In 4 elements of building comfort (temperature, light, noise, air quality), light and temperature have more impact to building design process; noise and air quality have less impact to building design process.

However, air quality is the most important of the four. People can withstand a little cold or a little hotter, a little noise or the room too dark they can turn on lights ... people will easily adapt if the environment can clearly feel so they can easily to adjust to achieve comfort. 

 

For air quality, it will be harder for people to perceive, for example fine dust particles ...
So it will be easy to lead to subjectivity and disregard for this element.
Affection from indoor air pollutants may immediately or for many years.

Therefore, must pay special attention to this element. Ventilation in the building is a must-do thing.

To ventilate and make air quality meet the requirement we must clearly quantify and to quantify we must do simulation.