Systems need to be turned on before people arrive at the building, or before peak occupancy hours.
It must be ensured that the outdoor air intakes are open and that there are no sources of pollutants nearby (e.g. air intakes located in a garage).
Use adjustable thermostats that enable occupants to regulate the temperature a few degrees up or down but which do not have many more settings.
Check the interior of the systems frequently, have a maintenance programme in place and monitor and control the build-up of water in the cooling tower drain trays.
Do not allow water to enter the systems and ensure that there is no stagnant water inside them. If this were to occur, dry the systems quickly.
If possible, all duct fibreglass that is exposed to air flow should be removed or replaced with insulation that does not contain fibreglass. It would be a good idea to at least coat the ducts with an antimicrobial hard surface suitable for this purpose. Any microbial contamination must be removed as soon as it appears.
Air conditioning splits must be cleaned every year and the ducts, every 5 to 10 years. The best possible filtration that can be operated by the system must be used.
Make up for the deficiencies of the central ventilation and air conditioning systems with stand-alone filtration systems.
