Ventilation guide for school

Ventilation instructions for teachers and students in classrooms

A good indoor climate is crucial for students' learning, concentration and health. When CO₂ levels become too high in the classroom, it can lead to fatigue, difficulty concentrating and headaches, which significantly impairs learning. SKYEN helps you keep track of air quality – and gives you an easy reminder when it's time to air out.

When should the classroom be aired out?

When the SKY lights up red, the CO₂ level has risen above 1,000 ppm (parts per million). This is not a dangerously high level, so you do not need to consider it an alarm, but more of a friendly reminder. However, it is recommended to air out within the next 30 minutes to improve the indoor climate and the students' learning conditions.

Many people mistakenly believe that it is best to air out the room when you arrive at the classroom in the morning. This is actually not true for school buildings.

Classrooms have often been empty all night and have therefore ventilated themselves through small cracks and openings in the building. The first ventilation is therefore most necessary when CO₂ levels have increased after the first lesson or two – when many students have been gathered in the room for an extended period of time.

Tip: Take advantage of natural breaks to ventilate:

• During recess – get some fresh air while students are out, so they come back to a fresh classroom
• During subject changes – have students stand up and open windows while you change materials
• At the start and end of class – make it a regular routine to designate the "ventilation person of the day"
• During group work – when students move around the class it can be a good opportunity to vent.
• When changing teaching activities – combine a movement break with ventilation
• After sports or other physical activity – students have higher CO₂ production after physical activity

Indoor climate and learning – did you know?

Research shows clear links between indoor air quality and cognitive performance. A Harvard study found that cognitive performance dropped by up to 50% when CO₂ levels rose to 1,400 ppm compared to 600 ppm. For students, the effect is even more pronounced, as children are particularly sensitive to poor indoor air quality.

At CO₂ levels above 1,000 ppm, the following problems may occur in students:

• Reduced ability to concentrate (up to 23% reduction)
• Slower reaction time (15-20% increase)
• Increased fatigue and headaches (reported by 30% more students)
• Poorer test scores (average 15% lower)
• More restlessness in class and difficulty maintaining attention

How do you properly ventilate the classroom?

Openings and drafts

A single opening provides slow ventilation, as the air must both enter and exit at the same point. Two or more openings create a through draft, which is much more effective. Opening windows on opposite sides of the classroom achieves the best air circulation, as the air pressure is equalized across the room.

Example 1: Ventilation with only one opening

When you ventilate with only one opening, a window or a door, the wind trying to enter the room will create a natural overpressure and therefore will not reach very far into the room before the overpressure pushes the fresh air out again.

This can be compared to inflating an almost-full balloon with more air – it's difficult because there is already pressure inside.

Example 2: Ventilation with two or more openings

When you ventilate with 2 or more openings, windows or doors, the air will have free passage through the classroom. There will be no overpressure in the room, as the air can freely pass out of the opposite window.

To use the previous example with the balloon, it can be compared to making a hole in the opposite end of the balloon – now the air flows through easily.

Special situations in schools

Be aware that opening doors to hallways can be problematic if hallways also have poor air quality. Prioritize windows facing the outdoors, where you know the air is fresh.

In larger schools, it may be a good idea to have SKYEN units in all classrooms so you can see where the air quality is best. A good rule of thumb is to never ventilate by opening up to a room with a red SKYEN, unless that room has a window that can be opened to fresh air, so you can create a draft through both rooms.

Take advantage of the "chimney effect"

If the classroom has skylights or windows at different heights, take advantage of this. Warm air rises, so by opening windows both high and low in the room, a natural draft is created, with the warm air escaping through the upper openings while fresh air enters through the lower ones.

Avoid keeping windows ajar all day long.

It is a common misconception that it is best to leave windows ajar all day. This leads to unnecessary energy loss without effective ventilation, and can create drafts and cold close to the windows. Instead, you should ventilate with the greatest possible draft for the shortest possible time - until the SKY turns blue again.

Make it a learning opportunity

Let students participate in the venting process as a practical element in the lesson:

• Let them observe how the CLOUD changes color as CO₂ levels rise and fall.

• Make it a competition to see how quickly the class can get the SKY to change from red to blue.

• Use it as an opportunity to talk about air quality, CO₂ and learning in science classes

• Appoint "Heroes of the Air" in turns among the students who are responsible for keeping an eye on the SKY.

ÅBN offers a Luftens Heroes kit that helps teachers and students remember to ventilate through a hoodie scheme and fun brain breaks.

Seasonal differences

In winter, ventilation is actually more effective than in summer due to the greater temperature difference between inside and outside. The warm air inside will flow out faster and be replaced by cold air from outside, creating a stronger chimney effect. In summer, when the temperature difference is smaller, it may be necessary to ventilate for a slightly longer period or create artificial drafts on days when the wind is not blowing.

Save energy

Turn off radiators and other heat sources while you are airing out. This significantly reduces energy waste, as heat sources will otherwise work extra hard to compensate for the cold air. Ask students to wear a sweater while airing out during the cold months, but explain to them why it is important to get fresh air in.

Remember to turn the heating back on at the same level after ventilating so that the room quickly reaches a comfortable temperature again.

Ventilation systems in schools

If you experience the need for frequent ventilation despite the school having mechanical ventilation, it may be a sign that the ventilation system is not functioning optimally or is clogged. In this case, contact the school's technical service manager to have the system inspected.

Involve students in responsibility for a good indoor climate

By making the indoor climate visible with SKYEN and actively involving students in ventilation routines, you not only create a better learning environment here and now – you also teach students the value of a good indoor climate. This is an important lesson that they can take with them throughout their lives.

Place the SKY at eye level with the students so they can monitor the air quality themselves and learn to react when it becomes poor. This way, indoor climate management becomes a natural part of everyday life in the classroom.

Download our free venting guide

Would you like to share these good recommendations with your colleagues? In addition to sharing this article, you are of course very welcome to download and print our ventilation guide. Print it out and hang it near the SKY so that you can all work together to create a better indoor climate in the classrooms – and thus better learning for the students. Download the ventilation guide here