Actual size: 15.5 x 19.5 x 3.75 inches
Deep pleated air filters for whole-house and commercial HVAC systems
MERV 11 filters remove up to 95% of common particles including fine dust, smoke, and smog particles. These filters reduce allergy symptoms and protect against outdoor air pollution.
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MERV 11 air filters are designed for homes with allergies and in some cases, asthma. Those with respiratory illnesses or compromised immune systems may benefit from MERV 11 air filters due to these filters being significantly more powerful than alternative MERV filters at capturing smaller particles, such as MERV 8.
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Check the label on your current filter or use a tape measure to get the exact length, width, and depth before selecting your size.
Nominal size
Nominal size is what you normally see printed on the label. This is usually a rounded size which is often not the true size of your filter.
Actual size
Actual size is the true size of the air filter, usually written in smaller font below the nominal size.
Measure your current air filter or the length, width, and depth of the opening slot to get the actual size. Round it up to the nearest whole inch to get the nominal size.
Installing 16x20x4 air filters couldn't be easier. Just make sure to align the arrow printed on the side with the airflow direction!
Remove the air filter from the package
Locate the arrow and point it in the direction of the fan
Slide the filter in to the slot of the central unit
For return grills, insert the filter into the grill, pointing the arrow inwards
Keeping your air filter replacement schedule in mind can be challenging to say the least. Make your life easier with Filter King's auto delivery.
The 16x20x4 air filter's nominal size is slightly larger than its true dimensions, which are actually approximately 15.5 x 19.5 x 3.75 inches. This small reduction allows the filter to slide in easily with proper sealing.
Most filters of this size can be changed every 6–9 months. However, homes with extreme levels of dust, pets, or allergens may need replacements around 6 months.
No. You can only use a 5-inch filter if your media cabinet is designed for a 5-inch filter. Forcing a 5-inch filter can restrict airflow or damage the housing.
Not always. In systems designed for 4-inch media filters, MERV 13 will typically maintain acceptable airflow. This added depth provides more surface area, which helps avoid airflow problems commonly associated with 1-inch MERV 13 filters.
Yes. A media cabinet or compatible filter rack is essential. 4-inch filters cannot be installed in standard 1-inch filter slots.
4-inch filters use more filter media, last longer, and provide better airflow stability. This results in fewer replacements, often making them more cost-effective over time.
No. Vacuuming can damage the filter media and reduce filtration effectiveness.
A 4-inch filter offers more surface area, better dust-holding capacity, steadier airflow, and a longer lifespan. A 1-inch filter is thinner and will require frequent replacements, as it can clog more quickly (especially with higher MERV ratings).
MERV 8 filters