1. What is the Watts To Foot Candle Calculation?

The Watts To Foot Candle calculation converts electrical power consumption (watts) to illuminance (foot candles) by considering the efficacy of the light source and the area being illuminated. This is essential for lighting design and energy efficiency assessments.

2. How Does the Calculator Work?

The calculator uses the Foot Candle formula:

Where:

• \( Watts \) — Electrical power consumption in watts (W)
• \( Efficacy \) — Light output efficiency in lumens per watt (lm/W)
• \( Area \) — Illuminated area in square feet (ft²)

Explanation: The formula calculates how much light (in foot candles) is produced per unit area based on the power consumption and efficiency of the light source.

3. Importance of Foot Candle Calculation

Details: Accurate foot candle calculation is crucial for proper lighting design, ensuring adequate illumination for various tasks while optimizing energy consumption and complying with lighting standards.

4. Using the Calculator

Tips: Enter watts as a positive number, efficacy in lumens per watt, and area in square feet. All values must be valid (greater than 0).

5. Frequently Asked Questions (FAQ)

Q1: What is a foot candle?
A: A foot candle is a unit of illuminance equal to one lumen per square foot. It measures how much light reaches a surface.

Q2: What are typical efficacy values for different light sources?
A: Incandescent: 10-17 lm/W, Halogen: 15-22 lm/W, CFL: 50-70 lm/W, LED: 80-120+ lm/W.

Q3: What are recommended foot candle levels for different spaces?
A: Hallways: 5-10 fc, Offices: 30-50 fc, Retail: 50-100 fc, Surgery: 1000-2000 fc.

Q4: How does this differ from lux calculations?
A: Foot candles are imperial units (lm/ft²), while lux are metric units (lm/m²). 1 fc = 10.76 lux.

Q5: Why is efficacy important in lighting design?
A: Higher efficacy means more light output per watt of electricity, leading to energy savings and lower operating costs.