What is CADR?
CADR (Clean Air Delivery Rate) measures how much clean air a purifier delivers, typically for smoke, dust, and pollen. A higher CADR means the unit can clean a larger space faster. CADR tells you throughput; room size tells you how much air there is to clean — you need to match the two.What is ACH (air changes per hour)?
ACH is how many times a purifier can filter the entire volume of air in a room each hour. For general air quality, around 4–5 ACH is a good target; for allergy or asthma sensitivity, higher is better. More air changes means cleaner, more consistently filtered air.How does the AirPro’s coverage translate?
The AirPro is rated to clean about 430 sq ft in 10 minutes and 1,200 sq ft in 30 minutes with its 360-degree airflow. A complete cleaning every 10 minutes for a 430 sq ft room works out to roughly 6 air changes per hour for that space — comfortably above the general target. In a larger open area it still delivers strong, if slower, turnover.How do I size a unit to my room?
- Measure the room’s square footage.
- Match it to the purifier’s rated coverage with a little margin to spare.
- For sensitive users, choose a unit rated for a larger room than yours so it delivers more air changes.
- For rooms over the rated coverage or multiple rooms, use more than one unit — doors and walls block airflow between rooms. See multi-unit recommendations.
Why does placement affect real-world performance?
Even a well-sized unit underperforms if airflow is blocked. Keep 6–12 inches of clearance around the intake, avoid tucking it in tight corners, and elevate it toward your breathing zone where possible — full guidance is on the room coverage page.Manufacturer coverage figures assume an empty room and ideal placement. In a furnished room with normal activity, give yourself extra capacity for the best real-world results, and run the unit continuously rather than in short bursts.