0816 Long-Run Neon: 8×16mm, 10W/m, 24V or 36V Guide

The line looks dimmer than the sample, but the meter says the strip is drawing its rated wattage. The problem is geometry: an 8 × 16 mm body in a 25 mm deep reveal has its 8 mm emitting face set well back from the opening, and the reveal walls cut the light before it reaches the surface.

An 8 × 16 mm profile is the tall narrow body in the Long Run range. The extra height buys thermal mass and mechanical stiffness. It does not buy a wider beam. Understanding that trade is the difference between a crisp reveal detail and a line that looks underpowered.

1. What the 16 mm height changes

The optical output is the same 120 LEDs/m at 10 W/m. What changes is how much of that output clears the reveal.

2. The shadow rule for a deep reveal

A body set back inside a slot loses light to the side walls. The loss depends on the depth-to-width ratio, not on the LED. For an 8 mm face in a reveal:

• Depth up to about 1.5 × the face width (12 mm): the line reads clean, with a slight softening at the edges.
• Depth 1.5–2.5 × face width (12–20 mm): the effective beam narrows; the line is visible but the walls are no longer lit.
• Depth beyond 2.5 × face width (20 mm+): the body is effectively a point source at the bottom of a well; output at the surface falls away and the detail reads dim.

For a 25 mm deep reveal, either bring the body forward, widen the slot, or accept a narrower line and specify the body for its look rather than its output. Adding a diffuser cover at the slot opening helps only if it sits close to the body; a cover at the top of a deep slot becomes another shadow.

3. Electrical: 24 V or 36 V, and why it matters here

This model is available in 24 V DC and 36 V DC. Same 10 W/m, different current:

The 36 V version draws one third less current for the same wattage. That directly reduces the resistive drop in both the feed cable and the strip track, so the practical feed interval extends. On a long outline where 24 V would need a tap every 5 m, 36 V can often stretch the interval — but confirm the exact driver and the segment plan with the factory before designing around it; the 36 V model is a different electrical product, not a setting.

Driver sizing stays at total wattage plus 20 % headroom: a 5 m 24 V segment needs 60 W, a 10 m 36 V pair needs 120 W. Do not mix 24 V and 36 V segments on one driver.

Feed drop at the segment current (5 m out + 5 m back):

Use 0.75 mm² as the floor; step up to 1.00 mm² where the driver sits more than 5 m from the first tap.

4. Thermal: the tall body is the better heat sink

The 8 × 16 section has 48 mm of perimeter — the same as a 12 × 12 body — with a larger cross-sectional area. In a closed slot that translates to a lower surface temperature at the same wattage.

• Free air: expect roughly 12–16 K rise above ambient at 10 W/m.
• Against a metal channel: lower still; the channel is doing most of the work.
• In an unvented deep reveal: the slot itself becomes the insulator. Vent both ends or provide a metal substrate.

The extra height is also mechanical: the body resists bowing between clips better than the 8 × 12, so clip spacing can stay at 200–250 mm on straight runs rather than 150–200 mm.

5. Fixing, bending and sealing

• Clips: 200–250 mm on straights, 100 mm through a curve, plus a clip at each tangent point. Offset clips by half a pitch so they never sit over an emitter.
• Bending: bend in the designed plane on a template. The 16 mm height makes the body stiffer in the other axis; forcing a twist will crack the silicone at the corner.
• Cutting: only at the marked points — 50 mm, six LEDs at 120 LEDs/m.
• Sealing: moulded cap and potted joint on every outdoor end. In a deep reveal, keep the joint at the high end so water cannot pool against it.

6. Commissioning checks

7. Engineering FAQ

Should I specify 24 V or 36 V for a long outline?

Choose 36 V when the outline is long enough that 24 V would need more than two or three taps, or when the driver must sit far from the first segment. Choose 24 V when the project standardises on 24 V drivers and controls. Do not mix the two on one circuit.

Will the 16 mm height make the line look wider?

No. The emitting face is still 8 mm. What changes is the body's depth in the reveal and its stiffness. If you need a wider line, step to 12 × 12 or 12 × 20.

Can I add a diffuser cover over a deep reveal?

Only if the cover sits close to the body. A cover at the top of a 25 mm slot adds another aperture and cuts more light. A better fix is to bring the body forward or widen the slot.

8. Specification summary

Working inside a deep reveal? Send the slot depth, width, and the surface you need to light. We will return the correct body position and a 24 V or 36 V segment plan.