Energy Efficiency

Understanding IAQ: What You Need to Know About Indoor Air Quality?

The World Health Organization, known as the WHO, has warned that indoor and outdoor air pollution is the world’s ...

The World Health Organization, known as the WHO, has warned that indoor and outdoor air pollution is the world’s leading cause of mortality and disease. With policies and regulations, ambient air quality monitoring is conducted by policy measures and regulations; what about the inside?

With the COVID-19, indoor spaces become a hotspot since that airborne transmission has a significant role in spreading the SARS-CoV-2 virus. So, it is our responsibility to ensure that our employees, customers, or families breathe air as healthy as possible.

For us at Sensgreen, our primary goal is indoor air quality monitoring and providing scientific and technical oversight of air quality to ensure a healthy indoor environment. Our mission has always been to eliminate air pollution from the planet and improve all lives in all buildings. In light of the ongoing air pollution problem, it is time to learn more and take indoor air quality seriously worldwide for the sake of our health and wellbeing.

So, What Exactly is IAQ?

IAQ is the initials of Indoor Air Quality, which refers to the air in and around buildings. Air quality is often defined as the types & concentrations of pollutants and the thermal comfort parameters found in the indoor environment.

Why should you worry about IAQ?


First, IAQ directly affects occupant health, comfort, and productivity. When IAQ is poor, that means it contains high levels of pollutants. Well established, common health impacts are building-related illnesses such as asthma, weariness, irritability, and headache can affect occupants. Modern lifestyles and the COVID-19 lead us to nonstop contact with the inside ambient conditions, most of our time in offices, schools, and houses. It is easy to say that inhalation exposure is ongoing, and our most extensive exposure to pollutants occurs indoors.

The air quality is typically considered a health indicator, but another primary concern is the strong relationship between building energy efficiency and IAQ, especially in commercial and institutional buildings. Heating, Ventilation, and Air Conditioning (HVAC) systems are one of the largest energy consumers in buildings. The term '"HVAC" refers to equipment that can heat, cool, filter outdoor air, and manage humidity in the building to maintain comfortable conditions. The IAQ heavily depends on HVAC performance, and proper air exchange is essential for energy efficiency and IAQ in buildings. It’s a well-documented fact that IAQ is like a provision for occupants and energy efficiency.

Factors Affecting Indoor Air Quality

IAQ is affected, for better or worse, by many factors. The key factors affect the indoor air quality, including:

-        The outdoor climate;

-        Human activities;

-        Building components and furnishings,

-        The building’s heating, ventilation, and air conditioning (HVAC) system;

It is essential to understand the role of each of these factors in preventing, investigating, and resolving indoor air quality problems.

Many pollutants are found indoors that can harm our health. Understanding and controlling some of the common pollutants present in workplaces, hospitals, schools, and homes help improve indoor air quality and lower occupants’ risk of health problems associated with IAQ.

A Wide Range of Different Pollution Sources

Air pollution is caused by various sources. These include vehicle traffic, shipping emissions, building heating, industrial production, agricultural emissions, fossil fuel, and biomass energy generation, and etc. Although outdoor air pollution is often on the headline, indoor air pollution doesn’t seem like breaking news.  Even more, the harsh reality is that indoor air is more contaminated than outdoor air.

What is the paradox behind this?

In addition to pollution in the outdoor air, indoor pollutants source from human breath, cleaning and cooking products, toxins emitted by paints, walls, floor coverings, and more. There is apparently no end to the list of common indoor pollutants known as particulate matter, benzene, organic volatility, formaldehyde, ozone, allergies, etc.

Common Indoor Air Pollutants

Indoor environments differ from region to region and country to country due to differences in climatic conditions, lifestyles, and construction practices. Regardless of these differences, many industrialized cultures are increasingly faced with a growing number of very similar indoor air quality problems. 

As earlier mentioned, quality is a function of the concentration of pollutants in the air within the building. It includes a mixture of physical, chemical, and biological pollutants from outdoor ambient air or inside the building, from building materials, furniture, furnishings, or even activities performed by the occupants themselves.

-        Physical pollutants (particulates, asbestos fibers, artificial mineral fibers, electromagnetic fields)

-        Biological pollutants (viruses, bacteria, molds, pet allergens, mite allergens)

-        Chemical pollutants (semi-volatile and volatile organic compounds or VOCs, inorganic gases)

To learn more detailed information on some of these pollutants, please check our latest eBook below.

     Request a Demo    

Covid-19 and Indoor Air Quality

According to WHO, poorly ventilated buildings are among the main reasons for spreading the SARS-CoV-2 virus. This is because aerosols remain suspended in the air or travel farther than 1 meter. Different types of air quality parameters affect aerosol suspension in the air.


According to a very recent study, the infection risk of SARS-CoV-2 (Covid-19) is also proportional and highly related to the CO2 levels in an area. It is observed that if an influx of people makes CO2 jump from 800 to 1600, the risk of Covid transmission triples. *


Maintaining the relative humidity in the 40%-60% range in indoor spaces could help slow the spread of the coronavirus. Humidity can affect virus transmission in three ways. Studies suggest that higher humidity can enhance the body’s ability to fight off infection; that the coronavirus decays faster at 40- 60% relative humidity than at other levels; and that drier air can lead to greater numbers of tiny coronavirus particles that travel farther and penetrate deeper into the lungs.

Particulate Matter(PM2.5-PM10): 

The virus can cling to very small particles and travel along with the air for spreading.  A 10 μg/m³ increase of pollution level was associated with an 8.1%-11.5% increase in the number of cases for PM2.5 and PM10, respectively.

Ways to Achieve Good Indoor Air Quality

Good IAQ requires consideration of both indoor air pollution levels and thermal environmental parameters. The U.S. Environmental Protection Agency states (EPA) defines different fundamental ways to improve indoor air quality (IAQ):

-       Detect and control the sources of pollution;

-        Increase ventilation; and

-        Maintenance of thermal health. 

-   Regular maintenance of Air Filters(Hepa, Merv, ...)

-   Using Air Purifiers

Monitor IAQ: Anytime Anywhere

Although there are no existing legal controls on air quality, IAQ is more critical than ever with COVID-19. Times changed with the dawn of the digital age. In a broader sense, monitoring in buildings will provide large amounts of data on indoor air and new insights that will guide future rules for designing and operating buildings.

Big data collection with more capable indoor air quality sensors enables us to investigate more complicated problems. Now, in real-time monitoring, you can make sure that your building is running as safely as possible.

Developed by Sensgreen, the SensNode and Sensboard are intelligent IAQ solutions which allow building owners and managers to make data-driven decisions to improve their IAQ. With Sensgreen technology, you can: 

-        Provide real-time air quality data;

-        Determine the level of air pollution in your building;

-        Support implementation of air quality goals or standards;

-        Track the big data to follow trends of air pollution  

-   Get insights into the source of pollution 

Which standards and guidelines are in place for IAQ management?

Various international guidelines, standards, codes, and other efforts are in place or under development to promote, and in some cases require, the design and sustain a good IAQ. Guidelines and standards have been produced by international organizations such as WHO, EPA, EU ASHRAE, OSHA, NIOSH, etc. Also, a number of national regulations and recommendations have been established for indoor air quality and proper ventilation. Just check their website to ensure your air is clean and safe. 

To meet and follow their recommendations properly and sustain well-maintained, pollution-free air, let's get in touch!

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