Symptoms that lead to chronic employee fatigue, headaches and eye, nose and throat irritation are often labelled as Sick Building Syndrome (SBS), a condition that arises from poor air quality. Accumulation of airborne contaminants is its primary cause.
A very effective solution is to fit High-Efficiency Particulate Absorption (HEPA) filters in air-conditioning systems. These are known to trap almost 99.7% of air borne particles that can adversely affect health conditions. However, it is a static system that can only treat air filtering through it. Anything more like removing gasses or odours will need fitting of an extra activated carbon filter. HEPA filters also need to be cleaned at regular intervals.
Another option for quality air is UV-C light for cleaning AC ducts and coils. But these have limited applications and are not useful for removing odours. For HVAC systems installing HEPA filters is the best option.