When it comes to air quality, higher Merv ratings are the most effective. However, they can also cause damage to your HVAC system. This is because a higher MERV rating means greater resistance, which in turn reduces airflow. Generally, a filter with a higher MERV rating will reduce airflow.
But there are other factors that come into play, such as the size of the filter and the type of fan motor in your HVAC system. The answer is yes, but it's not usually a problem. Most modern HVAC systems can handle higher MERV filters without any issues, which is why so many homeowners rely on them. The main risk of high-efficiency air filters is that they need to be changed more often than lower-efficiency filters.
If you keep up with changing your filters regularly, you should not experience any problems with your HVAC system. In general, filters with higher MERV ratings capture more particles, including smaller particles. MERV-13 is usually the highest rating you'll need for residential use. Research shows that in general, HVAC systems with high MERV filters have a higher pressure drop across the entire filter.
This is consistent across all three studies. Using an air filter with a MERV rating that is too high can be just as bad as using one that is too low. Air filters with higher MERV ratings can filter more particles, but the thickness of the filter material can restrict airflow. This can lead to decreased comfort, increased energy use, and accelerated 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. If you're worried about the effects of inhaling fine air particles, then you should opt for a MERV 11 air filter instead of a MERV 8 air filter. Low-efficiency filters are usually rated between MERV 1-4 and high-efficiency filters are rated at MERV 13 or higher. In fact, even filters with high MERV ratings can be used in some systems without causing too much pressure drop.
Ultimately, if you want peace of mind then it's worth investing in a high MERV filter - just make sure to replace it regularly (which could be every week or two depending on the MERV rating and how many particles enter your home). This comparison table helps to illustrate the differences between MERV 8 and MERV 11 filters so you can make an informed decision about which one to use. Even air filters with the lowest MERV rating (1) can capture pollen, dust mites, cockroach debris, sanding dust, spray paint dust, textile fibers, and carpet fibers. Meanwhile, air filters with a MERV 14 rating or higher are designed for commercial HVAC systems that can handle the coarsest filter material. Not all filters have a Merv rating - many of them are purchased at large stores.
A MERV 8 carbon filter will provide more than enough filtering of dust and allergens and will filter dozens of toxic gases that will pass directly through a MERV 13 filter. However, if you're concerned about outdoor air pollution or have family members with respiratory problems or pets in the house then it might be worth investing in a higher MERV rating. One thing to keep in mind is that a MERV 11 air filter may need to be changed more frequently than a MERV 8 air filter.
