Natural ventilation can help dissolve indoor pollution, but at the cost of introducing contaminants, without any control
by Sodeca
The use of natural ventilation as the preferred method of air treatment inside buildings can generate the following:
• Provoke a false sense of security
• Have dire consequences for health in the short/medium term
"The source of pollution can be both indoor and outdoor," says Carlos Martínez, Technician specialized in indoor air quality at SODECA IAQ, who also warns that "not promoting correct mechanical ventilation and extensive air treatment can have dire consequences for health in the short / medium term."
For example, the Ministry of Health in Spain has declared, in a document issued on February 9, 2021, natural ventilation as the preferred option to face the pandemic caused by COVID-19. This statement and the actions applied in school environments, according to Martínez, "have provoked in society a false sense of security and the belief that natural air is the best for health."
Indoor Air Quality
The concept of Indoor Air Quality, CAI (in English, IAQ) refers to the levels of pollutants present in the air inside buildings and aims to establish a direct relationship between these and the health and comfort of society. The source of this contamination can be both indoor and outdoor. To understand how to carry out a correct air treatment, the origin and characteristics of each of these pollutants must first be understood.
Figure 1. Main pollutants associated with the air we breathe. SOURCE: SODECA IAQ
Daily contact with contaminants
Using natural ventilation to renew the air inside buildings and dilute the pollutants present can lead to the entry of other dangerous pollutants. Large population centres suffer from sometimes very poor outdoor air quality, with high concentrations of pollutants generally associated with transport activities, such as nitrogen oxides (NOx), Volatile Organic Compounds (VOCs) and suspended particles.
Figure 2. Natural ventilation can help dissolve indoor pollution, but at the cost of introducing pollutants from outside, without any control. SOURCE: SODECA IAQ
Carlos Martínez refers to the INMA Project (Childhood and Environment), which has been monitoring the growth and development of 3,700 children in different parts of Spain for 20 years: "The results show the impact of pollution present in large cities on birth size, development of lung function or cognitive function. Daily contact with these pollutants can cause severe respiratory conditions, headaches and even reduce the lung and cognitive development of children. Likewise, in Europe there are up to three times more deaths related to external pollution than those caused by traffic accidents."
Efficiency and comfort
In addition to the health problems associated with natural ventilation, it is worth noting the negative effect that this has on energy efficiency and thermal comfort inside buildings. Legislation, both European and Spanish, has focused in recent years on the importance of energy efficiency of buildings. Promoting natural ventilation as a preferred option clearly jeopardizes the commitments of the building with energy efficiency.
That is why, it must be ventilated with enough fresh air previously treated and / or directly treat the indoor air. In either case, the path always goes through efficient mechanical ventilation and complete air treatment.
Figure 3. For a correct elimination of indoor pollution, it must be ventilated with sufficient amount of fresh air previously treated and / or treat the indoor air directly. SOURCE: SODECA IAQ
Carlos Martínez, as Technician specialized in indoor air quality of SODECA IAQ, concludes that "the best possible strategy and, therefore, the preferred option to ensure the highest quality of indoor air is to carry out a correct ventilation with fresh air, correctly filtered and properly disinfected".
Air Quality with certified equipment
Every time the equipment that exists in the market for air treatment. However, some of them may not have guarantees that certify their efficacy and safety. The indoor air purification solutions of the SODECA IAQ division are certified for compliance with the EN 14476 standard and have certifications validated by external laboratories and independent organizations, as well as field tests following standardized methods.
* SODECA IAQ is the division specialized in improving indoor air quality of the company SODECA.
