If you want a budget-friendly, high-volume solution for standard residential systems that fits easily into tight spaces, choose Simply 14x20x1; if you need superior particle capture with a longer replacement cycle and a cleaner installation experience, choose HEALTHY CLIMATE Lennox X6670.
• Simply 14x20x1: Strengths include a massive six-pack bundle, MERV 8 efficiency, and Made in USA construction; the trade-off is the shorter three-month lifespan and lower filtration grade compared to premium options.
• HEALTHY CLIMATE Lennox X6670: Strengths feature a robust MERV 11 rating, a one-year durability window, and included cleaning tools for better maintenance; the trade-off is the higher upfront cost per unit and significantly thicker profile requiring deeper slots.
• Best for: The Simply filter suits homeowners on a strict budget who change filters frequently, while the Lennox option targets those seeking maximum air purity and fewer interruptions.
The Simply 14x20x1 Air Filter is designed for the pragmatic homeowner who values volume and consistent performance over cutting-edge filtration technology. With a MERV 8 rating, this filter does exactly what it promises: it captures dust, mold spores, pet dander, and pollen. If your home has average traffic, standard pets, or seasonal allergies that aren't severe, this filter hits the sweet spot between cost and function.
One of the most compelling aspects of this product is the packaging strategy. You receive six units in a single box, each measuring 13.75" x 19.75" x 0.75". This "actual size" ensures they slide smoothly into slots marked as 14x20x1 without forcing them, accommodating almost any brand of HVAC system. The pleated technology mentioned in the specs suggests a higher pleat count than typical retail filters, which helps optimize airflow and prevents the system from struggling against resistance. This is critical for older furnaces that might choke on denser media.
However, the longevity is the defining constraint here. The manufacturer states these filters last up to three months. For a family with heavy usage, multiple pets, or a dusty environment, this means you are swapping out filters four times a year. While the sheer quantity of six filters covers a full year plus two extra, the labor of changing them quarterly can add up. Furthermore, because they are only 0.75 inches thick, they fit into shallow return grilles where thicker filters simply won't go. If your slot is deep enough to hold a 4-inch filter, you might be underutilizing the space available by choosing this thinner model.
This product is perfect for renters, budget-conscious buyers, or anyone running a standard AC unit in a home with moderate air quality needs. It is less ideal for people with severe asthma or those who want to minimize the frequency of their maintenance tasks. The fact that they are made in the USA using recycled materials adds a layer of local manufacturing appeal, but the core decision rests on whether you prioritize the low cost-per-filter and high availability over extended service intervals.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-11-05 · 7 min read · Independent comparison
The HEALTHY CLIMATE Lennox X6670 steps up the game with a MERV 11 rating, positioning itself as a high-performance media filter rather than a standard basic unit. This higher rating allows the filter to capture a wider range of airborne particles, specifically targeting impurities as small as 1.0 to 3.0 microns. If you are dealing with fine dust, smoke residue, or significant allergy triggers, the jump from MERV 8 to MERV 11 represents a tangible difference in how clean the air circulating through your vents actually is. It is an excellent choice for improving indoor air quality in homes, offices, schools, and hospitals where stricter standards often apply.
Beyond raw filtration power, the design philosophy here focuses heavily on convenience and longevity. A single unit is marketed to last up to one year, depending on your home's condition, with a recommended replacement window of 6 to 12 months. This is a massive shift from the quarterly schedule required by the Simply filter. You essentially install it once and forget it for the majority of the year. Additionally, the package includes a cleaning cloth, instructing users to wipe down the furnace or air handler before installing the new filter. This attention to detail in the user experience ensures optimal airflow and prevents debris buildup that could otherwise negate the benefits of a high-efficiency filter.
The physical dimensions are a major factor to consider. With an actual size of 15.75" x 24.75" x 4.38 inches, this is a thick, substantial block compared to the thin 0.75-inch profile of the competitor. It is designed to fit specific systems like the X6660 HCC16-28 Air Cleaners, as well as compatible Lennox, Carrier, and Honeywell systems. If your HVAC return slot is only deep enough for a 1-inch filter, this will not fit. You must verify that your ductwork can accommodate the 4.38-inch depth before purchasing. However, for those with the space, the thickness usually correlates with more media surface area, which contributes to both the longer lifespan and the higher filtration efficiency.
This product is best suited for homeowners with larger, modern HVAC systems who have the physical room for a 4-inch filter and want to reduce maintenance frequency. It is also the logical choice for households with severe allergies, respiratory issues, or high levels of indoor pollutants. The inclusion of the cleaning tool shows a commitment to a complete cleaning process, ensuring the system runs efficiently. While it costs more upfront and requires a specific slot depth, the value proposition lies in the reduced labor and superior air purification capabilities.
• Filtration Efficiency: Choose HEALTHY CLIMATE Lennox X6670 for its MERV 11 rating, which captures smaller particles (1.0-3.0 microns) compared to the MERV 8 level of the Simply filter.
• Maintenance Frequency: Choose HEALTHY CLIMATE Lennox X6670 if you prefer replacing your filter once a year rather than every three months.
• Physical Fit: Choose Simply 14x20x1 if your HVAC return slot is shallow (approx. 1 inch); choose HEALTHY CLIMATE Lennox X6670 only if you have a deep slot capable of holding nearly 4.5 inches.
• Bundle Value: Choose Simply 14x20x1 for immediate bulk savings, as you get six filters in one box versus a single unit from Lennox.
• Installation Experience: Choose HEALTHY CLIMATE Lennox X6670 for the added convenience of the included cleaning cloth to prep your air handler before installation.
• Airflow Dynamics: Choose Simply 14x20x1 if you run an older furnace that struggles with high-resistance media; the thinner profile offers easier airflow passage.
• Long-Term Durability: Choose HEALTHY CLIMATE Lennox X6670 for a "set it and forget it" approach that lasts up to a full year of operation.
• Manufacturing Origin: Choose Simply 14x20x1 if supporting American-made components using recycled materials is a priority for your purchasing decision.
After weighing the specifications, I would buy the HEALTHY CLIMATE Lennox X6670 for my own home. The leap to MERV 11 filtration provides a noticeable upgrade in air purity that justifies the extra effort of finding a compatible slot. The ability to leave the filter in place for up to a year eliminates the hassle of frequent changes, and the included cleaning cloth ensures the whole system stays clean. That said, if you are strictly constrained by a shallow 1-inch return grille or need to equip a bike rack setup with a temporary, low-profile solution, the Simply 14x20x1 remains the practical workhorse. For long-term health and convenience, the Lennox option wins on pure merit.
Yes, the nominal measurement is 16x25x5, but the actual size is 15.75" x 24.75" x 4.38". It is designed to fit specific models like the X6660 and other Lennox, Carrier, and Honeywell systems, so verifying your exact slot depth is crucial.
If you have pets or a dusty home, you may need to check it monthly, but the recommendation is generally quarterly.
A thicker filter with a MERV 11 rating typically maintains airflow better over time than a clogged thin filter, potentially saving energy. However, if your fan motor is weak, the increased resistance of a 4-inch media filter could theoretically strain the system, though it is designed for efficient operation.
The kit includes a cleaning cloth specifically intended to remove dirt and debris from your furnace or air handler before installing the new filter. Using it to keep the intake area clean helps ensure optimal airflow and extends the life of the filter.
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