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Watts per Square Foot Formula:
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Watts per square foot (W/ft²) is a measurement of power density, indicating how much power (in watts) is distributed over a given area (in square feet). This calculation is commonly used in electrical engineering, lighting design, and HVAC systems.
The calculator uses the following equation:
Where:
Explanation: The calculator first converts the area from square inches to square feet by dividing by 144, then divides the power by this area to get power density.
Details: Calculating watts per square foot is essential for designing electrical systems, determining heating/cooling requirements, and ensuring safe power distribution in buildings and electronic devices.
Tips: Enter power in watts, length and width in inches. All values must be positive numbers. The calculator will automatically convert the area to square feet and compute the power density.
Q1: Why convert from square inches to square feet?
A: Many applications require power density in W/ft², while dimensions are often measured in inches. The conversion ensures consistent units.
Q2: What are typical W/ft² values for different applications?
A: Office lighting: 1-2 W/ft², data centers: 50-200 W/ft², residential spaces: 3-5 W/ft² for general lighting.
Q3: Can I use feet instead of inches for dimensions?
A: Yes, but you would need to adjust the formula by removing the /144 conversion factor if using feet directly.
Q4: How does this relate to heat generation?
A: Watts per square foot directly correlates with heat output, as 1 watt = 3.41 BTU/h. Higher W/ft² means more cooling required.
Q5: What's the maximum safe W/ft² for electrical wiring?
A: This depends on wiring type and insulation, but general circuits are often limited to 5-8 W/ft² for safety.