Wireless indoor environmental quality (IEQ) monitoring in classrooms and laboratories (VOC's, CO, CO2, and T)

Poor air quality in school classrooms is a serious problem now since school classrooms can have occupancy levels as high as 40 sq. ft per persons compared to average office occupancy of 140 sq. ft. per person. Other considerations include the number of portable classrooms being used on a semi-permanent basis. Many of the urban schools are old, situated near industrial sites and have poor HVAC equipment. With class rooms that have individually controlled HVAC, improving the air quality could be accomplished by simply monitoring CO2 and using that to control the HVAC system. Of course, most schools do not have that capability.
We have developed an indoor environmental quality (IEQ) sensor package that has the capability to monitor CO2 in the crowded class rooms (high levels of CO2 cause drowsiness), temperature, VOC's from a variety of sources, and a fourth sensor that can be selected. The CO2 sensor is an low power IR sensor with a range of 0-2,500 ppm and the VOC's will be measured with an electrochemical sensor with ppb capability. The third sensor is air temperature. The fourth sensor can be chosen from a variety (30 different) of electrochemical sensors. The Bluetooth wireless datalogger module has four analog inputs that are supplied from the sensor amplifier.
The sensor package power is only a few milliwatts so a battery operated system with the capability to run for 450 hours provides nearly three weeks of data which would be sufficient to evaluate a class room and make decisions about the corrective actions to be taken. The datalogger in the system has Bluetooth wireless capability that can send a signal 200-300 ft. so a PC with a wireless receiver (in the area) can be used to collect the data on a weekly basis without disaturbing the classroom. A variety of classrooms will be evaluated with the sensor package including labs, portable class rooms and lecture halls to evaluate the IEQ.