There is no denying that every person out there requires healthy air to breathe, whether indoors or outdoors. So, while we cannot directly make the outdoor air clean, we always have air filters that can help us breathe healthy and fresh air indoors.
When it comes to air filters, various factors affect their Efficiency. MERV or Minimum Efficiency Reporting Value is one such important factor that determines your air filter’s effectiveness.
So, read on to know everything related to MERV rating and which one to use.
What MERV Rating Should I Use?
If you are going for an air filter, you should always ensure that it has a MERV rating above 8, be it for residential or commercial use.
Air filters, having a MERV rating above 8, can help filter out most of the pollutants from your home. Thus, helping you breathe only healthy and purified air.
What is a MERV Rating?
As you know which MERV rating you should go for, you might also want to know a MERV rating and its significance?
MERV, which also stands for Minimum Efficiency Reporting Value, is an evaluating system developed by the American Society of Heating, Cooling, and Air-Conditioning Engineers.
The MERV system helps in gauging an air filter’s performance by rating its Efficiency in filtering out particles of different sizes.
Hence, keep in mind that the higher is the MERV rating of an air filter, the higher is its filtering capabilities.
How Does the MERV Rating System Work?
A MERV rating system works in a highly systematic manner. First of all, the MERV system consists of 20 ratings, namely from 1 to 20. Out of these, 1 is the lowest air filtering rating, whereas 20 is the highest.
Moreover, most of the air filters you’ll find for home use have a MERV rating between 5 and 13. Yet, as mentioned above, it is always a good idea to opt for one having a rating of at least 8.
So, how exactly do air filters get their MERV ratings? The answer is – based on their filtering capabilities depending on the particle size.
To answer it more clearly, there are particles present in the environment having
different sizes. Now, in the laboratory, an air filter has to go through six different tests. In each test, the before and after particles are counted.
Once the before and after observations are made, the difference between them is converted into a percentage. The lowest or the minimum percentage of all the six tests is taken as the official MERV rating. Hence, the term ‘minimum’ is used with ERV.
What Is the Benefit of Using the MERV Rating?
The MERV rating of an air filter is essential as well as beneficial due to the below main reasons:
Understanding the Efficiency of an Air Filter
As mentioned earlier, the MERV rating of any air filter talks about its Efficiency of filtering out particles having different sizes.
So, if you know the MERV rating of a particular air filter, you can get to know whether it is efficient enough or not.
Comparing Different Air Filters
If you search for an air filter, you will probably find plenty of them available in the market today. So, how will you come to know which one is well-suited for you? Well, with the help of a MERV rating.
When you know the MERV rating of air filters, you can compare them and their effectiveness. This will help you make a well-informed choice.
Categorize Different Air Filters
Depending on the MERV rating, you can differentiate between air filters – whether for residential use, office use, or medical use.
For instance, air filters having MERV between 5 and 13 are suitable for home use. On the other hand, those having ratings between 16 and 20 are mainly for clinics, hospitals, and power plants, like nuclear power plants.
So, MERV ratings can help you figure that out as well.
MERV Minimum Particle Size
Different MERV-rated air filters have a range of particle sizes that they can filter out, along with percentages. Given below is a tabulated form that will help you get a clear idea.
|MERV Rating||Filtered Particle Size (in microns) and Minimum Particles Removed (in percentage)|
|1 to 4||3.0 microns to 10.0 microns (< 20%)|
|6||3.0 microns to 10.0 microns (around 49.9%)|
|8||3.0 microns to 10.0 microns (around 84.9%)|
|10||1.0 microns to 3.0 microns (50% to 64.9%)
3.0 microns to 10.0 microns (> 85%)
|12||1.0 microns to 3.0 microns (80% to 89.9%)
3.0 microns to 10.0 microns (> 90%)
|14||0.3 microns to 1.0 (75% to 84%)
1.0 microns to 3.0 (> 90%)
|16||0.3 microns to 1.0 (> 75%)|
Is Higher or Lower MERV Better?
If you are still unsure which MERV rating is better – the higher or, the lower one, let’s make it a bit clearer.
The MERV rating of your air filter signifies its Efficiency in filtering particles of different sizes. So, the higher the MERV rating, the more your air filter can filter out particles.
Hence, a higher MERV denotes a higher capability in filtering out particles. So, a higher MERV is much better than a lower one.
Why Should You Choose a MERV Rating of 8 or Higher?
It is always suggested to go for an air filter having a MERV rating of at least 8 or higher.
Air filters having a MERV rating of 8 or more can filter out quite many particles that can harm you. For instance, an air filter having an 8 rating helps explicitly in filtering out pollen, dust, and mold spores. Thus, it is ideal for residential and commercial use too.
Additionally, if you are more susceptible to allergies, then going for an air filter having a rating around 10 or 11 is a better option. It can filter out mold spores, smog, dust, and pet fur or dander too!
Lastly, for hospitals, smoking lounges, and such places, it is highly recommended to go for a 12 to 16 MERV rating.
Why Are the Highest Rated MERV Filters Not Used in Residential Applications?
Most residential applications do not make use of high-rated MERV filters. It is mainly because filters having high MERV ratings can reduce airflow. This can get quite damaging.
Moreover, it can also cause damage to the cooling and heating systems of residential applications.
MERV 8 vs MERV 11 vs MERV 13
Now, let’s compare the three main MERV ratings, which are pretty common in air filters today – MERV 8, MERV 11, and MERV 13.
MERV 8 is one of the ideal ratings for residential or commercial air filters.
- It can filter more than 20% particles in the range of 1 micron to 3 microns
- It can also filter out more than 70% of particles in the range of 3 microns to 10 microns.
- Hence, it can filter out pollen, dust, and some amount of mold spores too.
- The filtering material here is made up of polyester and pleated cotton.
MERV 11 is better for those requiring a more efficient air filter for both residential and commercial use.
- Unlike MERV 8, it can filter more than 20% of particles in the range of 0.3 microns to 1 micron
- It can filter more than 65% of particles in the range of 1 micron to 3 micron
- It can also filter out more than 85% of particles in the range of 3 microns to 10 microns.
- Hence, it can filter out mold spores, smog, dust, and pet dander.
- The filtering material here is made up of pleated cotton and microfine fiberglass. It is also 2 inches thicker usually.
MERV 13 denotes an extremely high-quality filter used in hospitals, smoking lounges, and other such areas.
- MERV 13 can filter more than 50% of particles in the range of 0.3 microns to 1 micron.
- It can filter more than 85% of particles in the range of 1 micron to 3 microns.
- It can also filter out more than 90% of particles in the range of 3 microns to 10 microns.
- Due to its high filtering capabilities, it can filter out viruses, bacteria, smoke, and microscopic particles too!
- The filtering material here is made up of pleated cotton and microfine fiberglass. It is 4 inches thicker.
Other Things to Consider When Choosing a New Air Filter
Other than the MERV rating, there are also other things that you might want to consider before choosing a new air filter. These include:
- Filter Model and Size: It is essential to find an air filter that can fit well with your overall air system. Hence, make sure you go for the right model as well as size.
- Type of Air Filter: Air filters can be of different types like – HEPA filters, electrostatic filters, carbon filters, and electronic filters. So, choose the one that fits your requirements.
- Air Quality of Your Home: Depending on your home’s air quality or wherever you want to install an air filter, choose one. For instance, you might want to go for a more efficient air filter if you are constantly exposed to smoke or dust.
- Your Requirements: Do you have any severe allergies? Do you have respiratory problems like bronchitis or asthma? If you do, keep this in mind and only go for an air filter to filter out the harmful particles.
- Filter Cost: Lastly, if you have a budget, consider the cost of an air filter and make sure you choose quality over price always.
To conclude, before you go for any air filter, always make sure to check its MERV ratings and whether or not it fulfills your requirements.
Also, consider the above factors to make sure that you choose the right air filter.