Security Lighting

They serve two related but distinct jobs. Exit signs mark the location and direction of egress — they tell occupants where the way out is. Emergency lighting illuminates the path to that exit (corridors, stairwells, exit discharge, and the area outside the exit door) so people can actually see to travel it during a power failure. Both are required in most commercial occupancies, and they're often combined into a single "combo" unit that pairs a lighted exit sign with one or two adjustable emergency lamp heads.

Several overlapping documents apply. NFPA 101 (Life Safety Code) sets the performance requirements for means of egress, illumination levels, and testing. The NEC (NFPA 70) covers the electrical installation, including Article 700 for emergency systems. The IBC addresses sign placement and building design. UL 924 is the product listing standard that emergency equipment must meet. And OSHA (29 CFR 1910.37) requires that exit routes be adequately lit so employees can see them. Most jurisdictions adopt some combination of these, so compliance usually means satisfying all of them at once.

A minimum of 90 minutes (1.5 hours) of continuous illumination after loss of normal power. This applies to both emergency lights and the internal battery in self-powered exit signs, and it's the duration verified by UL 924 listing and the annual full-duration test.

Under NFPA 101, emergency illumination must initially provide an average of 1 foot-candle and a minimum of 0.1 foot-candle at any single point, measured at the floor along the path of egress. Because batteries decline over the 90-minute period, the code allows the level to drop to an average of 0.6 fc and a minimum of 0.06 fc at the end of the duration. The maximum-to-minimum uniformity ratio along the path must not exceed 40 to 1, which prevents bright pools next to dark gaps.

Legibility under smoke and stress. Standard internally illuminated signs use letters at least 6 inches high with principal strokes at least 3/4 inch wide. Signs must be visible and legible from any direction of approach, and directional chevrons must be added wherever the path to the exit isn't obvious.

Both are used, and NFPA 101 does not mandate a single color nationally, it defers to the AHJ. Red is the most common color in the United States, while green is standard internationally and is required by some U.S. jurisdictions and local codes (for example, certain cities specify green for better contrast against typical building interiors). Because this is one of the most common points of local variation, confirm the required color with your AHJ before ordering.

UL 924 is the safety standard for emergency lighting and power equipment. A UL 924 listing confirms the product's battery, charger, transfer circuitry, and output have been tested to perform during a power failure for the required duration. Specifying UL 924 listed equipment is effectively a baseline requirement, and non-listed fixtures generally won't pass inspection for life-safety duty.

These are non-electrical alternatives. Photoluminescent ("glow-in-the-dark") signs absorb ambient light and re-emit it. They need a minimum level of charging light during normal occupancy and require no wiring or battery. Self-luminous (tritium) signs use sealed radioluminescent tubes and need no external power or light at all, but they have a fixed service life and disposal requirements. Both are useful where running power is impractical, but each has placement and maintenance conditions that must be verified against local code.

There are three common approaches. Unit equipment (self-contained battery) packs a battery inside each fixture or exit sign. These are simple, decentralized, and common in smaller buildings. A central inverter system supplies emergency power to many fixtures from one location, simplifying testing and maintenance in larger facilities. A generator (with proper transfer equipment) can serve emergency loads but must meet the 10-second transfer and run-duration requirements of NEC Article 700. Many buildings mix approaches.

These units automatically run their own required tests and signal a fault with an LED indicator or audible alarm if the battery or lamp fails. They satisfy the code's functional-test obligations without staff manually triggering each device, which is a major maintenance saver in buildings with dozens or hundreds of units, and they reduce the risk of a missed test going unnoticed.

NFPA 101 requires two recurring tests for most equipment. A monthly functional test of at least 30 seconds confirms the unit switches to battery and illuminates. An annual test runs the equipment for the full 90-minute duration to verify the battery holds up. Written records of both must be kept and made available to the AHJ. Self-testing units can automate the functional checks, but documentation is still required.

Placement follows the means of egress. Exit signs are required at exit doors and wherever the direction of travel isn't immediately apparent, positioned so no point in an exit-access corridor is more than the sign's rated viewing distance (commonly 100 feet) from the nearest visible sign. Emergency lighting is required throughout the egress path – corridors, stairs, landings, and at the exit discharge outside the building – and in spaces where loss of light would create a hazard, such as windowless rooms and assembly areas. A design professional or AHJ review confirms exact coverage for your occupancy.

New York City commercial building exit sign requirements are significantly stricter than national standards. All signs must feature red lettering, be housed in durable metal, and be connected to a reliable backup power supply. Letters must be at least 6 inches high. However, in assembly areas (theaters, restaurants) and transient residential spaces (hotels), letters must be at least 8 inches tall. High-rises are also mandated to have photoluminescent egress markings. Check with your local governance to make sure you will be meeting all requirements.

Chicago has uniquely strict fire and building codes (Chapter 13-160 of the Chicago Municipal Code) that mandate specific exit sign designs. Approved signs must feature red letters on a white background, be housed in metal (20-gauge steel) bodies, and include a 90-minute battery backup. Words like "EXIT" or "STAIR" require a minimum letter height of 6 inches with a 3/4 inch stroke. (Alternately, depending on the specific code subsection, standard letters must be at least 3 and 3/8 inches high with a 9/16 inch stroke). Any directional chevrons/arrows must be placed directly beneath the wording and must match the width of the lettering. Check with your local governance to make sure you will be meeting all requirements.

Good exterior lighting supports three goals at once: deterrence (well-lit sites are less attractive targets), detection (occupants, guards, and cameras can see what's happening), and safety (occupants and visitors can navigate parking lots and walkways without trips or falls, reducing liability). The aim isn't simply "more light" — it's the right light levels with good uniformity and minimal glare.

There's a lot of overlap, the same pole-mounted area lights that illuminate a parking lot also provide its security lighting. The distinction is usually one of emphasis. General area lighting prioritizes even, comfortable illumination for normal use. Security lighting additionally emphasizes coverage of vulnerable points (entrances, perimeters, loading docks, ATM and cash-handling areas), adequate vertical illuminance for facial and camera recognition, and freedom from shadows where someone could conceal themselves.

They solve different problems and are often combined. A photocell turns lights on at dusk and off at dawn automatically providing reliable baseline coverage. Motion sensors activate light only when movement is detected, saving energy and creating a startling "something just lit up" deterrent effect. The popular middle ground is bi-level control: fixtures run at a low standby level all night via photocell, then boost to full output on motion. This keeps a site continuously visible (good for cameras) while still cutting energy and signaling activity.

Most security applications land in the 4000K–5000K range. This neutral-to-cool white renders scenes clearly to both the human eye and cameras, and aids color recognition (vehicle color, clothing) better than the warm yellow of old high-pressure sodium. A CRI of 80 or higher noticeably improves how accurately colors are perceived, which helps with identification. Some municipalities now cap CCT (often at 3000K) to limit blue-light spill, so check local rules before specifying cooler product.

These describe unwanted light. Light trespass is light spilling onto neighboring property, glare is excessive brightness that impairs vision (and ironically can reduce security by creating contrast and shadows), and sky glow is wasted uplight that brightens the night sky. Full-cutoff (fully shielded) fixtures direct light downward to control all three, and many communities now require Dark Sky–friendly designs. The IES/IDA BUG rating (Backlight, Uplight, Glare) gives a standardized way to compare how well a fixture contains its light when meeting these ordinances.

Common options include pole-mounted area lights (parking lots, large open areas), wall packs (building perimeters, entrances, loading docks — available in standard and full-cutoff versions), flood lights (aiming light at facades, signage, or specific zones), and bollards (low-level path and landscape lighting). Selection comes down to mounting location, the distribution type needed, target light levels, and how much glare and spill control the site requires.

Yes, and it's increasingly common. Beyond basic photocells and motion sensors, networked lighting controls allow scheduling, dimming, occupancy-based bi-level operation, and remote monitoring across a whole site. These controls can cut energy use further, flag fixture outages automatically, and in many areas help qualify a project for utility rebates, improving the payback on an LED upgrade.