Architectural Lighting Fixture Spec Sheet: Wall Washers, Floodlights, Linear and Pixel Lights
Short answer: decide the fixture type and mounting position first (wash the facade, light the crown, outline the edges, or build a pixel canvas), then choose the beam angle for the required throw and coverage, then wattage and density for brightness, and finally the control protocol. Keep the number of fixture types on one building to three or four — more types mean harder spare parts management, more colour variation and higher maintenance cost.
Values below are common practice for architectural lighting, compiled with reference to GB 50034 (lighting design of buildings), GB 51348 (electrical design of civil buildings), CJJ/T 307 (urban lighting planning) and the GB 7000 luminaire series. Actual projects require a designer's illuminance and luminance calculation and must comply with local urban lighting plans and light-pollution limits.
1. Quick reference: eight common fixture types
Fixture
Typical wattage
Beam angle
IP rating
Mounting
Purpose
Wall washer (linear)
12–36 W/m
Rectangular: 10°×60°, 20°×45°, 30°×60°
IP65–IP67
Ground or sill, 0.3–0.6 m from wall
Even facade wash, reveals material texture
Floodlight (narrow / wide)
10–400 W (rises with throw distance)
10° / 15° / 25° / 45° / 60° / 90°
IP65–IP66
Ground, roof, podium deck
Column capitals, roofs, sculpture, long throw
Linear light
8–20 W/m
110°–120° or custom
IP65–IP67
Eaves, curtain-wall joints, canopies
Outlining, linear composition
Pixel dot
0.3–3 W/point
120° or lensed
IP65–IP67
Facade grids, mesh screens
Pixel animation, media facade
Window-sill light
3–12 W
Asymmetric (towards wall)
IP65
Sills, cornices
Horizontal light bands, rhythm
In-ground uplight
3–36 W
15°–60°
IP67 or higher
Recessed in ground
Tree pits, column bases, upward wash
Underwater light
3–36 W
15°–60°
IP68
Fountains, pools
Water features (must be low voltage)
Pixel tube / digital tube
Per segment
120° or louvred
IP65–IP67
Outlines, bridges
Chasing, running patterns, text
2. Choosing a beam angle
Beam angle
Effect
Application
Narrow < 15°
Small spot, high intensity, long throw
Roofs, spires, capitals, distant accents
Medium 20°–40°
Balanced throw and coverage
Mid-distance facades, sculpture, landmarks
Wide 45°–60°
Broad, even coverage
Close-range facades, large-area floodlighting
Extra wide > 90°
Diffuse, soft
Close fill light, shadow softening
Rectangular (e.g. 10°×60°)
Spread horizontally, tight vertically
Standard for wall washing — creates a light curtain
Rule of thumb: the narrower the beam, the higher the centre intensity and the longer the throw at equal wattage, but the smaller the coverage. Wrong beam selection is a common cause of rework on site — decide from the throw distance first, then the angle, and only then the wattage.
3. Wall washers: setback and spacing
Setback from wall: commonly 0.3–0.6 m. Too close creates a hot band at the base of the wash; too far reduces the throw height and leaves the top dark.
Fixture spacing: typically 0.8–1.0 times the fixture length (spacing slightly less than or equal to length) so adjacent beams overlap evenly on the wall.
Wash height: a single row of wall washers has a practical wash-height limit. Tall facades need staging (fixtures at multiple cornice levels) or supplementary medium-throw floodlights.
Surface material: rough stone and dark tiles have low reflectance and need higher power density; glass curtain walls transmit light, so switch to interior lighting or outline treatment.
A good wall wash is judged by the absence of bright/dark banding. Banding usually comes from excessive spacing or too small a setback, not from insufficient wattage. Always install a mock-up section and aim it on site before full installation.
4. Control protocol comparison
Protocol
Characteristics
Application
DMX512 / RDM
Mature, real-time, 512 channels per universe; RDM adds bidirectional addressing and status feedback
Media facades, RGBW dynamics, pixel lights
DALI
Addressable, groupable, comprehensive status feedback
Functional exterior and interior lighting needing fine dimming
0–10 V
Simple, low cost, intensity only
Basic dimming of wall washers and floodlights
Art-Net / sACN
DMX over Ethernet; strong on channel count and distance
Large media facades, multi-building shows
KNX
Building bus integrating lighting with other systems
Whole-building automation projects
Selection advice: facades that are mainly static white light work fine on 0–10 V or DALI at controlled cost. Anything with animation, pixels or festive scenes requires DMX512/RDM or Art-Net/sACN — and the fixture segmentation, address plan and circuit capacity must be fixed at design stage, because changing protocol later is expensive.
5. CCT, colour rendering and consistency
CCT: 3000 K (warm, reveals texture) or 4000 K (crisp, contemporary) for main facade lighting. Keep one building consistent.
Colour rendering: Ra ≥ 80 is typical for landscape and architectural work; raise to Ra ≥ 90 at nodes where stone, tile or timber texture matters.
Consistency: for large schemes require one batch and one LED bin, and sample-check CCT and output on delivery.
RGBW layered with white: use colour for festivals and special nodes, keep white as the daily mode — continuous colour running reads as light pollution and draws complaints.
6. Electrical, structural and maintenance
Circuits and voltage drop: feed long linear runs in sections and check end-of-run drop, otherwise the far end shows visible colour shift and dimming.
Driver location: place drivers in serviceable positions rather than burying them all inside inaccessible curtain-wall cavities.
Surge protection and earthing: roof-level and spire fixtures must be within the lightning protection zone, with metal housings earthed and surge protection on signal lines.
Glare and light pollution: limit light aimed at residential windows and the sky; add louvres or shields and restrict the upward light ratio where required.
Serviceability: provide maintenance walkways for high-level fixtures or use replaceable modules; for curtain-wall integrated fixtures coordinate access panels with the facade contractor.
FAQ
How far from the wall should a wall washer be, and what spacing?
Setback is commonly 0.3–0.6 m, with fixture spacing at 0.8–1.0 times the fixture length so beams overlap evenly. If banding appears, adjust spacing and setback rather than increasing wattage, and always aim a mock-up section first.
How do I choose a floodlight beam angle?
Choose by throw distance: below 15° for long-distance accents, 20°–40° for mid-distance facades, 45°–60° for close-range floodlighting. For wall washing use a linear wall washer with a rectangular beam such as 10°×60°. Distance first, then angle, then wattage.
DMX512 or DALI for facade lighting?
DALI suits mainly static white dimming with group control and status feedback. Projects with pixel animation, colour changing or festive scenes require DMX512/RDM, and very large media facades use Art-Net/sACN. Fix the protocol at design stage; changing it later is costly.
What IP rating do architectural luminaires need?
IP65 as a baseline for standard exterior use; IP67 or higher for in-ground; IP68 dedicated submersible units on low-voltage circuits for water features. In coastal and humid regions upgrade materials and corrosion protection, and add surge protection to signal lines.
What CCT should facade lighting use?
3000 K or 4000 K are the usual choices and must be consistent across one building. Ra ≥ 80 is typical, rising to Ra ≥ 90 where material texture matters. Large schemes should specify a single LED batch.
Why do luminaires at the far end look dim and colour-shifted?
Most often excessive voltage drop. Feed long linear runs in sections and check the end-of-run drop, increasing conductor size or adding feed points as needed, and confirm driver compatibility and joint quality.
Zhongshan Haohong Lighting & Decoration Co., Ltd. · QIJIUJIU ｜ mjzh@hhlighting.cn
General technical reference only. Project-specific values must follow the design documents and local codes.