CADR Calculator for Construction & Renovation Dust
Find the minimum Clean Air Delivery Rate for your room.
Home renovation and construction generate extremely fine, hazardous dust. Drywall dust (calcium sulfate) is 1–10 μm, sawdust ranges from 1–100 μm, and silica dust from cutting tile or concrete is dangerously fine at 0.5–5 μm. These particles are not just annoying — they're a genuine health hazard.
During active renovation, dust generation is constant and heavy. Standard ACH recommendations don't apply — you need maximum air turnover. We recommend 8+ ACH during active construction, dropping to 5 ACH for the 2–4 week cleanup period afterward.
Critical: construction dust destroys filters fast. HEPA cartridges that normally last 8 months can clog in 2–4 weeks during heavy renovation. Budget for multiple filter replacements.
📐 How CADR Is Calculated
Formula: CADR = (Sq Ft × Ceiling × ACH) ÷ 60
AHAM recommends ≥ 4.8 ACH. Allergies: 6 ACH. Smoke/Asthma: 8 ACH.
Based on 240 CFM minimum Smoke CADR:
💡 Tips for Construction Dust
- ✓ Close off the renovation area with plastic sheeting to contain dust spread.
- ✓ HEPA filters clog fast during construction — check weekly and replace as needed.
- ✓ Run the purifier 24/7 during renovation, even when you're not in the room.
- ✓ For silica dust (tile cutting, concrete), use a P100 respirator in addition to air purification.