[Evaluation of technical indoor air ventilation systems in operating departments from the health viewpoint]

By means of measurement examples it is shown that the examination of the cfu-concentration in the supply-air is not a sufficient criterion for the hygienic-microbiological evaluation of air-conditioning systems in operation wards. Maximum upper values for cfu-concentration were only exceeded a little in some cases. Particle measurements, carried out simultaneously, gave further information on the hygienic status of the air supplied by the air-conditioning system and permitted an evaluation of the ventilation system (for example an air-supply ceiling with a stabilized air ventilation). An efficient air-ventilation system should have the effect that the air quality in the operation area is of nearly the same quality as the supply-air. On the basis of own measurements maximum upper values and recommended values for cfu- and in particular particle-concentrations in the supply-air of air-conditioning systems with three-step filtration were proposed. The set-up and the carrying out of the measurement is described to standardize a "hygienic evaluation" of air-conditioning systems in operation theatres. Help for the interpretation of measurement results is given by means of measurement examples.