Wildfire Smoke CADR Calculator

Tecnobosque Interactive Smoke Tool Size clean-air delivery for wildfire smoke

Change room dimensions, target air changes and purifier capacity and watch the required clean-air delivery and purifier count update instantly.

Live CADR Room visualisation Feet & metres Purifier sizing

Interactive inputs Cleaner-air room

Results update as the room or target cleaning rate changes.

Room dimensions

Room length L

6 ft 50 ft

Room width W

6 ft 50 ft

Ceiling height H

6 ft 16 ft

Target air changes per hour ACH

ACH

1 ACH 10 ACH

Smoke CADR of one purifier CADR

cfm

50 cfm 800 cfm

Illustrative rooms

Required clean-air delivery 120 cfm 204 m³/h

8 ft ceiling

AIR
CLEANER × 1

15 ft 12 ft

5.0 ACH

Target air-change rate

Room volume 1,440 ft³

Purifiers required 1 purifier

ACH from one purifier 10.4 ACH

ACH with required units 10.4 ACH

1,440 ft³ × 5 ACH ÷ 60 = 120 cfm

Method Clean-air delivery from room volume

V = room volume

ACH = target air changes per hour

CADR = required clean-air delivery rate

CADR = V × ACH ÷ 60

Size an air cleaner for the room

Clean Air Delivery Rate represents the volume of filtered air delivered over time. A larger room or a higher target air-change rate requires more clean-air delivery.

When a manufacturer provides separate CADR values for smoke, dust and pollen, use the smoke CADR for wildfire-smoke particle planning.

Why the number of purifiers changes

The tool divides the calculated clean-air requirement by the smoke CADR entered for one purifier and rounds upward to the next whole unit. It also shows the resulting theoretical ACH from that number of purifiers.

Important limitation

Important: this is an educational planning calculator. Actual indoor smoke conditions depend on outdoor smoke, building leakage, ventilation, filter condition, purifier placement, fan speed and room mixing. Follow official public-health and emergency guidance during wildfire smoke events.