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21" x 26" x 4"
21x26x4 Lennox X6667 / X6669 Air Filters
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Products
MERV Rating
Filter Life
Annual Cost
Value Pack
SpiroPure N
Lennox Compatible (MERV 9)
$50.99
2 Filters
($25.50 / filters)
MERV 8
Learn more
6 Months
$50.99
Best Value!
$50.99
2 Filters
($25.50 / filter)
Aprilaire
261 Air Cleaner Filter
$112.99
1 Filters
($112.99 / filters)
MERV 10
Learn more
12 Months
$112.99
$112.99
1 Filters
($112.99 / filter)
Lennox
Lennox Air Filters X6667
5 stars
$54.99
1 Filters
($54.99 / filters)
MERV 11
Learn more
6 Months
$109.98
$54.99
1 Filters
($54.99 / filter)
Lennox
X8348 Healthy Climate PureAir Maintenance Kit
$415.99
1 Filters
($415.99 / filters)
MERV 11
Learn more
12 Months
$415.99
$415.99
1 Filters
($415.99 / filter)
SpiroPure N
Lennox Compatible (MERV 13)
$57.99
2 Filters
($29.00 / filters)
MERV 13
Learn more
6 Months
$57.99
$57.99
2 Filters
($29.00 / filter)
SpiroPure O
Lennox X6669 Replacement (MERV16)
$118.44
1 Filters
($118.44 / filters)
MERV 13
Learn more
6 Months
$236.88
$118.44
1 Filters
($118.44 / filter)
Lennox
X6669 Healthy Climate 21" x 26" x 4"
$198.99
1 Filters
($198.99 / filters)
MERV 13
Learn more
6 Months
$397.98
$198.99
1 Filters
($198.99 / filter)
Lennox
X8344 Healthy Climate PureAir Upgrade Kit
$488.99
1 Filters
($488.99 / filters)
MERV 13
Learn more
12 Months
$488.99
$488.99
1 Filters
($488.99 / filter)
Lennox
X8345 Healthy Climate PureAir Upgrade Kit
$549.99
1 Filters
($549.99 / filters)
MERV 13
Learn more
12 Months
$549.99
$549.99
1 Filters
($549.99 / filter)
MERV Rating
- Contaminant Removal Guide
MERV Rating
8
11
12
13
Lint & Dust
Dust Mite Debris
Pollen
Mold Spores
Pet Dander
Auto Emissions
Smoke
Tobacco
Bacteria
Note:
equals efficient removal of contaminant by filter.
×
MERV
stands for
Minimum Efficiency Reporting Values
and is an industry-created standard that evaluates the efficiency of air filters. The MERV rating of any particular air filter ranges on a scale of 1 to 16, with a filter rating 1 being the least efficient and a filter rating 16 being the most efficient.
While it is important for the quality of the air in your environment to choose the most efficient filter possible, it is not always as simple as buying a filter with the highest MERV rating. Because the pores allowing for air flow in a highly-rated MERV filter are very small, the filter creates more resistance against air flow and may put too much pressure on the fan of your furnace, air conditioning, or air cleaner unit. It’s important to choose an air filter with the highest MERV rating that your particular unit will allow for maximum air flow. Information about specific MERV ratings and recommendations will generally be included with the documentation that came with your system.
We recommend choosing an air filter with a MERV rating between 8 and 11 for most residential units in order to adequately remove airborne contaminants. If your system can handle a filter with a higher MERV rating, you may wish to use a filter with a rating of 13 for even greater contaminant removal. However, it’s important to remember that filters with a higher MERV rating must be replaced regularly (every 3 months for 1" filters and every 6-12 months for 3-6" box-type filters) to avoid restricted air flow and negative effects on your system’s performance.
×
Lint and dust
particles are typically present in any indoor environment and can range in size from .3 microns to 100 microns. Household dust is made up of a variety of ingredients including dead skin cells, small insect and plant parts, tiny particles of dirt, and loose fibers from fabric (commonly known as lint). Like any allergen, too much exposure to dust and lint can kick the immune system into gear, causing allergic reactions like sneezing, runny nose, and watery eyes.
Removing lint and dust particles both prevents dust build-up on the fan and coils of your filter unit and stops these potential allergens from being released into the air. Nearly any air filter with a MERV rating of 8 or higher will efficiently remove these contaminants from the household air.
×
Dust mites
are tiny insects that are closely related to spiders and ticks. They feed on the dead skin cells that flake off our bodies and are present wherever humans live. Although the dust mite itself is typically larger than 10 microns, the debris a mite leaves behind (shed skin, feces, and other excretions) can be anywhere in size from .3 microns to 10 microns.
Dust mite debris
is second only to pollen as the most common cause of allergic reactions in humans. Like any allergen, too much exposure to dust mite debris can kick the immune system into gear, causing allergic reactions like sneezing, runny nose, and watery eyes. Nearly any air filter with a MERV rating of 8 or higher will efficiently remove these contaminants from the household air.
×
Pollen
is a tiny particle created by flowers as a part of the reproduction process. It is carried by the wind from flower to flower and is often present in both indoor and outdoor air. Pollen is the most likely of any other airborne contaminant to cause an allergic reaction, and once it finds its way into the body it can cause symptoms like sneezing, runny nose, and water eyes.
Pollen particles are relatively large (ranging in size from 10 to 100 microns) and can be efficiently removed by any air filter with a MERV rating of 8 or higher.
×
Mold
is a tiny organism that belongs to the fungi kingdom, meaning it is not classified as either plant or animal. Mold is commonly present in any household because it likes to feed on things like wood beams, ceiling tiles, wallpaper, paint, carpet, and insulation. When mold reproduces, it creates a number of tiny mold spores (approximately 3 to 40 microns in size) that function like seeds. If mold is disturbed during the reproduction process, it can release these spores into the household air.
Like any allergen, too much exposure to mold spores can kick the immune system into gear, causing allergic reactions like sneezing, runny nose, and watery eyes. Nearly any air filter with a MERV rating of 8 or higher will efficiently remove these contaminants from the household air.
×
Pet dander
refers to the tiny flakes of skin that animals naturally shed as their skin cells die and flake off. For most people who suffer from pet allergies, it is the dander and not the hair of the animal that causes an allergic reaction. Pet dander is often in the air and can stay suspended in the household air for many months after an animal has been in the home.
Particles of pet dander are typically 10 to 100 microns in size and can cause a range of allergic reactions including sneezing, runny nose, watery eyes, coughing, wheezing, and even asthma attacks. Nearly any air filter with a MERV rating of 8 or higher will efficiently remove these contaminants from the household air.
×
Auto emissions
are fumes that are released into the air as a part of the combustion process in a gasoline engine. The fumes are made up of a number of different gases including unburned hydrogen carbon, carbon monoxide, nitrogen oxide, and carbon dioxide. While they are more commonly a concern in commercial or industrial buildings, auto emissions can enter the household air through vents that suck air from the outside and the opening of household doors. Breathing in too many of these fumes can irritate and/or damage the lungs.
Particles containing auto emission fumes typically range from 1 to 3 microns in size and can be efficiently removed by an air filter with a MERV rating of 9 or higher.
×
Smoke
can enter the household air from a variety of sources including cigarettes, cigars, wood-burning fireplaces, and industrial activities outside the home. In addition to a number of different carcinogenic gases and chemicals, smoke can also contain tiny particles of wood tars, ashes, and soot. Too much exposure to smoke can cause the typical allergic reactions of sneezing, runny nose, and water eyes, as well as burning eyes, bronchitis, and asthma attacks.
Because particles of smoke are quite small (typically 0.3 to 1.0 microns in size), an air filter with a MERV rating of 11 or higher is required to efficiently remove them.
×
Tobacco smoke
is typically only present in the household air if you or someone else in the house smokes. It contains many different carcinogenic chemicals and gases, and too much exposure can cause the typical allergic reactions of sneezing, runny nose, and water eyes, as well as burning eyes, bronchitis, asthma attacks, and some types of cancer.
The particles of tobacco smoke that stay in the air and cause odors are typically less than 1 micron in size and can only be removed by an air filter with a MERV rating of at least 13.
×
Bacteria
are tiny microorganisms that are present everywhere. They are in everything we touch and breathe, and the bacteria found within our bodies actually outnumber our own cells. There are a variety of good bacteria that help us to digest food and fight off sickness, but there are also some types of harmful bacteria that can cause illnesses like pneumonia, strep throat, and a number of infections.
Bacteria particles in the air are very small (ranging in size from 0.3 to 1.0 microns) and require a filter with a MERV rating of at least 13 to be efficiently removed. However,
if you are concerned about bacteria in your household air, the best method for removal and treatment is a
HEPA air filtration
unit
.
×
The All Filters
Odor Eliminator
filter uses a revolutionary carbon filter media called Gray Matter to efficiently remove household odors without reducing the overall air flow. The Gray Matter media works by reducing the average carbon granule size in the filter to maximize total surface area. The smaller granules create more outer surface area for odors, fumes, and other air contaminants to adhere to, greatly increasing the filter’s efficiency.
The lightweight, durable filter fits into existing filter housings to provide guaranteed odor control without the need for expensive re-fittings or fans.
The carbon media is also resistant to moisture and microbial growth, keeping your household air safe from re-contamination.
This valuable filter provides efficient, safe odor control at a price that competes with standard pleated air filters!
×
Permatron filters have a
lifetime warranty
and are
washable
, making them a reusable, permanent solution. The manufacturer recommends washing the filter once a month for optimum performance.
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