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The document contains a practical exam problem from a course on "Energy Efficiency and Energy Audits" related to designing a lighting system for an office. The problem involves selecting the best type of luminaires (lighting fixtures) from three options to achieve energy efficiency based on specific requirements.

### Problem Summary

1. **Objective**: Design an energy-efficient lighting installation for an office.
   
2. **Requirements**:
   - **Lamp Type**: Fluorescent lamps, 40 W with a light output of 2500 lm.
   - **Luminaires Options**:
     - **Type 1**: Industrial suspended general diffuse.
     - **Type 2**: Direct-indirect, semi-indirect.
     - **Type 3**: Suspended-indirect.
   - **Installation Specifications**:
     - **Working Plane Height**: 0.76 m above the floor.
     - **Installation Height**: 2.5 m above the floor.
     - **Maintenance Factor**: 0.3.
     - **Reflection Coefficients**: Ceiling: 0.5, Walls: 0.5, Floor: 0.1.
     - **Recommended Illuminance**: 500 lux on the working plane.
     - **Natural Illumination**: 0 lux.

3. **Steps to Solve**:
   1. Determine the average illuminance level (Em).
   2. Choose the lamp type (incandescent, discharge).
   3. Choose the lighting system (direct, indirect, etc.).
   4. Determine the suspension height for luminaires.
   5. Calculate the room index.
   6. Determine the reflection coefficients.
   7. Determine the utilization factor.
   8. Determine the maintenance factor.

4. **Selection of Distribution**:
   - Based on the first vowel in the student's name:
     - "a" → Distribution 1: 6 m x 4 m x 3.5 m
     - "e" or "i" → Distribution 2: 7 m x 8 m x 4 m
     - "o" or "u" → Distribution 3: 8 m x 7 m x 4.5 m

### Solution Approach

1. **Calculate Room Index (K)**:
   \[
   K = \frac{\text{Length} \times \text{Width}}{\text{Height} \times (\text{Length} + \text{Width})}
   \]

2. **Determine the Utilization Factor (UF)**:
   - Depends on the type of luminaire and room index.

3. **Determine the Required Number of Luminaires**:
   \[
   \text{Number of luminaires} = \frac{\text{Required Illuminance} \times \text{Area}}{\text{Lamp Lumen Output} \times \text{UF} \times \text{Maintenance Factor}}
   \]

4. **Compare Energy Efficiency**:
   - Calculate power consumption for each option and compare.

Would you like a detailed calculation for a specific distribution, or any clarification on the problem steps? 

### Follow-Up Questions

1. How to calculate the room index for different room dimensions?
2. What is the role of the utilization factor in lighting design?
3. How does the maintenance factor affect the choice of luminaires?
4. What are the differences between direct, indirect, and semi-indirect lighting systems?
5. How to optimize energy efficiency in a lighting system?

### Tip

Always consider the reflection coefficients of the room surfaces when calculating the utilization factor, as they significantly affect the overall illuminance and energy efficiency.

Learn how to design an energy-efficient lighting system for an office. This problem involves calculating the number of luminaires required, utilizing the room index, maintenance factor, and lamp output. Suitable for students in university-level courses on energy efficiency.

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