Buildings are growing smarter every day. It wasn’t all that long ago when robotic vacuums and voice assistants were little more than science fiction. But in 2021, artificial intelligence combined with the Internet of Things can transform even the most traditional of structures into smart buildings. 

The array of smart appliances and other smart home features ranges across everything from locks and security systems to lighting and HVAC. The smart home market also now includes devices to monitor and control a building’s indoor air quality – and not a moment too soon. According to at least one major study of almost 50,000 buildings, more than 96% of the homes tested positive for at least one of six primary IAQ problems: particle allergens like mold, bacteria and pollen, chemical pollutants including known carcinogens, carbon dioxide, temperature, humidity and carbon monoxide. 

If that wasn’t bad enough, 83% exhibited two or more IAQ issues, and almost half had three or more problems. Seven out of ten homes tested positive for chemical pollutants that can cause cancer. IAQ isn’t just a comfort issue, it can have a significant impact on occupants’ health. After all, the Environmental Protection Agency warns that air inside a home can contain as much as five times more pollutants than outside air, and most people spend around 90% of their time indoors.

“As people age, their bodies are less able to compensate for the effects of environmental hazards,” explains the EPA on its website. “Air pollution can aggravate heart disease, stroke, lung diseases such as chronic obstructive pulmonary disease and asthma, and diabetes. This leads to increased medication use, more visits to health care providers, admissions to emergency rooms and hospitals, and even death.”

Smart IAQ devices work together to improve a building’s air quality. Much like a thermostat can signal a furnace to warm a home, a smart IAQ monitor’s sensors can identify an increase of humidity or pollutants, and by using a WiFi signal it can automatically trigger another device like a dehumidifier or an air purifier to correct the issue. The most effective air quality monitors can measure particulate matter as small as 2.5 microns, a size that can deeply penetrate the lungs and infiltrate blood. While some can detect an even smaller particulate, they might not detect other pollutants. Likewise, a person with specific allergies might look to identify specific pollutants, while a person with asthma or general wellness concerns might seek a device with a wider range. 

Various smart IAQ monitors report pollutants in different ways, and some even provide a mobile app for remote IAQ monitoring. The best devices, however, monitor for the most common indoor air pollutants, including:

1. Radon

The radioactive gas might be odorless and colorless, but its presence is far more common than most realize and accounts for about 21,000 deaths from lung cancer each year. Radon is emitted from soil and rock beneath a building, and it enters a home through tiny cracks and leaks in its foundation. It can even more easily enter a home with a continuous concrete foundation from exposed ground below the building.

2. Secondhand smoke

A common household pollutant, secondhand smoke –  also known as environmental tobacco smoke – contains more than 7,000 substances, many of which are carcinogenic. Since the 1964 Surgeon General’s Report, 2.5 million adult nonsmokers died from breathing secondhand smoke, including 34,000 nonsmokers who die from heart disease each year.

3. Combustion pollutants

Combustion pollutants include any gases and particles such as smoke and soot created by burning fuels such as wood, kerosene, charcoal, natural gas or tobacco. The primary chemicals emitted through combustion are carbon monoxide, nitrogen dioxide, formaldehyde, polycyclic aromatic hydrocarbons and other ultrafine particles that can irritate and harm lungs. 

4. Volatile organic compounds

VOCs include a variety of particles emitted from various products, chemicals and activities in the home, including aerosol sprays, cleaning products, disinfectants, furniture, paint, building materials or stored gasoline. Cooking also can release VOCs into indoor air. VOCs not only cause irritation of eyes, nose and throat, but they can even lead to more serious health reactions, including cancer. According to the EPA, VOCs can be concentrated as much as 10 times higher indoors than outdoors.

5. Mold

Even the cleanest buildings can be hiding mold in warm and humid corners and other unseen areas. The fungi release spores that can cause irritation and worse allergic reactions in many people. While many IAQ monitors can detect particulate including mold, most are not yet capable of identifying mold from other similarly-sized particles in the air. 

6. Dander

Most often associated with pets, dander is just another name for dead skin cells, so it exists even in homes with only humans. Both pet dander and human dander can result in allergic reactions, but to the naked eye either one is just dust. Similar to mold, dander cannot be specifically identified by most IAQ monitors apart from general particulate of a similar size. 

7. Pollen 

Pollen is one of the most common culprits of poor IAQ, as millions experiencing hay fever and other airborne allergies take note of pollen counts in the outdoor air. But like in other pollutants, pollen concentrations indoors sometimes can be far higher than those experienced outside. While many IAQ monitors can identify allergens, very few can differentiate one form of pollen from another. 

8. Carbon monoxide 

The poisonous gas is colorless and odorless, but it can be emitted by space heaters, poorly-ventilated furnaces, gas-powered hot water heaters, wood stoves and fireplaces, gas stoves, car exhaust and many other common household items and activities. This makes it particularly dangerous to unknowing occupants. High levels of carbon monoxide can quickly lead to death. 

9. Carbon dioxide 

Another colorless and odorless gas, carbon dioxide is a component of every breath we take. Our lungs absorb the oxygen from the air, and they exhale the carbon dioxide. A poorly-ventilated building can lead to a higher concentration of carbon dioxide and reduce the concentration of oxygen in the indoor air. Combustion activities in the home also can create an increase in carbon dioxide, which at even moderate levels can cause physical ailments including headache, drowsiness, nausea and impaired judgement. High concentrations of the chemical can result in death. 

10. Humidity and temperature

A thermostat might monitor and help control indoor temperature levels, but the amount of heat in the building can impact more than mere comfort. Higher temperatures and humidity levels create an environment more prone to mold and mildew growth, as well as other pulmonary symptoms similar to airborne allergies. High humidity even can cause damage to household items and structural damage to the entire building. Humidity, however, is one of the easier IAQ issues to control, as a smart IAQ monitor can signal a dehumidifier to correct the problem.

11. Pathogens

Indoor air includes all sorts of bioaerosols, which are aerosolized liquid droplets in exhaled air. These bioaerosols contain a variety of organic materials including cell fragments, microbes and pathogens like bacteria, viruses and fungi. Every time a person coughs, laughs or sneezes, tens of thousands of virus-filled droplets can be exhaled into the surrounding air, spreading illness and disease in homes, schools, offices, stores and other indoor settings. 

Other respiratory diseases can be spread by airborne bacteria, such as a 1976 outbreak at a convention where the hotel’s ventilation system was contaminated with the biologic pathogen. Most IAQ monitors do not detect the presence of pathogens, but some score other air quality aspects that can contribute to the spread of viruses, bacteria and fungi. For example, measuring a Virus Index doesn’t determine the presence of a virus, but instead scores the likelihood of virus survival based on factors like temperature, humidity and the concentration of other VOCs. 

12. Air Quality Index (AQI)

Some IAQ monitors don’t identify specific particulates in the indoor air, but instead rate a building’s IAQ using the EPA’s Air Quality Index. IAQ scores range from 1 to 500, with the higher numbers indicating the greater levels of air pollution and greater health risks. The scores are based on the presence of five major air pollutants regulated under the Clean Air Act, including ground-level ozone, particle pollution for matter measuring PM2.5 and PM10, carbon monoxide, sulfur dioxide and nitrogen dioxide.