This Standard applies to ventilation and air conditioning systems and defines the initial assessment criteria of cleanliness, cleaning procedures of these systems, and the validation of the effectiveness of cleaning applies also to products, which conform to EN 1505, EN 1506, EN 13053, EN 13180 and EN 13403, used in air conditioning and ventilation systems defined in the scope of CEN/TC 156. This standard specifies requirements and procedures necessary in assessing and maintaining the cleanliness of ventilation, including: how to assess the need for cleaning (visual, measurements); assessment frequency (general guidance); selection of cleaning method; how to assess the result of cleaning. This standard is a parallel standard to EN 12097, which specifies requirements for dimension, shape and location for access panels for cleaning and service in ductwork systems This standard is made as an umbrella standard with informative annexes that can be added over time with the following topics: Air Handling Units (AHU) Filter Humidifiers Ductwork Terminal devices The main target groups of this standard are building owners, services companies, maintenance companies, end users and consultancy and control companies.