Ventilation air intake - first line of defence against an unfavourable outdoor climate.

The ventilation air intake (louver) is the first line of defence against an unfavourable outdoor climate. Unfortunately, the importance of this component is often an underestimated issue in the design process of many heating, ventilation and air conditioning (HVAC) systems. Field studies and inspections of a representative number of HVAC plants carried out between 1995 and 1998 in and around the city of Trondheim revealed that snow, and in several cases rain, easily passes through the air intake louver. Such intrusion of humidity can lead to unwanted microbial growth in the HVAC system.