Walk into a swimming pool, a factory floor, or an airport terminal and look up. You may see rows of rectangular panels hanging vertically from cables, or clusters of flat panels floating horizontally below the structural deck. These are acoustic baffles and clouds — the solution for spaces where a traditional suspended ceiling is impossible or undesirable, but noise control is essential.
TLDR
Acoustic baffles are sound-absorbing panels hung vertically from a ceiling, while acoustic clouds are absorbing panels hung horizontally. Both address the same problem: reducing reverberation in large-volume spaces where a conventional suspended ceiling grid cannot be installed — due to height requirements, exposed services, crane rails, fire sprinkler clearances, or architectural design intent. Baffles and clouds are made from mineral wool, fibreglass, PET felt, or foam cores wrapped in fabric or encased in perforated metal. A single baffle absorbs sound on both faces, effectively doubling its surface contribution compared to a ceiling tile of the same area. Typical installations achieve NRC-equivalent performance of 0.70 to 0.95 per unit area. They are standard practice in gymnasiums, swimming pools, factories, warehouses, atriums, open-plan offices, and any space with high ceilings and hard surfaces.
Real-World Analogy
Imagine hanging bath towels from a clothesline in a tiled bathroom. Even though the towels do not cover the ceiling, they intercept sound bouncing between the hard surfaces and absorb a significant portion of it. The more towels and the thicker they are, the less echo you hear. Acoustic baffles are engineered versions of those towels — sized, spaced, and positioned to maximise absorption in the room's critical frequency range.
Technical Definition
Baffles (Vertical)
Vertical baffles are rectangular panels, typically 1200 mm x 600 mm or 1200 mm x 300 mm, hung from the ceiling by cables or chains in parallel rows. They are spaced 300 mm to 600 mm apart, allowing air, light, and sprinkler coverage to pass between them. Because both faces are exposed to the room, a single baffle absorbs sound from two sides. The effective absorption area of a baffle is therefore approximately twice its face area.
The absorption of a baffle array depends on:
- Material: Mineral wool or fibreglass core (50 to 75 mm thick) provides NRC 0.85 to 1.00 per face.
- Spacing: Closer spacing increases total absorption but reduces the per-baffle efficiency due to acoustic shadowing. The optimal spacing-to-height ratio is 0.5 to 1.0 (i.e., spacing equal to 50% to 100% of baffle height).
- Mounting height: Baffles should be hung in the reverberant field — typically at least 2 metres below the structural ceiling in tall spaces — where sound energy density is highest.
Clouds (Horizontal)
Horizontal clouds are flat panels (circular, rectangular, or custom-shaped) hung horizontally from cables. They absorb sound on their underside (facing the room) and to a lesser extent on their topside. Clouds are often used in spaces where the visual design calls for discrete elements rather than continuous rows — atriums, lobbies, and architecturally significant spaces.
Cloud performance depends on size, thickness, and mounting gap. A cloud hung with at least a 200 mm gap above it absorbs on both faces, similar to a baffle. Without a gap (flush against the ceiling), only the room-facing surface absorbs.
Performance Standards
Baffle and cloud absorption is measured per ISO 354:2003 using the mounting type appropriate for the product (typically Type A for free-hanging elements). Manufacturers report absorption per unit of baffle area (both sides included), which allows designers to calculate total room absorption from the number of baffles and their dimensions.
Why It Matters for Design
Many high-volume spaces cannot accommodate suspended tile ceilings. Gymnasiums need clear height for ball trajectories. Swimming pools have corrosive environments that damage tile grids. Factories need crane access and overhead lighting. Warehouses have sprinklers and ventilation that must remain unobstructed. In all these spaces, reverberation times without treatment can exceed 4 to 6 seconds, making speech unintelligible and noise levels unbearable.
Baffles and clouds provide absorption without closing the ceiling plane. They can be installed around obstacles, at varying heights, and in whatever density the acoustic analysis requires. In a gymnasium with an RT60 target of 1.5 seconds (per ANSI S12.60 for multi-use educational spaces), an array of 100 vertical baffles (1200 mm x 600 mm x 50 mm mineral wool) at 400 mm spacing can reduce RT60 from 5.0 seconds to the target.
Clouds also serve an acoustic focusing function in open-plan offices. Positioned above a team cluster, a cloud reflects early sound downward (improving speech intelligibility within the group) while absorbing reverberant energy that would otherwise spread across the open floor plate.
How AcousPlan Uses This
AcousPlan's material database includes baffle and cloud products from Armstrong, Ecophon, Rockfon, and other manufacturers. When you assign baffles to a ceiling zone, the platform calculates effective absorption based on baffle quantity, dimensions, spacing, and the product's per-unit absorption data. The RT60 and STI calculations then reflect the baffle array's contribution, letting you optimise the number and spacing of baffles to meet your target.
Related Concepts
- What Are Acoustic Ceiling Tiles? — Continuous ceiling alternative
- What is RT60? — The metric baffles reduce
- What is NRC? — How baffle absorption is rated
- What is STI? — Speech clarity baffles improve in large spaces
- What Are Acoustic Wall Panels? — Wall-mounted absorption
Calculate Now
Model baffle and cloud arrays in your large space. AcousPlan calculates the RT60 reduction from your specific baffle layout so you can optimise quantity and spacing.