The use of higher MERV ratings is often seen as the most effective way to improve air quality. However, it is important to understand that these filters can also have a negative impact on your HVAC system. A higher MERV rating means higher resistance, which can lead to reduced airflow. This is not always the case, however, as there are many other factors that come into play, such as the size of the filter and the type of fan motor in your HVAC system.
In general, modern HVAC systems are designed to work with higher MERV filters without any issues. Millions of homeowners rely on them without any problems. The main risk of high-efficiency air filters comes from not changing them regularly. If you are aware of this and change your filter regularly, you should not experience any issues with your HVAC system.
Using an air filter with a MERV rating that is too high can be just as bad as using one that is too low. The thickness of the filter material may restrict airflow, leading to decreased comfort, increased energy use, and accelerated 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. Research has shown that overall, HVAC systems with high MERV filters have a higher pressure drop across the filter.
This is true for all three studies conducted on this topic. The MERV rating is a good indicator of how effective an air filter is in your central HVAC split system. The higher the rating, the better the filter will be at filtering out particles of certain sizes. For example, Merv 13 filters can remove bacteria, tobacco smoke, car fumes, insecticide dust, pet dander and more. The difference between Merv 8 and Merv 11 air filters may seem small but they do have some distinct differences.
How much more airflow resistance you will experience with a high-efficiency filter will depend on your household and HVAC system but modern technology has made it so that it is usually marginal. It is important to adhere to the oven manufacturer's recommendations or consult an HVAC professional to determine exactly which MERV rating is best for your specific system. You may need to change a Merv 11 air filter more often than a MERV 8 air filter but this will depend on your household and HVAC system. On average, it is recommended that most homes and retail spaces in general have a filter with a MERV rating of at least 5 to 12 in the high-end. It is also important to understand that using a filter designed just to do so does not jeopardize the operation of the system if it is maintained regularly. In conclusion, while higher MERV ratings are effective for air quality, they can also reduce airflow in your HVAC system if not used correctly. It is important to adhere to the oven manufacturer's recommendations or consult an HVAC professional to determine exactly which MERV rating is best for your specific system.