View from above into Roskilde Cathedral School through roof Skylights. Photo: STAMERS KONTOR
The impact of air quality in schools
Providing high indoor air quality is imperative in the design of schools. Better air quality is linked to better learning outcomes and better overall health. Poor indoor air quality will not only make for an environment that is difficult to concentrate and thrive in, but can lead to an increase in illness and school absenteeism.
According to the US Environmental Protection Agency (EPA), indoor levels of pollutants may be two to five times higher than outdoor levels. Since children breath in more air – in proportion to their body size – than adults, they are all the more susceptible to these pollutants.
To make matter worse, the EPA indicates that almost one in 13 children of school age already suffer from asthma, which would only be exacerbated by such pollutants.⁶ It is, therefore, imperative to address classroom air quality and the main way that this can be done is through proper ventilation.
Increased ventilation can improve classroom performance by as much as 15%, one study shows.⁷ Another study indicated significantly faster and more accurate responses for choice reaction, colour word vigilance, picture memory and word recognition in the classrooms with higher ventilation rates.²
It is critical, then, that the establishments that shelter our children must be adequately ventilated, particularly within densely populated classrooms.
Creating classrooms with cleaner air
When designing for indoor air quality, first and foremost, you will want to take into account international building codes and standards. Beyond this, though, you will want to look at four considerations brought forth by the summary report of the Head Project, the Clever Classrooms report (2015): controlled ventilation, mechanical ventilation, room volume and CO₂; sensors in classrooms.²
Achieving better air quality is as simple as ensuring better ventilation. Windows with large openings that allow for air to escape can provide a great natural ventilation solution. This is particularly true of top-opening windows, as they allow the hottest and stalest air to escape.
Bear in mind, though, children are particularly sensitive to thermal change, which is inevitable when using natural ventilation. During colder times of year, you will want to consider venting when students are out of the room, or consider using mechanical ventilation during these months.
Mechanical ventilation, or the use of electric fans to direct airflow into a building, can be a solution where natural ventilation is not sufficient. In the design of schools, it is often beneficial to use a hybrid solution, combining natural and mechanical ventilation.
The larger the volume of space in a classroom, the longer the air supply in that space can be considered good quality. Generally speaking, classrooms consist of a large volume of students packed into a relatively small space. This means that air quality can become poor in as little as 30 minutes.
It is important that you take the volume of a space into consideration when planning your ventilation solution. To find out more and get useful advice, read our guide about how building type can affect ventilation.
CO₂ levels are often looked to as an indicator for the quality of air. Outdoor air, as an example, contains a CO₂ concentration of approximately 400 ppm, whereas an indoor CO₂ level of 1150 ppm can be considered adequate air quality.
The range you will want to consider is from 1400 ppm, which will ensure good indoor air quality in most situations, to 1600 ppm, which indicates poor air quality. Using CO₂ sensors is a good way to monitor levels and ensure CO₂ levels remain within the lower end of this range.
Achieving cleaner air with Modular Skylights
A really attractive choice for ensuring high air quality in your school design is through VELUX Modular Skylight venting modules.
The modular skylight venting modules are equipped with hidden chain actuators that allow them to automatically open and close, either by command or in response to pre programmed conditions. When closed, they look exactly the same as regular fixed modules.
With VELUX Modular Skylight venting modules, it is even possible to link your windows to CO₂ sensors, allowing them to open automatically to regulate levels.
See how Ryparken Lille Skole in Copenhagen, Denmark did just that. They used VELUX Modular Skylights to turn a run-down textile factory into a lively school.
Use our tools and evaluation methods to evaluate your future ventilation solution and find out ways you can improve upon it.
A checklist for better indoor air quality in schools
Now that we know the benefits of good indoor air quality and the factors we need to consider when designing for it, let’s recap:
Open windows and air out classrooms between lessons.
Innovative natural ventilation solutions, e.g. demand controlled natural ventilation, can maintain the CO₂ level within the recommended range.
Mechanical ventilation systems can ensure an optimum level of air quality without compromising thermal comfort in colder months.
Hybrid solutions can combine the advantages of both natural and mechanical ventilation.