This week, we’re re-airing a discussion about keeping your indoor air clean and healthy to breathe. Wirecutter senior writer Tim Heffernan walks us through how to reduce the outdoor pollution that inevitably seeps into your home, what to do if you're dealing with wildfire smoke, and surprising and free ways to keep your air clean.  Tim covers exactly why you shouldn’t overspend on an air purifier, and how often you really need to change the filter. Plus he does some myth busting about whether plants clean the air. This episode covers:  • Monitoring outdoor air: How to use the free EPA Air Now app to track local Air Quality Index (AQI) levels, so that you and know when to wear an N95 mask or seal up your home. • Wildfire preparedness: Practical, low-cost steps to prevent outdoor smoke from contaminating your indoor air, from adjusting your HVAC settings to designated shoe-and-clothes drop zones. • Air purifier science: How HEPA filters capture microscopic particles, why you don't need to replace filters as often as manufacturers claim, and where to position your unit for maximum coverage. • Gimmicks to avoid: Why plants won't clear wildfire smoke and why expensive non-HEPA technologies fail Wirecutter's rigorous testing. Products we recommend:  • The best indoor air quality monitor: AirGradient One (https://www.nytimes.com/wirecutter/out/link/73150/222641/57/260726) • The best app for basic monitoring: AirNow (https://www.nytimes.com/wirecutter/out/link/47425/175531/57/260727) • The best air purifier of 2026: Coway Airmega Mighty2 (AP-1512N) (https://www.nytimes.com/wirecutter/out/link/79836/236179/57/260728) • Another great air purifier: Coway Airmega AP-1512HH Mighty (https://www.nytimes.com/wirecutter/out/link/7595/150104/57/260729) • A great pair of pliers: Knipex Carpenters’ End Cut Pliers (https://www.nytimes.com/wirecutter/out/link/63954/242370/57/260731) Additional reading: • The 4 Best Air Purifiers of 2026 (https://www.nytimes.com/wirecutter/reviews/best-air-purifier/) • How Can I Clear My Home of Wildfire Smoke? (https://www.nytimes.com/wirecutter/blog/air-purifier-wildfire-smoke/) • How to DIY an Air Purifier (https://www.nytimes.com/wirecutter/blog/how-to-diy-an-air-purifier/) • LifeStraw Escape Water Purifier Review: I Drank Swamp Water to See If It Works (https://www.nytimes.com/wirecutter/reviews/lifestraw-escape-water-purifier-review/) We independently review everything we recommend. When you buy through our links, we may earn a commission. Learn more› (https://www.nytimes.com/wirecutter/about/) The Wirecutter Show is executive produced by Rosie Guerin and produced by Abigail Keel.Engineering support from Maddy Masiello and Nick Pitman. Episodes are mixed by Catherine Anderson, Efim Shapiro, Rowan Niemisto, Sophia Lanman, and Sonia Herrero. Original music by Dan Powell, Marion Lozano, Elisheba Ittoop, Catherine Anderson, Rowan Niemisto and Diane Wong. Wirecutter’s deputy publisher and general manager is Cliff Levy. Ben Frumin is Wirecutter’s editor-in-chief. Hosted by Rosie Guerin, Caira Blackwell and Christine Cyr Clisset. #AirPurifier, #AirQuality, #WildfireSmoke, #HEPAFilter, #TheWirecutterShow, #Wirecutter, #IndoorAirQuality, #CleanAir, #AllergyRelief, #HomeHealth, #podcast Instagram: /wirecutter (https://www.instagram.com/wirecutter/) Threads: /@wirecutter (https://www.threads.com/@wirecutter) Twitter: /wirecutter (https://x.com/wirecutter) Facebook: /thewirecutter (https://www.facebook.com/thewirecutter/) TikTok: /wirecutter (https://www.tiktok.com/@wirecutter)