What is an acoustic ceiling sail?
Indoors, an acoustic ceiling sail is a fabric panel hung flat below the ceiling, so that it reads as a floating plane rather than part of the structure. From below you see the face of the fabric, and a woven relief such as Cubic Pico, a geometric, three-dimensional weave, catches light from windows and fittings across its face. Cubic Giga, from the same family, is the thickest Cubic fabric at 5.4 mm, against 3.8 mm for Cubic Pico.
Getzner uses both words. It makes its suspended ceiling element as the acunic cloud, while the project notes for its own offices in Bludenz list "ceiling sails", and this guide uses the two words for the same thing. Getzner Textil's offices occupy the listed Alte Weberei building, where high ceilings and hard surfaces posed particular acoustic challenges; Getzner lists the systems there as "ceiling sails, wall cladding for skylights with cubic pico" and reports a noticeable improvement in room acoustics, as the Getzner Textil offices in Bludenz show.
When does a sail make sense?
A sail suits a room with a hard ceiling, a high volume and little free wall. Where the walls are glazed, lined with joinery or kept for art, the ceiling is often the largest surface left for absorption.
Getzner's project at Gesundheitscampus Bludenz used ceiling sails where reverberation was the problem. It is an event space in a historic attic, used for meetings, lectures and yoga, where pronounced reverberation had significantly impaired speech intelligibility. Getzner lists the acoustic systems as ceiling sails and acoustic curtains, and Cubic Giga fabric as an acunic frame with timber frames, and reports that the textile ceiling elements and acoustic curtains reduced the reverberation time, as the Health Campus Bludenz project describes. Finished sails in use are on the Acunic ceiling sails page.
How is a sail's absorption rated?
A sail hangs in the air, away from the room's surfaces, so a laboratory measures it as an object, not as a covering on a surface. ASTM C423, the American test method, describes separate procedures for the absorption of an object, such as an office screen, and for the absorption coefficients of a specimen of absorptive material, such as ceiling tile. The laboratory that tested Acunic reported its suspended panels in this way, as a space absorber, in Sabins per panel at each frequency band, while NRC and αw are ratings for a specimen of material in a set mounting. Each kind of figure has its own unit, which is why a sail is compared in Sabins per sail; how Sabins, NRC and αw differ explains each measure.
In Christchurch, Canterbury Acoustic Testing Services measured six suspended single-sided Cubic Pico panels, each 1.2 x 1.5 m on a 50 mm frame, hung vertically from wires with both faces open to the room. Each panel measured 1.14 Sabins at 1000 Hz and its highest value, 1.64 Sabins, at 5000 Hz (AS ISO 354:2006, Canterbury Acoustic Testing Services report 2026-316.3).
In the table, each tested Cubic Pico construction is rated in its own unit: Sabins per object for the towers and the suspended panel, and NRC and αw for the framed wall panels.
Tested with Cubic Pico
How many sails does a room need?
The number of sails comes from the room, not from a rule of thumb. The usual design measure for a room is its reverberation time, and AS/NZS 2107:2016 gives recommended design reverberation times for building interiors; the standard is listed as Pending Revision on the Standards Australia store. An acoustic consultant models the room, its volume, its finishes and the Sabins of each sail, and from that sets how many sails the room needs and where they hang.
What goes into a sail: fabric, frame and suspension?
Getzner Textil's acunic cloud shows what a finished sail includes. Getzner describes a fabric covering in Polyester FR, Trevira CS, a soft-edge aluminium frame in black, white or silver anodised finish, or a "wooden line" frame in oiled solid oak. It comes in 2000 x 1220, 1500 x 1220 and 1220 x 1220 mm, in every fabric of the collection, with mounting hardware for concrete or plasterboard and suspension of as much as 1,000 mm. A PLUS option adds absorber inserts.
A custom sail is made by a panel maker from Acunic fabric. For cleaning, Getzner's datasheets say the Cubic fabrics are non-washable and that surface dirt can be removed by carefully patting or vacuuming; the care of each Acunic fabric is compared in how to clean architectural fabric.
Do ceiling sails need a fire rating?
Specification 7 of the NCC handles a ceiling lining and an attachment to a ceiling differently, and the building certifier decides which one a hung sail is. Ask the certifier before the fabric is chosen.
AKA Acoustics' Technical Product Summary (Version A, October 2024) gives every Acunic fabric its own Group Number. Cubic Pico is Group 1 (Technical Product Summary). Cubic Giga is Group 2 (Technical Product Summary). Because the acunic cloud comes in every fabric of the collection, the table gives the Group Number of each fabric.
Australian fire Group Numbers
How a Group Number differs from non-combustibility, and what a certifier will ask to see, are covered in Group Numbers and the NCC.
How do shape, colour and light change a sail?
Shape sets the rhythm of a ceiling. The acunic cloud is rectangular or square, and Getzner's acunic frame, which can also be fixed to ceilings, comes square, round or hexagonal, with backlighting available.
Colour changes how a sail sits against the ceiling. Acunic's standard colours are off-white, black and beige, and any Acunic fabric can be custom dyed; Getzner's datasheets say technical specifications may differ for dyed fabric, so performance is confirmed for each order. The standard colours and custom dyeing are shown together, and how custom dyeing works covers the process.
Light can also be part of the sail. At Sparkasse Götzis, Getzner and METEX GmbH fitted ceiling luminaires by NEULICHT lighting solutions GmbH with Cubic Giga, so the fabric diffuses the light and adds a textile surface to the bank's customer area.
