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Wilmington, DE Noise from Specific Sources: HVAC & Mechanical Noise (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Daytime limit (residential)
65 dBA, 7 a.m.-8 p.m.
Nighttime limit (residential)
55 dBA, 8 p.m.-7 a.m.
Enforcing agency
Licenses and Inspections dept.
First-offense fine
$250 to $1,000
Temporary exemption
Up to 10 days, § 11-62

Summary

Wilmington caps stationary noise sources like HVAC condensers and heat pumps at fixed decibel levels, 55 dBA at night and 65 dBA by day in residential zones, enforced by Licenses and Inspections.

(5)No persons shall operate or cause to be operated any stationary source of sound in such a manner as to create a 24-hour equivalent A-weighted sound level which exceeds the leq limits set forth for the receiving land use category...: a.Residence districts: 65 dBA between the hours of 7:00 a.m. and 8:00 p.m., 55 dBA between the hours of 8:00 p.m. and 7:00 a.m. b.Business districts: 75 dBA between 7:00 a.m. and 10:00 p.m., 65 dBA between 10:00 p.m. and 7:00 a.m. c.Industrial districts: 85 dBA.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 72).

Full Breakdown

Under City Code § 11-65, any stationary source of sound, including outdoor air conditioning condensers, heat pumps, and rooftop HVAC units, cannot push the property-line noise level above 65 dBA in residential districts between 7:00 a.m. and 8:00 p.m., dropping to 55 dBA overnight from 8:00 p.m. to 7:00 a.m. Business districts get 75/65 dBA and industrial districts a flat 85 dBA ceiling. The department of licenses and inspections enforces the limit with a calibrated ANSI-standard sound level meter, and owners can seek a temporary exemption under § 11-62 while installing quieter equipment.

Violations & Fines

First offense fines run $250-$1,000, second offense $500-$2,500, third and later offenses $1,000-$5,000: each day of continued excess noise counts as a separate violation under § 11-59.

Frequently Asked Questions

Does Wilmington's noise limit apply to my AC unit or heat pump?
Yes: any stationary source of sound, including outdoor condensers and heat pumps, must stay within the § 11-65 decibel limits measured at the neighboring property line.
What if my HVAC unit is too loud to fix quickly?
You can ask the commissioner of licenses and inspections for a temporary exemption under § 11-62, good for up to ten days while you install quieter equipment.

Sources & Official References

Other rules in Wilmington

All Wilmington rules

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