Carbon Dioxide (CO₂) is used in HVAC to control the amount of fresh air in buildings. This is especially useful in buildings with varying occupation levels. Typical examples would be schools, auditoriums and convention centers, but modern office buildings may also have highly variable occupation levels.

Recent research shows that employee performance decreases significantly already at CO₂ levels previously considered good, approximately 1000 ppm. As employee wages amount to about 90% of the total office costs it pays off to measure and control CO₂ levels properly. Even with an automation system in use, no amount of intelligence there will help you if the sensor measuring the actual conditions has drifted.

It is also not enough that accuracy requirements are met out of the box; the requirements should be maintained during the lifetime of buildings. On one hand, indoor air conditions are considered benign for sensors. On the other hand, sensors used in building automation are rarely calibrated or serviced once the system has been commissioned. Miswired or faulty sensors are common, so at least one comparison measurement should be done during the system commissioning. For proper measurements most CO₂ sensors need at least some maintenance. Therefore, it is advisable to check the installed sensors after a couple of years against a reliable handheld instrument.

In this webinar our expert Lars Stormbom will give tips on how to choose the right CO₂ sensor for your case and what to look for in a sensor to make maintenance easy. Access this free-of-charge webinar here.