The short answer is yes, but it's not really a problem, except in extreme circumstances. Most modern HVAC systems have no problem working with higher Merv filters, which is why millions of homeowners depend 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 keep abreast of changing filters, you are unlikely to experience any filter related issues with your HVAC system.In general, 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. 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. As you can see above, research shows that in general, HVAC systems with high MERV* filters have a higher pressure drop across the entire filter. This part is common to the three previous studies.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.
Another unwanted effect of this reduced air flow occurs on the cooling side. The air conditioner has a hot coil outside, the condenser and a cold coil in the air handler inside. 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 passing through that coil's copper tubing.
With a higher Merv filter that reduces airflow through this crucial part of the air conditioning system, the cold coil can eventually freeze into an ice ball shape, restricting airflow completely. Unprocessed, this causes more costly problems in the outdoor condenser coil.A MERV rating is a good indication of the effectiveness of an air filter in your central split HVAC system. The higher the rating, the better the filter. As the MERV rating increases, fewer and fewer contaminants and dust pass through the filter, making the incoming airflow of better quality.
It turns out that you see this type of size classification because “particles of intermediate size around 0.5 microns” are the HARDEST to filter out. Ironically, the effectiveness of low-efficiency air filters increases as the filter becomes loaded with dirt and dust. Another consequence of low airflow is that the air conditioner coil can get too cold and even freeze. This is important to keep in mind, because many homeowners believe the ratio is simply linear, meaning that as filtration efficiency increases, so does resistance to airflow at the same rate.While air filters with a MERV of one to four are effective at removing large particles, such as carpet fibers, airborne paint droplets, and sanding dust, they cannot help with contaminants such as hairspray, mold spores, or even flour that could have escaped from the mixer.
Also, if I tried this modification of the MERV13 filter myself, I would make a lot of filter discs and change them after each exposure to several people. I washed the filter material and it responded wonderfully: it became softer and it's still easy to breathe. If the filter does not fit properly in the filter chamber, it can obstruct airflow and collapse in the unit, causing a blockage. Keep in mind that as the MERV rating increases, the filter becomes more restrictive and more pressure and energy will be needed to propel the air.With the lowest MERV rating (1-), your filter will continue to capture pollen, dust mites, cockroach debris, sanding dust, spray paint dust, textile fibers, and carpet fibers.
They tested all filters at the same width and height (16″ x 25″) but the depth varied from 1″ to 4″. It is recommended to change filters in this category every two to four weeks, which may be difficult for some to maintain. If you have questions about which filter rating is right for use with your HVAC system, seek professional guidance from your HVAC technician.
