What is the difference between MERV 13 and 14?

Author: Stephen Lang  |  Last update: Friday, June 20, 2025

ASHRAE currently recommends using a minimum MERV 13 filter, which is at least 85% efficient at capturing particles in 1 µm to 3 µm size range. A MERV 14 filter is at least 90% efficient at capturing those same particles.

Is MERV 14 better than Merv 13?

MERV 13 will prevent less than 75% of the 0.3-1.0 micron particles from passing through, MERV 14 will get up to 84%, MERV 15 up to 94% and MERV 16 can trap 95% or more of the smallest particles.

Is MERV 14 too high for residential?

The abbreviation stands for Minimum Effective Reporting Value. In other words, it's a measurement showing how small the holes are in the filter. The higher the MERV number, the smaller the holes, and the less that can pass through. Ultimately, this is what makes MERV 14 filters not a good choice for home use.

Is Merv 13 too high for a home?

The MERV rating system goes from 1 to 20, the highest (20) being the rating used for filters in places such as hospitals. So while the MERV rating does go above 13, it will be best to stray from going any higher in your home. People that should consider using the MERV 13 filter include those with: A newborn baby.

Do you really need a Merv 13 filter?

If you need to remove large particles from the air, such as dust or pollen, then a MERV 13 filter is a good option. If you need to remove small particles from the air, such as viruses or bacteria, then a MERV 14 or MERV 16 filter is a good option.

You're Probably Using The Wrong Air Filter In Your Home. -HVAC Merv Ratings Explained-

Does Merv 13 restrict airflow?

MERV 13 filters can trap more contaminants than MERV 8 filters, but they are more costly and can restrict airflow to the point that they are incompatible with some HVAC systems.

Is there a downside to high MERV filters?

High-MERV filters increase the static pressure of your system, and if the ductwork is already marginal, this can cause the airflow to drop to a level where the temperature exceeds the furnace's limit.

What MERV rating is best for airflow?

For most homes, a rating of MERV 8-13 is a good start to keep your air healthy.

How often should I replace my Merv 13 filter?

MERV 13 filters typically need to be changed every three to six months. However, the frequency with which you need to change your filter depends on a number of factors, including: The type / brand of filter you're using. The size of your HVAC system.

Do better air filters make AC work harder?

Air filters with higher efficiency ratings may do a better job clearing the air. Still, they'll also force your HVAC system to work harder, resulting in performance challenges and higher energy bills.

What MERV rating is too restrictive?

The MERV 11 air filter is the wrong choice for people who do not own pets and do not have any breathing trouble; this is because it can lead to restricted airflow. Air filters with higher ratings can also have negative effects on HVAC components.

Will MERV 13 stop mold?

A MERV 13 rating has a high level of filtration. It's able to catch small particles. Even microns as small as 0.3 to 1.0. A MERV 13 filter catches dust, pollen, mold, bacteria and viruses.

How long do MERV 14 filters last?

MERV 13 - 16

The MERV scale stops at 16 so this is the most efficient you can get outside of a HEPA filter. These filters have a lot of stopping power so they will catch the most amount of pollutants and allergens in your HVAC system. These filters are recommended to be changed every year.

Does CDC recommend MERV 13 filters?

ASHRAE has similar guidance, which is to "use combinations of filters and air cleaners that achieve MERV 13 or better levels of performance for air recirculated by HVAC systems." The simplest way to meet this guidance is to use a MERV 13 filter in your appropriately-designed HVAC system, if the system is able to ...

What MERV number should I buy?

In general, the best MERV rating for a home is somewhere between 8-10. These filters will capture a large portion of the airborne particles and improve indoor air quality without making your energy costs rise significantly.

Will MERV 14 filter smoke?

MERV Rating 14-20

These filters offer the highest level of filtration and are not usually needed for regular homes and businesses. An air filter with a MERV rating of 14-20 can remove smoke, bacteria, carbon dust, and viruses from the air. Highly rated filters like these are often used for hospitals and laboratories.

Is MERV 14 better than 13?

A: Our current recommendation is to use a filter with a Minimum Efficiency Reporting Value (MERV) of 13, but a MERV 14 (or better) filter Is preferred. Of course, the ultimate choice needs to take the capabilities of the HVAC systems into consideration.

What does mold on an air filter look like?

Though the appearance of mold will vary depending on what type it is, it shouldn't be too hard to identify. Watch for green, yellow, black, or white stains developing on your AC system's walls and air filter that display a fuzzy, velvety texture.

What is one disadvantage of the highest MERV rated filters?

One disadvantage of the highest MERV rated filters is that: The pressure drop across high MERV filters is more.

What MERV can my AC handle?

These high-quality filters trap particles as small as one micron, including Legionella and humidifier dust. MERV 9 to 12 filters are the best filters that a residential HVAC system will accommodate without serious system modifications.

What MERV rating is considered a HEPA filter?

All HEPA filters have a rating of a MERV 17 or higher. A HEPA filter with a MERV 17 rating will trap 99.97% of air particles that are 0.3-1.0 micron in size and an even better % of particles below 0.3 microns and above (HEPA filters are rated at their worst performance).

Do you want a higher or lower MERV rating?

What MERV rating you choose between 7 and 13 depends on what level of filtration you require. If your family has allergies or asthma, a higher MERV rating will be good for you. If your family doesn't suffer from any breathing difficulties, a lower filter like a 7 will save you some money on your energy bill.

What MERV rating are throw away filters?

1“ Throw Away Filter

1” throw away filters are typically a MERV 2 rating. Most Bard products can use either a 1” throw away or a 2” throw away filter. Upgrading from a 1” filter to a 2” filter will give you a higher filtration value. Remember to reference your manual for what your Bard product is capable of handling.

Is MERV 13 too restrictive?

A MERV rating between 8 and 13 for most households provides a good balance, offering adequate filtration to improve air quality without significantly impacting system performance. Consult your HVAC manufacturer's recommendations to ensure you choose the most suitable filter for your home.

What is the highest residential MERV rating?

Well, MERV ratings range from 1 to 20, with 1 being the lowest level of filtration, and 20 being the highest. Filters that are MERV 16 through 20 are usually only found in hospitals, cleanrooms, and nuclear power plants. The home air filters you're looking for have a MERV rating anywhere between MERV 5 and 13.

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