Open-source three-dimensional IoT anemometer for indoor air quality monitoring

Ventilation in an enclosed space can significantly influence people's comfort, health, and safety. Poor ventilation can generate temperatures dangerous to health or obstruct the dispersion of environmental pollutants, such as toxic gases or pollution. Measuring indoor environmental conditions can thus help improve the quality of the environment and protect people's health and comfort. This work proposes the design of an open-source anemometer to measure wind speed and direction in three dimensions. The purpose of this anemometer is to monitor wind conditions in enclosed spaces and environmental conditions related to air quality and temperature. The prototype uses an array of six unidirectional flow sensors, each pointing towards a different axis. Carbon dioxide (CO ${}_2$ ), volatile organic compounds (VOC), temperature, humidity, pressure, and gas presence sensors are integrated to monitor indoor environmental conditions accurately. Measuring the vertical component of the wind provides more detailed information on wind conditions. Test results show that the device can detect variations in wind speed with a deviation of 0.25 m/s, detect changes in horizontal wind direction with a deviation of 3.7°, and detect vertical wind direction variations with a deviation of 3.02°. These measurements demonstrate that the proposed device is capable of detecting wind changes in three dimensions, validating its potential for detailed indoor airflow monitoring.