Sonoma, CA Noise from Specific Sources: HVAC & Mechanical Noise (2026)

The City of Sonoma's noise ordinance, Chapter 9.56, does not have a section devoted solely to HVAC equipment, but its definitions and limits reach it directly. Section 9.56.020(D) defines 'constant' noise as a continuous noise with no noticeable change in level, and it specifically lists air conditioners and pool equipment as examples. Constant-noise sources are held to the tightest numbers in the city's limit table at Section 9.56.040(A): on residential property, no more than 50 dBA in the daytime, defined as 7:00 a.m. to 9:00 p.m.

Sunday through Thursday or to 10:00 p.m. Friday and Saturday, and no more than 40 dBA at night. On mixed-use property the residential-adjacent constant limits rise to 55 dBA daytime and 45 dBA nighttime, and on commercial property the limit is 55 dBA constant unless a use permit specifically authorizes more. All levels are measured with an ANSI-compliant sound level meter at any point on the receiving property, using the average (Leq) reading for constant sources. A condenser or heat pump that trips these numbers is also independently reachable under Section 9.56.030, which bars any noise raucous or nerve-wracking enough to disturb the peace regardless of whether it stays under the numeric limit.

No standard exception in Section 9.56.050 covers ordinary HVAC operation, so a chronically loud unit is a straightforward complaint to the city's code enforcement, enforceable as an infraction or misdemeanor under Section 9.56.100.