San Luis Obispo County, CA Noise from Specific Sources: HVAC & Mechanical Noise (2026)
Key Facts
- Older equipment limit
- 55 dB (installed before 6/4/1992)
- Newer equipment limit
- 50 dB (after 6/4/1993)
- Governing section
- County Code § 22.10.120(D)(1)
- Measurement point
- Property line, per § 22.10.120(E)
- Relationship to general table
- Overrides Subsection B.1 standards
Summary
Air conditioning and refrigeration equipment in unincorporated San Luis Obispo County is held to a stricter exterior noise cap than general sources: 55 dB for units installed before June 1992, dropping to 50 dB for anything installed or used after June 1993.
D.Other noise sources. The noise level standards in this Section apply to the following.1.Air conditioning and refrigeration. Notwithstanding the provisions of Subsection B.1, when the intruding noise source is an air conditioning or refrigeration system or associated equipment installed prior to June 4, 1992, the exterior noise level as measured as provided in Subsection E. shall not exceed 55 dB, except where the equipment is exempt from the provisions of this Chapter. The exterior noise level shall not exceed 50 dB for equipment installed or in use after June 4, 1993.
Full Breakdown
1. Equipment installed before June 4, 1992 may not exceed 55 dB measured at the property line under the measurement procedure in Subsection E, while any unit installed or placed in use after June 4, 1993 is held to the stricter 50 dB ceiling, unless the specific equipment is otherwise exempt under the chapter. Measurement follows Subsection E: a calibrated A-weighted sound level meter is used, and exterior readings are taken at the property line of the affected noise-sensitive land use, with the microphone positioned five feet above ground and away from reflective surfaces where practical.
Because this standard applies notwithstanding the general table, an HVAC or refrigeration unit that would otherwise pass the ordinary 45-70 dB standards for its zone and time of day can still be a violation if it exceeds the 50 or 55 dB HVAC-specific ceiling that applies to it.
Violations & Fines
An air conditioning or refrigeration unit that exceeds 55 dB (pre-June 1992 equipment) or 50 dB (equipment installed or used after June 4, 1993), measured at the affected property line under Section 22.10.120(E), violates Section 22.10.120(D)(1) and can be the subject of a code enforcement noise complaint against the property owner or operator.
Frequently Asked Questions
What noise limit applies to my HVAC unit in unincorporated SLO County?
Does the general daytime/nighttime dB table apply to AC units instead?
How is HVAC noise measured for a complaint?
Sources & Official References
Other rules in San Luis Obispo County
California rules heatmap·Compare San Luis Obispo County to another location·View the California noise from specific sources overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.