This standard applies to air-conditioning systems (HVAC) used to ventilate or air-conditioning rooms and work areas. It deals with the noise-protection requirements necessary for the installation of such systems and the measures to be taken for this purpose. However, these measures do not apply to buildings in which the installations have already been installed. The standard provides guidance for the acoustic planning and design of the HVAC systems. In addition, an approximation method is presented to determine the sound pressure level generated by the HVAC system inside the area. The revised version of this standard has undergone extensive adjustments. Example calculations are presented in VDI 2081 Part 2.