Acoustic requalification for a restaurant room: a practical example

Riqualificazione acustica ristorante-Caruso Acoustic

Project: restaurant of about 60 places
Volume of the venue: 249 m³
Acoustic problem: elevated reverberation in the room with consequent dissatisfaction among both customers and the restaurant staff.

If we talk about comfort in restaurants, we often only think about the quality of the service provided or space comfort. In this situation, acoustics plays a strategic role in giving a pleasant and cosy touch to the environments. In restaurants indeed, we have to raise our voices, thus contributing to create noise with consequent disaffection and tiredness, a potential relaxing moment, such as the lunch break, risks becoming a source of stress. A good acoustic planning can improve considerably the liveability of indoor premises to the benefit of the clients who will be more inclined to return, and of the staff who will work better.

The acoustic renovation project here proposed has as its object a restaurant room with the capacity of about 60 places; the volume of the place is of 249 m³. At the design stage, the functional needs of the room have been examined and later a phono-metric analysis has been carried out to find out the reverberation time before the acoustic treatment and the result achievable after the installation of Caruso Acoustic sound-absorbing panels. The frequencies taken into consideration are between 250-2000 Hz, namely those involved in speech. In addition, given the lack of illumination inside the room, a lighting calculation has been made, in order to study the angle of the light beam and guarantee the right light output.

The following chart shows the reverberation time (RT) determined in the venue before and after the installation of Hanging Silente sound-absorbing panels.

Reverberation Time without panels Reverberation Time with panels
2,21 s 0,88 s

The reverberation time, calculated in the room before the installation, is around 2,21s. According to the standard UNI11690, that shows the reverberation time around 0,5 s for venues up to 500 m³, and considering the volume of the place, it has been set as goal the reverberation time of 0.80 s at 250-2000 Hz, to ensure a suitable acoustic comfort to the room.

With the purpose of reaching these results, we have installed 12 Hanging Silente sound-absorbing panels with integrated LED lighting system. Hanging Silente is a single-sided sound-absorbing panel covered with fabric, particularly recommended for high rooms; it allows the customer to adapt freely the distance from the ceiling to intercept effectively both the direct and reflected sounds. The panel is available with inner sound-absorbing material in Basotect® melamine resin by Basf® or Whisper® material by Stratocell®.

The poor lighting conditions (of scarce illumination) of the room have been improved through the integration of LED lights on each sound-absorbing panel. 60×30 cm LED spotlights (25W power) have been installed for a total power of 300 W. As it can be deduced by the lighting calculation, there is now a higher light output equal to 30120 lm against the previous 20392 lm, therefore around 48% more than before. All that consuming 1200 W less in comparison to the previous halogen illumination system which consumed around 1500 W.

Light output without panels Light output with panels
20392 lm 30120 lm

The acoustic and lighting renovation project for the restaurant room has allowed us to reduce the reverberation time, thus significantly improving the quality of the environment. On top of this, thanks to the integration of lighting elements in the sound-absorbing panels, it has been possible to ensure the right illumination. The aesthetics of the place has improved too: the sound-absorbing Hanging Silente panels are available in 22 fabric colours, enabling the customer to personalise and to furnish the environment.