4 min reading

10 December 2021

10 December 2021

Indoor Air Quality Monitoring and Control

Indoor Air Quality Monitoring and Control
Indoor Air Quality Monitoring and Control

As the world shifts to a new normal of working from home and spending most of our time indoors, it has become increasingly important to ensure that our indoor environment is safe and comfortable. Indoor Environmental Quality (IEQ) monitoring and control can help us better understand the various parameters of the spaces we work and live in and how to adjust them to meet indoor air quality standards. In this article, we will explore how IEQ monitoring can help improve indoor air quality, occupant comfort, and create a healthier environment.

What’s the Difference between Air Quality and Environmental Quality?

Air quality is a measure of the number of pollutants in the air, including particulate matter and chemicals. It is measured using the Air Quality Index (AQI).

Indoor Environmental Quality (IEQ) is the consideration of all impacts that the indoor environment has on human health and performance.

Parameters of IEQ

The main parameters of the IEQ include the following:

  • Carbon dioxide (CO2)

Carbon dioxide is a naturally occurring gas that is emitted from the respiration of humans and animals and the combustion of fossil fuels. It is an important indicator of indoor air quality, as it is linked to the number of people in a room, and can be an indication of the need for indoor air ventilation, which makes CO2 monitoring necessary for sustaining a healthy environment.

  • Temperature

High temperatures can lead to increased levels of pollution and air contaminants, while low temperatures can reduce these levels. Additionally, the temperature can affect the rate at which pollutants disperse and affect the performance of air filtration systems. With this in mind, the temperature of the indoor area has to be monitored and adjusted as needed.

Temperature Range Level of Comfort
18°C–21°C Comfortable temperature
Higher than 24°C Cardiovascular risk
Lower than 12°C  Cardiovascular risk
18°C  Minimum for Comfort
12°C–16°C Respiratory risk
9°C  Hypothermia risk
  • Relative humidity

Humidity is important for controlling the growth of mold and mildew, as well as for maintaining the comfort of the occupants. When it is too high, the chances for mold growth and the development of respiratory diseases are significantly higher. At the same time, low humidity levels lead to dry and itchy skin, eye dryness, asthma, and allergy flare-ups, as well as an increase in static electricity.

Temperature Range Recommended Humidity %
Higher than 10°C Max. 45%
-3°C to 10°C  Max. 40%
-17°C to -3°C 30% – 40%
-28°C to -17°C 20% – 30%
Below -28°C 15% – 20%
  • Volatile organic compounds (VOCs)

VOCs are organic compounds that evaporate easily at room temperature and can be found in a variety of products, such as paint, varnish, cleaning products, and aerosol sprays. They can cause a variety of health problems, including frequent headaches, nausea, and irritation of the eyes, nose, and throat.

  • PM2.5 and PM10 particles

PM2.5 and PM10 particles are small particles of dust, soot, and other pollutants that are present in the air. These particles can be inhaled and can cause a variety of health problems, such as respiratory and cardiovascular diseases.

Annual average standards 24-hour standards
PM 2.5  12.0 µg/m 3 with 98th percentile forms and levels of 35 µg/m 3
PM 10 15.0 µg/m 3 with one-expected exceedance forms and levels of 150 µg/m 3
  • Radon entry levels

Radon is an odorless, colorless, and naturally occurring radioactive gas that can enter a building through its foundation, cracks, and other openings. It is important to test for radon levels in buildings, as it can cause serious health risks if it accumulates to high levels.

A generally accepted action level established by the World Health Organization (WHO) is 100 Bq/m3, or 2.7 pCi/L.

  • Airborne bacteria

Airborne bacteria are microscopic organisms that can be found in the air. These bacteria can cause respiratory infections and illnesses, especially in people with weakened immune systems.

In most indoor environments In more sterile environments
Less than 500 colony-forming units (CFU) per cubic meter of air Less than 10 CFU per cubic meter of air

Reasons Why it’s Important to Control IEQ

IEQ control protects the people who work in or live in a building from poor health outcomes and helps to conserve the environment.

Well-Being of Workers

As we have already mentioned, poor IEQ can cause a range of health problems. By controlling the IEQ, in turn, these issues can be avoided or minimized. Secondly, insufficient IEQ can lead to decreased productivity and even absenteeism due to illness. It can also contribute to the development of Sick Building Syndrome (SBS).

Sick Building Syndrome (SBS) is a term used to describe a range of symptoms that people experience while in a certain building or environment. Symptoms of SBS can include:

  • Headaches
  • Nausea
  • Eye and throat irritation
  • Fatigue
  • Dizziness
  • Difficulty concentrating.

It is often associated with poor air quality and is most commonly found in office buildings. SBS can be caused by a range of factors, such as inadequate ventilation systems for the size of the building, the use of synthetic materials and cleaning products, and the presence of air pollutants. Improving ventilation, controlling temperature and humidity levels, and using natural materials and cleaning products can help reduce the risk of SBS. Additionally, proper maintenance of air conditioning systems and ensuring timely change of air filters can help reduce the risk as well.

A comfortable working environment with good air quality, proper temperature regimen, and noise level can help to ensure that employees or students are productive and can work to their full potential.

Environmental Conservation

Controlling the IEQ can help to reduce energy consumption, as well as reduce the number of pollutants that are released into the environment. This helps to make the air cleaner and healthier and can help to preserve resources and reduce the impact on the ecology. With IEQ, your business will have a green building and will not be one more pollution source, which can reduce footprint fees and other environmentally related expenses.

Industries Where Indoor Environmental Quality is Critical

1. Healthcare

In healthcare, the quality of the environment is important because it can directly influence the health conditions of the patients, especially those with low immunity and respiratory illnesses. IEQ is linked to the health and well-being of occupiers, especially in hospital rooms, laboratories, and recreational facilities.

Insufficiently working ventilation system and over-occupancy can be a nurturing environment for different air-transmitted viruses and air pollutants.

2. Education

Educational facilities have to be designed and sustained in such a way that students and professors can focus on studying and teaching, as well as be productive, energized, and involved.

CO2 exposure and excessive levels are major issues for the educational sector. With the high levels of carbon dioxide, in turn, building occupants become sleepy, and tired, experiencing headaches and reduced cognitive abilities. To address this problem, TEKTELIC has created a BREEZE air quality sensor, which periodically measures CO2, humidity, and temperature and reports data to the user. It is a perfect solution for the school or university teachers to adjust the HVAC system accordingly, based on the data received. The sensor itself is small in size and easily mounted on the wall or ceiling, without additional equipment required.


3. Private Offices

There are many factors, which influence the way office building operate, including light levels, indoor environmental engineering, occupancy levels, and ventilation system. The reasons behind the need for monitoring in office premises are the same as in educational institutions.

Inadequate IEQ can affect employees’ quality of work and overall employee satisfaction. So, if your facility manager doesn’t address the factors affecting occupant health criteria, workers will simply leave for another company with a better environment. Plus, insufficient IEQ can also lead to higher energy costs due to over-cooling and heating.

We have successfully implemented cases for both smart home sensors in our portfolio. VIVID was successfully integrated into the office environments to monitor occupancy with its PIR lens and air conditioning efficiency by analyzing temperature and humidity measurements. The main challenge was to provide continuous access to internal conditions, so that building operators could adjust the HVAC system. With TEKTELIC VIVID this problem was solved, providing healthy buildings and thermal comfort.

Another case, addressing HVAC systems monitoring needs was with the COMFORT sensor. The issue to address was optimizing the indoor environment and ventilation to keep fresh air in the offices and at residential buildings to sustain good occupants’ well-being. With COMFORT indoor air quality monitor, building managers can maintain optimal climate conditions for a continuous improvement of occupants’ comfort based on temperature and humidity measurements.

Factors affecting IEQ

A number of factors can affect IEQ, including:

  • Air quality

Poor air quality can lead to health problems, such as respiratory infections and allergies, as well as decreased concentration and productivity. That is why, while indoors, a building manager needs to track if air delivery is acceptable and if people do not inhale recirculated air.

  • Lighting

Lighting affects how comfortable people feel in a space, how well they can see, and their overall productivity. The proper lighting should be provided to ensure safety, reduce eyestrain, and improve the overall health and comfort of occupants.

  • Energy consumption

Buildings should be designed to be energy efficient and use renewable resources whenever possible. This will help reduce greenhouse gas emissions and save money in the long run.

  • Optimal occupancy levels

Too many people in a space can lead to overcrowding and poor IEQ, while too few people can lead to decreased productivity. It is important to determine the optimal occupancy levels for any space to ensure the health and safety of occupants.

TEKTELIC Solutions for Monitoring Indoor Environmental Quality

TEKTELIC provides a range of innovative LoRaWAN-based solutions for different purposes, including healthcare, industrial, smart cities & buildings, LoRaWAN-based asset tracking, and IEQ. Our products include LoRaWAN sensors that measure temperature, humidity, and CO2 levels as well as end-to-end solutions for occupancy monitoring.

In addition to the sensors, we’ve already mentioned, TEKTELIC has the TEMPO Meeting Room Booking Solution, which allows management and control of meeting room occupancy in real time. It is fully integrated with Microsoft Outlook and Google Calendar, so you don’t need any additional software to use it effectively. In addition to that, by choosing this solution, you will have access to the Meeting Room Booking Application Platform to analyze space usage, see the most frequently occupied spaces, and optimize rooms accordingly. TEMPO solution perfectly suits small, medium, or large offices, universities, hotels, or public libraries.


Speaking about solutions, it is fair to mention separately the BREEZE-D CO2 monitoring solution. The main difference from BREEZE is that it goes with a pairable e-Ink display and KONA Micro gateway right away, so all you need is to take it out of the box and mount it. The display communicates with the sensor via Bluetooth Low Energy (BLE) technology. All the devices, including the BREEZE sensor, e-Ink display, and gateway are fully wireless, so they can be mounted on the wall, or ceiling without additional effort to find outlets.


TEKTELIC also offers the BREEZE-V variation of the device, which has all the same features and sensing abilities as the Breeze, but it is also capable of human motion detection like the VIVID sensor. BREEZE-V is available with or without an e-Ink Display as well, so you can choose the best option for your needs.

Governmental Regulations for IEQ in the US/Canada

Governmental regulations for IEQ in the US/Canada are related to different aspects of construction activities, air quality, environmental quality, and building design.

The US Requirements

The U.S. Environmental Protection Agency (EPA) requires all building types to adhere to the Clean Air Act, which sets standards for indoor air quality. This includes limiting emissions of certain pollutants, such as VOCs and ozone (EPA, 2023). It also sets standards for ventilation and filtration systems to ensure good indoor air quality.

The Occupational Safety and Health Administration (OSHA) in the U.S. regulates indoor environmental quality in the workplace with standards that set limits on exposure to chemical and biological contaminants (OSHA, 2023). This includes requiring employers to measure and monitor indoor air quality, as well as providing personal protective equipment to employees as necessary.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has established indoor air quality standards that all commercial buildings must meet. These standards include minimum ventilation rates, filtration requirements, and temperature and humidity control (ASHRAE, 2020).

The U.S. Green Building Council (USGBC) has established Leadership in Energy and Environmental Design (LEED) green building certification standards, which include requirements for indoor environmental quality. This includes requirements for energy efficiency, ventilation, and filtration systems to ensure that indoor air is clean and safe (U.S. Green Building Council, 2023).

Canadian Requirements

Health Canada has established standards, which focus on limiting levels of CO2 up to 1000 ppm and ensuring adequate ventilation to reduce the levels of pollutants in the air (Health Canada, 2021).

The International Building Code (IBC) and the National Fire Protection Association (NFPA) both regulate indoor environmental quality in the U.S. and Canada. The IBC sets requirements for indoor air quality in newly constructed or remodeled buildings, while the NFPA focuses on fire safety and smoke control.

The U.S. and Canadian governments both have mandatory energy efficiency codes for commercial and residential buildings, which include requirements for indoor environmental quality. These codes set standards for insulation, ventilation, and other features that help buildings use energy more efficiently and improve indoor air quality.

How to Improve Indoor Environmental Quality?

In order to improve indoor environmental quality, you have to address all factors affecting IEQ and follow the governmental regulations for sustaining healthy environments.

Monitor Air Quality

You need to keep track of air quality indoors. For instance, you can install air quality monitors to measure levels of pollutants in the air, carbon dioxide, temperature, and humidity. Based on the data, it will be possible to adjust ventilation, install air filters where needed, and cut down on indoor sources of air pollution, such as smoking, burning candles, and using harsh cleaning products.

Monitor Occupancy

For healthy IEQ, it’s necessary to sustain optimal occupancy. As occupancy levels in buildings change throughout the day, indoor environmental conditions change as well. Monitoring occupancy can help to ensure that the building’s environmental conditions are maintained within acceptable ranges for comfort and health.

Occupancy levels can influence the thermal comfort of a space, as more people present in an indoor environment can increase the temperature and CO2 exposure. This can be mitigated by adjusting the air conditioning system to cool the space, or by providing adequate ventilation. Monitoring occupancy can also help to reduce the risk of airborne contaminants, as there will be more people to disperse the contaminants.

Provide Sufficient Light Levels

In order to sustain healthy and comfortable levels of lighting in a room. For this purpose, building owners can use environmental monitors and add lighting exposure if there is not enough natural light or vice versa shut off the lights if nobody is in a room.

Adequate lighting allows people to see colors and shapes accurately, reduces eyestrain, and helps create a pleasant atmosphere. In addition, providing sufficient light levels can help reduce energy consumption, so organizations can lower their operational costs.

Control Noise Levels

In indoor environments, it is critically important to ensure high IEQ. Too much noise can be distracting, disruptive, and even damaging to people’s health. When designing a space, it is important to consider the types of materials and furnishings used. For example, the use of absorbent materials such as carpets, curtains, and upholstery can help to reduce noise levels. Additionally, sound-dampening features like acoustic panels can be used to reduce noise even further.

Wrapping up

A large percentage of people spend 90% of their time indoors – at home, in office buildings, or shopping malls. It makes good sense to ensure that the indoor environment is conducive to their health and productivity. A great deal of research and knowledge has been built around how air, temperature, humidity, and ventilation impact people’s health, and how it can negatively affect their performance and productivity in the workplace. So, with this in mind devices for IEQ monitoring are a necessary addition to your building management itinerary.

TEKTELIC Communications is ready to become your partner and provider of IEQ sensors, with continuous support. So, you’ll be able to sustain a healthy, productive, and cost-efficient building.

For additional information and consultation, please get in touch with our sales team.


ASHRAE. (2020). ASHRAE Position Document on Indoor Air Quality. Atlanta, Georgia; ASHRAE.

EPA. (2023). Regulatory and Guidance Information by Topic: Air. EPA. Retrieved February 15, 2023, from,new%20and%20modified%20stationary%20sources.%20Laws%20and%20Regulations

Health Canada. (2021, March 19). Carbon dioxide in your home. Retrieved February 15, 2023, from

OSHA. (2023). Department of Labor Logo United States Department of Labor. Permissible Exposure Limits – Annotated Tables | Occupational Safety and Health Administration. Retrieved February 16, 2023, from

U.S. Green Building Council. (2023). What is LEED certification? U.S. Green Building Council. Retrieved February 16, 2023, from

Image credits: Designed by Jonathan Borba / Unsplash

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