Quick answer
A filter rating; higher MERV captures smaller particles.
MERV rates how effectively an air filter captures particles, on a scale where higher numbers trap smaller particles. Most homes use MERV 8–13. A filter that's too high-MERV for the system can restrict airflow, so filtration should be matched to the equipment's capacity.
Why MERV matters
Indoor-air terms connect comfort to health-related basics like filtration, humidity, and ventilation. The right solution depends on airflow and the whole HVAC system, not just one add-on product.
When you'll see this term
You will usually hear this term when discussing dust, allergies, humidity, odors, ventilation, filters, and whole-home indoor-air upgrades.
Questions to ask your technician
- Will this improve air quality without restricting airflow?
- Does my current system support this upgrade?
- How should it be maintained after installation?
Go deeper
Indoor air quality basics