Indoor-CO2-Map: CO2 Monitoring and Data Collection

Overview: The Indoor-CO2-Map Data Collector app is an open-source and open-data Android and iOS application designed to collect and display CO2 levels in non-residential buildings such as shops, restaurants, hospitals, and other public spaces. The goal is to provide a comprehensive map of indoor CO2 levels, contributing to public awareness and better air quality management.

Why Measure CO2 Levels Indoors? High CO2 levels in indoor settings are often caused by a high amount of exhaled air and serve as a good indicator for the risk of acquiring airborne infections. Unlike water and outdoor air, there is minimal data available for indoor air quality in many areas. By measuring and collecting CO2 data in various non-residential buildings, individuals can make informed decisions to reduce their risk of infections. Additionally, the dataset can support scientific analysis and advocacy for better indoor air quality.

How CO2 Monitoring is Conducted:

1. Equipment Required:
   • An Android smartphone or an iPhone with the Indoor-CO2-Map Data Collector app installed.
   • A supported CO2 monitoring device (Aranet4, Airvalent or Inkbird).
2. Data Collection Process:
   • Installation and Setup:
     • Download and install the Indoor-CO2-Map Data Collector app from the Google Play Store or TestFlight for iPhone.
     • Pair your CO2 monitoring device with your smartphone via Bluetooth. (Make sure to update to the latest firmware and set the data interval to 1 minute.)
   • Recording CO2 Levels and Submitting Data:
     • Open the Indoor-CO2-Map Data Collector app and ensure that your CO2 device is connected.
     • Visit any non-residential building (e.g., shops, restaurants, hospitals) where you wish to measure CO2 levels.
     • Tap “Update nearby locations” to find your current location within the app.
     • Select your location and tap “Start recording” to begin monitoring CO2 levels.
     • Allow the device to take stable measurements for at least 5 minutes to ensure accurate data.
     • Tap “Submit Data” to stop the monitoring session.
     • Optionally trim the recorded data before submitting it to the database.
3. Data Verification and Quality Control:
   • The app uses GPS coordinates to verify the location of the CO2 measurement.
   • Users are encouraged to take multiple readings at different times to improve data reliability.
   • All data transmitted is restricted to the minimal necessary amount, with sensor IDs encrypted on the client side to ensure privacy.
4. Data Presentation:
   • All collected data is displayed on the Indoor CO2 Map website as a publicly accessible map.
   • The map provides a visual representation of CO2 levels in various locations, categorized by building type and CO2 concentration.
   • Users can filter and search for specific locations or types of buildings to view CO2 level data.
   • The data is freely accessible and downloadable via the website.

User Guidelines:

• Ensure your CO2 device is calibrated and functioning correctly before taking measurements.
• Avoid taking measurements in extreme conditions (e.g., directly next to open windows or doors) to prevent skewed data.

Purpose and Benefits:

• Public Awareness: By providing accessible CO2 level data, the app aims to raise public awareness about indoor air quality.
• Research and Policy: The collected data can support research on indoor air quality and inform public health policies.
• Community Engagement: The app encourages community participation in monitoring and improving indoor air quality.
• Political Advocacy: The data can help put indoor air quality on the political agenda and support initiatives campaigning for better air quality.

Interpretation of Data:

• Place-Specific Variability: CO2 measurements are place-specific, meaning that air quality can vary significantly between different buildings or even different rooms within the same building. One area may have excellent air quality while an adjacent area may have poor air quality.
• Temporal Changes: Air quality can change drastically over time, influenced by factors such as ventilation practices, weather conditions, and occupancy levels. For example, a place that ventilates well on warm days might have poor ventilation on colder or rainy days.
• Data Significance: Currently, most locations do not have enough measurements to provide statistically significant conclusions. More data and measurements are needed to achieve accurate interpretations.
• Precautionary Measures: Users should not rely solely on CO2 measurements for safety. Even if previous measurements show good air quality, it is essential to continue taking precautions such as wearing well-fitted masks, especially in poorly ventilated or crowded indoor spaces.

Call to Action: Anyone with a mobile phone and a supported CO2 monitoring device can participate in data collection. Currently, the app supports Aranet4, Airvalent and Inkbird devices. Every single measurement is valuable, whether in new locations or previously measured ones. If you have a compatible monitor, you are encouraged to join the effort.

The Android version of the app is currently in open testing and can be downloaded from the Google Play Store. The iPhone app is also in open testing and can be accessed via TestFlight. The source code is available on GitHub, ensuring transparency and encouraging community contributions.

Community and Feedback: Users can join the Indoor-CO2-Data-Collection Discord server to discuss the app, provide feedback, and suggest improvements. Direct feedback can also be given via DM or email.

Conclusion: The Indoor-CO2-Map Data Collector app offers a user-friendly and reliable method for measuring and sharing CO2 levels in public spaces. By leveraging the power of open data and community involvement, it aims to contribute to healthier indoor environments for everyone.