Public places: ventilation to achieve good air quality

A good air quality in indoor spaces is an issue that has gained special relevance over the last few years. Especially since the COVID-19 pandemic revealed its importance in preventing the spread of SARS-CoV-2. However, there are many other pollutants that can negatively affect our health. Therefore, at Siber, we want to talk about the importance of ventilation to achieve adequate levels.

Air quality in a public place

Measuring the concentration of carbon dioxide (CO2) present in the air of a public place is the easiest way to control its quality. For this, we only need a specific measuring probe that can be easily found on the market.

It is important to point out that, although CO2 is not a pollutant in itself, its concentration reflects the activity in the space and the need for ventilation. Because, for example, outside where air quality is optimal, CO2 concentrations tend to be around 400 parts per million (ppm). Meanwhile, indoors, the Technical Code of Building (CTE) in Spain establishes by regulation that acceptable CO2 levels in public places can reach up to 1,000 ppm, considering this value a reasonable limit to maintain adequate indoor air quality.

Even, between 1,000 and 1,600 ppm might be considered acceptable, although in this range it is already recommended to ventilate the space, since from these values the air quality deteriorates and immediate mechanical and controlled ventilation (VMC) is necessary to avoid adverse effects on health.

Appropriate ventilation levels

To achieve a correct level of air quality, having the recommended ventilation flows is essential. According to what is stated in the Regulation on Thermal Installations of Buildings (RITE), it should be between 12.5 liters per second (l/s) and 20 l/s per person. This factor is the most commonly used to define the capacity of a public space.

In this sense, the appropriate ventilation levels can be achieved in several ways. The simplest is to go for natural ventilation, but always with a lot of care to ensure that cross ventilation does not occur. In other words, avoid having the stale air from one room end up in another, instead of outside. Therefore, it is advisable to carry it out always individually.

However, it is more common to have to resort to forced ventilation systems. These, additionally, usually incorporate filters inside that help to further increase air quality. How? Thanks to their ability to retain harmful agents present in the outside air. We are talking about, for example, pollen particles, mold-causing fungi, bacteria, and other microorganisms.

However, we must be careful with the use of filters, as they can reduce the ventilation flow. In fact, generally, the higher their efficiency, the more load losses they will generate. A fact that must be compensated through air purification systems.

Controlled ventilation systems in public places

Undoubtedly, air treatment units are the most commonly used ventilation systems in public places. They offer the advantage of continuously ventilating the interior of buildings and establishments.

For example, in public places with high occupancy, it is recommended to keep them on 24 hours a day. However, two hours before opening, it reaches nominal speed, which is reduced two hours after this occurs and during the entire usage time.

Ultimately, these aspects are part of several basic ideas of the ventilation regulations for buildings in Spain to take into account. Not for nothing, the air quality inside public spaces is of utmost importance. For this reason, proper ventilation is essential to ensure the health and well-being of individuals