Practical spacing methods for remote heads—how to hit light-level targets, choose beam spreads, and set center-to-center distances for corridors, stairs, and open areas. For product options, see LED remote head emergency lights; for fundamentals, use the remote head sizing and wiring guide.
Last updated: October 2025
Overview & Method
Remote head spacing isn’t one magic number—it depends on mount height, beam spread, room geometry, and required light levels. Start with the code targets below, pick a beam appropriate to the height, then iterate placement and aiming until the farthest points on the egress path meet spec. For system sizing and wiring, see the remote head sizing and wiring guide.
Quick spacing idea: As a starting point, try center‑to‑center ≈ 1.0–1.5 × mount height (MH) in straight corridors, then tighten/loosen after a quick photometric check.
Design Targets (fc, uniformity, duration)
- Light levels: Initial average of 1 fc on the egress path, minimum of 0.1 fc anywhere, with uniformity not exceeding 40:1.
- Duration: Maintain illumination for at least 90 minutes on battery.
- Practical tip: Validate near the end of the 90‑minute test; the farthest head is your canary. For a standards overview, see the code requirements overview.
Corridor Spacing
- Measure the corridor: Width, height, and any turns or door alcoves.
- Choose beam spread: Narrow for tall ceilings and long throws; medium for typical 8–12 ft mounts; wide near low ceilings or to wash walls/door landings.
- Place heads near decision points: Ends, turns, and doors first—then fill the middle using center‑to‑center distances that keep the dim point ≥ 0.1 fc.
- Overlap beams: Slight overlap down the aisle helps keep uniformity within 40:1.
- Check glare & shadows: Avoid aiming directly at reflective signage; keep hot spots off the floor.
| Mount Height (MH) | Narrow Beam (spot‑to‑med) | Medium Beam | Wide Beam |
|---|---|---|---|
| 8 ft | 8–10 ft | 9–12 ft | 10–13 ft |
| 10 ft | 10–12 ft | 11–15 ft | 12–16 ft |
| 12 ft | 12–14 ft | 13–18 ft | 14–20 ft |
These are initial centers for typical LED heads; confirm with your photometric sheet and a quick runtime test.
Stair & Landing Coverage
- Landings first: Wash landings, door thresholds, and turns so there’s no “hesitation” zone.
- Aim along the path: Light treads from the side or above; avoid glare in the descent view.
- Redundancy: Cover each flight with more than one source; a single failure should not darken the path.
- Protection: Use damp/wet or tamper‑resistant heads where required by environment and usage.
90° switchback tip: Place one head above or opposite the inner corner and a second on the next flight; overlap beams at the landing midline.
Open-Area Grids
Use a staggered grid (checkerboard) so no point is far from multiple beams. Start with a spacing near the beam diameter at floor (based on MH and beam angle), then tighten the grid until average/minimum targets are met across aisles and exit approaches.
- Mount height drives diameter: Higher mounts enlarge the lit circle; narrow beams help keep intensity at the floor.
- Keep aisles bright: Prioritize egress lanes; add fill heads only where needed to fix low spots.
- Document the grid: Record center‑to‑center, aiming notes, and any obstructions.
Mount Height, Beam Spread & Aiming
- Match beam to height: Narrow beams for tall spaces; medium beams for typical corridors; wide beams for low ceilings and close‑in work.
- Use the cone: Treat each head’s beam like a cone—spacing is set where cones overlap enough to keep the low points above 0.1 fc.
- Fine‑tune aiming: Rotate heads to clear dark pockets at corners and door landings; avoid direct glare in the line of sight.
- Distance to farthest head: Long runs may dim the end head from voltage drop—plan conductor gauge and voltage accordingly. See 12V vs 24V for long runs and check the wire‑gauge distance tables. For outdoor layouts, apply IP65 spacing & aiming.
Field Workflow & Quick Checks
- Sketch the path: Mark exits, stairs, turns, obstacles, and reflective surfaces.
- Place decision‑point heads: Doors, landings, corridor ends.
- Fill spacing: Lay provisional centers (see corridor table); aim for light overlap.
- Runtime test: Kill power and check at 0, 30, and 90 minutes—note the dimmest points.
- Adjust & document: Re‑aim, move, or add a head if needed; save a simple drawing with measurements and aiming notes.
Common Spacing Mistakes
- Setting equal spacing without checking corners, turns, or door landings.
- Using wide beams at high mounts (bright ceiling, dim floor).
- Ignoring uniformity—hot spots surrounded by very low areas.
- No redundancy—one lamp failure leaves a stretch of path dark.
- Voltage‑drop starve on the farthest head late in the 90‑minute test.
FAQs About Remote Head Spacing
What center‑to‑center spacing should I use in a 10‑ft corridor?
Start around 1–1.5 × MH and adjust with your head’s beam chart and a live test. Emphasize doors, turns, and dead‑ends.
How do I handle an L‑shaped corridor?
Treat each leg as its own run and place heads at the turn and endpoints first; then fill the straights with overlapping cones.
Do higher ceilings mean fewer heads if I use narrow beams?
Not necessarily—narrow beams maintain intensity at the floor, but you may still need more heads to meet uniformity and cover decision points.