Abstract
<jats:p>This article presents the Real-time Air Data Box (RADBox), an open-source, low-cost device designed to mon-itor indoor air quality in K-12 classroom settings. The device simultaneously measures five air-quality parameters: CO2, volatile organic compounds (VOCs), nitrogen oxides (NOx), temperature, and humidity in real time using an Arduino microcontroller paired with Grove sensors. The graphical user interface, written in Python, provides live data visualization and automatic data logging. Two versions are presented: RADBox Lite (which only measures CO2) and the full RADBox (which measures five parameters). RADBox can be freely modified to add or remove complexity as the user desires. The device was tested in middle school, where students ob-served how everyday activities, such as opening a window, use of a lighter, or using aerosol sprays, produce measurable changes in air quality. To support classroom implementation, a complete lesson plan aligned with British Columbia’s science curriculum is included, along with assembly instructions, 3D-printable cases, and executable software.</jats:p>