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The Air Purifier Guide

CADR Calculator for Dust Removal

Find the minimum Clean Air Delivery Rate for your room.

Dust is a complex mixture of skin flakes, fabric fibers, dust mite feces, pollen, soil particles, and microplastics. Particle sizes range from 0.5 μm (fine dust that stays airborne for hours) to 100 μm (visible dust that settles quickly).

For effective dust control, we recommend the standard 4.8 ACH. A True HEPA filter captures 99.97% of dust particles at 0.3 μm, which covers the vast majority of dust composition.

The key to dust control isn't just CADR — it's consistent filtration. Running a purifier 24/7 on low is far more effective than intermittent high-speed bursts. Dust accumulates continuously, so your filtration should be continuous too.

ACH: 5
Minimum CADR Required
240
CFM
Room: 180 sq ft · Vol: 1,440 cu ft
Dust CADR
240
CFM
Pollen CADR
240
CFM
Smoke CADR
240
CFM
🏠 Your room, to scale (top view)
180 ft² Purifier
15 ft × 12 ft floor plan · purifier placed in a corner
Filters all the air in your room per hour — about once every 15 min.
That's roughly a 17 m² bedroom-sized space.

📐 How CADR Is Calculated

Formula: CADR = (Sq Ft × Ceiling × ACH) ÷ 60

AHAM recommends ≥ 4.8 ACH. Allergies: 6 ACH. Smoke/Asthma: 8 ACH.

Recommended Air Purifiers

Based on 240 CFM minimum Smoke CADR:

✅ Next steps
Aim for an air purifier rated at least 240 CFM (smoke CADR 216 CFM) for this room.

💡 Tips for Dust

📚 Related Guides

← Back to the main CADR Calculator