Nordic Pure 20x25x5 Lennox Replacement MERV 15 Air Filters - 4 Pack

In this review of the Nordic Pure 20x25x5 Lennox replacement air filters, the bottom line is simple: this 4 pack is for homeowners or light commercial operators who need high-efficiency filtration and a reliable fit for systems that accept Lennox X6673 or X6675 style media filters. The reviewer found the single biggest reason to buy is the MERV 15 level filtration that captures fine particulates while maintaining steady airflow in properly sized housings, provided you confirm the actual dimensions first.

Key Features

• Actual Size Accuracy: The listed actual size of 19.75 x 24.75 x 4.38 in helps buyers confirm fit before ordering to avoid installation issues.
• Lennox Compatibility: Made to replace Lennox X6673 and X6675 filters, so it fits systems and housings designed for those media filters.
• High Filtration Efficiency: Nordic Pure MERV 15 performance is equivalent to MPR 2800, which filters very small particles and improves indoor air quality.
• Pack Quantity: Sold as a 4 pack, offering an immediate supply for quarterly or more frequent changes depending on use and environment.
• Made in USA: Manufactured in the United States, which many buyers prefer for perceived quality control and supply reliability.
• Depth Variance Warning: The item clarifies that this traditional 5 filter measures an actual 4 3/8 in depth, helping avoid mismatches with 4 7/8 or 5 1/4 in housings.

Who It's For

This filter set is aimed at homeowners, renters, and small commercial users with furnaces or air handlers that accept Lennox-style media filters and who want high-efficiency particle capture for allergy reduction or improved indoor air quality. It is a sensible choice for anyone who measures their existing filter or housing and confirms the actual 19.75 x 24.75 x 4.38 in dimensions.

It is less suitable for buyers who cannot confirm the actual depth and face dimensions of their filter slot, or for systems requiring the thicker 4 7/8 in or 5 1/4 in media. Those users should measure carefully or select a filter explicitly matching the alternate actual depth.

Pros & Cons

Pros

• High-efficiency MERV 15 filtration captures fine dust and improves air quality.
• Designed to replace Lennox X6673/X6675, making it easy to swap into compatible systems.
• Made in the USA and sold as a convenient 4 pack for multiple changes.
• Clear actual size listing reduces risk of ordering the wrong fit if you measure first.

Cons

• Actual depth is 4 3/8 in which can cause fit issues if your housing expects a different nominal 5 in or deeper media.
• Some customers reported mixed opinions on build quality, so expectations should be tempered for heavier commercial use.

Specifications

Brand	Nordic Pure
Nominal Size	20 x 25 x 5 in
Actual Size	19.75 x 24.75 x 4.38 in
MERV Rating	MERV 15 (equivalent to MPR 2800)
Replaces	Lennox X6673, X6675
Quantity	4 pack
Manufactured	Made in the USA

Our Verdict

For anyone with a compatible Lennox-style housing who measures and confirms the actual 19.75 x 24.75 x 4.38 in dimensions, this Nordic Pure 4 pack is a practical, high-efficiency choice. It delivers MERV 15 level capture and good value for regular replacement cycles, though buyers should verify depth compatibility before ordering.

Frequently Asked Questions

Will this filter fit my furnace?
Measure your current filter or housing and compare to the listed actual size of 19.75 x 24.75 x 4.38 in to ensure a proper fit.

How efficient is the filtration?
The filters are rated MERV 15, equivalent to MPR 2800, which captures very small particulates and improves indoor air quality.

Is this the same as a nominal 5 in filter?
It is sold as a traditional 5 filter but the actual depth is 4 3/8 in, so confirm your housing accepts that depth before buying.