Indoor Air Quality: What You Need to Know About the Air in Your Home

We think a lot about the air outside. We check air quality alerts before going for a run, look at pollen ⁴ counts during allergy season, and pay attention to smoke ¹ from wildfires.

But how often do you think about the air inside your home?

Indoor air quality (IAQ) refers to the quality and characteristics of the air inside buildings and how they can affect the health, comfort, and well-being of the people inside. According to the U.S. Environmental Protection Agency (EPA), people spend approximately 90% of their time indoors, making the air inside our homes an important part of our everyday environment.

October is National Indoor Air Quality Awareness Month, making it a great time to take a closer look at the air inside your home and learn what you can do to create a cleaner indoor environment.

What Is Indoor Air Quality?

Indoor air quality, often abbreviated as IAQ, describes the condition of the air inside your home, workplace, school, or other enclosed space.

Good IAQ generally means minimizing indoor air pollutants and maintaining an indoor environment with appropriate ventilation, temperature, and humidity.

Indoor air quality can change throughout the day depending on what's happening inside and outside your home. Cooking dinner, cleaning, using certain household products, opening a window, running your HVAC system, showering, or bringing pets inside can all influence the air around you.

And because many indoor pollutants are invisible, you may not always know they're there.

Why Is Indoor Air Quality Important?

Your home is designed to protect you from the elements, but it can also trap pollutants indoors.

The EPA identifies a wide range of potential indoor air pollutants, including particulate matter, smoke¹, mold ⁴, pollen⁴, volatile organic compounds (VOCs⁵), radon, carbon monoxide, and other contaminants ³. Sources can include household products, building materials, furnishings, combustion appliances, moisture, outdoor air, and everyday activities.

Some indoor pollutant levels can also be higher than outdoor levels. The EPA notes that indoor concentrations of some pollutants can be several times higher than typical outdoor concentrations.

That doesn't mean every home has poor IAQ or that every indoor pollutant presents the same level of concern. It does mean that understanding where indoor pollutants come from, and how to reduce them, is an important part of maintaining a healthier home environment.

What Are Common Indoor Air Pollutants?

Indoor air pollution can come from many different sources. Some pollutants are particles that can become airborne, while others are gases or vapors.

Dust ³ and Particulate Matter

Dust ³ is one of the most noticeable forms of indoor air pollution, but household dust ³ can contain a mixture of different materials.

Fine particulate matter, often referred to as PM2.5, consists of very small particles that can remain suspended in the air. Indoor particulate matter can come from sources such as cooking, smoking, combustion, outdoor pollution, and other household activities.

Pollen⁴

Pollen⁴ from trees, grasses, and plants can make its way indoors through open doors and windows, on clothing, and on shoes or pets.

Once inside, pollen⁴ can settle on furniture, floors, and other surfaces. Some airborne pollen⁴ can also be captured through filtration.

Pet Dander⁴

Dogs, cats, and other pets can introduce dander⁴ and other particles into the indoor environment. Pet-related particles can become airborne when pets move around the home or when settled particles are disturbed.

Regular cleaning can help reduce the buildup of pet-related particles, while air filtration can supplement those efforts.

Smoke¹

Smoke¹ can come from a variety of sources, including tobacco, fireplaces, candles, cooking, and outdoor wildfire smoke¹ that enters the home.

Smoke¹ contains both particulate matter and gases, which means addressing smoke¹-related indoor air pollution may require more than one strategy.

Mold⁴ and Moisture

Moisture is an important part of indoor air quality. Water leaks, condensation, flooding, and excessive humidity can create conditions that support mold⁴ growth.

The EPA generally recommends maintaining indoor relative humidity between 30% and 50% in homes.

Controlling moisture at its source is an important part of managing indoor air quality.

Volatile Organic Compounds (VOCs ⁵)

Volatile organic compounds, or VOCs ⁵, are gases emitted by certain products and materials.

Potential sources include paints, cleaning products, aerosol sprays, pesticides, adhesives, furnishings, building materials, and other household products. Some VOC⁵ concentrations can remain elevated in indoor air after a product has been used.

Outdoor Air Pollution

Indoor air isn't completely separate from the outdoor environment.

Outdoor pollutants can enter through doors, windows, ventilation systems, and other openings. This can include wildfire smoke¹, vehicle-related pollution, pollen⁴, and other airborne particles.

That's why opening windows isn't always the right solution for improving IAQ. When outdoor air quality is poor, bringing more outdoor air inside can introduce additional pollutants.

What Can Affect Indoor Air Quality?

Almost everything that happens inside a home can have some impact on IAQ.

Common factors include:

• Cooking and frying
• Cleaning and disinfecting
• Candles and fireplaces
• Smoking or vaping indoors
• Pets
• Dust ³ and tracked-in debris
• Household chemicals and air fresheners
• Paints, adhesives, and building materials
• Furniture and furnishings
• HVAC systems and HVAC filters
• Water leaks and excess humidity
• Outdoor wildfire smoke ¹
• Pollen ⁴ and outdoor pollution
• Poor ventilation
  

The good news is that there are several practical ways to address many of these sources.

How to Improve Indoor Air Quality at Home

The EPA identifies three primary strategies for improving indoor air quality: source control, improved ventilation, and air cleaning/filtration.

Using all three together can help create a more comprehensive approach to managing the air in your home.

1. Control Pollution at the Source

One of the most effective ways to improve IAQ is to reduce pollutants before they become an indoor air problem.

For example:

• Don't smoke ¹ indoors.
• Use kitchen exhaust fans when cooking, especially when they vent outdoors.
• Use bathroom exhaust fans during and after showers.
• Keep household chemicals tightly sealed when not in use.
• Address water leaks promptly.
• Keep indoor spaces clean and dry.
• Maintain fuel-burning appliances according to manufacturer recommendations.
• Use doormats and consider removing shoes at the door to reduce tracked-in dirt and pollutants.
  

Source control is particularly important because filtration cannot eliminate every type of indoor pollutant.

2. Improve Ventilation When Outdoor Conditions Allow

Ventilation helps replace stale indoor air with outdoor air and can reduce the concentration of some indoor pollutants.

When outdoor air quality, weather, and temperature permit, opening windows and doors can increase natural ventilation. Kitchen and bathroom exhaust fans that vent outdoors can also help remove pollutants and moisture from the home.

However, ventilation isn't always appropriate.

If outdoor air quality is poor because of wildfire smoke¹, heavy pollution, or high pollen⁴ levels, opening windows may bring additional pollutants indoors. In those situations, filtration can be an important supplemental strategy.

3. Use Air Filtration and Air Cleaning

Air filtration can supplement source control and ventilation by helping remove airborne particles from indoor air.

Portable air cleaners, often called air purifiers, are designed to filter air in a room or specific area. The EPA notes that portable air cleaners can help reduce indoor air pollution, although no air cleaner can remove every pollutant from a home.

When choosing an air purifier, consider:

Room Size

Choose an air purifier designed for the size of the room or space where it will be used.

Filtration Technology

Different filters are designed to address different types of pollutants.

HEPA filtration is designed to capture airborne particles, while activated carbon can help address certain gases and odor ¹-causing compounds. The EPA recommends checking the specific product information because filters vary in what they are designed to remove.

CADR

Clean Air Delivery Rate, or CADR, is one metric used to evaluate how quickly a portable air cleaner can remove particles from the air.

Generally, a higher CADR means an air cleaner can filter more air over a given period. The appropriate size depends on the room or area where the purifier will be used.

Filter Maintenance

Filters need to be replaced according to the manufacturer's recommendations.

A dirty or overloaded filter may not perform as intended, so keeping up with filter replacement is an important part of maintaining an air purifier.

How PuroAir Can Help Improve Indoor Air Quality

A comprehensive approach to indoor air quality starts with controlling pollution sources and maintaining good ventilation when outdoor conditions allow.

PuroAir HEPA Air Purifiers can add another layer of filtration to your indoor air routine.

PuroAir air purifiers combine high-efficiency filtration with features designed for everyday home use. Depending on the model, PuroAir systems can help filter airborne particles such as dust³, pollen⁴, pet dander⁴, smoke¹, and other unwanted particles.

All PuroAir air purifier models include CarbonTech ™ activated carbon filtration to help address certain household odors¹ and gases.

For homes with pets, a PuroAir air purifier can provide continuous filtration while your family goes about its daily routine. In bedrooms, living rooms, offices, and other frequently used spaces, portable air filtration can supplement the home's existing HVAC filtration.

Think of an air purifier as one part of a bigger IAQ strategy. Not the entire solution.

The goal is to reduce pollution at the source, bring in clean outdoor air when conditions allow, and use filtration to help manage airborne pollutants.

Indoor Air Quality Room by Room

Different rooms can introduce different IAQ challenges.

Kitchen

Cooking can produce airborne particles, smoke¹, and odors¹.

Use your range hood or exhaust fan when cooking, especially when it vents outdoors. An air purifier can provide supplemental filtration for airborne particles and certain odors¹.

Bedroom

Bedrooms are where many people spend a significant portion of their time.

Regularly wash bedding, reduce dust³ buildup, keep pets' sleeping areas clean, and maintain your HVAC and air purifier filters.

A quiet air purifier can also provide ongoing filtration while you sleep.

Living Room

Living rooms can accumulate dust³, pet dander⁴, tracked-in debris, and particles from everyday activities.

Regular vacuuming and dusting can help reduce settled particles, while portable air filtration can help address particles that become airborne.

Bathroom

Moisture is the primary IAQ concern in many bathrooms.

Use an exhaust fan during and after showers to help remove moisture. Address leaks and persistent condensation, and monitor humidity if moisture is a recurring problem.

Home Office

Home offices may contain printers, computers, furniture, cleaning products, and other potential sources of indoor pollutants.

Ventilate when outdoor conditions permit and keep the space clean and well maintained.

How Do You Know If Your Indoor Air Quality Is Poor?

Indoor air quality isn't always easy to judge by sight or smell.

Some pollutants are invisible and odorless, which means you may not notice them simply by walking into a room.

There are, however, signs that can prompt you to take a closer look at your home's IAQ:

• Persistent musty or unusual odors ¹
• Visible mold ⁴ or signs of water damage
• Excessive dust ³ buildup
• Persistent indoor smoke ¹ or odors ¹
• Condensation or excessive humidity
• Poor ventilation
• A noticeable increase in airborne dust ³ or particles
• Recent renovations or construction
• Exposure to wildfire smoke ¹ or outdoor pollution
  

An indoor air quality monitor can also provide information about certain conditions in your home. Depending on the device, IAQ monitors may measure factors such as particulate matter, temperature, humidity, carbon dioxide, or VOCs⁵.

Keep in mind that no single monitor measures every possible indoor pollutant.

Is an Air Purifier Enough to Improve Indoor Air Quality?

An air purifier can be an important part of an IAQ strategy, but it shouldn't be viewed as a complete solution.

The EPA recommends combining source control, ventilation, and filtration to improve indoor air quality.

For example, if you are dealing with cooking smoke ¹, you might:

1. Use a range hood or exhaust fan.
2. Reduce the source of smoke ¹ when possible.
3. Ventilate when outdoor conditions permit.
4. Use an appropriately sized air purifier to supplement filtration.
5. Maintain the purifier's filter according to the manufacturer's recommendations.
   

This layered approach can help address indoor air quality from multiple directions.

Do Houseplants Improve Indoor Air Quality?

Houseplants are a popular way to bring a little more nature indoors, but can they actually improve your indoor air quality?

The short answer: potentially, but don't rely on houseplants as your primary air-cleaning strategy.

Some laboratory studies have found that certain plants can absorb or help break down compounds such as volatile organic compounds (VOCs⁵). However, these studies are often conducted in small, controlled chambers that don't accurately represent the air exchange and ventilation found in a typical home.

The EPA notes that there is currently no evidence that a reasonable number of ordinary houseplants can remove significant quantities of indoor pollutants in homes or offices.

That doesn't mean you need to get rid of your plants. Houseplants can still be a great addition to your home. Just think of them as part of your indoor environment, rather than a replacement for proven IAQ strategies.

If You Have Houseplants, Keep Them Healthy

There is one important IAQ consideration when it comes to plants: moisture.

Overwatering plants or allowing soil to remain excessively damp can encourage the growth of microorganisms. The EPA recommends avoiding overly damp planter soil and keeping indoor humidity under control.

For better indoor air quality:

• Don't overwater your plants.
• Remove standing water from saucers.
• Keep leaves and surrounding surfaces clean.
• Watch for mold ⁴ or persistent moisture in potting soil.
• Maintain indoor humidity around 30–50% when possible.
  

Your Indoor Air Quality Checklist

Use this simple checklist to give your home's IAQ a reset this October:

☐ Check your HVAC filter
Replace or clean it according to the manufacturer's recommendations.

☐ Check your home's humidity
Aim for approximately 30–50% relative humidity.

☐ Look for moisture problems
Check under sinks, around windows, in bathrooms, and anywhere water leaks or condensation may occur.

☐ Improve ventilation
Use kitchen and bathroom exhaust fans and bring in outdoor air when conditions allow.

☐ Reduce indoor pollution sources
Keep chemicals sealed, avoid indoor smoking, and follow product instructions for ventilation.

☐ Clean regularly
Dust³, vacuum, and clean surfaces to reduce the buildup of particles.

☐ Pay attention to outdoor air quality
Check outdoor air conditions before opening windows, especially during wildfire smoke¹ or high-pollution events.

☐ Consider portable air filtration
Use an appropriately sized air purifier to supplement your home's existing HVAC filtration.

☐ Maintain your air purifier
Replace filters every 90 days, or according to PuroAir’s recommendations.

Make Indoor Air Quality Part of Your Home Routine

Indoor air quality isn't something you need to think about only once a year.

October's National Indoor Air Quality Awareness Month is a good reminder to take a closer look at the air inside your home and build better IAQ habits that can continue throughout the year.

From controlling pollution sources to improving ventilation and adding supplemental air filtration, small changes can make indoor air quality a more intentional part of your home's overall environment.

Because the air inside your home is worth paying attention to.

Explore PuroAir HEPA Air Purifiers and find the right level of filtration for your space.

Choosing the Right Air Purifier:

Not all purifiers are created equal. When shopping, consider:

• Room size (match the purifier’s coverage to your space)
  
• Filter type (HEPA + activated carbon is ideal)
• Noise level
• Smart features (auto mode, sensors, app control)
• CADR rating
• Maintenance and filter costs

Model	Room Size	Lowest Decibel	Auto Mode	App Control
PuroAir 100i	550 sq ft1	22 dB		✅
PuroAir 130i	750 sq ft1	27 dB		✅
PuroAir 240	1,000 sq ft1	24 dB	✅
PuroAir 400	2,000 sq ft1	31 dB	✅

If you want a purifier that’s powerful, quiet, and easy to use, PuroAir models are a strong fit for every home.