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Logging CO2 at the Smart Buildings Center

December 14, 2015 By Vamsi

At the Smart Buildings Center we like to talk about how Smart + Efficient can really help transform building energy efficiency. There are many ways to go about this, but we wanted to share a simple experiment logging CO2 we ran in October.

Many of you were able to join us for our Grand Opening (hopefully some of you still remember it after that second glass of wine). During the event our Tool Lending Library Staff deployed some Onset HOBO loggers to measure CO2. The way we did this was by connecting an Onset Tellaire 7001 CO2 Sensor with an Onset HOBO U12. The Tellaire handles the actual measurement of CO2 while the HOBO U12 keeps the log of that measurement (along with Temperature and Relative Humidity).

Smart Buildings Center Tool Lending Library room
The Tool Lending Library just before the grand opening crowd arrived.

Below is a graph of CO2 measured by Parts per Million (ppm) over time. We actually measured CO2 over almost 6 days, October 23rd through October 29th, but where it gets interesting are two very obvious spikes. The first one, is where we had a handful of Tool Lending Library staff working to get the space ready for the opening. Also, there were a couple of contractors getting some of the equipment in the Tool Lending Library set up. The second, much larger spike, was during the Grand Opening. At approximately 6:55pm, the CO2 levels shot up to over 1300 ppm. At this point we had tens of people in the space, many more than we are used to having. The system reacted to this and within minutes started to bring more fresh air into the room (also, many people started to leave).

Data graph showing tall spike of CO2 on Oct 27

Why log your building’s CO2?

Logging CO2 levels help the owners and operators of buildings understand the relationship between the number of occupants in a space and the amount of ventilation, at a given time. Tools like these are instrumental in determining whether your ventilation system is operating efficiently, and responding correctly to variable demand. Please visit our Tool Lending Library for your CO2 logging needs.

Filed Under: SBC News, Tool Library

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