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

Chapter 9.52, enacted by Ordinance No. 847 in 2006, otherwise caps exterior sound at levels tied to the general plan designation of the property receiving the noise: Section 9.52.040's Table 1 holds most residential areas to 55 dBA from 7 a.m. to 10 p.m. and 45 dBA overnight, with commercial and industrial ceilings running from 65 to 75 dBA. Section 9.52.020 exempts sixteen categories of sound from those limits and from every other requirement in the chapter, and subsection L is simply 'Heating and air conditioning equipment,' with no qualifying language limiting the exemption by size, age, decibel output or time of day.

Because HVAC units get their own dedicated exemption, they are not swept into the separate 'Power Tools and Equipment' special sound source standard in Section 9.52.060(B), which caps other equipment noise at inaudible inside a neighboring dwelling between 10 p.m. and 8 a.m. and at no more than 100 feet away otherwise. A rooftop condenser, window unit or ducted heat pump running continuously next to a property line therefore cannot be measured against Table 1 or cited under the power-tool curfew; the enforcement officials named in Section 9.52.080, the sheriff and code enforcement, have no basis to act on HVAC noise complaints under this chapter alone.

The exemption is chapter-wide and applies equally across unincorporated communities; it does not extend into the county's 28 incorporated cities, such as Temecula, Murrieta or Riverside, which regulate mechanical equipment noise, if at all, under their own municipal codes.