Method to determine the suitability of non-dispersive infrared carbon dioxide sensor models in Heating, Ventilation and Air Conditioning systems

In this paper a method to test the latency, accuracy and power as well as energy demand of carbon dioxide sensors with the target on Heating, Ventilation and Air Conditioning (HVAC) applications is presented. In 24 trials the CO2 concentration in a measurement chamber was increased from ambient air to 1860 parts per million (ppm) in four steps. The CO2 concentration in the chamber was measured by the Testo 480 Indoor Air Quality (IAQ) analyzer and nine different non-dispersive infrared (NDIR) CO2 sensors. Furthermore, the design and components of the measurement chamber and the system to read the sensor values and measure the power and energy demand of the sensors are described. Although the measured data do not allow a statement about the actual sensor accuracy due to the small sample size and the accuracy of the used reference analyzer it is possible to declare if a sensor suitable for the application in demand control ventilation systems. To determine the sensor latency a method to measure the time a sensor needs to settle in a specific bound is shown.