Selecting an HVAC system with the right MERV rating is very important. It plays a crucial role in air filters because it defines the level of efficiency of the system in filtering the dust particles present in the air of your home.

This article will discuss selecting the proper MERV ratings for your HVAC system.

What Is The MERV Rating?

The complete form of MERV is ‘Minimum Efficiency Reporting Value.’ As the name suggests, the MERV rating defines the air filter's efficiency in filtering your house's air with each use. Each air filter got a rating based on the amount of debris it could block. This rating lies between 1 and 20, and the higher it is, the more efficient it is in cleaning your home's air.

What Is HVAC System?

HVAC represents the heating, ventilation, and air conditioning system. This system uses various technologies to control an enclosed place's temperature, humidity, and air. This system helps in keeping your house warm during winters and cool and fresh during summers.

Over the years, the technology in HVAC systems has advanced a lot.

How Are MERV Ratings Determined?

The MERV rating of an HVAC system is determined based on how well it can block particles of debris of different sizes. In deciding the MERV rating, twelve particles of various sizes are tested, ranging from 0.3-10 micrometres in diameter. These particles are divided into three categories:
  • E1 – In this, particles measuring between 0.3 to 1.0 micrometres in diameter are grouped.
  • E2 – In this, particles measuring between 1.0 to 3.0 micrometres in diameter are grouped.
  • E3 – In this, particles measuring between 3.0 to 10.0 micrometres in diameter are grouped.
In the process of testing, particles are carefully counted. After that, they are these particles. Then, they are sprayed through the filter for testing. After that, particles that can move to the other side are counted again. To determine the MERV rating of the filter, it must go through 6 tests of particles of each size and category, which means a filter must go through 72 tests to decide the MERV rating. After the end of the test, each category's worst score is used to determine the filter's rating. But sometimes, a filter can work more efficiently than the rating suggests, but the MERV rating is genuine because it reflects the minimum capacity of a product filter.

What Is The Right MERV Rating For A Home?

Selecting an HVAC system with the right MERV rating for the home is essential. The higher the score a filter gets on the MERV test, the higher it is efficient in cleaning the particles from home. But it does not mean that the filter with the highest MERV rating is suitable for your home. The filters with high MERV ratings, i.e., between 16 to 20, are used in places that require a completely sterile environment, like nuclear power plants, hospitals, etc. Therefore, these filters benefit the medical domain and some specific industries, not the home. In addition, these filters are very thick, which can cause pressure drops when used with air conditioning systems in homes.

To avoid the effects of pressure drop, the right MERV rating for your home's HVAC system should be between 5 to 13.


MERV rating of filters is very beneficial for investing in the right HVAC system for your home. So, always check whether the filter of your HVAC system stands in the standard rating of filters or not before buying.