Understanding MERV Ratings for Air Filters cover image

Understanding MERV Ratings for Air Filters

Kaitlyn ColliganKaitlyn Colligan avatar

Kaitlyn Colligan

4 minute read

When it comes to maintaining clean and healthy indoor air quality, choosing the right air filter is crucial. Air filters remove pollutants, allergens, and other harmful particles that may affect human health and comfort. But with a wide range of options available, how do you determine which filter is best suited for your specific needs? This is where MERV ratings come into play. MERV ratings provide a standardized measurement to assess the performance and efficiency of air filters. Understanding the significance of MERV ratings is essential to helping you make informed decisions when selecting air filters. Join us as we explore the world of air filtration efficiency and take control of the air you breathe.

What is a MERV Rating?

MERV stands for Minimum Efficiency Reporting Value, which is a rating system that measures the effectiveness of air filters. The rating system was developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE).

MERV ratings range from 1 to 20, with a higher number indicating a higher level of filtration and ability to capture smaller particles. MERV ratings are based on three fundamental factors: particle size range, particle capture efficiency, and resistance to airflow.

Particle Size Range:

MERV ratings for air filters indicate the size range of particles that the filter can capture. Particles include dust, pollen, mold spores, pet dander, and bacteria. The higher the MERV rating, the smaller the particle size that the filter can capture.

Particle Capture Efficiency:

MERV ratings also measure the filter's ability to capture particles efficiently. A higher MERV rating means that the filter can remove a higher percentage of particles that pass through it.

Resistance to Airflow:

MERV ratings take into account the filter's resistance to airflow. A filter's resistance to airflow is measured by testing the pressure drop across the filter. The higher the resistance to airflow, the harder the HVAC system has to work to move air through the filter.

Choosing the Right MERV Rating

Selecting the right air filter with the appropriate MERV rating is crucial to improving indoor air quality. The MERV rating should be selected based on the specific needs of the indoor environment, including the following factors:

Pollutant Level:

The MERV rating should be selected based on the level of pollutants in the indoor environment. In highly polluted environments such as manufacturing facilities, hospitals, and laboratories, higher MERV ratings are needed to keep the indoor air quality at desirable levels.

Allergen Sensitivity:

For individuals with allergies, asthma, and other respiratory problems, filters with a higher MERV rating are recommended to reduce the amount of allergens in the indoor air.

HVAC System Capacity:

The MERV rating should be selected based on the capacity of the HVAC system. Higher MERV rated filters have higher resistance to airflow, which may cause strain on the HVAC system, reducing its efficiency. It is essential to choose a filter that does not exceed the HVAC system capacity.

MERV Rating Scale

Below is a scale indicating the particle size ranges and typical applications for different MERV ratings:

  1. MERV 1-4: Filters human hair, carpet fibers, and other large particles. Ideal for residential use.
  2. MERV 5-8: Filters mold spores, cement dust, and animal dander. Ideal for residential, commercial, and light industrial use.
  3. MERV 9-12: Filters fine dust, auto emissions, and smoke. Ideal for commercial and industrial use.
  4. MERV 13-16: Filters lead dust, bacteria, and virus carriers. Ideal for healthcare facilities, clean rooms, and other critical environments.
  5. MERV 17-20: Highly efficient filters for removing small particles. Ideal for applications that require the highest level of indoor air quality, including semiconductor manufacturing and pharmaceutical production.

MERV ratings are an essential factor when selecting air filters for maintaining indoor air quality. Understanding the rating system and selecting the right MERV rating based on the specific needs of your indoor environment can help improve indoor air quality, reduce allergies, and create a healthy environment. When selecting air filters, it is important to consider the particle size range, particle capture efficiency, and resistance to airflow to ensure that the filter is effective, efficient, and compatible with the HVAC system. If you’re unsure which MERV rating is the correct choice for your environment, let us know! Our filtration experts will be happy to help!

Unveiling the Power of Melt-Blown Filter Cartridges

Previous Post

Exploring the Differences Between Pleated and Depth Filter Cartridges

Next Post