Scientific blog · Acoustics and liability

Noise from extraction fans and hoods: limits, liability and cases before the Court of Cassation

Artur Cokaj · 16 October 2026 · Updated 21 October 2026

Extraction, vibration and nearby homes: how noise is assessed, which consequences are documented and why catalogue decibels are not enough.

Equipment essential to a kitchen can become the cause of criminal proceedings. This happened to a restaurant ventilation system in the case decided by Court of Cassation judgment no. 31279/2017. For a business operator, extraction fan noise therefore deserves the same attention as fume capture: check what reaches homes, when it reaches them and by which routes.

A restaurant, a ventilation system and a conviction

Criminal Court of Cassation, Section III, judgment no. 31279 of 22 June 2017 examined the appeal of the manager of a public establishment convicted of disturbance caused by its ventilation system. The lower court decision was based on witness statements and ARPA measurements. The Court ruled the appeal inadmissible, ordering procedural costs and €2,000 to the Cassa delle ammende, in addition to the conviction already imposed.

The reasoning distinguishes a mere exceedance of acoustic limits from additional facts that may constitute criminally relevant disturbance. The case demonstrates a concrete risk; it does not justify equating every numerical exceedance with a criminal offence.

Noise follows several paths

In an extraction system, noise can be generated by the fan and by air movement through components. It may escape through the casing, travel along the inlet and discharge, or reach the building as vibration transmitted through connections. An internally lined enclosure does not, on its own, demonstrate that all these paths have been controlled.

Sound power describes source emission under stated conditions; sound pressure describes sound at a receiving point and also depends on distance and the environment. A catalogue value must therefore be accompanied by test conditions. The principles and transmission paths are described in the Suissetec technical information sheet of May 2025, used here for installation physics, not to apply Swiss requirements in Italy.

Which limits must be checked

The DPCM of 14 November 1997 distinguishes source emission, overall sound immission and the differential criterion. Absolute limits depend on the area's acoustic classification. Within residential premises, the differential limit, where applicable, is 5 dB during the day and 3 dB at night. Article 4 provides exclusions and thresholds below which noise is negligible: these figures are not universal limits applicable to any measurement.

Annex A to the Ministerial Decree of 16 March 1998 defines daytime as 06:00 to 22:00 and night-time as 22:00 to 06:00. The differential compares ambient noise with residual noise measured with the disturbing source excluded. Measurements, duration and operating conditions must represent the phenomenon; an occasional check beside the machine does not replace the assessment required at the receiver.

Penalties, restrictions and liability are different matters

Article 10(2) of Law 447/1995, as amended by D.Lgs. 42/2017, provides for an administrative penalty from €1,000 to €10,000 for exceeding the limit values referred to in the provision. The applicable amount and legal classification depend on the specific findings.

Where the exceptional and urgent needs specified in Article 9 of the same law arise, the competent authority may issue reasoned temporary restriction measures, up to partial or total prohibition of certain activities. This is not automatic closure following a complaint.

In civil law, Article 844 of the Civil Code refers to normal tolerability, taking local conditions into account. Administrative assessment and assessment of a dispute between neighbours must therefore remain distinct.

The 2026 case: costs do not end with the fine

In Criminal Court of Cassation, Section III, judgment no. 20496 of 4 June 2026, disturbance from a restaurant-bar included machinery, voices and furniture movement. The appeal was dismissed. The judgment records a €309 fine at first instance, damages to be assessed separately and an interim payment of €2,500; at the Cassation stage, procedural costs and €3,686, plus additional charges, for the civil party's legal representation were added.

The Court considered whether the conduct could disturb an indeterminate number of people, including within an apartment building. The limited number of complainants did not exclude that requirement. The case concerns multiple sources and behaviours: it must not be attributed solely to the electric motor.

Check the result after remedial work

Civil order no. 7855 of 25 March 2025 (Section II) concerned a lift motor. The Court of Cassation criticised the decision that had considered the problem resolved merely because work had been carried out, without actually verifying its effectiveness, which those affected contested. It quashed the decision and remitted the case, rather than making a new final damages award.

For professional extraction, this provides a methodological lesson: documenting work and checking the result are different activities. Silencers, anti-vibration mounts and duct modifications must be selected according to frequencies, noise paths and airflow performance.

What to ask before ordering an extraction fan

1. Identify receivers, operating hours and acoustic classification with the qualified acoustics technician.
2. Define the required flow rate and pressure considering ducts and air treatment; obtain acoustic data under the manufacturer's declared conditions.
3. Design for airborne and structure-borne noise paths, also checking silencer pressure drop and compatibility with the effluent.
4. Schedule operating checks and post-modification assessments, retaining documentation and maintenance records.

These are technical prevention criteria to adapt to the installation. For an ETC supply, discussion must start with these data: fan and treatment selection must be coordinated with the installation design. The relationship between motor, fan curve and consumption is discussed in Motors and fans for fume extraction.

Sources and scope of the article

Consulted on 16 October 2026. National framework; assessment of an installation requires the applicable territorial provisions. Judgments were read in the linked full reproductions from Canestrinilex, Lexambiente and Giuricivile, not copies obtained directly from the Court's portal. The amounts describe individual cases, not a forecast of the cost of other disputes.