According to ASHRAE standards, what is the maximum sone rating for a continuous mechanical ventilation system?

The maximum sone rating for a continuous mechanical ventilation system is 1.0 sone according to ASHRAE standards. This rating reflects the acceptable noise level for such systems to ensure comfort in residential applications. Ventilation systems operate continuously and, therefore, should not be excessively loud to avoid disrupting daily life.

A sone is a unit of measurement for loudness, and a 1.0 sone is perceived as equivalent to the sound of a quiet refrigerator. This standard is designed to strike a balance between adequate ventilation for indoor air quality and maintaining a comfortable acoustic environment. A rating higher than 1.0 sone, such as 1.5 or 2.0 sone, would indicate a noisier ventilation system that could potentially lead to disturbances within a living space, making 1.0 sone the upper limit for continuous mechanical systems. The lower ratings like 0.5 sone suggest even quieter systems, but the key takeaway for continuous systems is that they should ideally operate at or below the 1.0 sone threshold for effective and comfortable ventilation.