When it comes to air quality, higher MERV ratings are often the most effective. However, they can also cause damage to your HVAC system. A higher MERV rating means greater resistance, which in turn reduces airflow. When researching HVAC systems, it's important to consider the airflow that will be generated.
The higher the filter rating, the smaller the particles it will capture and the higher the percentage of particles it will trap. Low-efficiency filters are usually within the MERV 1-4 range, while high-efficiency filters are MERV 13 and above. The MERV scale is not linear; the difference between a MERV 6 and a MERV 8 is almost double in terms of the percentage of particles captured. It's also important to remember that as the MERV rating increases, the filter becomes more restrictive and more pressure and energy will be needed to propel the air. 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. In general, filters with higher MERV ratings capture higher percentages of particles, as well as smaller particles.
And MERV-13 is practically where you want to be. 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 can filter more, but the thickness of the filter material can restrict airflow. This can decrease comfort levels, increase energy use, and accelerate wear and tear on HVAC components. In particular, using an air cleaner with a MERV rating that is too high can damage the compressor, heat exchanger, and air conditioner coil. The MERV rating is there to tell you how efficient the air filter is at filtering particles of certain sizes.
If someone has an allergy or respiratory problem, choose a MERV 11 air filter or even a MERV 13 air filter. If you're worried about the effects of inhaling fine air particles, that's another reason to choose a MERV 11 air filter instead of a MERV 8 air filter. The higher MERV rating means that an air filter will capture the most dust, while the lower rating means that a filter will capture the least amount of dust. It's important not to choose an air filter that exceeds the recommended MERV rating your HVAC system is designed for. Each air filter has its advantages and disadvantages, but both MERV 8 air filters and MERV 11 air filters are suitable for residential use. A MERV 13 is likely to help if your goal is to prevent droplets from passing through.
If you're considering modifying a MERV 13 filter yourself, it's best to create multiple discs and change them after each exposure to several people. When selecting an air filter for your HVAC system, it's important to consider all factors at play. A higher MERV rating may be more effective at trapping particles, but it can also reduce airflow and cause damage to your system if it exceeds its recommended rating. Ultimately, both MERV 8 and MERV 11 filters are suitable for residential use.