Where To Find The Best Indoor Air Purifiers Of 2025

Why is it a good idea to have an air purifier for your home?

Since we spend around 90% of our time indoors, according to the EPA, indoor air quality can actually be more harmful to our health than outdoor air pollution. An air purifier can make a huge difference in reducing common indoor pollutants that can affect our health, especially if you suffer from allergies or asthma.

An air purifier is designed to trap aggravating particles like dust, pollen, and pet dander, to relieve itchy eyes, sneezing, and difficulty breathing. 

Indoor air purifiers with activated carbon filters can also tackle unpleasant odors from cooking or pets, and even remove harmful pollutants like wildfire smoke and VOCs. This helps to create a cleaner, fresher, and more comfortable environment that can improve your sleep and your overall health.

Common Indoor Air Pollutants and How They Affect Your Health

• Particulate Matter (PM2.5): You know when the light shines through the window just right and you can see dust glimmering in the sunlight? That’s particulate matter referred to as PM2.5. These minuscule menaces can come from all sorts of places, like outdoor air pollution coming in through windows, smoke generated in the kitchen, smoking, and even the dust clinging to your furniture and carpets.

Breathing in PM2.5 can lead to serious respiratory issues, like asthma attacks, bronchitis, and reduced lung function. Long-term exposure to these pesky particles has also been linked to a higher risk of heart disease and lung cancer.

• Ultrafine Particles: Ultrafine particles are a sneaky category of PM2.5 particles. They’re even smaller, measuring less than 0.1 microns in diameter. They can come from similar sources like cooking, burning candles, or using certain appliances and personal care products. Because they’re so small, ultrafine particles can make their way deep into your lungs and even enter your bloodstream, potentially causing cardiovascular and respiratory issues.

• Volatile Organic Compounds (VOCs): VOCs are one of the largest culprits behind indoor air pollution. These gases can emanate from a host of household products, from paints and cleaning supplies to furniture and even your favorite personal care items.

Exposure to VOCs can cause eye, nose, and throat irritation, as well as headaches and dizziness. Some VOCs, like formaldehyde, are known carcinogens, which means they can pose serious health risks if you’re exposed to them for too long.

• Carbon Monoxide: You’ve likely heard of carbon monoxide. It’s virtually odorless and short-term exposure to high levels can be fatal. This toxic gas can be produced by malfunctioning appliances, gas leaks, or poor ventilation.

Carbon monoxide works by reducing the oxygen supply to your organs and tissues, which can be very dangerous. While acute exposure can be lethal, long-term exposure can increase your risk of heart disease.

• Mold, Bacteria, and Allergens: Mold, bacteria, and allergens like dust mites, pet dander, and pollen love to make themselves at home, especially in damp or poorly ventilated areas. These invaders can trigger asthma attacks, allergic reactions, and respiratory issues. Some molds and bacteria, like Legionella, can even cause serious respiratory infections.

• Smoke: Whether it’s from cigarettes, a smoky kitchen, or a nearby wildfire, exposure to smoke can wreak havoc on your indoor air quality. Smoke can cause eye, nose, and throat irritation, and even more serious health problems like lung cancer and heart disease.

Secondhand smoke is filled with toxic compounds that can affect the health of everyone in your household, even if they’re not the ones lighting up.

How do air purifiers work to remove pollutants?

It all comes down to a powerful combination of filters and technologies that trap and destroy indoor air pollutants. Filters are the most powerful tool for removing physical particles from the air and the quality of an air purifier typically comes down the quality of the filter. 

HEPA Filters

High-Efficiency Particulate Air (HEPA) filters are the foundation of most air purifiers. These filters are designed to capture at least 99.97% of airborne particles as small as 0.3 microns, including dust, pollen, pet dander, and even some bacteria and viruses. 

HEPA filters use a dense network of fibers to trap particles as air passes through the filter. As air circulates through the purifier, the HEPA filter captures these tiny particles, preventing them from recirculating in your indoor environment. HEPA filtration is essential for reducing allergens and other particulate matter that can trigger respiratory issues.

Activated Carbon Filters

While HEPA filters excel at capturing particulate matter, they are not effective at removing gaseous pollutants and odors. This is where activated carbon filters come into play. Activated carbon filters are crucial for reducing exposure to harmful VOCs and eliminating unpleasant odors from sources like cooking, pets, or new furniture.

Activated carbon is highly porous, with an extensive surface area that allows it to trap gaseous molecules. As air passes through the activated carbon filter, VOCs and odor-causing compounds adhere to the surface of the carbon. 

UV-C Light and Photocatalytic Oxidation (PCO)

UV-C light uses ultraviolet radiation to kill off microorganisms like bacteria, viruses, and mold spores. When these pollutants are exposed to UV-C light, their DNA is damaged, rendering them harmless and unable to reproduce. 

PCO, on the other hand, combines UV light with a catalyst (usually titanium dioxide) to break down VOCs, odors, and other pollutants into harmless substances like carbon dioxide and water vapor. As the UV light activates the catalyst, it creates a reaction that oxidizes and neutralizes the pollutants, leaving you with cleaner, fresher air.

What are some additional ways I can improve the air quality in my home?

The most effective approach is to eliminate or reduce sources of indoor air pollution. This includes:

• Choosing low or no-VOC paints, furniture, and cleaning products to minimize off-gassing of VOCs.
• Ensuring proper ventilation during home improvement projects like painting, sanding, or using adhesives to reduce exposure to fumes.
• Maintaining fuel-burning appliances like gas stoves and furnaces to prevent carbon monoxide buildup.
• Not allowing smoking indoors, as secondhand smoke contains harmful particulates and gases.
• Regularly cleaning carpets, rugs, and upholstery to remove dust, dander, and other allergens.

Proper Ventilation

Opening windows and doors regularly when weather permits allows fresh outdoor air to circulate and dilute indoor pollutants like volatile organic compounds (VOCs), particulate matter, and odors. This natural ventilation helps expel stale indoor air containing allergens, dust, and moisture that can lead to mold growth.

Installing exhaust fans in kitchens and bathrooms is an effective way to directly remove moisture, cooking fumes, and odors at the source. Properly vented bathroom fans prevent moisture buildup that enables mold growth and improves indoor air quality.

Whole-house fans or mechanical ventilation systems provide controlled air exchange by continuously introducing fresh outdoor air while expelling stale indoor air. These systems help reduce concentrations of pollutants like radon, VOCs, and particulate matter that can accumulate indoors over time.

Mechanical ventilation is especially beneficial in tightly sealed, energy-efficient homes where natural ventilation may be inadequate.

Invest in Air-Cleaning Plants 

Investing in air-cleaning plants is an effective and natural way to improve indoor air quality. Certain plant species have been found to remove toxic airborne substances through their leaves and root systems. NASA studies showed plants can remove up to 87% of indoor air toxins like benzene, formaldehyde, and trichloroethylene. 

Common houseplants like aloe, peace lilies, and snake plants are excellent toxin eliminators.

How often should I replace the filters in my air purifier?

For your HEPA filters (the ones that catch all the tiny particles), plan on replacing them every 6-12 months if you’re using your purifier regularly. But keep in mind, if you live in an area with lots of pollution, or if you’re running your purifier on high speed all the time, you might need to change it more often.

Activated carbon filters (the ones that help with odors) usually need to be replaced around the same time as your HEPA filters. And don’t forget about your pre-filters! These are the mesh screens that catch all the big stuff before it gets to your HEPA filter. Give them a good vacuum or wash every 2-4 weeks to keep them working their best.

These are just general guidelines. The best way to know for sure when to change your filters is to check what the manufacturer recommends. They usually base this on how much use they expect the average person to get out of their purifier.