Capabilities and limitations of wireless CO_2, temperature and relative humidity sensors

摘要

Wireless indoor environment sensors that can measure temperature, relative humidity and CO2 concentration have recently developed to a stage where they can be used in Building Management Systems (BMS) for building control or could be used to develop a remote commissioning process for buildings without BMS. This provides new opportunities for user involvement and fault detection but if the sensors are not accurate and reliable, it could introduce faults in itself.The performance of different wireless indoor environment sensors in terms of their accuracy in the measurement of CO2 concentration, temperature and humidity and the factors affecting their CO2 measurement error were investigated. Six different types of sensors were tested in a climate chamber. The measurements of temperature, relative humidity and CO2 concentrations obtained by the sensors were compared to high precision reference instruments to quantify any deviations from the actual conditions. Linear regression was implemented to identify to what degree temperature, relative humidity, CO2 concentration and calibration temperature of the CO2 sensor affected the CO2 measurement error of each device.Determining the capabilities and limitations of these sensors makes it possible to quantify their effects on the HVAC system operation, energy use and indoor environment, if their measurements were used as inputs to the HVAC system.The sensors performed satisfactorily in terms of temperature measurement and can be used to control the indoor temperature in buildings; however, this was not the case for measurements of relative humidity or CO2 concentration.