Acoustic ceiling rafts and baffles

A ceiling raft or acoustic island hangs horizontally, parallel to the ceiling, acting like a floating partial surface. An acoustic baffle hangs vertically, on edge, and is arrayed in a grid. Both absorb on both faces and around the edges. Baffles offer a lot of absorption on little footprint and are especially suited to tall rooms and halls.

A is the equivalent absorption area in m² per element. It states how many square metres of perfect absorption a single raft or baffle replaces. Because free-hanging elements absorb on both faces and around the edges, their effective area is larger than their footprint. That is why A is used instead of αw alone.

Quantity and spacing drive the result. You sum the A values of the planned elements and calculate the reverberation time from them. Rafts or baffles distributed with gaps realise almost their full A value, because more edge area contributes. Hung close together, the effect per element drops. Keep the stored measurement distance from the structural ceiling.

Yes, that is a key advantage of free-hanging solutions. They can be hung from an existing ceiling later, without closing the ceiling over its whole area. This suits rooms with visible building services, exposed concrete or active concrete-core cooling, where a closed acoustic ceiling is ruled out. The amount of absorption can be dosed precisely through the number of units.

A ceiling raft is the right choice when the ceiling cannot or should not be closed over its area: with active concrete-core cooling, visible ventilation and services, a deliberate industrial look, or when retrofitting an existing room. A closed acoustic ceiling acts more evenly across the whole room and makes sense when the ceiling area is freely available.

The fire class ranges from A1 (non-combustible) to F. In ordinary offices fire safety is rarely mandatory, but it is required in escape routes and certain public buildings. Since free-hanging elements hang exposed in the room, the class is worth checking. You can filter by minimum fire class in the search.