Only an ill maintained air conditioning system can make you ill. A well maintained air conditioning system can only contribute to a healthier environment.
Because it controls humidity levels the growth of dust mites and molds is reduced. Air conditioning maintains humidity levels of 40 - 60% which is positive for persons with allergies.
Air conditoning may have integrated ventilation. Mechanical ventilation is getting more and more important because of the way houses are built these days. The supply of fresh air will prevent the sick building syndrome.
All units are equipped with a filter. Depending on the type of system and the needs of the customer, the type of filter will vary. The effecitiveness of a filter goes from catching dust and particles over fine dust and pollen, bacteria, virusses and odours and even microbes and smoke.
It is essential to replace the filters on a fixed period. When you replace the filters too late you risk that the oversaturated filters start distributing bateria instead of catching them.
When the equipment is correctly selected there will be no draught. This is the job of specialists and should be calculated by an installer. A system with too low capacity will not be able to reach the desired temperature. A system with too high capacity will lead to draught and fluctuating temperatures.