Ensuring sufficient air quality is a vital part of creating a healthy indoor air environment and living space.

While you may not know it many schools, universities, restaurants, and offices commonly use carbon dioxide (CO2) sensors to monitor and control indoor air quality. However, with the Covid-19 pandemic, there has been a recent focus on proper air quality and additional guidelines are being issued for educational institutions and businesses to enhance ventilation in order to assist in mitigating the transmission of many air-borne illnesses.


Much like the importance of indoor air quality requirements for monitoring air in homes, many new regulations and updates have been placed surrounding indoor air in food and beverage establishments. Just as homes are looking to better fine tune and create safe environments for their families during Covid-19, indoor air quality has also become very much of a focal point for employees and dining.

Take for instance Governor Jay Inslee from the state of Washington who has partnered with the Washington Brewers Guild to collaborate with industry partners and state authorities in order to set the ‘Open Air and Outdoor Seating Requirements’. The most important takeaway is that many restaurant owners across the country are now understanding the term “open air” and not just “outdoor” mentioned in the requirements.

In stating this, the updates outlined four potential options that restaurants, beverage industries, and breweries can offer to their customers which applies to both permanent, temporary, and open air dining experiences. The key to complying with the set guidelines is utilizing any combination of the four options and by installing a CO2 monitor in your structure where two entry ways are present.

It’s important for restaurant owners, franchisees, and managers to also take advantage of emerging HVAC (Heating, ventilation, and air conditioning) technologies in order to lower the change of airborne illnesses amongst their staff, patrons, and establishments. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), air filters with MERV of 13 or greater are capable of blocking airborne viruses and those with a MERV greater than 14 are recommended. For restaurants which already have established HVAC systems, it is important to continue to utilize CO2 indoor air quality monitoring to ensure that their HVAC system is efficient and to provide further indication of poor indoor air quality and proper ventilation.

Other indoor settings

Source: CO2Meter

Aranet4 Pro Indoor Air Quality Monitor

Whether your indoor air environment is a home, classroom, or restaurant, having a constant flow of fresh conditioned air makes the space comfortable for individuals who work, learn and live. For reference, ambient outdoor air is composed of approximately 21% oxygen and 0.04% carbon dioxide. Indoors, a lack of proper air circulation can dramatically alter the gas concentrations from being balanced and healthy to unbalanced and harmful resulting in physical ailments from airborne contaminants – including elevated CO2 levels.

In the past, getting fresh air was not a huge problem because many buildings were porous and outdoor air ‘leaked’ into the buildings near windows and underneath doorways. As energy prices rose in the 1980s, design standards began to advance in an effort to ‘close the envelope’ and reduce the air intrusion from outside to minimize energy consumption. While saving energy costs is important, the consequence of poor indoor air can seal in mold, bacteria, and potentially harmful gases like CO2, VOCs, and radon. These harmful gases and airborne particulate matter all directly affect your cognitive abilities.

The term ‘sick building syndrome’ was created to describe the effects of dangerously sealed and trapped indoor structures. HVAC designers and installers developed systems to combat this condition and provide a constant flow of fresh, outdoor air into buildings. However, previous schools trained you that wasting energy to condition outdoor air was the price you had to pay to provide fresh air indoors. In some cases, these HVAC systems either provided non-stop fresh air, or in other cases they were set on timers that would open fresh air controls when the building was occupied. In many cases, the only solution to providing fresh air was to open a window.

In environments where energy is more expensive, an alternative method of providing fresh air was used. Instead of constantly providing fresh air, buildings used carbon dioxide sensors to ‘sense’ when the buildings were occupied. When enough people enter a room, the CO2 level rises because of the CO2 from their exhaled breath, and the HVAC system begins to bring in the fresh air. When the people leave, the CO2 level drops because they are no longer breathing in the room, and the fresh air controls close. This system of using CO2 monitoring devices to trigger/control HVAC systems is continuing to expand across the US and internationally too. Most educational facilities and commercial buildings are now designed to meet LEED (Leadership in Energy and Environmental Design) specifications.


One common CO2 monitor designed specifically for HVAC applications is the CO2, Temp, and RH Indoor Air Quality Monitor. This device is a simple, low-cost, and maintenance-free fixed wall-mounted device. It is used primarily to provide a digital readout for individuals to view the current CO2 concentration levels and to easily monitor and control CO2 levels specific for homes, classrooms, offices, and commercial buildings.

At CO2Meter, we get dozens of inquiries a week asking what CO2 sensors and devices are low-cost options for controlling air-flow for LEED certification, as defined by the USGBC. We recommend the CM-225 which complies with the current LEED requirement stating that a permanent CO2 monitoring system must provide automatic/manual feedback of concentrations, generate an alarm when CO2 levels exceed threshold (generally 800ppm), and can notify a building automation system or indicate by audible alert to building occupants.

Having a particularly specialized focus on ASHRAE Standards and being a main supplier to the HVAC industry, CO2Meter will also be participating in their tenth year at the AHR 2022. This year, however, CO2Meter will be proud not only to provide fixed/wall-mounted and desktop gas detection technologies, but also showcase a plethora of raw sensor modules that OEMs can also build into their own devices. One commonly sought-after CO2 sensor in the HVAC industry is the NDIR Single Beam CO2 Sensor Module designed for long-term battery and indoor air applications. These low-power sensors are already being designed into many devices with long-life span and WiFi so they can easily be installed in every room and can report back to any HVAC system to modify the environment in ‘real-time’. The benefits of incorporating a CO2 sensor, are endless.

Solutions such as CO2 sensors and gas detectors have filled the initial gap in the market that so long ago desperately needed advancements in technologies to fulfill their requirements and further their discoveries. Today, research facilities, hospitals, and restaurants are constantly monitoring and adjusting their CO2 levels to improve patrons’ comfort.

As a leading source in gas detection technologies and solutions, CO2Meter has long been a reputable source for providing both indoor air quality and CO2 safety solutions to restaurant and beverage industries, worldwide.

About the author

Morgan Morris is Vice-President of Marketing at CO2Meter.