AirGuard AirWaves - July

Carbon Dioxide (CO2) Explained

CO2 is regarded as waste inside our bodies

In the human body, our cells form and give off CO2 as a waste product of #metabolism and respiration. The cells release it into the bloodstream where it binds with #haemoglobin, displacing #oxygen molecules in the process, and transported to the lungs, where it is ultimately removed from the body through exhalation.

Once out of our bodies it becomes a major indoor air #pollutant. Humans are the main source of such #pollution, though the combustion of carbon fuels by cars, buses, trucks, etc. contribute as well.

Changing CO2 levels can lead to acidosis or alkalosis

When #CO2 levels are high, the concentration of H+ ions in the bloodstream rises, lowering the pH and introducing a state of acidosis. In contrast, low levels of CO2 result in alkalosis.

As levels of CO2 in the blood rise and fall, the body can respond through hyperventilation or hypoventilation respectively.

With CO2 playing such an important role in regulating blood pH and breathing, it is no surprise that excess CO2 levels can cause disturbances in the human body. Excessive CO2 retention (known as hypercapnia or hypercarbia) may result in tachycardia, dyspnea (irregular breathing), flushed skin, confusion, depression, headaches, and dizziness.

Indoor Air Quality plays an important role in managing CO2 levels

Indoor CO2 level #monitoring is now widely seen as a proxy for evaluating the transmission risk of various respiratory diseases, including #COVID19. If a particular indoor setting does not maintain adequate ventilation (measured as ACH – air changes per hour), CO2 levels will exceed the regulated range and the potential for pathogen transmission will be amplified accordingly.

Multiple #studies have shown that high levels of CO2 can make the occupants of a room feel drowsy, reduce their #cognitive #performance, cause headaches and affect concentration. So apart from helping to reduce the potential transmission of #airborne diseases, CO2 monitoring can also facilitate a more pleasant environment for employees and aid in their productivity.

AirGuard Industries ' CO2 monitors will help identify areas of poor #ventilation, allowing us to make the necessary changes to keep fresh air flowing either by mechanical ventilation or simply ensuring doors and windows are kept open.

High CO2 levels pose a health threat at workplaces

The importance of managing CO2 levels cannot be stressed enough. Poor CO2 levels make employees drowsy and less creative, decreasing overall satisfaction and performance.?

The above CO2 levels were taken from a work environment where both #officeworkers and technicians work together. The data from our sensors show that towards the end of the day, CO2 levels steadily increase, meaning that the air is stagnant and the space poorly ventilated. From the chart, we can also identify lunch hour (12-1pm), when CO2 levels drop slightly. The less people at the office, the lower the CO2 readings.

These readings are averages taken over the whole week, showing that the #workenvironment is not optimal and IAQ does not contribute positively to #employee #wellness and #performance.

Everything you need to know: Carbon Dioxide Sensors

Following on from the topic of CO2, it is worth mentioning the sensors available in the market.

There are two main types of CO2 sensor: non-dispersive infrared (NDIR) and eCO2. NDIR sensors are the most common type and are used in a wide variety of applications, including for IAQ monitoring, HVAC systems, and industrial processes. eCO2 sensors are a newer type of CO2 sensor that are less expensive than NDIR sensors but are not as accurate.

How NDIR Sensors Work?

#NDIR #sensors work by measuring the absorption of infrared light by CO2 molecules. When infrared light passes through a sample of air, some of the light is absorbed by the CO2 molecules in the air. The amount of light that is absorbed is proportional to the concentration of CO2 in the air.

NDIR sensors are very accurate and can measure CO2 levels in the parts per million (ppm) range. They are also relatively stable and do not drift over time. However, they can be expensive, especially for high-accuracy sensors.

How eCO2 Sensors Work

#eCO2 sensors measure the concentration of CO2 in the air indirectly, by measuring the concentration of total volatile organic compounds (#TVOCs) in the air. TVOCs are a group of organic compounds released into the #air from a variety of sources, including combustion appliances, cleaning products and furniture.?

As both CO2 and TVOCs are released into the air by human activity, their concentration is correlated but it is by no means perfect, so eCO2 sensors are not as accurate as NDIR sensors. They are, however, less expensive, and so while NDIR sensors are typically used for #IAQ monitoring, #HVAC systems and industrial processes, eCO2 sensors are typically used in applications where accuracy is not as critical, such as consumer products or for hobbies.

NDIR and eCO2 sensors are great options to measure CO2

NDIR and eCO2 sensors are both useful tools for measuring CO2 levels. The best type of sensor for a particular application will depend on specific requirements with regards to:

1. Sensitivity: A measure of how small a change in CO2 concentration can be detected by the sensor.
2. Resolution: How precisely the sensor can measure CO2 concentration.
3. Response time: How quickly the sensor responds to changes in CO2 concentration.

AirGuard prefers the accuracy of NDIR sensors so that we know we can rely on the resulting data to arrive at our customer solutions.

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