Modern people spend most of the day indoors. Indoor air quality is therefore very important for health and well-being. Indoor air quality is largely determined by the way we use and ventilate our homes as well as by emissions from building materials, furnishings and consumer products.

Depending on the personal daily routine, a person often spends time in several different indoor spaces. These can be the private living space, the workplace or public buildings, such as cinemas, theaters, shopping and sports facilities. Vehicles and public transportation also count as indoor spaces.

The air quality in these indoor spaces and the climatic conditions are largely determined by the type of use of the room, the length of time people spend there and the air exchange (air change rate).

As many residential buildings today are heavily sealed for energy saving purposes, they only have a low natural air change rate. Airborne pollutants are therefore introduced less by outdoor air and more by indoor sources. Human activities such as cooking, cleaning, handicrafts, smoking, and sport, sweating and breathing, also influence the indoor air quality. Fragrance products may also negatively impact indoor air quality. 

In some cases, the use of electrical appliances can also contaminate the indoor air. Combustion processes indoors are generally problematic and, depending on the type, can heavily contaminate indoor air with particles and other combustion by-products.

Therefore, correct and effective ventilation in living spaces is an important measure to ensure a healthy indoor climate. You can find tips on our topic page  "Proper Ventilation".

A relatively new trend is the use of techniques to purify indoor air (i.e., filtering, binding, or breaking down airborne pollutants). This can be done passively using active wall paints, fabrics or floor coverings, or actively using electrically operated air purifiers. You can learn more about this topic on our topic page "Air Purification" page.