At the start of the school year, faced with the coronavirus and its aerosols transmission mode, CO2 monitoring and more particularly the CO2 covid sensor in schools, offices and all occupied spaces is proving to be an effective solution. Measuring carbon dioxide in occupied indoor spaces makes it possible to judge the presence of contaminating aerosols in ambient air and to ventilate a room accordingly. Specialist in gas detection, the GazDetect team reviews this type of monitoring equipment and presents the ideal solutions for occupied spaces: the CO2 detection column and the indoor air quality CO2 sensor.
Why measure carbon dioxide in a room?
CO2 and indoor air quality
In an occupied room of a school, an office or an administration, for example, the presence of carbon dioxide is normal. This gas is naturally released by the human body. Therefore, the more people there are in a room, the more the CO2 concentration in ambient air increases and degrades the indoor air quality. At the same time, certain activities like singing or physical activity also increases the gas concentration level.
While it does not depend solely on the presence of this gas, the indoor air quality (IAQ) can be properly gauged by measuring the CO2 concentration in a room. Measuring this gas is the easiest way to apprehend the air quality and assess the ventilation quality in a room. When the concentration is too high (above 1000 ppm) indoor air is not considered healthy. The room must then be ventilated (window opening, ventilation, etc.).
The dangers of carbon dioxide
A busy enclosed space such as a classroom, office, or meeting room naturally contains a CO2 concentration. However, above 2000 ppm of this gas in ambient air, carbon dioxide has immediate harmful effects on health:
- Reduced intellectual abilities (difficulty concentrating & decision-making, etc.)
- Physiological disorders (headache, increased respiratory rate, eye irritation, tremors, sweating, etc.)
Therefore, in a closed room, health effects from carbon dioxide and poor air quality are significant. In addition to these reasons, monitoring CO2 in ambient air is also proving useful in the fight against the coronavirus.
Against the coronavirus: indoor CO2 monitoring
Covid-19 aerosols & CO2
Covid-19 is transmitted in 3 different ways: by droplets projection, by direct or indirect contact, and by aerosols. Aerosols are very fine droplets (less than a micron in diameter) that are emitted into ambient air when a person breathes or speaks. These particles are likely to remain suspended in a room’s ambient air for several hours. They constitute a contamination risk when the person disseminating them is contaminated with the SARS-CoV-2 virus.
Because people emit aerosols like they emit carbon dioxide, the CO2 air quality indicator can be used to determine the presence of pathogens in a room. Thus, a high target gas concentration implies the presence of aerosols (Covid-19 contaminated or not).
Monitoring carbon dioxide to reduce the Covid-19 risk
Faced with the observation of Covid-19 aerosols contamination, health authorities advocate for good ventilation in occupied rooms and present it as the first line of defense against the virus. CO2 monitoring, as an indoor air quality indicator, is therefore an excellent solution for identifying the need for ventilation.
In an occupied space, a continuously operating carbon dioxide detector will help control indoor air quality and the contamination risk. When the gas concentration becomes too high, the detector signals the danger to the room’s occupants (audible and/or visual light alarm depending on the chosen device). The room must be ventilated by opening windows, doors or by the activation of a ventilation cycle. Evacuating aerosols by renewing the room’s air will then guarantee a lower risk of Covid-19 contamination.
The CO2 detector for schools, offices and occupied spaces
The multitude of carbon dioxide detectors on the market is extremely complex. Between a portable CO2 detector, a fixed detector, the different types of sensors and the different measurement ranges, the choice, use and maintenance of a gas monitor for a classroom, a business, offices or different rooms can be particularly difficult. Faced with the precise need of carbon dioxide monitoring for interior spaces, two pieces of equipment stands out as efficient solutions: on one side the CO2 detection column and on the other side the CO2 sensor for monitoring indoor air quality.
The CO2 COVID sensor and air quality analyzer
Easy to use and very intuitive, the HTRAM CO2 sensor (transmission risk air monitor) monitors indoor air quality by indicating the carbon dioxide level, the temperature and the relative humidity (hygrometry) in the room.
This air quality analyzer has a screen showing the CO2 level, an integrated audible alarm and a color display (red, yellow, green) to indicate the level of the contamination risk. This device is complete, discreet, practical and inexpensive. It works for 10 hours on battery (rechargeable with a USB plug) and can therefore be easily transported from one room to another. This air quality analysis equipment is undoubtedly the ally of choice for identifying contamination risks and for ventilating a room, office or classroom.
A CO2 light column
The Werma CO2 detector column is a measuring device in the form of a LED traffic light. The concentration of gas in ambient air is indicated by the different LEDs on the tower:
LED column signals
| LED color | Carbon dioxide concentration | Action |
| Green | less than 1000 ppm | |
| Yellow | between 1000 and 2000 ppm | ventilation required |
| Red | over 2000 ppm | ventilation imperative |
| Blinking red | over 3000 ppm | ventilation imperative, health risk |
The effectiveness of this CO2 monitoring device in the context of the Covid-19 epidemic is partly based on its clear, understood by all, LED light signals allowing to evolve continuously in a healthy environment. Thanks to this visual alert device coupled with an infrared CO2 sensor, a room’s air renewal quality is easily addressed and the contamination risk from viruses such as the SARS-CoV-2 is reduced. Indoors, installation of this equipment associated with social distancing, N95 or FFP2 masks, ideally FFP3 masks against Covid-19 will ensure maximum protection against the virus.
This equipment is now being deployed successfully in many spaces open to the public, whether it be schools, public spaces, local authorities grounds and even Covid-19 screening and vaccination centers.
A simple CO2 detector for occupied spaces
The effectiveness of the Werma CO2 detection column does not depend solely on the simplicity of its bright display. Indeed, with the objective of adapting as well as possible to all audiences and places affected by the problem of indoor air quality, this equipment has been designed for maximum performance and simplicity.
The CO2 monitoring column comes with its integrated and precalibrated infrared sensor. The device is immediately ready for use, all you need to do is plug it into a regular electrical outlet. Ideally placed in the center of the room at less than a 2 meters height, it very clearly indicates the continuous carbon dioxide concentration and the need for ventilation when necessary.
This ready-to-use CO2 monitoring and signaling device for IAQ covers the equivalent of a classroom. The installation of several detectors will control the carbon dioxide concentration level in larger spaces like stores, gyms, warehouses, or open space offices.