We usually assume the air quality in an office environment is at least acceptable. Still, with many indoor spaces, there is often no monitoring for unacceptable conditions or the presence of potential pollutants. So the first step is monitoring and detection, followed by actions to improve the environment when needed.
Common problems affecting indoor air are high levels of particulate matter (PM), carbon dioxide (CO2), and Volatile Organic Compounds (VOCs). Each requires specific sensors to capture levels, but all three types are available in a single device, along with other measurements like temperature, humidity, and noise level.
Particulate Matter
Particulate matter is solid particles or liquid droplets in the air. Solid particles frequently include dust, soot, and smoke, while cleaning agents are potential sources of liquid particulate matter.
Standards exist describing the thresholds where health impacts are likely when PM rises to a particular level. For example, the Environmental Protection Agency (EPA) standards for the United States include levels for inhalable particles and “fine” inhalable particles with descriptions of potential impacts to humans based on concentrations measured in micrograms per cubic meter of air.
Carbon Dioxide (CO2)
CO2 is a naturally occurring gas entering the atmosphere from many sources, including burning fossil fuels. One of the other sources affecting indoor spaces is the exhalation of humans, which can drive up the concentration in the air when rooms are crowded.
The impacts of high levels of CO2 in an office environment can include a loss of productivity. For example, some studies indicate drowsiness, often attributed to lack of sleep, or the “after lunch slump” may be due to high CO2 concentration. Another potential inference can be the existence of an environment conducive to spreading illnesses, particularly airborne viruses.
Volatile Organic Compounds (VOC)
Another concern is something known as volatile organic compounds (VOCs). These definitions are broad, and the impacts on office environments vary. In addition, there are no federally enforceable standards in the United States for their effects on air quality.
VOCs come from many different sources. Levels can rise from something as routine as daily cleaning of workspaces. Improvements like painting, carpeting, or even new furniture can increase concentrations. Copiers, printers, and markers emit VOCs, as well. They can also be introduced from outside air, flowing in through open windows and doors or via ventilation systems without the ability to filter adequately.
Because of the variety of causes and the varying degrees of impact on humans, the strategy for dealing with VOCs is less clear-cut. However, there is value in detecting something in the air and paying attention to it until confirmation that the risk is limited or nonexistent.
Managing Indoor Air Quality
The first step in managing indoor air quality is collecting data by installing devices to measure particulate matter, carbon dioxide, and volatile organic compounds. Placing them around the interior of a building to adequately collect data in all areas of interest and connecting them to a network to transmit the data to an application environment gets you started. Visualizing the data over time is vital, so charts are a must. Sensor locations overlayed on a building schematic shows where monitoring occurs and highlight where significant problems exist.
One means of mitigation is bringing outside air into the indoor space, ensuring outside air added to the mix is relatively free of pollutants. In many urban environments, outdoor PM levels are high for large portions of the day, requiring filtering first. Air purification systems are another option, either standalone or integrated into the HVAC system. With your monitoring capabilities in place, you can see the results of corrective actions in real-time.
|