Best 20x25x5 Air Filter

Many people wonder whether thick air filters, including the 20x25x5 ones, are suitable for their HVAC systems. This review covers this and several other concerns about this kind of air filter that you may have. We then show you how to choose the right furnace filter for your home.

Common Signs of a Dirty Air Filter

You do not want to have dirty air filters in your HVAC system. Filthy air filters are the number one cause of low indoor air quality. They cause an accumulation of contaminants in the air.

This may trigger allergic reactions in people if allergens are contained in the air. The best way of dealing with this is to ensure that you do not have dirty filters.

Here are simple signs that you can look out for to tell you if you have dirty air filters.

  1. Dirt around the air vents: Check the edges of your air vents to see if there is any dust that has accumulated. An accumulation of dust is usually the first tell-tale sign that your air vents are dirty. Dirty air vents fail to trap dust particles. The particles are then pumped through your vent system. They accumulate near the edges of the vents.
  2. A spike in the energy bills: If your furnace filter is dirty, your blower or AC fan will not be functioning correctly. They will be forced to work harder to maintain the ideal temperature in your house. When the blower or AC fan overwork, they consume additional electric energy. When you see your energy bills rising steadily, it may be because your filters are dirty, and the blower is overworking to keep you comfortable.
  3. Longer heating times: Your central heating and cooling system will take a long time to reach the ideal temperature if the air filters are dirty. Dirty air filters interfere with the free flow of air around the system. This, in turn, undermines the ability of your system to reach the desired temperature rapidly.

Are 20x25x5 Filters Good for Your HVAC System?

The main concern of using 20x25x5 furnace filters for an HVAC system is that the filters may interfere with airflow. If this happens, the blower may be forced to overwork to keep the home environment comfortable.

An overworking blower leads to high energy bills. Also, when the entire HVAC system or one of its components is overflowing, the chances of damage increase tremendously. This means that if you use the wrong filter, you will end up paying for your mistake dearly by footing the costly repair bills on your HVAC system.

However, a 20x25x5 furnace filter is suitable for use in your HVAC system as it is any other recommended air filter. It would be best if you were concerned with the MERV rating and not the thickness.

Furnace filters with highly high MERV ratings may cause your blower to strain. This is the reason why we recommend that you get a certified HVAC technician to select the right filter for your furnace.

When Should I Replace my 20x25x5 Filter?

The rule of thumb is that you should replace your 20x25x5 furnace filter every three months. Most furnace filters recommend that their pieces be replaced after every three months or 90 days. However, you can replace your furnace filter anytime that you feel it is necessary to do so.

When people around the house who are allergic to some things start experiencing allergic reactions, it may be time to replace your furnace filter. The filter prevents allergens from floating around the air in your home. When the filters become dirty, they fail to trap all kinds of allergens effectively. Therefore, if this happens, you can always replace your filter.

When the air in your house becomes generally dirty, it may be the proper time to replace your filter. You can detect a dirty air environment by looking at the edges of your vents. If they are clogged with dirt, it means that the filters are not doing their job correctly. You will have to replace them immediately to keep your indoors clean, healthy, and comfortable.

Remember that the length of time that a furnace filter remains useful depends on many factors, including its width, brand, and the general conditions in your home. Therefore, you do not necessarily have to stick to the period that the manufacturer has recommended.

How long does a 20x25x5 air filter last?

Several factors determine how long your 20x25x5 air filter will last. Here is a brief description of the most important ones.

The level of use of your HVAC system

The level of use of your HVAC system is the most important factor that determines how long your furnace filter lasts. If you use your HVAC for cooling and heating for only a few hours and on some days, the filters will last for a long time. The filters can even outlive the period that is usually indicated on their surfaces.

If you live in a place that forces you to run your HVAC system for long hours every day, you will have to replace your filters sooner than what is indicated on their packaging. This is because the furnace filters will run out of use fast because of the rapid accumulation of contaminants.

The quality of your indoor air

If your indoor environment is exceptionally dirty, your furnace filter will last for a long time. Indoor dirt arising from dust and smoke reduces your furnace filter’s life because the device has a lot of contaminants to deal with. Your furnace filter will become dirty within a few weeks if the inside environment of your home is full of contaminants.

The size of your home

Filters installed in the HVAC systems of significant homes have a lot of work to do than those in smaller homes’ HVAC systems. The large surface area in big homes means that many contaminants need to be trapped. Thus, if you have a large home, the chances are that you will be required to replace your furnace filter often than one would expect it to be.

How to Install 20x25x5 Filters

Installing your furnace filter need not be a complicated process. Thus, you do not need prior experience handling these devices for you to install one successfully. Here is a simple guide on how you can go about the process.

  • Unwrap the filter that you would like to install from its covering. Be careful not to mess up with the frame because it is an essential component of your filter. Just remove the plastic wrapping.
  • Align the arrows that are drawn on your filter with the direction of the airflow. If you install the filter with the arrows pointing in the opposite direction, it will not function.
  • Insert the filter into its slot correctly. Ensure that the filter is installed correctly and the frame has tightly fitted into the slot’s sides.

Factors to Consider when Purchasing 20x25x5 Filters

Choosing the right filter for your home may be a big challenge if you are unsure about the features you are looking for. Here are a few important things that you should consider when making a decision.

Filter performance

Filter performance is measured using MERV or MPR ratings. The higher the ratings, the greater the performance of your filter. It is ideal to go for filters that have MERV ratings of higher than 8 for optimal performance. You may go for filters with MERV ratings of even 14.

Filter type

The filter type is determined by the kind and nature of the material that is used. The best filters are those which have pleated surfaces. The pleating of the surfaces increases the surface area that is used to trap the contaminants. Some filters have electrostatically charged surfaces. Such filters are ideal for use because they attract and trap microorganisms in the air.

Can a 20x25x5 Air Filter Protect My House Against Odors?

Yes, a 20x25x5 air filter can protect your house against odors. Odors are caused by the presence of small particles in the air. When you have an air filter with a high enough MERV or MPR rating, you can have an odor-free indoor environment.

The furnace will attract and trap all the particles that cause foul odors in your house. This will prevent them from circulating in your indoor environment.

Best 20x25x5 Air Filter Comparison Table

1.Filtrete 20x25x5, AC Furnace Air Filter

Filtrete 20x25x5 Air Filter MPR 1550 DP MERV 12,...
  • Actual filter size is: 19.56 x 24.13 x 4.75 Inch
  • This filter is compatible with TrionAirBear furnaces calling for a 5" filter
  • #1 Recommended Brand* (*Filtrete Brand is the most recommended brand of HVAC Air Filters based on the US Filtrete Brand Health Tracker, Ipsos, June 2022)
  • The higher the MPR, the more microparticles--such as pollen, pet dander, smoke, bacteria and viruses--your filter will capture from the air passing through it
  • FOR OPTIMAL PERFORMANCE of your heating & cooling system or HVAC system, change your home air filter at least every 12 months for 4 in. and 5 in. filters
  • A dirty filter will slow down air flow and make the system work harder to keep you warm or cool--wasting energy. Sign-up for a filter change reminder program that works for you!
  • CAPTURES MORE PARTICLES than fiberglass air filters
  • ATTRACTS AND CAPTURES particles such as lint, pollen, dust, pet dander, smoke and smog
  • 54% SMALL PARTICLE CAPTURE, like bacteria and particles that carry viruses* (* % captured is based on ASHRAE 52.2 testing for 0.3 to 1 micron particles from the air passing through the filter, which relates to HVAC industry standard efficiency testing)
  • MPR 1550 has a rating of MERV 12

The Filtrete 20x25x5 AC Furnace Air Filter is certified to fight the spread of coughs, flu, cold, and other airborne conditions. Its surface can effectively attract and trap all the microorganisms that are contained in cough and sneeze. Thus, you do not have to worry about colds and flu spreading across the entire home when you have this filter.

This furnace filter has a relatively high MERV rating of 12. Furnace filters with high MERV ratings are more effective than those with low ratings. This is in terms of the volume of contaminants that can be attracted and trapped on the filters’ surfaces.

The only notable drawback of using this furnace filter relates to the number of pieces in the pack. With only two pieces, you will have to think about purchasing another pack faster than it would have been if there were many more pieces inside the pack.


  • Certified for controlling asthma and allergens
  • The air filter can effectively trap microorganisms that are contained in sneeze and cough droplets.
  • High MERV rating of 12 means that this air filter traps a considerable percentage of contaminants


  • There are only two pieces in every pack

2. Nordic Pure 20x25x5 Honeywell Replacement AC Furnace Air Filters

Nordic Pure 20x25x5 (19_7/8 x 24_7/8 x 4_3/8)...
  • Nominal Size: 20 x 25 x 5 H, Actual Size: 19 7/8 x 24 7/8 x 4 3/8 (19.88 x 24.88 x 4.38)
  • Measure your air filter for the exact size and compare it to our actual size to ensure proper fit.
  • Replaces Honeywell 20x25x4 and filters with an MPR rating with an actual depth of 4 3/8 and ideal for high efficiency air filtration and those with moderate allergies
  • Nordic Pure MERV 12 is equivalent to MPR 1500-1900
  • Made in the USA
  • Hypoallergenic, antimicrobial, and electrostatic filter media. Moisture resistant frame.

One of the most amazing things about the Nordic Pure 20x25x5 Honeywell Replacement AC Furnace Air Filters relates to the longevity. Unlike many other brands of 20x25x5 air filters, this one can last for six months.

Many other types of furnace filters need replacement only after about three months. Therefore, this furnace filter will give you value for money and save you the trouble of frequently having to replace your furnace filters.

Moreover, it can attract and trap about 90% of all the airborne contaminants in your house. This is because this air filter has a MERV rating of 12. Filters with such high MERV ratings are ideal for large and small houses because they capture almost all the contaminants floating around in the air.

The pleated strands on the surface of this filter complement the high MERV value. The pleating increases the surface area, and ultimately, the overall performance of this furnace filter.


  • It collects up to 90% of all airborne contaminants in a house
  • It has a pleated surface for maximum performance
  • The filters can last up to 6 months before requiring a replacement


  • There are two pieces only in every pack

3. Aerostar Home Max 20x25x5 Air Filter

Aerostar 20x25x5 Air Filter MERV 13, Furnace...
  • 20x25x5 replacement whole house air filters for your furnace, air conditioner, heat pump, or HVAC system (actual size: 19.88" x 24.75" x 4.38")
  • Our compatible furnance air filter is a standard replacement for the following model air filters: Honeywell F25 (#203720), F35 / F35R (#FC35A1027), F100 / F150 (#FC100A1037), F200 (#FC200E1037), Bryant (FILBBCAR0020, FILXXCAR0020, FILXXCAR0120), Carrier (CARF8250602, CARFC100A1037, CARL86469, EXPXXFIL0020, EXPXXLMC0020, EXPXXUNV0020, FILCCCAR0020, FILXXCAR0020, FILXXCAR0120), Day & Night (MACPAK20), Lennox (X8790, X0586, X5426, X6661, X6673, X7751, BMAC-20C, HCC20-28, HCF20-10, HCF20-16), Payne (MACPAK20)
  • MERV 13 (comparable with MPR 600 & FPR 5) protects homes from dust, pollen, and more by trapping 90% of airborne particles without impacting air flow
  • EASY INSTALLATION: Effortlessly install our 20x25x5 air filter for immediate results. Optimal replacement interval: Replace the air filter every 3-6 months for best performance. Increase the replacement frequency to 30 days during the peak summer and winter months for superior air quality.
  • 100% synthetic electrostatic media for high efficiency with low air flow resistance. Manufactured by Filtration Group, a world-leading manufacturer and supplier of filtration solutions making the world safer, healthier & more productive

The Aerostar Home Max 20x25x5 Air Filter is ideal for small, mid-sized, and large homes. It is made from a unique foam material and has a pleated surface.

The multiple-layered foam is also electrostatically charged. These features enhance the ability of this filter to attract and trap all types of particles.

It is designed to fight odors because it can trap the microparticles that cause bad smells in homes. It can also help to prevent allergic reactions among people who have allergies.

This is because the electrostatically charged and pleated surfaces successfully capture all the allergens that may attempt to find their way into your atmosphere.

However, as is the case with all good products, the Aerostar Home Max 20x25x5 Air Filter is not without weaknesses. This furnace filter does not last if one would expect it to do.


  • Superior filtration efficiency that is perfect for trapping all microparticles in the air
  • Highly durable because the frames are made from high-quality materials
  • Easy to install


  • The filter gets full of contaminants after a relatively short time

4. Lennox X6673 Lennox Filter Media

X6673 Lennox 20x25x5 Merv 11 Filter Media 2 Pack
  • MERV 11
  • Actual Size: 19-3/4" X 24-3/4" X 4-3/8"
  • 2 Filters
  • Manufactured by Lennox
  • Nominal Size: 20" x 25" x 5"

This is one of the best filters with a long lifetime, thanks to its design and the quality of materials used to make its frame. If you use it in a house whose indoor environment is not exceptionally dirty, the filter can last for as long as six months. This means that if you purchase a pack with two pieces, you will not have to think about replacing your filters more than once a year.

This furnace filter can withstand the effects of the elements. Its frame is made from high-quality materials. It can remain functional even when subjected to moisture and heat while protecting you against all manner of pathogens, including allergens, smoke, mite dust, and small pieces of pet fur.

The only significant drawback that is associated with this furnace filter is that it is made of fiberglass. Fiberglass furnace filters are not necessarily the best that you can find on the market.

They tend to collect more negligible amounts of contaminants than their counterparts which are made from different materials. Nevertheless, your X6673 Lennox Filter Media will get the job done.


  • The filter lasts for up to 6 months
  • Easy to install during replacement
  • Its 11 MERV rating is relatively high


  • It is made of fiberglass

5. AF Honeywell FC100A1037 Compatible Air Filter

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Several features make the AF Honeywell FC100A1037 Compatible Air Filter one of the best for residential and commercial use. Primarily, it has a pleated surface.

This means that the surface area available for capturing microparticles that may be found in your home or commercial premises is high. If particles fail to be trapped on the first instance when they fall on the filter’s surface, they can still be captured as they attempt to pass through its strands.

This furnace filter is powerful enough to protect you from foul odors, allergic reactions, and airborne conditions, including flu and cold. Its surface can capture minute contaminants that are as small as 0.3 microns large. Thus, it can protect you from the microorganisms that usually spread around indoor spaces and are contained in droplets from sneezing and coughing.

However, this furnace filter has a relatively low MERV rating of 8. The MERV rating indicates the percentage of contaminants that an air filter can trap. The higher the MERV rating, the more significant the percentage of contaminants that a furnace filter can trap.

If you are keen on having a furnace filter that can trap even 97% of the airborne contaminants in your home, you will have to get a different type from AF Honeywell FC100A1037 Compatible Air Filter.


  • The pleated surface increases the overall filtration performance of this air filter.
  • The furnace filter lasts for a long time.
  • Designed to protect homes from allergies and foul odors


  • The furnace filter has a relatively low MERV rating of 8


20x25x5 furnace filters are ideal for keeping your home free of odors and are friendly to your HVAC system. When choosing the right furnace filter, ensure that that you for brands that have electrostatically charged and pleated surfaces. Also, go for brands that have MERV ratings of at least 8. Such brands are perfect for trapping microparticles that may be found in your home.