Parking Lot Lighting Calculator

Lighting Fixtures Formula:

\[ \text{Fixtures} = \frac{\text{Area} \times \text{Footcandles}}{\text{Lumens Per Fixture} \times \text{UF} \times \text{LLF}} \]

Area:

sq ft

Footcandles:

Lumens Per Fixture:

Utilization Factor (UF):

Light Loss Factor (LLF):

Fixtures Needed:

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1. What is a Parking Lot Lighting Calculator?

Definition: This calculator determines the number of light fixtures needed to properly illuminate a parking lot based on area, desired illumination level, and fixture characteristics.

Purpose: It helps facility managers, electrical engineers, and contractors design efficient and compliant parking lot lighting systems.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{Fixtures} = \frac{\text{Area} \times \text{Footcandles}}{\text{Lumens Per Fixture} \times \text{UF} \times \text{LLF}} \]

Where:

Fixtures — Number of lighting fixtures required
Area — Parking lot area in square feet
Footcandles — Desired illumination level (typically 2-5 fc for parking lots)
Lumens Per Fixture — Light output of each fixture
UF — Utilization Factor (0-1, accounts for light reaching the surface)
LLF — Light Loss Factor (0-1, accounts for dirt and lumen depreciation)

Explanation: The formula calculates how many fixtures are needed to achieve the desired illumination level considering fixture efficiency and light loss factors.

3. Importance of Proper Parking Lot Lighting

Details: Adequate lighting improves safety, security, and visibility while meeting regulatory requirements and reducing energy costs through proper fixture placement.

4. Using the Calculator

Tips: Enter the parking lot area, desired footcandles (default 2 fc), lumens per fixture (default 20,000 lm), UF (default 0.7), and LLF (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical footcandle level for parking lots?
A: Most parking lots require 2-5 footcandles, with higher levels for security-sensitive areas.

Q2: How do I find my fixture's lumens?
A: Check manufacturer specifications - common values are 10,000-40,000 lumens for parking lot fixtures.

Q3: What affects the Utilization Factor?
A: UF depends on fixture type, mounting height, spacing, and reflectance of surfaces (typically 0.6-0.8).

Q4: What's included in Light Loss Factor?
A: LLF accounts for dirt accumulation, lamp lumen depreciation, and other factors reducing light output over time (typically 0.7-0.85).

Q5: Should I round up the fixture count?
A: Yes, always round up to the nearest whole number since you can't install a fraction of a fixture.