Building a Better Mousetrap
Prototype I was installed on the 1st floor of GVSU’s Cook Devos Center for Health Sciences. It worked, but it was a highly mechanical solution and therefore slow.
The team then:
- bought CO2 and strategically introduced it to test how quickly the sensor responded
- tried several different pumps – lots of noise, lots of maintenance and failures
- spent lots of time and effort trying to get the front-end BMS to get data to make decisions
Prototype II was a more elegant solution that optimized sample time, but still had pump and BMS issues.
Prototype III eliminated the mechanical pump, and Prototype IV incorporated a PLC controller to expose CO2 measurement and streamline communication to BMS.
After the team realized the expected energy savings on their first installation of Prototype IV, they prioritized the next installations based on the number of “cold calls,” which correlated with older, highly over-ventilated buildings.