Does a Merv 11 Filter Restrict Air Flow?

Learn about Merv ratings & how they affect airflow & efficiency when selecting an air filter for your home or business.

Does a Merv 11 Filter Restrict Air Flow?

Keep in mind that some retailers also use their own rating system instead of MERV. Using an air filter with a MERV rating that is too high is as bad as using one that is too low. Air filters with higher MERV ratings may filter more, but the thickness of the filter material may restrict airflow. Restricted airflow can decrease comfort, increase energy use, and accelerate wear of HVAC components.

In particular, using an air filter with too high a MERV rating can damage the compressor, heat exchanger and air conditioner coil. Typically, a filter with a higher MERV rating will reduce airflow. However, there are many other factors at play, such as the size of the filter and the type of fan motor in your HVAC system. The short answer is that it can, but it's not really a problem except in extreme circumstances.

Most modern HVAC systems have no problem working with higher MERV filters, so millions of homeowners rely on them. The main risk of high-efficiency air filters comes from the fact that they are not modified for long periods of time. If you're aware of changing filters, you're unlikely to experience filter-related issues with your HVAC system. They also found that airflow in high-MERV filters dropped by 7% and 11% in the two HVAC systems compared to low-MERV filters.

Similarly, the medium MERV filters also showed decreased airflow relative to the low MERV filters, this time 3% and 8% lower in both systems. If your furnace's MERV rating is too high, it can force it to work too hard and leave it vulnerable to damage. In addition, you may not get the air velocity needed to reach all parts of your house, leaving inconsistencies in temperature. MERV stands for Minimum Value of Efficiency Reporting.

A MERV rating indicates a score of 1 to 16 for residential air filters sold in the United States and 17 to 20 for commercial air filters. The scale evaluates how well a filter removes fine particles from the incoming air. The higher the MERV rating, the more particulates the filter will remove. On average, it is recommended that most homes and retail spaces in general have a filter with a MERV rating of at least 5 to 12 in the high-end.

However, for a person with respiratory problems, a specialist may recommend a different filter. Hospitals use air filters with a MERV rating of 13 to 16. Using an oven filter with a higher MERV rating than your use case requires may have adverse effects. The thickness of the filter material in a Merv 11 filter, for example, is greater than that of a MERV 8 filter. Therefore, in order for enough air to pass through the filter, a greater amount of energy is consumed.

More use can lead to increased wear and tear, so be sure to maintain your oven regularly. However, MERV 11 filters are not considered too high for residential use. Anything higher than a MERV 11 is designed for commercial households or households with family members suffering from respiratory problems. If the filter is too dirty or too sturdy, it can cause airflow problems that impair efficiency and performance.

Based on that information, I did some research and a well-known company offered a demonstration of its merv 13 filter against others. While ASHRAE recommends MERV 13 and 14, it is best to select a filter with the highest possible MERV rating for your specific HVAC system. All of these considerations are discussed below, and after reading this Pick HVAC guide for MERV 8 vs MERV 11 vs merv 13 air filters, you'll understand which one to choose. This comparison chart helps highlight the differences between MERV 8 and MERV 11 filters to make it easier to decide which one will work best.

Reducing airflow in your system can worsen air quality in your home and put a damaging amount of pressure on the fan in your boiler or air conditioning system. This then improves the air quality in your home by preventing waste from recirculating in the air. Overall, the highest MERV rating that is safe for residential use is MERV 13, although such a high rating is rarely needed in a residential home unless someone has severe dust allergies or asthma and needs an advanced air filter. A MERV rating is a good indicator of the effectiveness of an air filter in your central HVAC split system.

With the lowest MERV rating (1-), the filter will continue to capture pollen, dust mites, cockroach debris, sanding dust, spray paint dust, textile fibers and carpet fibers. According to the United States Environmental Protection Agency (EPA), filters in the 7-13 range often have little difference from higher MERV ratings but they will allow your system to operate much more efficiently. Low-efficiency filters are typically found within MERV 1-4 and high-efficiency filters are MERV 13 and later. As the MERV rating increases fewer and fewer contaminants and dust pass through the filter improving the quality of incoming airflow.