The Provost's office at Sonoma State University makes funds available for research equipment purchases. I used this opportunity to propose the purchase of a unit to measuring temperature, humidity, carbon dioxide, and sound level. Netatmo makes a very convenient to use device that posts the information over the internet and allows for visualization and downloading. I'm grateful for the support I received and I have installed this device at the Environmental Technology Center (ETC), the green building constructed by the Environmental Studies and Planning Department. The ETC is intended to be a living laboratory, and having easily accessible data for students to explore is part of that goal. With this simple tool, students can see the effect of solar gain, our floor heating, occupancy, and weather on the conditions of the room.

Our ETC student assistant, Kristen Ridgers, has begun the estimations. By estimating the volume of the room, using published numbers for human carbon dioxide exhalation, and measuring the slope of increase of CO2, she can estimate the number of people in the room. She is currently compiling slopes for different class days and comparing to the enrollments for those classes.

Going forward, we want to also estimate the relative contributions of solar gain, our natural gas floor heating, and human occupancy to the temperature. Another exploration is to infer the ventilation rate of the building by monitoring the decay of carbon dioxide after a class has ended. Since we have controllable windows, we can observe how the decay rate is influenced by the number of open windows.