What is the difference between Sound Power Level and Sound Pressure Level?

The noise levels produced by an air conditioner are often described by manufacturers using what is known as "Sound Pressure Levels" and "Sound Power Levels".

The Sound Power Level is a measure of the acoustic energy emitted from a source of noise, expressed in decibels. The Sound Pressure Level is the pressure disturbance in the atmosphere measured using predefined conditions such as the location of the equipment, the environmental conditions, and the distance of the measurement from the measurement point.

Sound Pressure is ultimately what our ears hear.

Due to the difference in these measurements, if you are using these to help you decide on your preferred air conditioning solution, it is important to make sure you are comparing the same measurement for an accurate comparison of these factors.