Indoor Air Quality

Comfort & Health

Spend time indoors safely …

In many different sectors, people are required to stay indoors almost the entire day, either working, studying or residing. Consider, for example, office buildings, daycare, schools, nursing homes and hospitals.

At first glance, they seem like safe and neutral places, nevertheless, the occupants or employees can also suffer from the Sick Building Syndrome (SBS). SBS comprises of various nonspecific symptoms which are experienced by the occupants of a building and seem to be linked directly to the time spent in the building and thus related to the indoor air quality. No specific cause or illness can be identified and the symptoms usually resolve soon after leaving the building.

It concerns apparently harmless and vague complaints such as headache, dizziness, nausea, irritation of eyes, nose or throat, sneezing, coughing, dry or itching skin. Ultimately, it can lead to much more severe symptoms and long-lasting diseases such as respiratory infections, cardiovascular problems, asthma, allergies, and even (lung) cancer.

Certain people are more vulnerable than others to indoor air pollution. These include children, pregnant women, people over 65 years of age, and persons suffering from cardiovascular and respiratory diseases (e.g. asthma).

Efficiency & Economy

Prevent unnecessary expenses …

Poor indoor air quality is not only a comfort case or health hazard for employees and occupants but it can be also a significant additional cost for companies due to poor concentration, lower productivity, and high illness absenteeism. In schools poor indoor air quality also leads to concentration problems and impaired learning, which in turn can have an impact on further development and later education.

These issues eventually lead to increased healthcare costs which contributes to the growing financial burden on health insurance funds and society.

As buildings become more thermally insulated, the importance of intelligent ventilation systems is growing, ensuring optimal indoor air quality while minimising energy loss. Every year, substantial amounts of money and energy are wasted due to inefficient heating, ventilation and air conditioning, with open windows being a significant contributor.

Modern ventilation systems regulate the indoor air quality based on different parameters, such as temperature (T), relative humidity (RH), carbon dioxide (CO₂), total volatile organic compounds (TVOC) and carbon monoxide (CO). These parameters change with the amount of people in the room, their time spent in the room, the outside temperature and the usage of certain pollutants.

In offices and workspaces, air quality sensors integrated into HVAC systems maximise energy efficiency and enable proper ventilation and good air quality, ensuring a healthy and productive work environment.

Viral Contamination

Lower the risk of viral infections …

Viruses spread via droplets and airborne aerosols, the risk of infection is much higher in crowded and poorly ventilated spaces. When someone coughs or sneezes, millions of droplets of mucus and saliva spray from their mouths. These droplets may be large, like raindrops, or too tiny to see. The droplets can land directly on other people and enter the airways or on nearby surfaces, where they can evaporate and leave virus particles behind. By touching these surfaces such as doorknobs or public touchscreens and subsequently the nose, mouth or eyes, virus particles can be transferred into the body.

In comparison with droplets, aerosols contain less infectious virus particles because of their smaller size (50 µm), but breathing in large numbers of aerosols containing the virus could add up to an infectious droplet. In addition, aerosols can stay airborne (and travel pretty far) for an extended period of time before settling on a surface or landing on a nearby person. If you are indoors and the room is not well ventilated, they may remain in the air for a longer period of time.

Ensuring proper ventilation reduces indoor airborne contaminants. One of the most effective ways to curb disease transmission indoors is to swap out most of the air in a room — replacing the stale, potentially germy air with fresh air from outside or running it through high-efficiency filters — as often as possible. Most ventilation systems are dimensioned to provide crowded spaces with sufficient fresh air. When the room is not occupied, the air volume flow rate can be reduced while still supplying sufficient fresh air. Circulating fresh air helps flush viruses out of vents so they do not build up indoors.

Information & Guidelines

Comply with applicable legislation …

Thanks to the expertise gained during the COVID-19 pandemic and the growing awareness of its importance for health, increasing attention is being given to good indoor air quality.

Several organisations, including the World Health Organization (WHO), the European Commission (EC) and the national governments, provide information and guidelines regarding the composition and maintenance of an acceptable indoor air quality. Some thresholds such as those provided by the EC, are legally binding for EU Member States.

The World Health Organization (WHO) is a specialised agency of the United Nations responsible for international public health and is composed of as many as 194 Member States. The WHO has issued guidelines for acceptable levels of pollutants in the indoor environment to protect public health worldwide. The WHO recommendations concern - amongst others - PM, CO, formaldehyde and VOCs.

The European Union (EU) has no comprehensive regulation for IAQ, but has established threshold limits for specific indoor air contaminants in buildings, including benzene and carbon monoxide (CO). The EU regulations to improve indoor air quality, include the Energy Performance of Buildings Directive (EPBD) and the Construction Products Regulation (CPR). These directives encourage better ventilation systems and set standards for building materials to reduce indoor air pollutants.

The revised Energy Performance of Buildings Directive (EU/2024/1275) entered into force in all EU countries on 28 May 2024 and helps increase the rate of renovation in the EU, particularly for the worst-performing buildings in each country. The directive contributes to the objective of reducing greenhouse gas emissions by at least 60% in the building sector by 2030 compared to 2015, and achieving a decarbonised, zero-emission building stock by 2050.

In Belgium, the law of November 6, 2022 sets reference levels for CO₂ concentrations and ventilation rates for enclosed spaces that are publicly accessible. This legislation is the basis for an ambitious policy regarding the improvement of indoor air quality in public spaces. As of January 1, 2027, operators and owners will be required to use at least one air quality meter, conduct a risk assessment, and, if necessary, establish an action plan.