Indoor CO₂ Build-Up

Measuring the amount of CO₂ in a classroom and observing the changing levels during a class period.

Lab Summary

Students will use a CO₂ Gas Sensor to measure the amount of CO₂ in a classroom. Measurements will be taken during a class period and students will observe the changing CO₂ levels.

Carbon dioxide is a colorless, odorless, incombustible gas that is a product of respiration and combustion and a natural component of the air on this planet. It is one of several byproducts generated by automobiles and is believed to be a leading contributor to the so-called "greenhouse effect" linked to rising temperatures around the planet.

The amount of CO₂ in a given air sample is commonly expressed as parts-per-million (ppm) -- the number of molecules of carbon dioxide per million molecules. The outdoor air in most locations contains about 400-450 ppm carbon dioxide. Higher outdoor CO₂ concentrations can be found near vehicle traffic areas, industry and sources of combustion.

Where indoor concentrations are elevated (compared to the outside air) the source is usually the building's occupants. People exhale carbon dioxide -- the average adult's breath contains about 35,000 to 50,000 ppm of CO₂ (100 times higher than outdoor air). Without adequate ventilation to dilute and remove the CO₂ continuously generated by occupants, CO₂ can accumulate. Students and educators can spend about half their waking hours at school. Therefore, maintaining adequate indoor air quality (IAQ) in buildings is becoming a top priority for school administrators.

Hypothesize: Will the CO₂ levels in a classroom increase or decrease during a class period? Why?

Published: December 2002

Downloads

• Indoor Carbon Dioxide Build-Up - PASPORT (56 KB, .zip)

  Includes experiment setup, procedures and Datastudio file

• Indoor Carbon Dioxide Build-Up - ScienceWorkshop (54 KB, .zip)

  Includes experiment setup and procedures

Here's What You Need

U.S. Educator prices shown.

Probeware (PASPORT Systems)

Xplorer GLX (PS-2002) - $349

The Xplorer GLX is a data collection, graphing, and analysis tool designed for science students and educators.

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PASPORT Carbon Dioxide Gas Sensor (PS-2110) - $259

Measures carbon dioxide concentration (parts per million) in gases such as air. For use with PASPORT Interfaces.

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Probeware (ScienceWorkshop Systems)

750 Interface, USB (CI-7650) - $679

The 750 Interface allows students to measure force, temperature, pressure, angular velocity, acceleration, current, and magnetic field with a built-in function generator and oscilloscope mode.

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Carbon Dioxide Gas Sensor (CI-6561) - $289

Measures carbon dioxide concentration (parts per million) in gases such as air.

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