If you want to clean your air and handle dust, mold, pollen and bacteria, then a Merv 8 filter is the way to go. It is important to note that 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. This can decrease comfort, increase energy use, and accelerate wear of HVAC components.
In particular, using an air filter with a too high MERV rating can damage the compressor, heat exchanger, and air conditioner 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. A MERV rating is a good indicator of the effectiveness of an air filter in your central HVAC split system. The higher the rating, the better the filter. As the MERV rating increases, fewer and fewer contaminants and dust pass through the filter, improving the quality of the incoming airflow.
Studies have found that airflow in high-MERV filters dropped by 7% and 11% in two HVAC systems compared to low-MERV filters. Similarly, medium MERV filters also showed decreased airflow relative to the low MERV filters, this time 3% and 8% lower in both systems. When selecting an air filter for your HVAC system, it is important to consider all factors such as size of the filter and type of fan motor in your system. It is also important to recognize that a MERV that is too high could cost you more in terms of your heating and air conditioning system.
The higher the MERV, the more restrictive the airflow through the device, causing the equipment to work harder. Your intention should be to achieve the right balance between air filtration levels, air flow and energy efficiency. If you're concerned about the effects of breathing fine air particles, that's another reason to choose a Merv 11 air filter instead of a MERV 8 air filter. Generally speaking, anything under a merv 13 filter should provide very efficient air purification in a house without affecting airflow.
ASHRAE recommends MERV 13 and 14 for hospital-level air quality; however, it is best to select a filter with the highest possible MERV rating for your specific HVAC system. It is also important to understand maintenance practices for your filters. The core of an oven filter never gets completely cleaned; over time, the accumulation of particles in the core reduces filtration efficiency and airflow. Consider all these considerations when buying a filter and make sure you understand MERV ratings before making a purchase.
