It's going to depend on the model/manufacturer. Typically, the inverter based outdoor compressors are much quieter than the single or dual stage compressors tha

It's going to depend on the model/manufacturer. Typically, the inverter based outdoor compressors are much quieter than the single or dual stage compressors that were common with the traditional American brands. If you can find the detailed spec sheet or service manual for the unit, they usually have decibal ratings listed.