– Sound Pressure Level
A sound pressure is the pressure deviation from atmospheric pressure caused by a sound wave, in pascals. The Sound Pressure Level depends on the distance, the position of the source and the environment.
Optimal sound pressure levels for HVAC and air conditioning equipment vary depending on the type of unit, the building accoustics and the usage of the building.. whether it needs to be an especially low-noise environment (e.g. a concert hall or library).
For outdoor units, an adequate sound pressure level is considered to be approximately 50-60 dBA. However, the sound pressure level of indoor units should be 30-40 dBA when the equipment is operating at moderate power. Operating at full power this level could be somewhat higher.