Nordic Pure 20x25x5 Lennox X6673 X6675 Replacement Filter - MERV 10

In this review the Nordic Pure 20x25x5 Lennox X6673_X6675 Replacement AC Filter is evaluated for homeowners and HVAC do-it-yourselfers who need reliable particle removal plus odor control. The bottom line: this two-pack of pleated plus carbon filters delivers consistent dust capture and improved indoor air quality without causing noticeable restriction in standard systems, and it is worth considering when you need a direct replacement for Lennox X6673 or X6675 units. Measure your existing filter and compare to the stated actual size before buying to ensure a correct fit.

Key Features

• Actual size clarity: The filter lists an actual size of 19.75 x 24.75 x 4.38 in so users can match their return box precisely and avoid fit issues caused by nominal sizing.
• Direct replacement: Made to replace Lennox X6673 and X6675 media filters, it fits systems expecting those part numbers without modification.
• MERV 10 filtration: The MERV 10 rating (equivalent to MPR 1000) provides effective capture of dust and common airborne particles while maintaining reasonable airflow for most residential furnaces.
• Activated carbon layer: A fused carbon layer helps attract and hold odorous gases and VOCs, reducing household smells compared with standard pleated filters.
• Made in USA: Manufactured in the United States, which can reassure buyers about materials and production standards.

Who It's For

This filter is best for homeowners with systems that require a 20 x 25 x 5 nominal filter where the actual dimension of roughly 19.75 x 24.75 x 4.38 in will fit the return or media slot. It suits families and allergy sufferers looking for improved dust capture and modest odor control without upgrading to a much higher-resistance filter.

It is not ideal for systems that require exact factory nominal sizing without room for the actual dimensions listed, or for installations that demand higher than MERV 10 performance such as clinical environments. Also, buyers who need a thinner or deeper custom media should look elsewhere.

Pros & Cons

Pros

• Good particle capture with MERV 10 media that balances filtration and airflow.
• Carbon layer adds measurable reduction of odors and VOCs compared with plain pleated filters.
• Customers report a snug, correct fit in compatible bottom return boxes and steady airflow without furnace strain.
• Made in the USA and sold as a convenient two-pack for periodic replacement.

Cons

• Actual size differs from nominal size, so buyers must measure carefully to avoid a poor fit.
• Some customers note mixed impressions of build thickness, so long-term durability may vary by usage and system.

Specifications

Brand	Nordic Pure
Nominal size	20 x 25 x 5 in
Actual size	19.75 x 24.75 x 4.38 in
Replaces	Lennox X6673, X6675
Filter rating	MERV 10 (equivalent to MPR 1000)
Material feature	Pleated media fused with activated carbon
Package	2 pack

Our Verdict

The Nordic Pure 20x25x5 replacement filter is a practical, good-value choice for homeowners who need a direct Lennox X6673/X6675 substitute with dust capture and mild odor control. Measure to confirm the actual dimensions will fit your system, and expect reliable filtration with minimal impact on airflow for typical residential furnaces.

Frequently Asked Questions

Will this filter fit my 20 x 25 slot?
Check the return or filter slot and compare to the listed actual size of 19.75 x 24.75 x 4.38 in; nominal 20 x 25 x 5 labels often differ from the true size.

How effective is the carbon layer?
The activated carbon layer helps reduce household odors and some VOCs while the MERV 10 media captures dust and common airborne particles.

Is this safe for all furnaces?
Yes for most residential furnaces that accept MERV 10 media; however, always confirm the system tolerates a thicker media and monitor airflow after installation.