If your HVAC system uses 5-inch thick filters, you know that finding the right MERV 11 rating is crucial for balancing air quality and airflow. This guide covers four top-rated models from Lennox, Filtrete, and BestAir, helping you select the best 5 MERV 11 furnace filter for your home. We focus on real-world performance and compatibility, so you can breathe easier without sacrificing system efficiency. For more on choosing the right air filter, browse our Air Filters category.
Pros
- Perfect fit for Lennox furnaces and air conditioners, with easy slide-in installation.
- Effectively reduces allergens and dust, leading to improved indoor air quality and relief for allergy sufferers.
- Durable construction that does not collapse under normal airflow, ensuring long service life.
- Convenient pull tabs and date-marking feature simplify filter maintenance.
- High MERV 11 rating balances filtration and airflow without straining the HVAC system.
Cons
- Higher cost compared to generic or lower MERV filters, but justified by OEM quality and performance.
- Only compatible with Lennox HVAC systems that accept 5-inch thick filters, limiting use for other brands.
- Some users may prefer a higher MERV rating for extreme allergy needs, though MERV 11 is sufficient for most homes.
The Lennox X6670 Healthy Climate Air Filter is a genuine OEM replacement designed specifically for Lennox HVAC systems. It comes in a convenient 2-pack, each measuring 16 by 25 by 5 inches with a MERV 11 rating. This filter is ideal for homeowners who want to maximize air quality without compromising system efficiency, especially those with allergies or pets.
Standout features include its ability to capture up to 85% of airborne particles down to 3 microns, such as dust, pollen, and pet dander. Real-world performance is excellent, with many users reporting noticeably cleaner air and reduced allergy symptoms. The filter's pleated fiberglass construction ensures low resistance to airflow, so your heating and cooling system runs efficiently while filtering effectively.
Build quality is top notch. Each filter has sturdy cardboard framing and built in pull tabs that make removal a breeze. A handy area on the filter allows you to write the installation date, helping you keep track of replacement intervals. The filters are individually sealed in plastic bags, which also serve as disposal bags for the old filter.
One potential drawback is the price, which is higher than generic or lower MERV options. However, the OEM fit and performance justify the cost for Lennox system owners. Additionally, the 5 inch thickness may not fit all filter slots, so check your system's specifications before purchasing.
Overall, the Lennox X6670 Healthy Climate Air Filter is a reliable, high efficiency choice for anyone with a compatible Lennox HVAC system. With a stellar customer rating of 4.8 out of 5 stars from over 1,800 reviews, it delivers on its promise of cleaner, healthier air. Highly recommended for those seeking OEM quality and proven results.
Pros
- Excellent particle capture for allergies and asthma
- Long 12-month lifespan means fewer replacements
- Fits Lennox systems securely and is easy to install
- Sturdy construction with electrostatic pleated material
- Good value with 2-pack pricing
Cons
- Actual dimensions slightly smaller than nominal (19.63 x 24.75 x 4.31 inches)
- May require weather stripping for a perfect seal in some furnaces
- Not ideal for systems needing a thinner filter (under 4.31 inches)
The Filtrete 20x25x5 MPR 1000 filter from 3M is a high-performance HVAC filter designed for homeowners who want cleaner indoor air. It is specifically compatible with Lennox systems and other setups that accept a 5-inch thick filter, making it a go-to choice for allergy sufferers and pet owners.
With a MERV 11 rating and Filtrete's exclusive 3-in-1 technology, this filter captures up to twice as many microparticles as standard MERV 11 filters. In real-world use, users report noticeable reductions in dust, pet dander, and allergy symptoms. The 12-month lifespan is a standout feature, simplifying maintenance and offering long-term value.
Build quality is solid, with a sturdy pleated polypropylene construction that holds its shape during installation. The electrostatic charge helps attract particles, and the filter slides easily into most standard slots. However, some users note that the actual dimensions are slightly smaller than the nominal 20x25x5 inches, which may affect fit in certain furnaces.
A potential drawback is that the filter may not seal perfectly in every system, requiring additional weather stripping to prevent air bypass. Also, it is not suitable for systems that require a thinner filter. These issues are minor for most users but worth checking before purchase.
Overall, the Filtrete MPR 1000 filter delivers on its promise of cleaner air and allergy defense. It is a reliable, cost-effective choice for homeowners willing to invest a bit more for superior filtration. We highly recommend it for Lennox systems and anyone prioritizing indoor air quality.
Pros
- High MERV 11 rating captures allergens small particles like smog, smoke, and mold spores effectively.
- Fits Lennox models perfectly according to actual size (15.63x24.74x4.31 inches) for a hassle-free installation.
- Sturdy pleated core prevents shedding and maintains airflow, so system strains not in use.
- Pack of 2 provides excellent value, with each lasting up to 12 months runs.
- Customer reviews highlight noticeable reduction in dust and allergy symptoms within weeks.
Cons
- Actual dimensions slightly differ from nominal 16x25x5: some units may require careful measurement first.
- A few users report needing to force or adjust filter if cabinet opening is slightly different.
- Price is higher than basic fiberglass filters, though justified by longer life and better filtration.
The Filtrete 16x25x5 Air Filter (MERV 11, MEP 1000) is a 3M product specifically sized for Lennox brand media air cleaners. Designed for homeowners who want serious allergy control without sacrificing HVAC performance, this 5 inch thick filter offers a premium balance of fine particle capture and long lasting life. Individuals with pets or sensitivity will particularly benefit from its ability to trap pet dander, mold spores, smoke, and smog.
Standout features include an efficiency rating of MEP 1000 combined with MERV 11, which independently trapping 2x more microparticles than MERV alone, says 3M. Exclusive Filtrete 3-in-1 technology pulls in particles while letting clean air pass. Real-world tests show noticeably cleaner surfaces within 2-3 weeks post installation, and multiple reviewer attest to clearer breathing and less dust buildup.
Build quality is robust with pleated electrostatic polypropylene material that does not shed fibers. The 4.31 inch thickness fits snugly into the media cabinet, and the filter is verified to contain at least 50% of recycled content by third party auditors. Each filter lasts up to 12 months, and the Filtrete Smart App reminders help keep changes on schedule.
A key potential drawback: the actual size is 15.63 x 24.74 x 4.31 inches, which may not match every 16x25x5 system exactly. Some users had to force alignment, so carefully measure your opening before purchase. Also, the premium price over basic filters is offset by longer life and performance.
Overall, for those with a Lennox side or compatible housing, this 2-pack is a smart investment in indoor quality and system protection. It is easy to install, delivers reliable relief from allergens, and offers great value when each filter lasts a full year.
Pros
- Excellent balance of filtration and airflow.
- Compatible with a wide range of specific air cleaner models.
- Positive customer feedback on fit and performance.
- Made in the USA for consistent quality.
- Three-pack offers good value for periodic maintenance.
Cons
- Not a standard 1-inch filter; requires compatible 5-inch deep filter housing.
- Some users note the thickness is slightly less than expected.
- Limited compatibility may not fit all furnaces or air handlers.
The BestAir 20x25x5 MERV 11 3-pack is a specialized air filter designed for use with Air Bear, Supreme, Skuttle, GeneralAire, and other compatible HVAC air cleaners. It is specifically optimized for models requiring a 5-inch deep filter, which means it is not a standard 1-inch filter. This filter is ideal for homeowners who want to improve indoor air quality without placing additional strain on their heating and cooling systems.
Standout features include a MERV 11 rating that targets common allergens like pollen, dust mites, and pet dander, while the construction minimizes airflow resistance. This careful balance helps the HVAC system run efficiently, which can lead to lower energy bills and reduced wear over time. Customer reviews highlight that the filter fits perfectly in compatible models, making replacement straightforward.
Build quality is solid, with a sturdy frame and dense media that hold shape even with consistent airflow. The filter is made in the USA, which adds to its overall appeal for buyers looking for domestic production. The actual dimensions (19.75x24.25x4.88 inches) are accurate, according to users, so ensure your filter slot matches these measurements before ordering.
However, a few caveats exist. Some users noted the filter thickness felt slightly less than their previous unit (though it still fits correctly). Additionally, this filter is designed for specific 5-inch deep systems, not generic 1-inch systems, which limits compatibility. Potential buyers should verify their system brand and model to avoid sizing issues.
Overall, the BestAir 20x25x5 MERV 11 3-Pack offers excellent filtration performance with minimal impact on HVAC efficiency. For owners of Air Bear, Supreme, Skuttle, GeneralAire, Source1, or Braeburn air cleaners, this is a top-notch replacement option that blends performance, build quality, and solid value.
Brand: BestAir
Model: AB2025-11R
Filter Size: 20x25x5 inches (actual 19.75 x 24.25 x 4.88 inches)
MERV Rating: 11
Material: Polyolefin
Pack Size: 3 filters
Compatible Systems: Air Bear (Supreme 2000, 435790-027, etc.); Skuttle (DB0-0025-020); GeneralAire (MAC2000); Source1 (S1-MAC102025000); Ultravation (90-007); Braeburn (162025, 162026); Braeburn (162025, 162026)
Manufacturer: RPS Products
Country of Origin: USA
Buying Guide: What to Consider in a 5-Inch MERV 11 Furnace Filter
Size and Fit: OEM vs. Aftermarket
Five-inch filters are not one-size-fits-all. Your system may require a specific nominal size (e.g., 16x25x5 or 20x25x5) and actual dimensions can vary slightly. OEM filters like the Lennox X6670 are engineered to fit perfectly in Lennox media cabinets, while aftermarket options like Filtrete and BestAir offer broader compatibility. Always measure your existing filter before buying.
MERV Rating and Filtration Efficiency
MERV 11 filters capture particles as small as 1.0 micron, including pollen, dust mites, and pet dander. This rating provides a good balance between air cleanliness and HVAC airflow. The Filtrete filters we reviewed (MPR 1000) meet MERV 11 standards and are certified asthma- and allergy-friendly, making them a smart choice for households with sensitivities.
Filter Lifespan and Replacement Schedule
Thicker 5-inch filters typically last longer than standard 1-inch ones. Most MERV 11 models in this roundup are rated for 12 months of use, depending on your system’s runtime and air quality. Regular replacement is key to maintaining performance; set app reminders using Filtrete’s smart app or a simple calendar alert.
Brand Compatibility and System Performance
Some 5-inch filters are designed exclusively for Lennox media air cleaners, while others fit multiple brands like GeneralAire or Air Bear. Check your system’s manual to confirm compatibility. Using the correct filter minimizes pressure drop and keeps your furnace or air conditioner running efficiently. For more HVAC tips, visit our Heating & Cooling section.
Final Thoughts
After reviewing the options, we recommend two filters that stand out for different needs. For exact OEM fit and proven reliability, the Lennox X6670 – (2-Pack) Healthy Climate 16″ x 25″ is an excellent choice. If you want similar filtration at a lower cost with a 12-month lifespan, the Filtrete 16x25x5 Air Filter MERV 11 delivers strong performance and is certified allergy-friendly. Both filters capture airborne particles effectively while maintaining good airflow in your HVAC system.
Frequently Asked Questions
What is the difference between MERV 11 and MERV 13 filters?
MERV 13 filters capture smaller particles (down to 0.3 microns) than MERV 11 but can restrict airflow more. For most homes, MERV 11 offers a good balance of filtration and efficiency, especially if you have a standard HVAC system. If someone in your home has severe allergies, you might consider MERV 13, but check your system’s static pressure first.
How often should I replace a 5-inch MERV 11 filter?
Most 5-inch filters are designed to last up to 12 months under normal conditions. However, factors like pets, smoking, or high pollen seasons may require more frequent changes. Always inspect the filter monthly during peak usage months and replace it when it looks dirty.
Can I use a MERV 11 filter in a Lennox system?
Yes, but for the best fit and performance, choose an OEM filter like the Lennox X6670 or a compatible aftermarket brand like Filtrete that is specifically designed to fit Lennox media cabinets. Using a mismatched filter can reduce efficiency and allow unfiltered air to bypass.
What size filter do I need for my 5-inch system?
Check the nominal size printed on your current filter or measure the slot where the filter sits. Common sizes for 5-inch filters include 16x25x5, 20x25x5, and 16x20x5. The actual dimensions may be slightly smaller (e.g., 15.63×24.74×4.31 inches) than the nominal size, so use the exact measurements when ordering.
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