How We Research

Trust is everything when it comes to the air in your home. This page explains how we research products and topics, and how we decide what to recommend.

Sources We Rely On

  • Guidance from government and public health bodies, such as the U.S. Environmental Protection Agency (EPA)
  • Industry test standards and certifications, such as CADR ratings and MERV filter ratings
  • Official manufacturer specifications and manuals
  • Independent testing and certification programs where available

How We Evaluate Air Purifiers

When we compare air purifiers, we look at the factors that actually affect performance and cost of ownership:

  • Clean Air Delivery Rate (CADR) and the recommended room size
  • Filtration type, such as HEPA and activated carbon
  • Noise levels across fan speeds, especially for bedrooms
  • Filter replacement cost and how often filters need changing
  • Energy use and running costs
  • Ease of use, controls, sensors and smart features

How We Evaluate Air Quality Monitors

  • Which pollutants and conditions the device measures (PM2.5, CO2, VOCs, humidity, temperature)
  • Display clarity, app features and data history
  • Sensor type and published accuracy information
  • Price and ongoing costs

What We Avoid

We avoid exaggerated health claims. No air cleaner removes every pollutant, and air purifiers are one part of a healthy home alongside source control and ventilation. We explain limitations clearly so you can make informed decisions.

Keeping Content Up to Date

Products and guidance change. We review and update our guides regularly, and each article shows when it was last updated.

Independence

Some links on our site are affiliate links, but commissions never decide our rankings. Learn more in our Affiliate Disclosure.