First, measure the square footage of the room so you know what size air purifier to look for. An undersized air purifier won’t clean a large room effectively, and an oversized air purifier will cost more money to purchase and use.
Next, consider the filter. We recommend a true HEPA filtration system. If you’re also concerned about cigarette smoke or pet odor, look for an air cleaner with an activated carbon pre-filter. Each of our top picks features both a true HEPA filter and an activated carbon filter.
If you have a very specific need, such as filtering out wildfire smoke particles, look up the clean air delivery rate (CADR) for that pollutant. Air cleaners have three CADRs:
- Smoke CADR
- Pollen CADR
- Dust CADR
A higher number is better.
Next, consider how much energy the air purifier uses each year. Air purifiers stay on all the time, which increases your electricity bill. Energy is measured in kilowatt-hours (kWh), and a lower number is better.
Prioritize a unit’s portability if you anticipate bringing it with you on vacation or moving it from room to room. Size, weight, and casters can make a big difference.