Vermilion Parish, LA Noise from Specific Sources: HVAC & Mechanical Noise (2026)

Section 26-65(d) of the Vermilion Parish Code is the parish's rule for mechanical equipment. If the source under investigation is a mechanical device that, in the investigating officer's opinion, emits a sound with a steady tonal quality, the permissible sound level limits in Table I are reduced by five dB(A). The sound must be a single frequency or a narrow cluster of frequencies, which the section describes as a whine, hum or buzz, and the measured level must not fluctuate by more than plus or minus three dB. The listed sources include heating, ventilating or air conditioning units, refrigeration units and transformers.

The subsection then sets a fixed cap: "Nothing to the contrary withstanding, sound sources from residential heating, ventilating or air conditioning units cannot exceed 55 dB(A) at night." The text does not tie that number to a clock time in the same sentence, and Table I in section 26-65(a) uses 10:00 p.m. to 7:00 a.m. as its night period for the residential column.

The basic test in subsection (a) is measured at any location at or within the property line of the receptor property, and readings above Table I are prima facie evidence of a violation. The definition of multi-use property in section 26-63 names air conditioners, boilers and automatic garage doors as devices that can raise sound levels for another use on the same parcel, such as apartments above a store.

Equipment sound is not amplified sound, so section 26-69(a) can classify a first violation as minor if it was not willful, reckless or grossly negligent and was not the subject of enforcement in the preceding 12 months. A minor violation gets an enforcement and compliance period and is punishable only if it is not corrected.