Filters are a little-seen but very important part of your home’s HVAC (heating, ventilation and air conditioning) system. Filters help your furnace and air conditioner run at their best and most efficient while keeping your indoor air clean and free of dust, pollen, and other particles that can irritate asthma and allergies.

By using a filter that has a high MERV (Minimum Efficiency Reporting Value) rating, you can keep your air even cleaner. MERV is an industry-standard rating of filter efficiency that indicates how effective a particular filter is at capturing and holding airborne particles from 0.3 to 10 microns in size. To give you an idea of scale, human hairs are often between 40 to 300 microns wide.

Filters with high MERV ratings remove smaller contaminants from your air, such as bacteria, viruses, mold spores and other microorganisms that cause disease and discomfort. MERV ratings range from 1 to 16, and the higher the rating, the more efficient a filter is at removing smaller particles from your air. A top-level MERV 16 filter, for example, traps very small particles such as bacteria, tobacco smoke, moisture droplets (such as from a sneeze) and powders. At the other end of the scale, a MERV 1 filter can handle only larger particles, such as textile and carpet fibers, larger dust particles and pollen.

Filters with a MERV rating of 1 to 4 are generally low cost, but they also are minimally effective. High-MERV filters offer the best level of filtration, and remove the greatest range of airborne contaminant types.

If you need even better filter performance, High Efficiency Particulate Air (HEPA) filters provide greater levels of filtration, at MERV levels of 17 to 20. HEPA filters are used where air quality is very important and airborne contaminants must be minimized as much as possible, such as hospitals and manufacturing clean rooms that house sensitive electronics.

Modern Mechanical is a trusted source of HVAC sales and service for customers in Northern Virginia and the neighboring areas in Maryland. We specialize in heating, air conditioning, plumbing, indoor air quality, and solar-power systems for residential customers. Contact us today for more information on HVAC filter efficiency and how filters with high MERV ratings can keep your indoor air healthier and clean all year long.