MERV Rating Comparisons – Which MERV Filter is Best?

Many people are unaware that some air filters have a MERV rating. They may see that the ones they buy at the store have a rating on them with variable numbers and may question what does the MERV rating mean? In this post, I’ll go over what MERV is as well as all of the different ratings, and for a bonus, I’ll compare different MERV ratings against each other.

What Is MERV? 

MERV (Minimum Efficiency Reporting Values) tells us about the ability of a filter to catch particles between 0.3 and 10 microns. It is simply a measure of a filter’s effectiveness and helps us compare different filters’ performances. MERV ratings range on a scale of 1 to 20. 

 MERV vs. MPR 

Minimum Efficiency Reporting Values (MERV) And MPR (microparticle performance rating) both measure the performance of a filter. But while MERV tells us about the ability of a filter to trap particles between 0.3-10 microns, MPR rates a filter’s ability to trap airborne particles between 0.3 to 1 micron. 

MERV vs. FPR 

Both MERV and FPR are similar in that they measure the performance of a filter. And while MERV is the industry standard, FPR was invented by Home depot to rate different brands of air filters in their marketplace. 

Unlike the MERV, whose scale ranges from 1 to 20, the FPR scale ranges from 1-10, with the 10^th level being equivalent to MERV’s 20th level. 

What Are the MERV Levels? 

MERV ratings or levels run from 1- 20, with 1 being the lowest and 20 being the highest in terms of performance, efficiency, and maximum filtration. 

That means a higher MERV rating corresponds to a greater percentage of particles captured on each pass. 

Generally, the higher the MERV of a filter, the better it is at catching specific types of particles. 

However, it must be well noted that higher MERV is not always suitable for your HVAC system. Using a filter with a higher MERV than the manufacturer’s recommended can bring more harm than good. This is because the smaller pores on the filters can restrict airflow, and this can cause the HVAC system to overwork. 

Below is a quick overview of the MERV levels and what each is ideal for. 

From the table, MERV 4 is grouped in the lower part of the scale. This filter rating provides the minimum filtration level and is commonly used for residential purposes in air conditioning.  

That said, fiberglass or synthetic panel filters are made of aluminum mesh, making it a washable type. They are also electrostatic, meaning they are self-charging woven panel filters. 

MERV4 filter can filter particles such as 

• Pollen 
• Dust mite 
• Sanding dust 
• Spray paint dust 
• Textile fibers 
• Carpet fibers 

What is MERV 6? 

From the MERV rating scale, MERV 6 is in the second quarter of the rating scale. If you want to decide on which filter to use, MERV 6 can provide above-average protection compared to ordinary fiberglass air filters. 

Even though MERV 6 is not recommended for allergy or asthma sufferers, this grade filter is eight times more efficient than ordinary glass fiber filters. Filters with this rating should be able to capture large particles like allergens, dirt, debris, mold, and dust mites. It has a dust spot efficiency of up to 20%. 

It is sufficient to catch out harmful pollutants from your household air. Merv 6 air filters come with advantages and disadvantages. Let’s look at these. 

Advantages of MERV 6 

Relatively cheaper compared to other filters with a higher MERV rating. 

Effective at filtering out dust and other pollutants from the hair 

Disadvantages of MERV 6 

• They need to be regularly changed to ensure that trapped articles do not affect the operation of the HVAC system. 
• They are not capable of removing many other smaller unwanted substances from the air, especially for people with allergies such as those with asthma. 
• They do not remove catch virus carriers.
• This type of filter is ideal for use only when there is no serious need to tackle allergy triggers.

More uses of MERV 6 filter include: 

• Homes (residential buildings) 
• Commercial Buildings 
• Paint Booth Inlets 
• Industrial Workplaces 

What is MERV 8?

If you are looking for something that does more than just improve air quality, MERV 8 filters do that job. These are about 20 times more efficient than regular glass fiber filters and with a dust spot efficiency of 30-35%. They are also more efficient than a MERV 6 filter. 

Their applications include commercial buildings, residential, industrial workplaces, and paint booth inlets. 

MERV 8 filter can catch many other particles, including the following:

• Hair spray
• Pudding mid 
• Textile/carpet fibers 
• Mold/spores 
• Dust lint 
• Cement dust 

What Is MERV 11?

In general, MERV 11 is more efficient than any filter with a lower MERV rating. This filter grade is ideal for superior residential use and improves air quality. This filter is 30 times more efficient than any regular fiberglass filter. 

In addition, it has a dust spot efficiency of up to 65%. MERV 11 can also catch up t0 85% of particles of size 3-10 microns. 

Particles that MERV 11 filter can catch include the following: 

• Legionella 
• Lead dust 
• Humidifier dust 
• Coal dust 
• Nebulizer dust 

These filters are also used in hospital settings. They are more expensive than MERV-8 and MERV-6 but are also commonly used in premium homes.   

What is MERV 13? 

Merv 13 provides even more protection against many smaller particles, including bacteria and some viruses.  This level filter is ideal for people with breathing problems or asthma. But before you consider going for this level filter, check the specifications on your HVAC system. 

While upgrading to a higher-rated filter could give you better quality and more protection from many bacteria and viruses, that is not always the case. Sometimes installing a higher MERV filter on an older system could strain the system. If MERV 13 is compatible with your system, the better; just make sure that the filter is correctly installed. 

Some particles that MERV 13 catches include the following:

• Tobacco smoke 
• Auto fumes 
• Sneeze nuclei 
• Insecticide dust 
• Copier toner 
• Pet dander 
• Face powder 

Some of the uses of the MERV 13 filter include the following: 

• In Hospitals, they are used in general surgery 
• They are also used in hospital inpatient care 
• Commercial buildings 

What Is MERV 16-20? 

MERV 16- 20 filters are in the upper quarter of the MERV rating scale. This means that anything in this range has the highest performance among all other MERV Filters. Filters with these ratings are primarily used in general surgeries and hospital inpatient care. On top of that, these are above 95% dust spot efficient. 

MERV 6 vs MERV 8 

MERV 6 vs MERV 13 

MERV 6 vs MERV 11 

MERV 8 vs MERV 11 

MERV 8 vs MERV 13 

MERV 8 vs MERV 12 

MERV 11 vs MERV 13 

MERV 11 vs MERV 12 

MERV 11 vs MERV 16 

What Is the Highest MERV Rating?

MERV ratings run on a scale from 1-20. The current highest MERV rating is 20. With this maximum MERV, a filter can catch the following particles which no other filter can catch.    

• Virus carriers 
• Carbon dust 
• Sea salt 
• Combustion smoke 
• Radon progeny 
• Odor 
• Microscopic allergens 

The MERV 20 filter is the final rating on the scale and has several critical uses. Its uses include cleanrooms and radioactive materials. It’s also used in Pharmaceutical Manufacturing Facilities. 

In hospitals, the MERV 20 is also used in Orthopedic Surgery Rooms. 

What is The Recommended MERV rating for an air filter for households? 

If you ask yourself, which is the recommended air filter for households?’ Well, there is no one specific recommended MERV-rated filter for households. This is because needs will differ from one household to another. So, if you are considering getting a filter, consider your needs first. 

·         If you want a filter that can just improve the quality of your indoor air, MERV 8 is sufficient. But not enough to combat asthma triggers, pet dander, and many other smaller particles.

·         On the other hand, if you want something to help with allergens or help with breathing problems for people who are asthmatic, then you might want to get something with a higher MERV rating, such as 13 MERV.   

MERV vs HEPA – which is better? 

When it comes to comparing which filter is better between a MERV and HEPA, it depends on the rating of an individual MERV filter. Generally, a HEPA is considered a preferred choice in many cases because of its ability to catch up to 99.97% of particles that are 0.3-1 micron in size. 

The performance of a HEPA filter is equivalent to MERV 17 filter. So, a HEPA can be a good choice if you have an older HVAC system in that A MERV 17 filter can put a strain on the system due to their more ‘air restrictive design. On the other hand, the HEPA filter can come as a standalone filter with its own fan specifically designed to improve the resistance of this type of filter. 

Tim David

HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.