When it comes to selecting the right air filter for your furnace, it can be difficult to decide between a MERV 8 and a MERV 11. While both are suitable for residential use, there are some key differences between the two that you should consider. A MERV 11 air filter has a higher efficiency rating than a MERV 8, meaning it can capture finer particles and remove more pollutants from the air. This makes it a great choice for large department stores and places that contain smoke or exhaust gases from cars. However, the mesh of a MERV 11 filter is denser than that of a higher MERV rating, so it won't put additional pressure on your furnace.
The MERV classification system is standard, making it easier to compare filters with different ratings. A MERV 5 filter traps up to 34%, the MERV 6 does so between 35 and 49%, the MERV 7 avoids it up to 69% and the MERV 8 traps up to 85% of the particles. A MERV 9 traps less than 50% of particles with a size between 1 and 3.0 microns, the MERV 10 stops up to 64%, the MERV 11 captures up to 79% and the MERV 12 is capable of trapping up to 89%. Raising only three MERV rating levels can be a smart decision to make the air cleaner or a harmful option for the entire air conditioning system considering the air flow capacity of the MERV 8 versus the MERV 11.
If someone has an allergy or a respiratory problem, opt for a MERV 11 air filter or even a MERV 13 air filter. When deciding if you need a MERV 8 or a MERV 11 filter, keep in mind that although ASHRAE recommends models 13 and 14, it's best to select a filter with the highest possible rating for your specific air conditioning system. The pros and cons of each should be weighed carefully in order to make an informed decision. It's important to note that while higher efficiency ratings are beneficial in terms of air quality, they can also put additional strain on your furnace. If you're considering upgrading your filter from a MERV 8 to a MERV 11, make sure you consult with an HVAC professional first. They can help you determine if your furnace is capable of handling the additional pressure. In conclusion, when selecting an air filter for your furnace, it's important to consider both the efficiency rating and the pressure requirements of your system.
A MERV 11 filter may be more effective at removing pollutants from your home's air, but it may also put additional strain on your furnace. Weighing all of these factors carefully will help you make an informed decision about which type of filter is best for your home.