Air purifier size calculator
Enter your room dimensions and use. We'll work out the clean-air delivery rate (CADR) you need and the right AIRE model — the same method our engineers use.
Uses air-changes-per-hour (ACH) — the standard way to size clean-air delivery. Estimates are a guide; we'll confirm for your exact rooms.
Room volume 108 m³ × 5 air changes/hour
Classic 400S
Covers 31–54 m² at 480 m³/h — ideal for clinic waiting rooms and offices.
View this modelHow the calculation works
Air-purifier sizing is based on air changes per hour (ACH) — how many times the unit can replace all the air in a room each hour. The formula is simple:
Recommended targets: homes 3–4 ACH, offices 4–5 ACH, clinics 5+ ACH, and dental / procedure rooms 6+ ACH because of aerosol generation. If one unit can't meet the required CADR, use two smaller units rather than one under-sized purifier. For the full method — including certifications and costs — see our clinic buyer's guide.