light from luminaires will illuminate a space.

Selecting Luminaires and Calculating Total Flux

Choosing Luminaires Based on Data Sheets

• Instructions are given on how to select luminaires by consulting data sheets that provide information about utilization factors related to specific indices.

Maintenance Factor Consideration

• After obtaining the utilization factor, it’s important to choose a maintenance factor appropriate for the environment before proceeding with total luminous flux calculations.

Finalizing Lighting Calculations

Total Luminous Flux Formula

• The formula for total luminous flux involves multiplying average desired illuminance by total area (in square meters), divided by both utilization and maintenance factors.

Number of Luminaires Required

• To find out how many luminaires are needed, divide total luminous flux by individual lamp output specified in technical data sheets.

Positioning Luminaires Effectively

Luminaire Placement Calculations

• A formula is provided for calculating luminaire spacing based on room dimensions. This ensures optimal distribution of light throughout the space.

Verification of Results

• Once placements are determined, recalculating illuminance using actual luminaire numbers should yield results equal to or greater than standard requirements outlined in tables.

Practical Application: Example Calculation

User Input Dimensions

• An example scenario begins where user-defined dimensions are gathered from plans—length set at 2.60m and width at 2.40m with a working height established at 2.30m according to standards.

Working Height and Lighting Calculations

Selecting Working Height

• The working height is crucial for lighting calculations, but it was not specified in the table. The speaker decides to select a working height of 0.75 meters (75 cm) from the ground level.

Local Index Calculation

• With the selected height, the local index is calculated to be 0.0805, which is derived from specific room dimensions and conditions. This value will influence further calculations related to lighting requirements.

Ceiling and Wall Reflection Factors

• The ceiling is assumed to be white or very light, while walls are also considered light-colored; this leads to reflection factors of 0.3 for ceilings and 0.5 for walls, impacting overall illumination levels in the room.

Luminaire Selection Process

• A specific luminaire is chosen based on its data; an interpolation process helps determine its suitability against calculated values of local index (0.805). This step ensures that the selected luminaire meets required standards for effective lighting in the space.

Utilization Factor Determination

• The utilization factor is determined through a series of intersections between calculated values, resulting in a coefficient of utilization at approximately 0.672 after considering maintenance factors relevant to clean rooms and necessary illuminance levels set by norms (50 lux).

Flow Calculation and Luminaires Requirement

Calculating Total Flux Required

• The total luminous flux needed for adequate room illumination is computed using the formula: illuminance multiplied by area divided by utilization factor times maintenance coefficient, yielding a requirement of approximately 580.301 lumens for proper lighting conditions in the bedroom setting according to standards.

Number of Luminaires Needed

• Based on a single luminaire's output (1100 lumens), only one unit will suffice to meet or exceed the required luminous flux, confirming compliance with established norms as it surpasses minimum requirements significantly (50 lux).

Verification Against Standards

• A verification step shows that luminance achieved (94.78) exceeds standard requirements (50), indicating successful compliance with lighting regulations; thus confirming that only one luminaire will be installed based on these calculations without needing adjustments or additional units.

Exploring Alternative Luminaires

Testing Different Luminaire Options

• To ensure cost-effectiveness and efficiency, another luminaire option with lower luminous output (650 lumens) is explored as part of a comparative analysis against previously selected options before finalizing decisions on installation choices based on performance metrics and costs involved in procurement processes.

Data Compilation for Comparison

Lighting Calculation Process

Initial Values and Adjustments

• The speaker discusses the initial values for a lighting calculation, noting that they are not equal to 0.8 and 1, leading to an adjustment in image size.

• Coefficients of reflection are selected based on calculations, with values of 0.60 and 0.69 being chosen for further analysis.

Calculating Total Luminous Flux

• The maintenance factor is set at 0.8, as per standards requiring a minimum of 50 Lux; total luminous flux is calculated to be approximately 647.494.

• The lamp's luminous flux is confirmed at around 650, indicating alignment with the calculated requirements.

Verification of Luminance Compliance

• The speaker verifies that the selected luminaria meets compliance standards after performing necessary calculations.

• A demonstration in AutoCAD shows the placement of luminaria in relation to room dimensions, confirming it fits centrally according to calculations.

Conclusion and Future Content