WELL Project Annual Calibration / Replacement

According to the Hardware Requirements of Continuous Monitoring Protocols for WELL, as stated in the Well Performance Verification Guidebook (Q1-Q2 2024 edition, pages 36-37)

• “All sensors measuring air quality parameters are recalibrated or replaced annually, and projects submit documentation attesting to their calibration or replacement annually through the WELL digital platform. Carbon dioxide sensors utilizing Automatic Background Calibration (ABC) algorithms can be recalibrated or replaced every three years.

• All sensors measuring thermal comfort parameters are recalibrated or replaced every three years, and projects submit documentation attesting to their calibration or replacement every three years through the WELL digital platform.

• Note: Field calibrations using a reference sensor are acceptable, provided that the procedure allows the sensors to perform within manufacturer’s listed specifications. The calibration period must capture a sufficient range and concentration of contaminant—either using known span gases or exposure to ambient pollution—to accurately perform Adjustments.

• If sensors are returned to manufacturers for calibration, up to one continuous month of sensor data may be excluded at no penalty to account for this. Project team should submit documentation that clearly documents the dates the sensor is away for calibration.”

Continuous Air Quality Monitor, Atmocube, is equipped with PM2.5, TVOC, CO2, temperature, and humidity sensors. Atmocube has RESET Grade B and Works with WELL certification. The PM2.5, TVOC, and CO2 sensors feature Automatic Background Calibration (ABC) algorithms by Sensirion. According to the manufacturer's specifications, the sensors' lifespan is 10 years. Sensor datasheets are available on our website as well: Sensor Accuracy and Technical Specifications‍

Based on the above, our CO2, temperature, and humidity sensors should only need calibration or replacement every 3 years. Meanwhile, our TVOC and PM2.5 sensors, even with ABC algorithms, should be calibrated or replaced annually.

Regarding the annual procedure for TVOC and PM2.5 compliance, we would like to offer a cost-effective solution for our WELL project clients.

Once a year, the building technician will remove the Atmocubes from the wall and ship them to our local accredited partner (U.S., U.K., E.U. (Portugal)). The accredited partner disassembles Atmocube according to the manual, tests the internal sensors, replaces PM2.5 and TVOC sensors as necessary, and ships them back, providing a digital certificate for the service. This entire process occurs within a month, in compliance with the IWBI Performance Verification Guidebook.

As a backup option for large projects, our technician may visit the WELL certified building to collect the sensor and conduct the procedure.