Lennox X6673 MERV 11 vs Aprilaire 213 MERV 13
Bottom line
This one is a tie in our scoring: both earn 6.0/10 and both score 8.0/10 on rating honesty, so we split it by what you need. We would pick the Aprilaire 213 when you want the higher true MERV 13 capture and run a system that can handle a 4-inch media filter; it is the technically right way to run MERV 13, with Aprilaire publishing a 0.15 in. w.c. pressure drop at 1200 CFM. The Lennox X6673 is the better pick when MERV 11 is enough and you want lower spend, since at about $36 a year it costs roughly $29 a year less; its 5-inch depth also gives low airflow restriction. Note that the X-series also sells MERV 13 and 16 cartridges, so confirm the exact part before buying.
The real split is filtration rating against running cost. The Aprilaire 213 is a true MERV 13 on the ANSI/ASHRAE 52.2 scale and runs about $65 a year on roughly yearly replacement; the Lennox X6673 is a true MERV 11 and runs about $36 a year. Both label their MERV honestly, with no proprietary MPR or FPR number to decode, and neither carries any third-party filtration certification we could verify. In our scoring both land at 6.0/10, a weak result driven by that lack of independent certification, not by either being mislabeled.
| MERV 11 | True MERV (ANSI/ASHRAE 52.2) | MERV 13 |
| 5.0 | Verified Filtration30% | 7.0 |
| 6.0 | Total Cost of Ownership25% | 3.5 |
| 8.0 | Rating Honesty20% | 8.0 |
| 6.0 | Airflow Fit15% | 6.0 |
| 5.0 | Practical Fit10% | 5.0 |
FAQ
- Is the Lennox Healthy Climate X6673 (5-inch media, MERV 11) better than the Aprilaire 213 (4-inch media, MERV 13)?
- In our scoring the Lennox Healthy Climate X6673 (5-inch media, MERV 11) rates 6.0/10 and the Aprilaire 213 (4-inch media, MERV 13) 6.0/10. This one is a tie in our scoring: both earn 6.0/10 and both score 8.0/10 on rating honesty, so we split it by what you need. We would pick the Aprilaire 213 when you want the higher true MERV 13 capture and run a system that can handle a 4-inch media filter; it is the technically right way to run MERV 13, with Aprilaire publishing a 0.15 in. w.c. pressure drop at 1200 CFM. The Lennox X6673 is the better pick when MERV 11 is enough and you want lower spend, since at about $36 a year it costs roughly $29 a year less; its 5-inch depth also gives low airflow restriction. Note that the X-series also sells MERV 13 and 16 cartridges, so confirm the exact part before buying.
- Which filters more, the Lennox or the Aprilaire?
- The Aprilaire 213 is rated higher. On the data it is a true MERV 13 on the ANSI/ASHRAE 52.2 scale, versus the Lennox X6673 at true MERV 11. A higher MERV captures a wider range of fine particles. Both label their MERV honestly, and neither carries a third-party filtration certification we could verify.
- Is the Aprilaire 213 worth the extra money?
- In our view it depends on whether you need MERV 13. The Aprilaire runs about $65 a year against roughly $36 for the Lennox, so it costs about $29 more annually for the step up from MERV 11 to MERV 13. If MERV 11 covers your needs, the Lennox is the lower-cost pick; if you want the higher capture and your system handles a 4-inch media filter, the extra spend buys real filtration.
- Do these filters restrict airflow?
- Both are deep media filters built to keep airflow restriction low. The Lennox is 5-inch media and the Aprilaire is 4-inch, and Aprilaire publishes a static pressure drop of 0.15 in. w.c. at 1200 CFM for the 213. Deep media is the technically correct way to run a higher MERV without choking airflow, unlike high-MERV ratings forced into a 1-inch filter.