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Indoor Air Quality Monitors: What They Are and What They Measure

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In the last few years, indoor air quality (IAQ) has worsened with air pollution. Homes have improved sealing to save energy and reduce leaks which reduces ventilation throughout the house and makes it harder for pollutants to escape, negatively impacting IAQ. The pandemic has highlighted the dangers of breathing stale air as well.

As a result, there has been a greater focus on IAQ in buildings that people spend a lot of time in, like offices, schools, restaurants, and residential apartments. Introducing better IAQ monitors to these places helps make them safer

If you're confused about why IAQ's impact on the real estate market has been so significant, it will help to better understand what an IAQ monitor is and how it helps keep the people in your building safe.


What Affects Indoor Air Quality?

Many factors can affect the overall air quality. A lot of particles and contaminants are mixed in the air we breathe, some of them harmful, some of them not. Mold is one of the major harmful factors, along with other bacteria, viruses, and allergens.

Carbon monoxide, Ozone, and Radon can be deadly and harmful concentrations will usually be found indoors. Some other chemicals such as formaldehyde and Particulate Matter can give cancer, especially the smaller size particles that can penetrate deep in the pulmonary system.  CO2 is another major IAQ contaminant, and although not especially harmful in usual indoor settings, it has a major impact on cognitive functions, which makes it an important contaminant to monitor in office and school settings. 

Humidity and temperature also play a role in air quality, because high temperatures and moisture can promote mold growth and enable viruses to stay in the air longer. If buildings reach too high a temperature, harmful chemicals can be released more easily as well. 


What Is an Indoor Air Quality Monitor?

To put it simply, an IAQ monitor is a device or system that checks the levels of different air contaminants and helps assess how safe the air is to breathe. It can alert people when some of those levels become unsafe. 


What Does an Indoor Air Quality Monitor Measure?

Different IAQ monitors measure different contaminants in the air to inform you about the air quality in your building. When measuring air quality, here are some metrics that an IAQ monitor will track:


Concentration of Particulate Matter

Some common sources of particulate matter indoors are cigarette smoke, candles, and outdoor pollution that gets in.

In general, particulate matter is any particle that hangs in the air, like pollen or smoke. It can also form when liquid droplets combine with solid particles, bacteria, or viruses floating in the air. These particles can be so small that only a microscope can detect them, though some are visible like pollen and smoke. 

The smallest particles can be the most harmful because, once you inhale them, they can get deep into your pulmonary system and even cause lung cancer.


Carbon Dioxide Levels

You probably guessed that carbon dioxide would come up, but you may not realize how bad it can be for people’s health. Studies have shown that carbon dioxide affects cognitive performance, reducing people's ability to make decisions across many metrics. Depending on the amount in the air, people can experience effects ranging from headaches and dizziness, to asphyxia and convulsions.

Carbon dioxide can enter a building in many ways:

  • It can build up in rooms that have too many people or animals.
  • Anything that causes combustion, like lighting a furnace, produces carbon dioxide.
  • In areas with high carbon dioxide levels in the soil, it can get into basements through stone walls or cracks in floors and foundations.

Stagnant carbon dioxide can even build up in large meeting spaces that do not have good ventilation.


Other Indoor Pollutants

Volatile organic compounds (VOCs) are the most common among the other indoor pollutants. You can smell their presence in most cases. You can find these in many household products, like:

  • Air fresheners
  • Dehumidifiers
  • Disinfectants
  • Cleaning agents
  • Building materials

Overexposure to these compounds can cause discomfort in the nose and throat, as well as allergic reactions. However, because there are various VOCs, some can be quite toxic, while others may not cause any known health effects. For example, some people have reported problems as severe as visual disorders and memory impairment soon after exposure to these contaminants.

Carbon monoxide is another pollutant that could have severe effects.  Since it is impossible to see or smell, a sensor is necessary to detect it. Small amounts of exposure to carbon monoxide can cause chest pain, impaired vision, and fatigue. In higher concentrations, it can be fatal. Carbon monoxide tends to build up near boilers, generators, and furnaces.

High concentrations of ozone can irritate the respiratory system and exacerbate asthma. Ozone can be found in certain air-cleaning devices. These devices claim to use ozone to destroy indoor VOCs, bacteria, and mold, but the amount of ozone they release can be harmful. Ozone can also enter buildings from outdoor air pollution, cars, refineries, and even some paints, cleaners, and solvents.


The Importance of Air Quality Monitoring

Most air pollutants don't affect health much in low concentrations, though most of the existing research focuses on outdoor air conditions. The sources of indoor air pollution make it nearly impossible to prevent. Air quality contaminants come from unavoidable daily activities and sources, such as cleaning and the respiration of those inside the building. 

Outdoor air quality causes indoor air quality issues and you may not know to what degree without a monitor. Wildfire smoke can carry many air contaminants, but you need a monitor to know how much particulate pollution is getting into the building.

Monitoring air quality lets you know when air contaminants reach unsafe levels in certain areas of your building. This gives you an indication of when to ventilate a room or building. If you find that certain rooms tend to have poor air quality, you can inspect them further to see if there has been a leak or if you need to increase the ventilation or install new air purifiers.


How To Know If You Have Good Air Quality Sensors

If you don't have IAQ sensors or if your air quality sensors aren't of the best quality, your building could have a high concentration of certain pollutants without you knowing. To make sure that you have good air quality sensors, look at their:

  • Measuring parameters. To have a clear idea of your IAQ, you need sensors that will detect the various contaminants present. Your building certification may require specific parameters, but you should measure particulate matter, carbon monoxide and dioxide, and total VOCs. Humidity and temperature monitoring are useful as well and some certifications may require it.
  • Data accuracy. All the parameters are of little to no help without accurate data. Monitors should undergo a "co-location" study that compares their readings to a regulatory reference instrument in order to judge their accuracy and any needs for calibration. You should also check that they conform to the latest building standards, such as the WELL standard.
  • Data collection. Many devices have a data output interval, meaning they take readings automatically after set amounts of time. Since the most up-to-date information lets you act quickest, you should look for a system with a low interval.
  • Data storage. Your sensors should be able to store data conveniently for you, ideally in the cloud to have access to real-time readings.


Why Commercial Businesses Are Investing in Air Quality Devices

With the spread of the COVID-19 virus, many commercial businesses have realized that they can't manage their HVAC systems just by temperature anymore. To address pressing air quality concerns, sensors are needed to provide the proper visibility. This is why businesses are investing in air quality devices that can monitor IAQ across a wide range of important parameters.

Companies like Boston Properties and Carr Properties are now investing in IAQ monitors because of the potential for monitors to show real-time data of particulate matter particles as small as 0.3 microns. Now that our perception of IAQ has expanded, the scope of IAQ monitors will as well. 


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