Does MERV Rating Affect Airflow?

Using a furnace filter prevents a buildup of dust, hair, and other particles from entering the blower fan. Better indoor air quality is preferred since dust and other pollutants are less likely to be recirculated. If you're wondering if the MERV rating of your filter affects airflow, here's a reliable answer we gathered after research. 

MERV ratings can influence your home's indoor air quality, the amount of energy you consume, and the health of your HVAC system. Poor airflow and reduced efficiency and performance may occur if your filter is too unclean. Filter manufacturers use the MERV rating method to measure their resistance.

Now that you know the importance of MERV ratings, there are questions you may have in mind. What does MERV mean exactly? What is the right MERV rating for a residential space etc.? Hang on and keep reading as we will talk about these in details. 

Technician checking a Medium -filter of air handling unit for replacement a new filter , Does MERV Rating Affect Airflow?

What Does MERV Rating Mean? 

Changing the Old, used and dirty air purifier filter with pollutants and dust particles with a new HEPA filter for clean and fresh indoor air.

An air filter's MERV (Minimum Effectiveness Reporting Value) is a method for determining a filter's effectiveness in trapping various-sized particles.

It tells you how well an air filter removes pollutants from the air in your house when it is installed. MERV was created by the American Society of Heating and Refrigerating Engineers ASHRAE.

How Does MERV Rating Affect Airflow? 

Higher-MERV filters tend to slow down airflow more. The size of the filter and the kind of blower motor in your heating and cooling system are other important considerations. Attention is paid to the filter's ability to remove particles from the air and clean it. However, adding a filter creates a barrier that might reduce airflow.

Using more powerful filters, however, raises the possibility of poor airflow. It's a given that a thicker air filter will lower the amount of air moving through your heating and air-conditioning system. Most homeowners, however, fail to account for the reduced airflow that comes with using a high MERV filter.

Will a Higher MERV Filter Affect My Airflow? 

White air purifier placed in the living room inside a house with copy space. Home pollution control and air purification system to remove air borne pollutants.

The greater the MERV rating, the less airflow there is. There will be many references to airflow while looking at HVAC systems. This is because it is critical to the efficiency and lifespan of your furnace and air handler. Comfortable living requires enough airflow.

The higher the MERV rating, the more work your furnace will have to do, and the more sensitive it will be to damage. In addition, you may not obtain the air velocity necessary to reach all regions of your house, resulting in temperature discrepancies.

MERV ratings vary from 1 to 20. The lower the MERV ratings, the greater the number of particles filtered out by the system. Hospital-level air quality requires a MERV rating of 13 to 16, which is unlikely to be needed in your home.

The degree of filtration you need will determine the MERV grade you choose from the range of 7 to 13. Like a 7 or 8, lower filters will save you money on your utility cost if no one in your household has any respiratory problems.

Disadvantages of High MERV Filter

Filters with a higher MERV rating are more resistant to clogging. Increasing the resistance may increase a more significant pressure drop across the filter. The furnace or air handler's blower is rated for a specific pressure drop.

When the pressure of the duct system (ventilation system) rises, the blower may have to work harder and use more energy. Interestingly, this occurs more often with ECM blower motors than PSC motors, despite lower efficiency. (ECM is for an electrically commutated motor, while PSC stands for a permanently split capacitor.)

This leads to the second issue, decreased air movement. When the filter uses up a system's rated pressure drops and half of that, you won't be able to receive the amount of airflow the system was meant to provide.

Reduced comfort is one of the side effects of insufficient airflow. Your system may not be able to provide adequate heating or cooling in the hottest or coldest conditions. Alternatively, it might be simply a few unpleasant rooms.

In addition, a lack of airflow might cause the air conditioner's coil to freeze up. As a result, the airflow is reduced, and the coil becomes increasingly colder until it is reduced to a block of ice. As a result, if the refrigerant doesn't evaporate, it returns to the compressor in the liquid condition, which might cause damage.

Is MERV 13 Too High For Residential? 

In terms of household usage, MERV 13 air filters are the best. Using an air filter with a rating greater than 13 can cause your HVAC system to malfunction, resulting in additional costs to repair it.

The MERV scale ranges from 1 to 20, with filters in medical facilities such as hospitals having a MERV rating of 20 or higher. Even though the MERV rating might go as high as 13, you should avoid going higher in your house.

Will MERV 12 Hurt My Furnace? 

Even though it is an expensive appliance designed to last for decades, a furnace still requires regular maintenance to ensure it performs as intended. Regular air filter replacement is part of this. You should also check the MERV rating of the filters you use.

If you suffer from seasonal allergies, investing in a MERV 10–12 filter might help alleviate your discomfort. If you do not obtain a filter with a higher MERV rating, pollen, pet dander, and fine dust could get through.

Most allergens may be removed from the air in your house with a MERV filter grade of 10 to 12. The phrase "allergy" or "allergen" will appear on the box of most air filters capable of removing common allergens. 

For the best indoor air quality, the EPA recommends MERV values between 9 and 12. Particulates as fine as 1 micron may be kept out of your HVAC system using a filter with this grade. This level of HEPA (high-efficiency particulate absorption) qualifies as a HEPA-certified filter.

A MERV 12 could be perfect for your usage in terms of the most crucial factors like price, compatibility with the environment, efficiency, and airflow.

DO MERV 11 Filters Restrict Airflow? 

A MERV 11 air filter is adequate. This is because it can remove more contaminants from the air and catch finer particles. There is no better or worse way to protect your home's air quality than using an air filter with an appropriately-low MERV rating. MERV-rated air filters can filter more.

However, the thickness of the filter material may limit airflow. As a result, reduced airflow may decrease comfort, increase energy consumption, and speed up component wear and tear. High-MERV filters may harm the compressor, heat exchanger, and condenser coil in air conditioners.

In most circumstances, a MERV 11 air filter is not too high for home usage. Anything below a MERV 13 air filter, in general, should offer excellent air filtration in a house without hindering airflow in any significant way. Air filters rated MERV 14 or above are built to handle thicker filter material for commercial HVAC systems.

Are MERV 14 Filters Bad For HVAC? 

Air freshener, air cleaner device. Fresh air in the house.

HVAC systems in most homes cannot handle MERV 14. HVAC systems in most homes are not rated to bear the stress of a MERV 14 rating. The tighter the filter is on MERV 14, the more power your HVAC system needs to use to keep it in place.

To put it simply, you're effectively shutting down your HVAC system using a filter that has smaller holes than suggested (e.g., the 14-MERV rating) and comes up as a pricey option. If you are considering purchasing a MERV 14, it is recommended that you go with a MERV 13 instead.

When it comes to air filters, every system, every house, and every person's requirements for air quality are going to be unique. You should ask yourself whether the filter you are now using is effective at performing what you need it to accomplish: removing dust and irritants from the air to preserve your HVAC system and your family's health. 

If it is not, read over the filter recommendations provided by the HVAC manufacturer. A good number are offered on their websites that provide customer care. The cost of air filters is also essential, but in the long term, you will save a lot of money if you use high-quality air filters to keep the air in your home clean.


The air filter unit, which is covered with an aluminum mesh, is placed on the green epoxy floor in the clean room to filter the exhaust air in the room.

Depending on the type of filter, air filters should be updated monthly, quarterly, or semiannually. Your air filter will become more restrictive and less effective if you don't replace it as directed by the manufacturer.

For more articles on MERV and air filters, check out these engaging articles: 

How Big Is a HEPA Filter? 

Can You Wash and Reuse HEPA Filters?

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