Following the release of addendum d to ASHRAE Standard 62.1-2022 on March 31st, we are pleased to confirm that all Senseair sensors previously compliant with Addendum ab also comply with the updated requirements.

Addendum ab introduced a new benchmark for CO₂ sensor accuracy in demand-controlled ventilation (DCV) applications, requiring sensors to maintain an accuracy of ±75 ppm at 600PPM, 1000PPM and 2500PPM CO₂ concentrations.

With addendum d, the requirements have been refined:

CO₂ sensors must now demonstrate an accuracy within ±30 ppm±3% of reading at measured concentrations of 600 ppm, 1000 ppm, and 2500 ppm, tested at sea level and 77°F (25°C).

In practice, this update means tighter tolerances at lower CO₂ concentrations and more relaxed tolerances at higher concentrations. This change more closely aligns the accuracy expectations with typical indoor air quality monitoring conditions, ensuring even greater reliability where precise ventilation control is critical.

At Senseair, delivering dependable, future-ready sensing solutions is part of our DNA. Our current portfolio that meets addendum ab already satisfies the updated addendum d requirements, and we are in the process of formally verifying compliance across the rest of our IAQ sensor range.

We appreciate your trust in Senseair as we continue to lead in setting the standard for air quality sensing.

You can find the official documentation of addendum d here: