Sone 523 Updated May 2026

If you are an HVAC contractor, a facilities manager, or a homeowner trying to choose the quietest bathroom exhaust fan, understanding what "sone 523 updated" means is essential. This update is not just a minor revision; it represents a fundamental shift in how manufacturers test, report, and compare noise levels.

For professionals, the message is clear: audit your product library. Any submittal data older than 2022 is likely obsolete. Insist on updated sone certifications, or risk unhappy clients and failed inspections. sone 523 updated

As smart home devices (smart speakers, smart thermostats with fans) become more prevalent, the updated scale will allow for better "quiet modes." Imagine your HVAC system automatically adjusting fan speed not just by temperature, but by the loudness you are perceiving at 2 AM. The noise surrounding the "sone 523 updated" standard is loud for a reason. It fixes decades of flawed comparisons and unrealistic lab results. For the average consumer, this means that when you buy a "quiet" product today, it will actually be quiet in your real-world bathroom or kitchen. If you are an HVAC contractor, a facilities

The "sone 523 updated" protocol introduces a reverberation correction factor, meaning manufacturers can no longer advertise laboratory-perfect numbers that are impossible to achieve in your home. Old sone metrics focused heavily on mid-frequencies (500 Hz to 4 kHz). The update now requires equal weighting for low-frequency noise (20–200 Hz) and high-frequency hiss. Low-frequency noise (like a deep rumble) is often more fatiguing, even at lower decibel levels. Why the Update Matters for Different Stakeholders For HVAC Manufacturers If you produce exhaust fans, range hoods, or air handlers, compliance with the "sone 523 updated" standard is now a legal requirement for Energy Star certification and many building codes (e.g., ASHRAE 62.2, CALGreen). Manufacturing lines must be re-tested. A product labeled "1.5 sones" pre-update may need to be re-labeled as "2.0 sones post-update," forcing a redesign of fan blades, motor mounts, and ducting. For Architects & Contractors Specifying quiet mechanical systems just got harder. You cannot rely on old spec sheets. When a client demands "maximum 1.5 sones for a master bath," you must ensure the product you select has been tested under the sone 523 updated method. Using legacy data could lead to a callback when the homeowner complains about a noise level that is technically compliant but perceptually louder. For Homeowners & Property Managers This update is ultimately good news for you—but only if you know how to read labels. If you are shopping online, look for the fine print: "Tested to ANSI/ASHRAE 113-2023" or "Sone rating per ISO 532 (Zwicker)." Avoid products that still cite pre-2020 standards. A fan claiming "0.3 sones" under the old method might actually be 0.8 sones under the sone 523 updated standard. How to Interpret the New Numbers: A Practical Guide Here is a quick reference table comparing old vs. updated sone ratings for common scenarios: Any submittal data older than 2022 is likely obsolete

Reality: Many local codes incorporate the International Mechanical Code (IMC) , which now references the updated acoustic standards. If you are doing a renovation, the inspector may require updated sone test reports.