Find Popular Lennox Filters by Model Number With Size 2025
Quick Answer: Popular Lennox filter models include X8309 (16×25×5), X8310 (20×25×5), X6670 (16×25×5 MERV 11), X6673 (20×25×5 MERV 11), and X6675 (20×25×5 MERV 16). Always verify actual dimensions as Lennox filters have specific measurements that differ from nominal sizes. Save money with Atomic compatible filters that meet or exceed OEM performance.
Find Your Lennox Filter Quickly
Enter your filter Part Number or Size (e.g., X8795 or 16x25x5)
Popular Lennox Filter Models with Exact Sizes
Finding the right Lennox replacement filter requires knowing your exact model number and understanding the difference between nominal and actual sizes. This comprehensive guide covers all popular Lennox filter models with their precise dimensions to help you order the correct replacement.
Most Popular Lennox MERV 10 & 11 Filter Models (2025)
| Model Number | Nominal Size | Actual Dimensions | MERV Rating | Shop Now |
|---|---|---|---|---|
| X8309 | 16×25×5 | 15¾" × 24¾" × 4⁷⁄₁₆" | MERV 10 | View → |
| X8310 | 20×25×5 | 19¾" × 24¾" × 4⁷⁄₁₆" | MERV 10 | View → |
| X6670 | 16×25×5 | 15¾" × 24¾" × 4⅜" | MERV 11 | View → |
| X6673 | 20×25×5 | 19¾" × 24¾" × 4⅜" | MERV 11 | View → |
| X0584 | 16×26×5 | 16⅜" × 26" × 5⁵⁄₃₂" | MERV 11 | View → |
| X0586 | 20×25×5 | 20" × 24¾" × 4⅜" | MERV 11 | View → |
| X0587 | 20×26×5 | 20⁷⁄₁₆" × 26" × 5⁵⁄₃₂" | MERV 11 | View → |
| X6667 | 21×26×4 | 20¾" × 25¾" × 3¾" | MERV 11 | View → |
| X6664 | 17×26×4 | 16½" × 25⅞" × 3¹⁵⁄₁₆" | MERV 11 | View → |
| X0444 | 28×17×6 | 28" × 17" × 6" | MERV 10 | View → |
| X0445 | 25×20×6 | 25" × 20" × 6" | MERV 10 | View → |
| X5422 | 20×26×3 | 20" × 26" × 3" | MERV 11 | View → |
Lennox MERV 16 Filters & Atomic Compatible Alternatives
💰 Save Money with Atomic Compatible Filters
Atomic compatible filters are designed to meet or exceed OEM performance at a lower price point. Same day shipping available when you order before 11:30 AM EST!
| OEM Model | Size/Actual | OEM Link | Atomic Compatible |
|---|---|---|---|
| X6672 | 16×25×5 15⅞" × 24⅞" × 4⅜" |
OEM X6672 | Save with Atomic → |
| X6675 | 20×25×5 19⅞" × 24⅞" × 4⅜" |
OEM X6675 | Save with Atomic → |
| X6666 | 17×26×4 16⅝" × 26" × 4" |
OEM X6666 | Save with Atomic → |
| X6669 | 21×26×4 20¾" × 25¾" × 3¾" |
OEM X6669 | Save with Atomic → |
| X7935 | 20×20×5 19¾" × 19⅞" × 4⅜" |
OEM X7935 | Save with Atomic → |
| X8788 | 20×26×5 20" × 25½" × 4⅜" |
OEM X8788 | Save with Atomic → |
| X8789 | 17×26×5 16.31" × 25.47" × 4.31" |
OEM X8789 | Save with Atomic → |
| X8790 | 20×21×5 20" × 20⅝" × 4⅜" |
OEM X8790 | Save with Atomic → |
| Y6604 | 20×26×5 20" × 20⅝" × 4⅜" |
OEM Y6604 | Save with Atomic → |
| Y6605 | 16×26×5 16⅜" × 25½" × 4⅜" |
OEM Y6605 | Save with Atomic → |
| Y6606 | 20×21×5 20" × 20⅝" × 4⅜" |
OEM Y6606 | Save with Atomic → |
Lennox PureAir Maintenance Kits - Complete Annual Solutions
Save money and ensure optimal performance with Lennox maintenance kits. Each kit includes MERV 16 filters, PCO cartridges, and UV lamps specifically matched to your system.
| Kit Model | Includes | For System | Shop |
|---|---|---|---|
| X8795 | (1) X8788 MERV 16 (1) X8791 PCO (2) X8794 UV lamps |
PCO20-28 | View Kit → |
| X8796 | (1) X8789 MERV 16 (1) X8792 catalyst (2) X8794 UV lamps |
PCO16-28 | View Kit → |
| X8797 | (1) X8790 MERV 16 (1) X8793 PCO (2) X8794 UV lamps |
PCO14-23 | View Kit → |
| X8345 | (1) X6669 MERV 16 (1) 75X66 catalyst (6) X8149 UV lamps |
PCO-20C | View Kit → |
| X8346 | (1) MERV 16 17×26×4 (4) UV-A lamps |
PCO System | View Kit → |
| X8347 | (1) X6666 MERV 16 (1) 75X73 catalyst (4) X8149 UV lamps |
PCO-12C | View Kit → |
| Y6608 | (1) Y6604 filter (1) Y6607 catalyst X8794 UV lamps |
PCO3-20-16 | View Kit → |
| Y6612 | (1) Y6605 MERV 16 (1) Y6607 cartridge (1) X8794 UV lamp |
PCO3-16-16 | View Kit → |
| Y6616 | (1) Y6606 filter (1) Y6621 PCO (1) X8794 UV lamp |
PCO3/PCO3S | View Kit → |
PCO Purification Cartridges
- Y6607 - PCO3-20-16 Air Purification Cartridge (Model 613860-01) - 20×26×5
How to Find the Right Lennox Filter for Your System
Where to Find Your Filter Model Number
Lennox prints the model number directly on the filter frame. Check the side of your current filter to find:
- Part number (e.g., X6673, X8310)
- Compatible model numbers from other brands (Honeywell, Trion Air Bear, Carrier)
- Nominal and sometimes actual dimensions
Where Are Lennox Filters Located?
Lennox furnace filters can be found in three main locations:
- Blower Compartment: Inside the furnace unit near the blower motor
- Filter Cabinet: A separate cabinet next to the air handler (for whole house filters)
- Return Air Grilles: In walls or ceilings throughout your home
Critical: Verify Actual Dimensions
⚠️ Important: Lennox filters have specific actual dimensions that differ from nominal sizes. A 20×25×5 filter from Lennox will NOT fit a 20×25×5 housing from another brand. Always:
- Measure your existing filter's actual dimensions
- Check our size charts for exact measurements
- Ensure measurements match within ¼ inch
Choosing the Right MERV Rating for Your Lennox System
MERV Rating Quick Guide
- ✓ MERV 8: Basic protection - Captures 65% of 3-10 micron particles (dust, pollen)
- ✓ MERV 10: Improved filtration - Captures 85% of 3-10 micron particles
- ✓ MERV 11: Better allergen control - Captures 85% of 3-10 micron particles plus smaller allergens
- ✓ MERV 13: Superior filtration - Captures 90% of 3-10 micron particles, recommended for allergies
- ✓ MERV 16: Hospital-grade - Captures 95% of 0.3-10 micron particles (bacteria, smoke, viruses)
Lennox Recommendation: Lennox recommends a minimum MERV 10 rating for optimal system protection and air quality.
Lennox 1-Inch Pleated Filters
For standard return vents and furnace slots, Lennox offers high-quality 1-inch filters in MERV 8 ratings. These 4-pack options provide excellent value:
| Model | Size | MERV | Pack Size | Shop |
|---|---|---|---|---|
| 91X23 | 14×20×1 | MERV 8 | 4-Pack | View → |
| 91X24 | 15×20×1 | MERV 8 | 4-Pack | View → |
| 91X25 | 18×25×1 | MERV 8 | 4-Pack | View → |
| 91X26 | 25×25×1 | MERV 8 | 4-Pack | View → |
🤧 Best Lennox Filters for Allergies & Asthma Relief
If you or your family suffer from allergies, choosing the right MERV rating is crucial. Here's what you need to know about Lennox filters for optimal indoor air quality and allergy protection.
Choosing the Right Lennox MERV Rating for Allergy Relief
| MERV Rating | Best For | What It Captures | Lennox Options |
|---|---|---|---|
| MERV 8 | Basic protection, no serious allergies | Dust, pollen, mold spores (3-10 microns) ~70% efficiency |
1-inch pleated filters (91X series) |
| MERV 10 | Moderate allergies, standard homes | Pet dander, fine dust, mold (1-10 microns) ~85% efficiency |
X8309 (16×25×5) X8310 (20×25×5) |
|
MERV 11 ✓ Recommended |
Allergy sufferers, pets | Pollen, pet allergens, dust mites, mold (0.3-10 microns) ~90% efficiency |
X6670 (16×25×5) X6673 (20×25×5) X0585, X0586 |
| MERV 13 | Severe allergies, asthma | Bacteria, smoke, virus carriers (0.3-3 microns) ~95% efficiency |
Available in PureAir kits (combines with UV) |
|
MERV 16 Hospital-Grade |
Maximum protection Severe allergies, immunocompromised |
Viruses, bacteria, smoke particles, all allergens (0.3+ microns) ~95% efficiency down to 0.3 microns |
X6672 (16×25×5) X6675 (20×25×5) X6666, X7935, X8788 |
🏠 Lennox's Official Recommendation
According to Lennox's HVAC buying guide, they recommend a minimum MERV 10 rating or higher for optimal system protection and air quality. For allergy sufferers, we recommend MERV 11 or MERV 16.
Top 3 Lennox Filters for Allergy Relief (2025)
Lennox X6673 - MERV 11
Size: 20×25×5
Actual: 19¾" × 24¾" × 4⅜"
Price: Mid-range
Best for: Most allergy sufferers
- Captures 90% of allergens
- Pet dander, pollen, dust mites
- Excellent airflow efficiency
- Lasts 6-12 months
Lennox X6675 - MERV 16
Size: 20×25×5
Actual: 19⅞" × 24⅞" × 4⅜"
Price: Premium
Best for: Severe allergies, asthma
- Hospital-grade filtration
- 95% efficiency down to 0.3 microns
- Captures bacteria, viruses, smoke
- Ideal for immunocompromised
Lennox PureAir™ System
Includes: MERV 16 + UV Light + Catalyst
Best for: Ultimate air purification
- Removes odors & VOCs
- Kills bacteria & viruses
- MERV 16 filtration
- Complete annual maintenance kits
What Common Allergens Does Each MERV Rating Capture?
| Allergen Type | Size (microns) | MERV 8 | MERV 11 | MERV 16 |
|---|---|---|---|---|
| Pollen | 10-100 | ✓ 70% | ✓✓ 90% | ✓✓✓ 95% |
| Dust Mites | 10-40 | ✓ 70% | ✓✓ 90% | ✓✓✓ 95% |
| Pet Dander | 2-10 | ~ 50% | ✓✓ 85% | ✓✓✓ 95% |
| Mold Spores | 3-40 | ✓ 65% | ✓✓ 90% | ✓✓✓ 95% |
| Bacteria | 0.3-10 | ✗ <20% | ~ 60% | ✓✓✓ 95% |
| Smoke Particles | 0.01-1 | ✗ Minimal | ~ 40% | ✓✓ 90% |
| Virus Carriers | 0.3-1 | ✗ Minimal | ~ 50% | ✓✓✓ 95% |
Choosing Between MERV 11 and MERV 16 for Allergies
Choose MERV 11 if:
- ✓ You have seasonal allergies or mild pet allergies
- ✓ You want excellent protection at a moderate price
- ✓ Your HVAC system is standard residential equipment
- ✓ You're looking for the best balance of filtration and airflow
Upgrade to MERV 16 if:
- ✓ You have severe allergies or asthma
- ✓ Someone in your home is immunocompromised
- ✓ You're concerned about smoke, viruses, or bacteria
- ✓ You want hospital-grade air quality
- ✓ Air quality is a top health priority
How Often to Change Lennox Filters for Allergy Relief
| Filter Type | Standard Home | With Pets | Severe Allergies |
|---|---|---|---|
| 1-inch MERV 8 | 30-90 days | 30-60 days | 30 days |
| 4-6 inch MERV 10-11 | 6-12 months | 4-6 months | 3-4 months |
| 4-6 inch MERV 16 | 6-9 months | 3-6 months | 2-3 months |
💡 Pro Tip: During peak allergy season (spring and fall), consider changing your filter more frequently—even MERV 16 filters can benefit from early replacement when pollen counts are high.
OEM vs Compatible Lennox Filters for Allergies
At Atomic Filters, we offer both genuine Lennox OEM filters and USA-made compatible alternatives. Here's what you need to know:
✓ Genuine Lennox OEM
- Official Lennox branded filters
- Guaranteed exact specifications
- Certified MERV ratings
- Premium pricing
💰 Atomic Compatible
- USA-made to meet/exceed OEM specs
- Same exact dimensions & MERV ratings
- Save 30-50% vs OEM
- Same allergen capture efficiency
The Bottom Line: Both options provide excellent allergy relief. OEM filters are the "name brand" choice, while Atomic compatibles deliver the same performance at a better price point—perfect if you're changing filters frequently for allergy management.
5 Additional Tips to Maximize Allergy Relief
- Change filters during peak allergy season more frequently - Don't wait for the full replacement cycle if pollen counts are high
- Run your HVAC fan continuously during allergy season - Constant filtration means cleaner air (use "fan on" setting)
- Check filter fit - Ensure no gaps around edges where allergens can bypass the filter
- Consider upgrading to a filter cabinet - Larger 5-6 inch filters have more surface area and last longer
- Pair with source control - Remove carpets, wash bedding in hot water, use allergen-proof mattress covers
🛒 Shop Lennox Filters for Allergy Relief
Choose from MERV 11 or MERV 16 options with same-day shipping
✓ Free Shipping on All Orders | ✓ Same-Day Shipping (Order by 11:30 AM EST, M-F)
Frequently Asked Questions About Lennox Filters
How often should I change my Lennox filter?
1-inch filters: Every 30-90 days depending on usage and environment
4-6 inch whole house filters: Every 6-12 months
MERV 16 filters: May need more frequent changes (4-6 months) due to higher efficiency
Tip: Check monthly and replace when visibly dirty or when airflow decreases.
Can I use any filter in my Lennox furnace?
You don't necessarily need OEM Lennox filters, but you must choose a filter with the exact same actual dimensions. Atomic compatible filters are specifically designed to match Lennox specifications at a lower cost. Always verify actual measurements, not just nominal sizes.
What's the difference between nominal and actual filter sizes?
Nominal size is the rounded label size (like 20×25×5), while actual size is the precise measurement. Lennox filters typically measure ¼" to ½" smaller than nominal. For example, a Lennox X6673 labeled as 20×25×5 actually measures 19¾" × 24¾" × 4⅜".
What MERV rating does Lennox recommend?
According to Lennox's HVAC buying guide, they recommend a minimum MERV 10 rating for optimal system protection and indoor air quality. Higher MERV ratings (13-16) are recommended for homes with allergy sufferers or those seeking maximum air purification.
Where is the Lennox ML193UH filter location?
The ML193UH filter is typically located on the side or bottom of the unit in the blower compartment. Units can be installed in upflow, downflow, or horizontal configurations, which may affect filter placement. Check your owner's manual for specific location.
How do I match my maintenance kit to my system?
Match the MERV 16 filter model in the kit to your current filter. For example, the X8795 kit includes the X8788 filter for PCO20-28 systems. Check your current filter model number and find the corresponding kit in our chart above.
Helpful Resources & Related Guides
- Shop All Lennox Filters →
- Complete List of All Filter Sizes with Actual Dimensions
- Understanding Nominal vs Actual Filter Sizes
- MERV 8 vs MERV 11: Which Is Right for You?
- How to Choose the Right Home Air Filter Every Time
- Browse All Furnace Filters by Size
- 16×25×1 Air Filters
- 20×25×1 Air Filters Guide
Need Help Finding Your Lennox Filter?
Our filter experts are here to help you find the perfect match!
📞 Call: 910-401-3910
Monday-Friday, 10am-5pm EST
Order by 11:30 AM EST for same-day shipping!
1 comment
I would like help with knowing the size of my air filter in my Lennox HVAC #LRP14HP30P-2A. Could you help me with the size please?!