Remote Head Spacing Guide: Corridors, Stairs & Open Areas

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.

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.

Corridor Spacing

1. Measure the corridor: Width, height, and any turns or door alcoves.
2. 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.
3. 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.
4. Overlap beams: Slight overlap down the aisle helps keep uniformity within 40:1.
5. Check glare and shadows: Avoid mounting directly opposite reflective signage; aim to avoid hot spots on the floor.

Rule of thumb: start with a provisional center-to-center near 1–1.5× the mount height, then adjust with actual photometric checks or a spacing chart for your head/beam.

Stair & Landing Coverage

• Landings first: Place heads to wash landings, door thresholds, and turns.
• Aim along the path: Light the treads from the side or above to reduce shadows; avoid glare in the descent view.
• Redundancy: Cover each flight with more than one source so a single failure won’t darken the path.
• Head protection: Use damp/wet or tamper-resistant heads where required by environment and usage.

Open-Area Grids

Use a staggered grid (checkerboard) so no point is far from multiple beams. Start with a spacing equal to about the beam diameter at floor (based on mount height and beam angle), then tighten 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 close-in work at low ceilings.
• Use the cone: Treat each head’s beam like a cone—your spacing is set where cones overlap enough to keep the low points above 0.1 fc.
• Fine-tune aiming: Rotate heads to remove dark pockets at corners and door landings.
• Distance to farthest head: Long runs may dim the end head from voltage drop—consider stepping up to 12 V systems for distance. See 12V vs 24V for long runs for when higher voltage wins.

Field Workflow & Quick Checks

1. Sketch the path: Mark exits, stairs, turns, and obstacles.
2. Place decision-point heads: Doors, landings, and corridor ends.
3. Fill spacing: Lay in provisional center-to-center distances; overlap beams slightly.
4. Runtime test: Kill power and verify at 0, 30, and 90 minutes—note the farthest dim points.
5. Adjust & document: Re-aim, add or move a head if needed; save a simple drawing with measurements.

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 after 90 minutes.

FAQs About Remote Head Spacing

What center-to-center spacing should I use in a 10-ft corridor?

Start near 1–1.5× mount height and adjust with your head’s beam chart and a live test. Place extra emphasis on 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 additional heads to meet uniformity and cover decision points.