MERV 8 vs MERV 11 Air Filters: Which Should I Use?

Nowadays, Indoor air can contain a variety of harmful particles, including allergens, dust, pollen, pet dander, bacteria, viruses, and other pollutants that can negatively affect our health. One of the key steps in Improving air quality is selecting the right air filter for your HVAC system. Two popular options are MERV 8 and MERV 11 filters, each furnace filter offering different levels of filtration. With so many options available in the market, it can be difficult to know which one is best suited for your needs. It depends on your specific requirements because a quality filter can capture harmful particles before they spread throughout your home.

An air filter is a device that removes impurities and particles from the air, typically as part of an HVAC system or air purifier. To choose the right air filter, consider your space size, air quality concerns (like allergens or pet dander), and the type of HVAC system. Another important factor is the filter's MERV rating, which indicates its ability to capture particles. These considerations will help you select the most effective filter for your needs.In this guide, we'll explore these key factors, helping you understand the differences between filter options and how to choose the best one for your needs.

What Is MERV Rating

The MERV (Minimum Efficiency Reporting Value) rating is a standardized system used to evaluate the efficiency of HVAC air filters. It measures how well a filter captures particles of different sizes, and is an essential factor when choosing the right filter for your home or business. The MERV rating scale, developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE), helps you understand how effective a filter will be at removing various airborne contaminants.

The MERV scale ranges from 1 to 16, with each number reflecting a filter’s ability to capture particles of varying sizes. While the MERV rating is based on the size of particles a filter can trap, it also indicates the filter’s overall effectiveness. Filters with higher MERV ratings offer better air quality by capturing more dust and pollutants than those with lower ratings. but they can also restrict airflow more than filters with lower ratings. Understanding these ratings helps you choose a filter that meets your needs, ensuring the air in your home or business stays as clean and healthy as possible.

Essential MERV Ratings To Understand

Many people think a MERV 20 filter is the best choice since it captures nearly all contaminants, but this level of filtration is often too high for most homes and commercial spaces. Understanding MERV ratings is important to choosing the right filter for your needs.

MERV 1 to 4: Filters with a MERV rating of 1 to 4 capture only larger particles, such as pollen, pet hair, and dust, typically 10 microns or larger. These filters are not ideal for most indoor spaces since they don’t trap smaller particles that affect air quality. They are usually used as pre-filters or in smaller air conditioning units with additional filtration systems.

MERV 5 to 8: MERV 5 to 8 filters offer improved filtration by capturing particles ranging from 3 to 10 microns, such as mold, dust lint, mildew, and cement dust. These filters are commonly used in commercial buildings and residential HVAC systems, providing effective filtration for environments with moderate air quality concerns. While not as efficient as higher MERV filters, they strike a balance between cost and performance, making them suitable for general use in both homes and smaller industrial settings.

MERV 9 to 12: MERV 9 to 12 filters are ideal for both homes and businesses, offering improved air quality by capturing particles as small as 1 to 3 microns, such as bacteria, coal dust, humidifier dust, and nebulizer dust. While not required in all settings, these filters are especially useful in environments with higher air quality needs, like hospital labs, upscale commercial buildings, and homes that require more advanced filtration. They provide a higher level of protection for spaces where air cleanliness is a priority.

MERV 13 to 16: Filters with MERV ratings from 13 to 16 capture particles as small as 0.3 to 1 micron. While they're mainly used in medical environments like surgical rooms and ICUs, they can also improve air quality in homes, especially for those with pets or severe allergies. These filters trap smaller particles that lower-rated filters miss, such as tobacco smoke, wood smoke, insecticide dust, and pet hair.

MERV 17 to 20: MERV 17 to 20 filters are rarely used outside specialized settings like pharmaceutical plants or research labs. These filters capture a broad range of contaminants, including radon, smoke, odors, small allergens, carbon dust, virus particles, and even sea salt smells. Since such tiny particles are mostly found in medical or lab environments, filters above MERV 17 are usually unnecessary for homes or typical workplaces.

Difference Between MERV 8 And MERV 11 Filters

Picking the right air filter can be confusing if you don't understand MERV ratings. With this useful comparison table, let's explore the main differences between MERV 8 and MERV 11 filters to help you make a better choice.

MERV 8 Filters:

Homeowners often choose MERV 8 air filters because they offer an excellent balance of affordability and performance, making them a popular option for maintaining healthy indoor air quality in most households. These filters are effective at MERV 8 filters are designed to capture particles ranging in size from 3.0 to 10 microns, which includes capturing roughly 80% of airborne particles, including common household contaminants like dust, mold spores, allergens, dust mites, pet dander, and germs and larger pollutants found in the air. As a result, they can provide sufficient filtration for most general home environments, offering a practical solution for families looking to improve their air quality

Airflow Resistance: MERV 8 filters have low to moderate resistance, which means they strike a good balance between cleaning the air and letting air flow smoothly. These filters let air pass through more easily because they don't filter out as many particles as higher-rated filters. These air filters provide protection against larger particles without imposing too much strain on the HVAC system. In fact, their lower airflow resistance makes them a popular choice for most standard residential HVAC systems, ensuring that the system runs efficiently without frequent maintenance.

HVAC Compatibility:MERV 8 filters are well-suited for homes with standard air quality needs. They provide a good balance of affordability and performance, making them ideal for households without significant allergy, asthma, or respiratory concerns, and in areas with relatively clean air. For homes with older or less powerful HVAC systems, or systems not designed for higher-efficiency filters, MERV 8 is a safer choice. Higher MERV filters can reduce airflow, putting pressure on systems not built to handle the additional stain. This leads to higher energy use, more electric bills, and reduced efficiency.MERV 8 filters help your HVAC system run smoothly, preventing strain and protecting functionality, especially in systems with smaller blower motors or those not designed for restrictive filters.

Replacement And Maintenance: MERV 8 filters should typically be replaced every 3 to 6 months, depending on factors like the level of airborne pollutants, the number of people in the home, and whether there are pets or high-traffic areas. Homes with more occupants or higher dust levels may require more frequent changes, such as every 2 to 3 months. If the HVAC system is used year-round for both heating and cooling, a quarterly replacement for furnace filters is recommended. MERV 8 filters are affordable, easy to find, and simple to replace without professional help. Since they have lower airflow resistance, they put less strain on the HVAC system, reducing maintenance costs and helping to extend the system's lifespan by ensuring it runs efficiently. Regular filter changes maintain efficient system function.

MERV 11 Filters:

If you're considering a MERV 11 air filter for your home or business, it offers significant benefits, especially if you live in an area with high pollution, have pets, or suffer from respiratory issues like asthma or allergies. MERV 11 filters capture smaller particles (1.0 to 3.0 microns) more effectively than lower-rated filters like MERV 8, providing better protection against fine pollutants that can cause long-term health problems. However, they come at a higher cost due to their increased filtration efficiency and better materials. Depending on how often you need to replace the filter, the extra cost can add up over time, so it’s important to weigh the health benefits against the additional expense.

Airflow Resistance: One of the main drawbacks of using a higher MERV filter, such as a MERV 11, is that it can restrict airflow more than a MERV 8 filter. A higher MERV rating means the filter has a denser material, which traps smaller particles more effectively. However, this increased filtration efficiency also creates more resistance to airflow as this added resistance can lead to higher energy consumption. As a result, the HVAC system may have to work harder to push air through the filter, which can reduce the overall efficiency of the system. If your system is older or not designed to handle the added pressure of a high-efficiency filter, it could put unnecessary strain on the components and shorten the life of your HVAC system.

HVAC Compatibility: Before switching to a MERV 11 filter, it's important to check if your HVAC system can handle the higher level of filtration. MERV 11 filters are more restrictive, which means they work best in newer or more powerful systems that are designed to handle the extra pressure without causing problems. If your system is older or smaller, it might not be able to maintain the right airflow with a MERV 11 filter. This could reduce the airflow, making the system less efficient. In some cases, the increased pressure caused by the filter can make the system work harder, which can lead to higher energy bills and could damage the system over time if it’s stressed too much.

Replacement and Maintenance: Just like MERV 8 filters, MERV 11 filters need regular replacement to maintain good air quality and keep your HVAC system running smoothly. Typically, you should replace a MERV 11 filter every 3 to 6 months, but this can vary depending on your home’s needs. If you have a lot of dust, smoke, pollen, pets, or a large household, you might need to replace it every 2 to 3 months. If your HVAC runs year-round for both heating and cooling, check the filter every 3 months and replace it as needed. In busy seasons like winter or summer, more frequent changes may be necessary. Dirty or clogged filters can make your system work harder, leading to overheating or breakdowns. Timely filter replacement reduces strain on the system, helping it run efficiently and preventing costly repairs.

Quick Overview: MERV 8 vs MERV 11 Air Filter

Conclusion

In conclusion, both MERV 8 and MERV 11 air filters are effective, but the right choice depends on your specific needs. If you're looking for an affordable option that filters out common particles like pollen, dust, and mold, MERV 8 filters are a great choice. They offer good protection and help maintain clean air in your home or business. On the other hand, if you need stronger filtration, especially for smaller particles, or if you have allergies, pets, or live in an area with high pollution, MERV 11 filters provide better performance without putting too much strain on your HVAC system.

At Custom Filters Direct, we offer high-quality filters designed to improve your indoor air quality. If you need help choosing the right filter, give us a call at 1-877-958-5612. We’re here to help you find the best filters for your home or business and ensure your HVAC system runs efficiently.

MERV 8 Air Filters

MERV 11 Air Filters

MERV 13 Air Filters

Frequently Asked Questions