What Is MERV & How Does It Work: An In-Depth Guide

The MERV (Minimum Efficiency Reporting Value) scale measures a filter’s ability to capture and remove particles from the air. It is one of the most important features to consider when shopping for your home or business furnace filters. But what does MERV mean, and how does it work? Let’s take a look.

Understanding MERV Ratings

The MERV rating system is a way of measuring filter efficiency in terms of the size of particles that can be removed from the air. MERV ranges from 1 to 16 and is determined by testing the filter. Filters with higher MERV ratings are more effective in trapping particles.

  • MERV 1-4: These filters are not generally used in residential or commercial HVAC (heating, ventilation, and air conditioning) systems but may be used in clean rooms or other industrial applications. They are designed to capture larger particles, such as pollen and dust mites.
  • MERV 5-8: These filters are designed to trap small particles that may be present in the air, such as mould spores, pollen, and dust. They are used in residential and commercial HVAC systems to improve air quality and reduce the amount of allergens and pollutants in a living or working space.
  • MERV 9-12: These filters are designed for use in areas where air quality is very important, such as medical facilities. They provide a higher level of filtration than lower-grade filters, helping to capture smoke, bacteria, and other harmful airborne particles. This helps ensure the air is clean and safe for people to breathe.
  • MERV 13-16: These filters are perfect for places that need extra protection from tiny particles. They are especially beneficial in places where potentially hazardous particles may be present, such as clean rooms or areas with hazardous materials. They can capture the smallest particles and provide an additional layer of safety.

How Does MERV Work?

MERV ratings measure filter efficiency on a particle size scale, meaning the higher the rating, the smaller the particles the filter can capture. The filter works by trapping particles in its fibres. As air passes through the furnace filter, particles smaller than the filter’s opening are trapped in the filter material. The higher the MERV rating, the more efficient the filter is at trapping particles.

The Benefits of High-Efficiency Filters

High-efficiency filters like MERV filters can help keep your home or business clean and healthy. Trapping particles in the filter material help keep the air you breathe clean. In addition, filters with higher MERV ratings can help improve the efficiency of your HVAC system by preventing clogs and reducing the amount of dust and debris that accumulates in the system.


MERV is a measure of the efficiency of air filters. It determines how well the filter can capture and remove particles from the air, with higher MERV ratings indicating more efficient filters. High-efficiency furnace filters, such as those with higher MERV ratings, can help keep the air in your home or business clean and help improve HVAC system efficiency.

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