Does a Merv 13 Filter Restrict Air Flow?

The short answer is that it can reduce airflow but it's not really a problem except in extreme circumstances. Learn more about how Merv 13 filters affect your HVAC system.

Does a Merv 13 Filter Restrict Air Flow?

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.

Usually, 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. Another unwanted effect of this reduced airflow is on the cooling side. The air conditioner has a hot coil on the outside, the condenser and a cold coil on the indoor air handler. This cold coil has a specific preferred operating temperature.

That temperature is based on a certain amount of hot air flowing through that coil and the coolant circulating through that coil's copper tube. With a higher MERV filter that reduces airflow through this crucial part of the air conditioning system, the cold coil can eventually freeze and become an ice ball, restricting airflow completely. Without elaborating, this causes more costly problems in the outdoor condenser coil. A higher MERV rating means greater resistance, which means less airflow. When researching HVAC systems, airflow will increase a lot.

This is because it is very important to the performance and longevity of your oven or your air handler. Airflow is also the key to a comfortable home. 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. In general, filters with higher MERV ratings capture higher percentages of particulates as well as smaller particles.

And MERV-13* is practically where you want to be. Technology for HVAC units has progressed since then, and most modern units in recent years should be capable of at least one MERV 8 filter. To further improve indoor air quality, household air purifiers employing HEPA (high-efficiency particulate air) filters can theoretically remove 99.97 percent of mold, pollen, bacteria and other particles as small as 0.3 microns, according to the U. S. Environmental Protection Agency (EPA).

This is of course the main one of KISS and does not suit those who sell more expensive filters that need a more frequent replacement or anyone else who spreads & taking advantage of people's uninformed fear. The HVAC system may have difficulty passing air through the air filter and expending more energy in its attempts. Since air filters in many residential homes contribute more than half of that pressure, it's clear that air filters are responsible for much of the pressure drop in an HVAC system. For increased maintenance of your HVAC system and guaranteed comfort, consider annual overhauls of your Missoula air conditioning unit. Oven filters are one of the most talked about oven components, but many people still don't know how to maintain them properly. It is important to keep this in mind, because many owners believe that the relationship is simply linear, that is, as filtration efficiency increases, so does the resistance to air flow at the same rate. I'm thinking of a typical Michigan basement oven with the filter 4 inches away from the blower motor and everything outside of that.

Fundamental principles in biohazard areas seem to focus on airflow (room changes) and air filtration. In my opinion, air cleaners should be on the return air grilles, not on the equipment. Air is hazy with poor visibility when air pollutant levels are high, which is when it becomes a concern for people's health. While ASHRAE recommends MERV 13 and 14, it's best to select a filter with the highest possible MERV rating for your specific HVAC system.

It turns out that you see these kinds of size classifications because “medium size” particles (about 0.5 microns) are the HARDEST to filter...