“Is it still possible to save energy when everyone is ventilating like crazy?”

Energy saving goes digital – Hanover school exchange and CO2 traffic light workshop on “Ventilation in times of corona”

Despite coronavirus and the resulting lack of opportunities to hold events in person, the Energy Efficiency and Energy Transition department has remained in contact with “its” schools as the school year draws to a close. Cross-school events such as the annual exchange meeting in the GSE energy-saving project (organized by the City of Hanover’s Building Management Department) and a workshop on building your own CO2 traffic lights have taken place online in recent months.

The school exchange on April 27 for Hanover schools focused on how energy can be saved even in times of continuous ventilation due to the pandemic. Corona in particular has given rise to new requirements that also have an impact on energy consumption. In addition to two exchange rounds, one with a pedagogical focus and one with a technical focus, the participating teachers listened to a presentation on “Aerosols, air exchange, window ventilation and CO2 values as a measurable point of reference for orientation”, in which the question of how the virus can be dangerous in schools and how the risk of infection can be minimized was explored. As part of the support for the committed energy savers, the schools were also offered a new event in the energy-saving project in addition to the offer to borrow CO2 traffic lights from the school authorities: the self-construction of CO2 measuring devices with a small group of pupils. On June 1, a CO2 traffic light workshop took place as part of the GSE project in cooperation with the building management department of the state capital of Hanover under the direction of Ms. Schacknat (engineer and school supervisor at UfU). Especially during the corona pandemic, there is great interest in schools in proper ventilation, and the self-built CO2 traffic lights are intended to support this and at the same time awaken the pupils’ spirit of research with this exciting STEM project. All 12 schools received the materials and assembly instructions by post in advance, as the workshop took place online due to the coronavirus. After initially having to solve technical problems, the components were quickly assembled by all groups and the programming could begin. The applications and algorithms required for this could be clicked together in a graphical user interface without any programming knowledge. The students created the individual modules with the support of their teachers on site. The first task was to show the display, the CO2 value and the temperature. Once everyone had succeeded in doing this, the LED was to light up in the appropriate color according to the CO2 content of the room air: the LED was to light up green at a value below 1000 ppm (parts per million), yellow up to 1,500 ppm and red above 1,500 ppm. In this way, a critical CO2 value can be immediately recognized and ventilated during subsequent use in the classroom. In addition, the CO2 traffic lights could optionally be connected to the WLAN so that the values could be called up graphically on an external website. Great traffic lights were created for use in times of corona, for which stylish housings were then creatively developed and built. Due to the many positive responses and other interested schools and groups of pupils, further CO2 traffic light self-construction workshops are planned for the new school year.