Question

Design an illumination scheme for a workshop with an area of 80 x 20 m in size. Assume a suitable space height ratio, utilization factor, and depreciation factor. Consider a lamp efficiency of 20 lumens/watt.

Answer 1

Designing an illumination scheme for a workshop involves several steps, including calculating the required illumination level, determining the number of luminaires needed, and choosing the appropriate types of lamps. Here's a detailed approach to designing the lighting scheme for your workshop.

### 1. Determine the Required Illumination Level

**Illumination Level (Illuminance)** is measured in lux (lx) and represents the amount of light falling on a surface. For a workshop, the recommended illumination level can vary depending on the type of work being done. For general workshop activities, a common standard is 300 to 500 lux. Let's use **400 lux** as a typical value for this design.

### 2. Calculate the Total Required Luminous Output

**Luminous Output** is the total amount of light needed to achieve the desired illuminance level across the entire workshop.

- **Area of the Workshop**: 80 m x 20 m = 1600 m²
- **Required Illuminance**: 400 lux

Total luminous output required = Illuminance × Area
\[ \text{Total Luminous Output} = 400 \, \text{lux} \times 1600 \, \text{m}^2 = 640{,}000 \, \text{lumens} \]

### 3. Account for Utilization Factor and Depreciation Factor

**Utilization Factor (UF)** accounts for the effectiveness of the lighting system based on the layout and reflectivity of the surfaces. A typical UF for a workshop can be around **0.6**.

**Depreciation Factor (DF)** accounts for the reduction in light output over time due to dirt accumulation and lamp aging. A common DF is **0.8**.

So, the total luminous output required considering these factors:
\[ \text{Adjusted Luminous Output} = \frac{\text{Total Luminous Output}}{\text{UF} \times \text{DF}} \]
\[ \text{Adjusted Luminous Output} = \frac{640{,}000 \, \text{lumens}}{0.6 \times 0.8} = \frac{640{,}000}{0.48} \approx 1{,}333{,}333 \, \text{lumens} \]

### 4. Determine the Lamp Efficiency and Wattage

Given:
- **Lamp Efficiency**: 20 lumens/watt

To find the total wattage needed:
\[ \text{Total Wattage} = \frac{\text{Adjusted Luminous Output}}{\text{Lamp Efficiency}} \]
\[ \text{Total Wattage} = \frac{1{,}333{,}333 \, \text{lumens}}{20 \, \text{lumens/watt}} = 66{,}667 \, \text{watts} \]

### 5. Select and Arrange the Luminaires

**Luminaire Selection**: Choose luminaires that suit the workshop environment and are available in standard wattages. For simplicity, assume using 200-watt luminaires.

To determine the number of luminaires:
\[ \text{Number of Luminaires} = \frac{\text{Total Wattage}}{\text{Wattage per Luminaire}} \]
\[ \text{Number of Luminaires} = \frac{66{,}667 \, \text{watts}}{200 \, \text{watts/luminaire}} \approx 334 \]

**Arrangement**: Luminaires should be spaced evenly to ensure uniform lighting. The spacing between luminaires depends on their beam spread and the layout of the workshop. Typically, for high-bay workshops, luminaires are mounted 4 to 6 meters apart in both directions.

### 6. Installation and Verification

**Mounting Height**: Assuming a standard mounting height of 5 meters, verify the arrangement and spacing of luminaires to avoid shadows and dark spots.

**Verification**: After installation, measure the actual illuminance in different areas of the workshop to ensure it meets the required level of 400 lux. Adjust the placement or number of luminaires if needed.

### Summary

- **Required Illuminance**: 400 lux
- **Total Luminous Output Needed**: 1,333,333 lumens (considering UF and DF)
- **Total Wattage Needed**: 66,667 watts
- **Number of 200W Luminaires**: Approximately 334
- **Luminaires Arrangement**: Space luminaires evenly, approximately 4-6 meters apart.

By following these steps, you can ensure adequate lighting for your workshop, improving safety and productivity.

Answer 2

To design an illumination scheme for an 80 x 20 meter workshop, follow these steps:

1. **Determine the Required Illumination Level**: For a workshop, a typical illumination level ranges from 300 to 500 lux. Let’s choose 400 lux for this calculation.

2. **Calculate the Total Luminous Output Needed**:
   \[
   \text{Total Lumens Required} = \text{Illumination Level} \times \text{Area}
   \]
   \[
   = 400 \, \text{lux} \times (80 \, \text{m} \times 20 \, \text{m})
   \]
   \[
   = 400 \times 1600
   \]
   \[
   = 640{,}000 \, \text{lumens}
   \]

3. **Apply the Utilization Factor (UF)**: This factor accounts for the efficiency of light distribution and room surfaces. Assume UF = 0.6 (typical for a workshop).
   \[
   \text{Effective Lumens Required} = \frac{\text{Total Lumens Required}}{\text{UF}}
   \]
   \[
   = \frac{640{,}000}{0.6}
   \]
   \[
   = 1{,}066{,}667 \, \text{lumens}
   \]

4. **Apply the Depreciation Factor (DF)**: This factor considers the reduction in light output over time due to lamp aging and dirt. Assume DF = 0.8.
   \[
   \text{Initial Lumens Required} = \frac{\text{Effective Lumens Required}}{\text{DF}}
   \]
   \[
   = \frac{1{,}066{,}667}{0.8}
   \]
   \[
   = 1{,}333{,}334 \, \text{lumens}
   \]

5. **Calculate the Number of Lamps Required**: Given lamp efficiency is 20 lumens/watt. Assume each lamp provides 10,000 lumens (a typical value for industrial lamps). First, determine how many lumens each lamp provides:
   \[
   \text{Lumens per Lamp} = 10{,}000 \, \text{lumens}
   \]
   Then:
   \[
   \text{Number of Lamps Required} = \frac{\text{Initial Lumens Required}}{\text{Lumens per Lamp}}
   \]
   \[
   = \frac{1{,}333{,}334}{10{,}000}
   \]
   \[
   = 134 \text{ lamps}
   \]

6. **Determine Power Requirements**:
   Each lamp is 20 lumens/watt:
   \[
   \text{Power per Lamp} = \frac{\text{Lumens per Lamp}}{\text{Lamp Efficiency}}
   \]
   \[
   = \frac{10{,}000}{20}
   \]
   \[
   = 500 \, \text{watts}
   \]
   Total power required:
   \[
   \text{Total Power} = \text{Number of Lamps} \times \text{Power per Lamp}
   \]
   \[
   = 134 \times 500
   \]
   \[
   = 67{,}000 \, \text{watts}
   \]

**Summary**:
To achieve 400 lux in an 80 x 20 meter workshop, you would need approximately 134 lamps, each consuming 500 watts, leading to a total power consumption of 67 kW. Adjustments might be needed based on the specific workshop layout and lamp types.