Have you ever wandered through the air filter aisle of your local home improvement store? When you go to replace a dirty filter, you suddenly become aware of all the different brands, types, and styles of filters that are available. Homeowners often have a difficult time deciding which one is the right fit for their home.
Each house is unique in the makeup of people and pets who live there, as well as your needs as an individual. A home with three people and two dogs may need a different filter than a single individual with severe allergies and a pet fish. Different filters can produce varying results when it comes to filtering allergens and debris out of your air.
What should you know about choosing the right air filter? Find answers to the most commonly asked questions about filter types below.
How are air filters rated?
Selecting the right air filter is essential to helping your HVAC system run more efficiently, but it can also help to improve your indoor air quality. Unfortunately, there isn’t one specific rating system that helps to determine the efficiency of all filters. The United States Department of Energy does not require manufacturers to utilize a standard rating system.
Instead, consumers should be encouraged to take a look at all of the data available on the package. You’ll likely encounter at least a couple of these criteria to help guide your decision-making process.
Minimum Efficiency Reporting Value (MERV)
This is probably the most popular rating available on air filters. This number helps to quantify the degree of air purification that a particular filter can offer your home. This 16-point scale can be a great measuring tool, particularly for individuals or families who are concerned with their allergies.
Under controlled laboratory settings, particles of twelve different sizes are introduced to the filter to determine which ones can pass through and in what quantities. An air sample is taken both before and after the air is exposed to the filter. Using this date, measurements are taken to determine which particles were filtered out of the air.
Commonly, filters will be exposed to contaminants like pet dander, dust, smoke, pollen, and different types of bacteria. The more particles that a filter is able to remove from the air, the higher the MERV rating is likely to be.
Homeowners should look for options that score in the middle of the range for maximum efficiency when it comes to purifying the indoor air without causing a pressure drop to the HVAC system. If the score is over a certain number, it can decrease the efficiency of your system by allowing less air to pass through. Over time, this can cause great wear and tear on your HVAC units.
According to the U.S. Environmental Protection Agency, you should purchase a filter with an MERV rating between five and thirteen. They even state that these “medium-efficiency” air filters can rival a true HEPA filter, which is considered to be the gold standard for air filtration. MERV ratings higher than this are better suited for commercial applications.
Filters with scores under four will do very little for your indoor air quality. These are often the least expensive options, but they also filter only the largest debris from entering your home. In this category, you may not even find an MERV rating listed on the package.
This number helps you to see how effective a filter is at capturing particles when it is first installed in the home. As you may have already guessed, any air filter is likely to be more efficient at first than it is over an extended period of time. This is why it important to also look at the very next number, which is the sustained efficiency rating.
The sustained efficiency rating is far more telling than the initial efficiency rating because it details how the filter will do over time. It won’t measure the efficiency of a filter that’s lived past its expiration date though. When the package says you should replace a filter every ninety days, it’s wise to follow the manufacturer’s instruction or you won’t truly get the benefits of this sustained efficiency rating.
A pressure drop helps to measure how well a filter can continue to capture particles compared to other filters at the same pressure drop. In essence, pressure drop can determine how much your air filter inhibits the efficient air flow in your system. A filter with a greater pressure drop may cause undue wear and tear on a residential HVAC system.
What are the different types of air filters?
Unfortunately, the ratings scales aren’t the only things that you will have to make a decision on when it comes to buying an air filter. Manufacturers produce a variety of constructions and materials to give homeowners a choice between price points and efficiencies. You should be aware of what the different types are, what they offer, and where their price points are before you make a single purchase.
Fiberglass air filters are the least expensive option for providing filtration to your home. They are typically flat as opposed to pleated, which doesn’t allow them to offer the higher MERV ratings of more efficient filters. These don’t offer much in terms of improving the air quality or the efficiency of your HVAC system. In many instances, you may not even be able to find the MERV rating on the packaging because it is so low.
These are the best option for homeowners who are concerned only with providing the bare minimum of protection for their unit. These will be discarded and changed on a very regular basis.
A pleated air filter provides a much greater degree of protection compared to a flat-paneled fiberglass filter. These are likely to have mid-range MERV ratings, which means they can filter out particles relatively efficiently. The number of pleats is often an indicator of their efficiency, with more pleats demonstrating a stronger ability to remove more particles.
You will find several pleated filters that provide budget-friendly protection for your HVAC unit. However, they are still disposable and will need to be replaced every one to three months. The frequency of replacing each filter will vary based on your home composition, your usage, and the recommendations of the specific manufacturer.
A filter categorized as “high-efficiency” tends to have the maximum recommended ratings for a residential application. MERV scores typically fall between fourteen and sixteen, which are extremely high and could decrease the overall efficiency of your unit. However, the trade-off could be worth it for consumers who are extremely sensitive to common allergens like dust, pollen, and mold.
Some manufacturers may even add a coating to the pleats of a high-efficiency air filter to kill certain types of bacteria. These are pricier options, but they could provide more comfort for allergy sufferers.
True HEPA Filters
A true HEPA (high-efficiency particulate air) filter is considered by most to be the gold standard of the HVAC industry. They are extremely efficient at removing particles from the air, but they require a specific setup to be used in an ordinary home. For the most part, a HEPA filter will have an MERV rating of seventeen to twenty. This means that they are practical for both residential and commercial applications, if you have a system that allows for their usage.
Because they filter particles so efficiently, they can cause serious restrictions to the amount of air flow into the home. Your HVAC system would have to provide much greater air pressure in order to still function well in the home. You would need to discuss the possibility of installing a whole-house air filtration system before you could utilize one of these higher-end models.
Ultimately, changing your air filter requires a lot of decision-making to determine your home’s specific needs. You may require a more expensive option with higher ratings that will filter more particles from your home’s air. Alternatively, you may be searching for budget-friendly options that still do a decent job at cleansing the air in your home.
No matter what you’re looking for, you should be aware that changing your air filter on a regular basis plays a big role in the efficiency of your HVAC unit. Changing the filter will be based on the specific needs of your family, as well as the type of filter you purchase. You can see some of Classic’ tips for how often you need to change your filter for more information.
Be sure to educate yourself on the various types of air filters before you go shopping. In the end, it will help to protect the integrity of your unit and improve the overall air quality in your home. This routine investment could help your home to run more efficiently and improve your health with just a little forethought on what type of filter is right for you.