What Is The Difference Between Merv 12 VS Merv 13?

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The MERV rating is an important indicator of the performance of a furnace filter. You need to get an air filter with the proper MERV rating to enjoy the full benefits of having this device in your house.

However, many people are at a loss when they must choose between MERV 12 and MERV 13. In this brief article, we discuss the most important things about these two MERV ratings.

MERV 12 vs MERV 13

Is MERV 13 Better than MERV 12?

You may be wondering whether MERV 13 is better than MERV 12. The answer lies in the percentage and type of contaminants that the furnace filters with either of the rating captures. Generally, an air filter with MERV 13 captures more contaminants and various sizes than a MERV 12 furnace filter.

Is MERV 13 More Restrictive than MERV 12?

MERV 13 is more restrictive than MERV 12. Using a highly restrictive furnace filter may interfere with the flow of air in your house. This is because the blower will be forced to overwork to push the air at the required rate to maintain a comfortable indoor environment.

Is MERV 12 Good?

MERV 12 is quite good at trapping small and large contaminants. Furnace filters with a MERV rating of 12 can trap contaminants ranging from 0.3 to 1.0 microns. They can also trap at least 93% of all the airborne contaminants in the building.

What is the MERV rating?

MERV rating is a measure for determining the capacity of a furnace filter to capture contaminants that measure between 0.3 and 1.0 microns. MERV stands for Minimum Efficiency Reporting Value. This measure was developed by the American Society for Heating, Refrigerating, and Air Conditioning Engineers. This body is called ASHRAE, in short.

The MERV rating is important because it enables one to compare the performance of different furnace filters. The rule of thumb is that the higher the MERV rating, the better the performance of the furnace filter. This means that furnace filters with a high MERV rating can capture large percentages of contaminants that vary in size from 0.3 microns to 1 micron in diameter.

What are the different categories of MERV ratings?

MERV ratings range from 1 to 14. However, furnace filters can be categorized based on the classes of the ratings. Furnace filters that fall within the category of MERV 1 to MERV 4 can successfully trap 20% of all airborne contaminants that range in size from 3 to 10 microns wide.

The second category is made of furnace filters with a MERV rating of 6. Such furnace filters can successfully remove about 49.9% of the contaminants in your home. Similarly, MERV 8 is suitable for trapping contaminants 3 to 10 wide contaminants (84.9%).

MERV 10 is more suitable for trapping small contaminants that are 1 to 3 microns wide and large contaminants that measure 3 to 10 microns wide. Such furnace filters can capture only 50% of the small contaminants but up to 85% of the large ones.

Furnace filters with a MERV rating of 12 can trap 80% of contaminants 1 to 3 microns wide and about 90% of the larger contaminants that measure 3 to 10 microns wide. MERV rating 14 is sufficient for trapping 75% of contaminants of 0.3 to 1 micron wide and over 90% of larger contaminants. MERV rating 16 is perfect for trapping over 75% of all small airborne contaminants that may be found in your indoor space.

Is a Higher or Lower MERV Rating Better?

Generally, the higher the MERV rating, the better the performance of the furnace filter. The performance is measured by the percentage and size of contaminants that the furnace filter can effectively trap.

Furnace filters with very high MERV ratings are ideal for trapping microparticles, including allergens that may be floating around in your house. Low MERV rating furnace filters are perfect for trapping large contaminants, including dust and hair particles, that may be found in your home.

However, high MERV ratings may directly interfere with the way the blower of your HVAC system functions. Therefore, it is ideal for balancing between the need to keep the Indoor Air Quality high and maintain the integrity of the blower.

MERV 12

MERV 12 is ideal for balancing between the effectiveness of removing large and small contaminants and the need to protect the blower of your HVAC system. MERV 12 is enough to remove a large percentage of large contaminants (90%). This means that when you have an air filter with this MERV rating, you will enjoy an indoor environment free of contaminants, including dust and smoke particles.

Also, a furnace filter with a MERV rating of 12 is powerful enough to remove 80% of contaminants that are very small in size (0.3 to 1.0 microns wide). These are allergens and even microscopic particles that may trigger illnesses, including flu and cough.

MERV 13

MERV 13 is excellent for trapping small-sized contaminants that measure between 0.3 to 1.0 microns. A furnace filter that has this MERV rating can trap over 80% of such small contaminants.

This performance is ideal for protecting people who have allergic reactions. It can also protect everyone in the house from flu, cold, and many other airborne illnesses.

Furthermore, MERV 13 is perfect for trapping large contaminants. Any air filter with a MERV rating of 13 is powerful enough to trap large contaminants, including dust and smoke. Such contaminants can cause allergic reactions in some people and lower the overall Indoor Air Quality of your home.

MERV 12 VS MERV 13 – Which one should you choose?

It is better to choose a furnace filter with a MERV rating of 12 than one with a MERV rating. The difference in the performance of a furnace filter with a MERV rating of 12 and one with a rating of 13 is negligible.

Both can trap high percentages of small and large contaminants in the house. However, the difference in their effect on your HVAC system is important. A 13 MERV furnace filter is likely to stress your blower more than a 12 MERV one.

Thus, installing such a furnace filter will compel your blower to overwork to keep the house either cool or warm enough as you would like it to be. In the end, this may cause damages to the blower.

Repairing any component of the blower is an expensive activity. Therefore, using a 12 MERV furnace filter will solve all your problems and keep the Indoor Air Quality of your home high.  

Factors that affect which MERV rating you choose

There are several factors that you should consider when choosing a MERV rating. Here are some of the most important ones.

Allergies

Allergies are reactions to specific contaminants, including dust, pollen, or even smoke. People who are sensitive to specific contaminants will get irritated when the air is dirty.

If you have people in your home who are allergic, you will be obliged to get furnace filters with high MERV ratings. Such furnace filters can effectively trap the large and small particles that may trigger allergic reactions.

The required airflow levels

If you need excellent airflow, consider above-average MERV ratings. If the airflow is not your concern, you can search for the highest possible MERV rating to improve the overall Indoor Air Quality.

Summary

The MERV rating of your furnace filter is an important indicator of its performance. You can use MERV ratings to compare different brands and types of furnace filters. It is necessary to choose a furnace filter with the proper MERV rating.

Choosing low MERV ratings may be ideal for ridding the home of large contaminants but not the small ones. Having a high MERV rating may be necessary to eliminate microscopic contaminants.

However, very high MERV ratings can interfere with the airflow in your HVAC. Therefore, you can choose MERV 12 over 13 to get the best of both worlds.

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