Yes – You Can install MERV 13 on your home central Air Conditioner

Are you wondering whether a MERV 13 or MERV 11 air filter might be too much for your home’s air conditioner? The simple answer is NO—these filters are not too high if you understand how they work and how to install them correctly. In fact, if you’re knowledgeable about air filtration and airflow management, using a MERV 13 filter could be a smart decision for improving your indoor air quality.

As described below the real issue is air velocity, and you need to know to manage airflow.

Let’s break it down and explain everything you need to know about MERV ratings, the impact of airflow resistance, and how to properly install higher-rated filters in your home without damaging your AC system.

What Is MERV?

Before diving into the installation of MERV 13 filters, it’s important to understand what MERV actually is.

MERV stands for Minimum Efficiency Reporting Value. It’s a rating system that was developed by Committee 52.2, which is a part of ASHRAE (the American Society of Heating, Refrigeration, and Air-Conditioning Engineers). This rating system is widely recognized internationally and measures how effectively an air filter can capture particles of various sizes.

When you’re shopping for air filters at stores like Home Depot or Lowe’s, you may notice different rating systems like FPR (Filter Performance Rating) or MPR (Microparticle Performance Rating). These terms are essentially marketing labels that manufacturers use to promote their products, but they aren’t based on the same standardized measurements as MERV. The MERV rating, however, is the real deal and is backed by stringent standards from Technical Committee 2.4 and ANSI/ASHRAE 52.2.

How MERV Ratings Work?

MERV ratings span from 1 to 16, with the higher numbers representing filters that can capture smaller particles more efficiently. The rating is determined based on the filter’s ability to capture particles within a specific size range, which can vary from 0.3 microns to 10 microns in diameter.

For instance, a MERV 13 filter is highly effective at capturing fine particles:

• It can trap up to 50% of particles that are smaller than 1 micron, such as smoke and bacteria.
• It captures around 85% of particles between 1 and 3 microns, which include things like pollen and pet dander.
• It is also able to catch about 90% of particles ranging from 3 to 10 microns, such as dust and mold spores.

On the other hand, a lower-rated filter, like a MERV 8, captures almost no particles at the submicron level. It might only trap larger particles, such as those that are over 3 microns, meaning it’s less effective at filtering out smaller, more harmful particles that contribute to poor indoor air quality.

A MERV 11 filter falls somewhere in between. It can capture 20% of submicron particles (those smaller than 1 micron) and around 65% of particles between 1 and 3 microns. While it’s better than a MERV 8, it’s still less effective than a MERV 13.

To put this into perspective, a vast majority—about 99% of the harmful particles in your home—are smaller than 1 micron. This fact is documented by the EPA. So, by using a higher-rated filter like MERV 13, you’re significantly improving your home’s indoor air quality, protecting your furnace and AC Evaporator Coil, especially when it comes to removing small, airborne pollutants. So how do you install a MERV 13 in your Central AC?

The Impact of Airflow Resistance

If MERV 13 filters are so much more effective, you might wonder why they aren’t the standard for every home. The answer lies in airflow resistance.

Higher-rated MERV filters, like MERV 13, are excellent at capturing particles, but they also create more resistance to airflow. This resistance, often referred to as pressure drop, can put additional strain on your air conditioning system. Since residential AC units aren’t always designed with intense filtration in mind, a filter that restricts too much airflow can cause the system to work harder, which can lead to reduced efficiency, higher energy bills, and even mechanical problems.

A common issue with restricted airflow is that the evaporator coils in your AC can freeze, which stops the system from cooling properly. This can happen when dirty or poor-quality filters clog up the system, limiting the airflow and causing the AC to overwork. If you’re dealing with freezing coils, you might be wondering what causes an air conditioner to freeze up, and airflow restriction due to a bad filter is often a key culprit.

How to Mitigate Airflow Issues with MERV 13 Filters

Does this mean you should avoid high-MERV filters like MERV 13? Not necessarily. If installed and maintained correctly, a MERV 13 filter can work perfectly well in a residential air conditioning system.

Here’s how you can reduce airflow resistance while using a higher MERV filter:

• Increase the size of your return duct. This is one of the simplest and most effective solutions. By increasing the surface area of the filter (double it), you allow more air to pass through with less resistance.
• Upgrade your HVAC system. Some older systems might struggle with high-MERV filters. If your AC system is outdated, consider upgrading to one that is more compatible with high-efficiency filters.
• Use a deeper filter. Filters that are 2 or 4 inches thick, as opposed to the standard 1-inch filter, have more surface area and create less resistance to airflow.
• Maintain your system regularly. Ensure that your air filters are replaced every 1 to 3 months, depending on usage, and have your system inspected by an HVAC professional to ensure it’s running optimally.

Conclusion

So, is a MERV 13 or MERV 11 filter too high for your home’s air conditioner? The answer is no—as long as you take the right precautions and understand how to manage airflow properly. A higher MERV rating can greatly enhance your indoor air quality by capturing harmful particles that lower-rated filters would miss.

By ensuring proper installation and maintenance, you can enjoy the benefits of cleaner, healthier air without overburdening your AC system. Choose your filter wisely, and keep your system running smoothly!