MERV — Minimum Efficiency Reporting Value — rates how well a filter captures particles, on a scale of 1 to 20. Here's what it means and why 13 is the number you want.
681 m³/h CADR, MERV-13, under 35 dB — powerful whole-home clean air — no proprietary lock-in, ships from the UK.
Check price →Use code CORSI10 for 10% off at checkout.The scale
Low MERV (1–8) catches only large dust and lint. Mid MERV (9–12) starts capturing finer particles. MERV-13 captures around 93% of airborne particles including PM2.5, pollen and smoke — the public-health sweet spot. Above 16 you're into HEPA territory, denser and airflow-throttling.
Why MERV-13 for a CR box
It's the best balance of capture and airflow. Higher grades resist air so much that a box fan can't push enough through; MERV-13 lets the fan move a lot of well-filtered air — the whole point of the design.
MERV-13 vs HEPA
See the full comparison in HEPA vs MERV-13.