Homemade air purifiers can filter air faster, making them an affordable alternative to more expensive commercial products.

“We find that thicker filters have two big advantages: They filter particles out of the air better and require replacement less often,” says Misha Kollontai, who oversees CR’s air filter testin ...

For more on water filters, see our water filter ratings and buying guide. Most air purifiers have a filter indicator (often a light) that alerts you when the filter should be checked and possibly ...

To combat hay fever or pet allergies, your air purifier should be equipped with a High Efficiency Particulate Absorbing (HEPA) filter. "These filters can remove up to 99.97% of small airborne ...