Specifics – Air Quality, demand-controlled ventilation
The quality of the indoor airport environment is a key issue for the protection of passengers’ and staff health and well-being. The significance of well-being in buildings was first recognised in conjunction with a noted increase in symptoms and complaints associated with buildings (Sick building syndrome). 'Sick Buildings' can lead to a reduction in the productivity of individuals or even an entire staff.
If the oxygen (O2) content of the air is too low, the carbon dioxide (CO2) level becomes too high. This can occur in overfilled, generally also overheated zones and can produce conditions ranging from drowsiness and lack or concentration to nausea and fainting. The air purity also plays a role; smoke, dust and stale air also cause discomfort - the only solution is to introduce a source of new, fresh air. Measurement of CO2 exhaled from the occupants in airport zones provides a perfect measurement of room occupancy. Mixed-gas or "VOC" sensors (Volatile Organic Compounds) which detect oxidizable (combustible) gases, measure additional odours and bad air from dirty ventilation systems, carpets, dust, smoke, fumes etc. Elements perceived by humans as bad air.
Siemens new combined CO2/VOC sensors combine CO2 with VOC to provide optimum room air quality measurement. The VOC values are transmitted as a maximum value (CO2 or VOC whichever is highest). These new sensors respond not only to combustible gases and vapours, but also to the humidity in the indoor air. Based upon Siemens case studies, the installation of CO2 or VOC based demand-controlled ventilation (DCV) into HVAC equipment is a proven method of protecting the air quality levels for occupants and at the same time saving huge amounts of energy, by reducing plant when not required. The patented Siemens sensors which measure indoor air CO2 / VOC concentrations are standard devices available globally from Siemens and available in room or duct variants.