With an extreme focus and rapid development in recent decades (in research, industries and all types of buildings), indoor air quality (IAQ) is often misused as a substitute for indoor environmental quality (IEQ). In short, IAQ is about what we breathe. IEQ, more comprehensively, is about what we breathe, see, hear, and feel in a building.
How it all began?
Definitely many thousands of years ago, when humans have started to live in caves and the air has been polluted by fires used for cooking and emitting lots of smoke. However, at those times people have spent more time outside (hunting for food, collecting water and playing), so the effects of the bad air were not immediately visible.
Jump to a few hundreds of years before Christ, and there was polluted air in crowded cities, dampness in buildings and problems with hygiene, and more.
Only a few hundreds years before the 20th century, the health effects of poor air, poor ventilation and poor temperature were also responsible for the spread of various diseases.
Only around 18-19th century, the impact of fresh air, hygiene, sunlight and natural ventilation were pioneered by the famous nurse. Which slowly has led to understanding, connecting of dots (why, what, how…) and subsequent changes.
The old equation was not complete! IAQ + Energy Efficiency!
Move to 19-20th century, when many great debates were focused on CO2 (ppm), airflow and health. But at that time, the main concept was all about indoor air quality (IAQ) and its parameters. And mainly the impact of energy efficiency was in the spotlights. But two decades later, problems have arisen with sick building syndrome (SBS) and other building-related illnesses (BRI).
The equation is simple! IEQ + Health!
Thankfully, bad outcomes have rather quickly turned things and minds around. Since the 1980s, the focus has changed and people started to realize that there is a need to connect the air with the environment and subsequently with health. Interest has shifted from buildings being just energy-efficient, to be sustainable and provide a healthy environment – all at the same time.
And this was the moment when IEQ became a broader subject, connecting indoor quality (air, thermal comfort, lighting and visual comfort with acoustical conditions) with the environment in buildings and health / well-being / productivity of all people indoors.
So now you know that IEQ is more complex than IAQ.