1. What is a Lighting kW per Square Foot Calculator?

Definition: This calculator estimates the total lighting power required based on the area and lighting power density.

Purpose: It helps electrical engineers, architects, and facility managers determine appropriate lighting loads for spaces.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — Total lighting power (kW)
• \( A \) — Area (square feet)
• \( k \) — Lighting power density (kW/ft²)

Explanation: The area is multiplied by the power density to get the total lighting load.

3. Importance of Lighting Power Calculation

Details: Proper lighting load estimation ensures adequate illumination, energy efficiency, and correct electrical system sizing.

4. Using the Calculator

Tips: Enter the area in square feet and lighting power density (default 0.02 kW/ft² for typical office lighting). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical lighting power density?
A: Office spaces typically use 0.02 kW/ft² (20 W/ft²), while retail may use 0.03 kW/ft² (30 W/ft²).

Q2: How does LED lighting affect this calculation?
A: LED lighting typically reduces the power density by 30-50% compared to traditional lighting.

Q3: Should I include emergency lighting?
A: No, emergency lighting is typically calculated separately as it represents a small additional load.

Q4: How do building codes affect lighting power?
A: Many jurisdictions have maximum allowable lighting power densities per space type (ASHRAE 90.1, IECC).

Q5: Does this include lighting controls?
A: No, this calculates total connected load. Controls may reduce actual energy consumption.