Air Quality Signal Ensures Fresh Air in the Classroom

If pupils are conspicuously tired during lessons, lack concentration or fidget around, it is due to stuffy classroom air caused by poor ventilation or the lack of it. This has now been confirmed by a study carried out at Bremen University under the leadership of Dr. Gerhart Tiesler. The scientists measured the carbon dioxide concentration during lessons in three different schools. Without separate ventilation, the CO2 concentration in the classroom had a detrimental effect on the pupils’ work after just 20 minutes. As the CO2 content in the indoor air increased, the pupils became increasingly inattentive and tired.

CO2 values above the DIN 1946 guide value of 1,500 ppm resulted in slower processing of visual and audio stimuli. By contrast, the pupils responded to additional airing with increased attentiveness, lowered physical stress, reduced noise level and a more intensive teacher-pupil dialogue. If children are to be able to concentrate in school, regular ventilation is required. But when, and for what duration?

The actual CO2 concentration depends greatly on the size of the room, the number of pupils, the pupils’ activity, the location of the school and general weather conditions. CO2 concentration can be measured by the air quality signal from J. Dittrich Elektronic (Germany) using a two-beam infrared photometer. Green light means fresh air with low carbon dioxide content. When the air is stuffy the traffic light switches to amber and when the air is stale it switches to red. On amber, opening windows fully is recommended, and absolutely essential when the light switches to

red. Reading is made easy by intuitive icons and acoustic signals. The device is ready for use and is simply connected to a wall socket.

If required, a data logger records the measured values. With the air quality signal the children are soon able to learn right airing behaviour and quickly recognise: when a lot of minds are at work one thing in particular helps them to solve the maths problem, and that is fresh air. Of course this is not only relevant to the classroom, but any other indoor work place when concentration levels are paramount.

So open windows in good time!