CO2 Sensors for Open Areas

Hey Jon,

LEED says,

C. Carbon Dioxide Monitoring Monitor CO2 concentrations within all densely occupied spaces. CO2 monitors must be between 3 and 6 feet (900 and 1 800 millimeters) above the floor. CO2 monitors must have an audible or visual indicator or alert the building automation system if the sensed CO2 concentration exceeds the setpoint by more than 10%. Calculate appropriate CO2 setpoints using methods in ASHRAE 62.1–2010, Appendix C.

Hope this helps.

LEED does not specify 'spacing of CO2 sensors' in large open areas. It is recommnended that the team follow the manufacuturer's guidance with respect to spacing of the sensors, as different sensors may have differant spacing requirements.

Dear Jon,

The CO2 sensor monitoring’s requirement is in all densely occupied space.

Since LEED defines occupied space as “occupied space an enclosed space intended for human activities, excluding those spaces that are intended primarily for other purposes, such as storage rooms and equipment rooms, and that are only occupied occasionally and for short periods of time.”

Since occupied space is an enclosed space, by right the densely occupied space is an enclosed space area with a design occupant density of 25 people or more per 93 square meters.

Therefore, CO2 sensor monitoring is not applied for open areas.

Thanks and regards.

Just a note that we have received LEED review comments back asking us to put in CO2 monitors in open spaces, but when we clarified that these were open to the adjacent circulation we were able to convince the reviewer of what the folks above said - not required by LEED in open areas.  We have had clients who wanted to include CO2 monitoring in some open office areas as David mentions - to be able to ramp the OA up and down in response to occupancy patterns, but this was separate from LEED.