Have you heard of the MERV rating? It’s a system that measures the effectiveness of air filters at removing particles like dust and allergens. It’s helpful for homeowners to understand this rating system so they can choose the right air filter for their home. For more advice on selecting and replacing your air filters, contact an HVAC specialist.
What Is a MERV Rating?
The term MERV rating stands for Minimum Efficiency Reporting Value Rating, and it’s a system for measuring the effectiveness of an air filter in removing particles from the air. MERV ratings range from 1 to 20, indicating filter efficiency levels.
While a higher MERV rating sounds good, it’s not always what you want. The higher your air filter’s rating, the more particles it will catch, including dust, pollen and bacteria. Higher MERV ratings effectively trap smaller particles such as bacteria and allergens. However, a higher rating also means that less air will flow through your filter.
According to Gary Cremeans, HVAC Operations Manager at ABC Home & Commercial Services, “The best filter in the world is a brick. Nothing’s going through a brick wall, but neither is air. So you gotta give a trade-off.”
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) developed the MERV rating system. It rates air filters on a scale of one to 20. Here is a quick breakdown of this scale:
- MERV 1 to 4: Basic filtration that mostly captures larger particles like dust mites and carpet fibers.
- MERV 5 to 8: Moderate filtration that’s good for residential use, capturing mildew spores and dust.
- MERV 9 to 12: Better filtration that removes finer particles like pet dander and auto emissions.
- MERV 13 to 16: High-efficiency filters that can trap smoke, bacteria and even some viruses, with excellent filtering capabilities for allergens and pollutants.
- MERV 17 to 20: Most commonly used in hospitals, these filters can remove extremely small particles, including viruses.
Air filters with high MERV ratings that restrict airflow can eventually strain your entire HVAC system. Reduced air flow can decrease energy efficiency, often resulting in higher utility bills and uneven cooling and heating.
It can also shorten the lifespan of your HVAC system, which can lead to you needing to replace it sooner.
Which MERV rating is best? The answer depends on your specific needs. For example, if you have pets, allergies or other sensitivities, a filter with a MERV rating of 9 to 12 is your best bet.
Most homeowners are satisfied with air filters with an 8 and 11 MERV rating. This range strikes a balance between air quality and air flow, and doesn’t put excess strain on the HVAC system.
If you want to know more about air filters with a higher MERV rating, consult with an HVAC professional first to make sure your system can handle a high-performing filter. It’s also a good idea to learn about alternative ways to improve indoor air quality.
An expert can give you a deeper understanding of the pros and cons of different types of air filters and help you choose the one that works best for your home and lifestyle.
Is There a Downside to High MERV Filters?
Air filters with high MERV ratings are the best at catching particles like dust, mildew spores, pollen and bacteria. If air quality is your top concern, a high MERV rating filter may be the right call.
However, it’s important to note that high MERV filters have a few downsides. First, these filters are dense, which leads to restricted air flow. When air has a harder time passing through a filter, it forces your HVAC system to work harder to heat and cool your home effectively.
Uneven temperatures and insufficient ventilation can make some rooms in your home feel uncomfortable.
Next, since your HVAC system has to work harder, higher MERV filters often require increased energy consumption. This can result in a higher utility bill.
High MERV filters can also increase the wear and tear on your HVAC system. Mechanical issues may become more common since the motors and fans have to work harder to push out air. Worse, the overall lifespan of your HVAC system can be shortened.
While air quality is important, it’s also important for homeowners to understand that high MERV filters are not always necessary. Unless you have severe allergies, respiratory issues or live in a particularly dusty or polluted environment, you may not need a filter with the highest MERV rating.
For most homes, a MERV rating of 8 to 11 strikes a good balance between air quality and system efficiency. Working with an HVAC specialist is the best way to determine which air filter is right for your home. A pro will walk you through your options, including HEPA air filters.
What MERV Rating is Best For Air Flow?
Air quality is not the only factor to consider when it comes to choosing an air filter for your home. You must also think about air flow.
Poor air flow leads to uneven heating and cooling, which is especially uncomfortable during extreme weather months. Additionally, when air flow is restricted, your HVAC system must work harder to push air through your filter, which can lead to higher utility bills.
Most homes thrive with an air filter that has a MERV rating between 8 and 11. These ratings find the middle ground between air quality and air flow for the best of both worlds.
However, it’s important to note that every home is different, and the type of air filter you need depends on several personalized factors. For example, if you have pets, you may want an air filter that can filter out pet dander.
People with allergies may be more concerned with air quality than those without allergies. Lastly, if you live in an older home that gets particularly dusty, you may want a higher MERV rating filter.
On the flip side, many homes don’t need to have a higher MERV filter as a lower rating works just fine and doesn’t put strain on the HVAC system.
The key to selecting the right air filter for your home is to work with an HVAC professional. They can assess your individual needs and make a personalized suggestion.
They can also inspect your HVAC system and perform routine maintenance or diagnose problems, such as why your AC is not blowing cold air. Working with a pro is the best way to keep your system running smoothly all year long.
How Long Do MERV Filters Last?
The MERV rating determines how well an air filter removes particles such as dust, pollen, mildew spores and bacteria. It does not determine how long an air filter lasts.
Most air filters, regardless of their MERV rating, are designed to be replaced every three months under normal circumstances.
Replacing your filters every three months is a great guideline to maintain the air quality and air flow in your home. It also keeps your HVAC system running smoothly, rather than working overtime to push air through an old and dirty filter.
However, if you live in a house with pets or heavy pollen, you may need to change your filters more often. If you or someone in your home lives with respiratory issues or you live in an area with poor air quality, you should also change your filter more often.
Under these conditions, it’s recommended that you replace your air filter every one to two months.
Waiting too long to replace your air filter or simply never replacing it can lead to several issues. First, a clogged filter reduces the air flow in your home, which leads to uneven cooling and heating.
Reduced airflow can also strain the blower motor and force your system to work harder. This can lead to higher utility bills and more wear and tear on your HVAC unit over time. You can end up paying more for costly repairs or a premature replacement.
Lastly, a dirty filter can’t catch particles as effectively, which reduces the air quality in your home. This leads to more dust, allergens and pollutants circulating throughout your house.
To maintain your air quality, air flow and the lifespan of your HVAC system, replace your air filters every three months. You should also work with an HVAC specialist to schedule regular maintenance to ensure that your system runs smoothly and efficiently for years to come.
Maintain Your HVAC System With Help From a Pro
For effective heating and cooling, regular HVAC system maintenance is important. This includes replacing your air filters, generally every three months. It’s also critical to use the correct filters for your system so that you don’t force it to overwork.
An HVAC specialist can tell you more about the MERV rating system and help you pick the right air filter for your home, balancing both air quality and air flow. Reach out to a local technician to get started.
ABC Can Advise You on the Best Air Filter for Your Home
We understand that you want to choose the right air filter for your home. The professionals at ABC Home & Commercial Services have a thorough understanding of HVAC systems and the filters that run best with them. While we’re there, we can assess your system and find ways to make your HVAC system more efficient. We even have a filter delivery service, so you never have to worry about running out of filters again.
