The German standard VDI 6022 specifies the scale of required operations in terms of maintenance and inspection of ventilation and air-conditioning systems with and without a humidifying chamber. Both operations require training and completion of a final examination. Hygiene inspections of these systems can only be carried out by verified engineers, technicians and craftsmen.
Inspection of the facility and its provided premises, incoporating a company physician as well as staff representation concerning occurring deficiencies are part of a hygiene inspection. During the inspection physical climate changes (temperature, humidity, air velocity) are measured in representative locations of the air conditioning plant and in the provided premises. An inspection of the total bacterial counts of legionella is carried out in plants with humidifying chambers. Spore output (mould spores) and the total bacterial counts are measured in some premises.
Filter condition is very important for a well functioning and low-germ working air conditioning plant. Filters have to be checked and changed regularly. In the course of the inspection, samples of the filters are taken accordingly to verify the bacterial count and spore output.
Samples are taken from many locations of the center and are then microbiologically cultured and determined. Cooling ceilings are also subject to the VDI 6022 regulations and are considered as air conditioning plants. Therefore they have to be checked as frequently as air conditioners.