Abstract :
It is of great importance to the indoor air quality that the ventilation systems, not only directly after taken into operation, operate as they were designed and according to the regulations. The objective of the paper is to show how well the systems satisfy the national regulations after being in operation for several years and what their main defects are. The requirement for a system to pass the test is that the ventilation performance conforms to the regulations that applied when the system was brought into operation. Of the 5625 evaluated systems, 34% passed the test.
