Our homes are our sanctuaries, but your indoor air might be dirtier than you think. That could be making it uncomfortable at home, and potentially even make you sick.

If you’re struggling with your indoor air quality, there are a few things you can do to help and devices you can buy, like an air purifier, a dehumidifier, and a humidifier. But they aren’t cheap. While their names are self-explanatory, it’s not as easy to figure out when you might need each one. We talked to experts, read research reports, and tested some products to give you the best advice.

For more in-depth info, check out our Best Air Purifiers and Best Robot Vacuums guides.

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Updated November 2022: We’ve added the Airthings View Plus Air Monitor, Vitruvi’s Cloud Humidifier, and a new section on cleaning. We’ve also updated prices and links throughout.

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Table of Contents

What’s the Problem With Indoor Air?

Depending on where you live, your indoor air quality could suffer. It may be full of dust; pet dander; outdoor pollutants, which could include wildfire smoke depending on where you live; formaldehyde, which can come from wood furniture; and particulate matter. Your indoor air can also include a number of volatile organic compounds. (VOCs overall aren’t a health issue, only specific ones, and those will vary from house to house.)

The World Health Organization estimates that nine out of 10 people are exposed to air pollution that increases their risk for several diseases, including stroke, heart disease, and cancer.

“There are many pollutants that can be found in someone’s home, depending on many factors such as geographic location or the age of the home and the building materials used,” says Joe Heaney, president of Lotus Biosecurity, a company in the indoor-air-quality-improvement business. “If you have a home with a wood-burning stove or fireplace, those are likely to introduce particulate matter into your indoor air, which can cause a range of respiratory symptoms and illnesses. Mold, dust, or pet hair can be a source of allergies, and pathogens (while not pollutants) introduced to the house by friends and neighbors may cause illness.”

On a basic level, when the air inside is stuffy, too dry, or too humid, it affects the way you feel, worsening cold and allergy symptoms, drying out your sinuses and skin, and even attributing to mold growth. But it can get much worse than that.

“Poor indoor air quality can affect even the healthiest lungs,” says Kenneth Mendez, president of the Asthma and Allergy Foundation of America. “Pollutants can irritate the eyes, nose, and throat, and cause headaches, dizziness, and fatigue. This can trigger allergy symptoms including chest tightness, coughing, wheezing, sneezing, shortness of breath, and even asthma attacks.”