How to Replace an Aprilaire Filter

Aprilaire whole-home air purifiers use deep-pleated media filters -- 4 to 6 inches thick -- that slide into a dedicated cabinet installed in the return air path of the HVAC system. These are not standard 1-inch furnace filters.

They are high-capacity filter packs designed to last 12 months in most households rather than the 2 to 3 months of a standard pleated filter, and they provide significantly broader particle removal across MERV 10 to MERV 16 performance levels.

Replacing the filter requires no tools, takes about two minutes, and is a once-a-year maintenance task on most systems.

Step 1 - Identify Your Aprilaire Filter Number

The filter number is printed on the cardboard frame of the existing filter or on a label inside the cabinet door. The filter number directly corresponds to the Aprilaire air purifier cabinet model it fits, the table below maps the most common filter numbers to their cabinet models and MERV ratings.

The 210 and 410 provide MERV 11 performance. The 213 and 413 provide MERV 13 performance in the same cabinet, upgrading from a 201 to a 213 (or a 410 to a 413) in the same cabinet captures finer particles without requiring any equipment change. This is worth considering for households with allergy or asthma concerns.

If the filter number is not visible, the cabinet model is usually on a label on the cabinet door or side. Aprilaire cabinet models 1xx0 (1210, 1410, 1510) and 2xx0 (2200, 2210, 2400, 2410) are the most common series in residential HVAC systems. The DFS Air Filter Finder can confirm the correct filter by cabinet model.

Step 2 - Locate the Aprilaire Cabinet

The Aprilaire air purifier cabinet is almost always installed in the basement, mechanical room, or utility area -- in-line with the main return air duct feeding the furnace or air handler. It looks like a metal box approximately 12 to 24 inches in each dimension, with an access door on the front or side.

On some installations the cabinet is mounted directly to the furnace return air inlet. The cabinet is almost always located where the large return air duct connects to the furnace, before the blower.

Step 3 - Turn Off the HVAC System

Turn the thermostat to "Off" or set the fan to "Off" at the thermostat. Allow the system to fully stop before opening the cabinet. Replacing the filter while the blower is running draws unfiltered air into the system during the brief period the filter is out.

Step 4 - Open the Cabinet and Remove the Old Filter

Open the Aprilaire cabinet access door -- on most models it is hinged on one side and swings open, or slides up and out. The filter media pack sits directly inside the cabinet. Grasp the filter at the top and bottom of the frame and slide it straight out toward you.

 The filter is typically 4 to 6 inches thick and has a cardboard frame, it is heavier than a standard furnace filter. Have a plastic bag ready to contain the old filter, which will be loaded with captured dust and particles.

Note the airflow direction arrow on the existing filter frame before discarding it. This confirms the correct orientation for the new filter.

Step 5 - Install the New Filter

Remove the new filter from its packaging. Confirm the filter number matches your cabinet model. Slide the new filter into the cabinet slot with the airflow arrow pointing toward the furnace (in the direction air flows through the system, away from the return duct side, toward the blower).

Aprilaire filters use a Self-Seal frame design, the cardboard frame is manufactured to compress slightly against the cabinet walls when fully inserted, creating a gasket seal that prevents unfiltered air from bypassing around the edges of the filter.

Push the filter fully into the slot until the frame seats against the cabinet walls on all sides. A filter that is not fully seated allows air bypass that defeats the purpose of a MERV 11 or MERV 13 filter. Close the cabinet access door until it latches.

Step 6 - Restore HVAC Operation

Return the thermostat to its normal setting. The system will resume normal operation through the new filter immediately.

When to Replace and Why Annual Replacement Works

Aprilaire's deep-pleated design provides approximately 75 square feet of filtration media surface area in a standard 20x25x6 filter -- compared to approximately 6 to 8 square feet for a standard 1-inch pleated filter in the same face dimensions.

This dramatically higher surface area distributes the particle load across a far greater media volume, which is why the filter can last 12 months without the pressure drop and flow restriction that would clog a standard filter in two to three months.

In households with pets, smokers, or residents with significant allergy or asthma concerns, checking the filter at 9 months and replacing by 12 months at the latest is the appropriate schedule.

For most standard residential households, annual replacement in conjunction with the heating system's annual tune-up is a practical and sufficient routine.

The full DFS Aprilaire replacement filter collection covers filter numbers 201, 210, 213, 401, 410, 413, 501, and 513 with same-day shipping.

For a broader understanding of MERV ratings and what each performance level captures, the DFS MERV ratings guide covers the full scale with guidance on household-specific selection.

Questions about which Aprilaire filter is right for your cabinet model? Call the DFS team at 1-800-277-3458.

Frequently Asked Questions

What is the difference between an Aprilaire filter and a standard furnace filter?

Standard furnace filters are 1 inch thick and fit into the filter slot of the furnace or air handler directly. Aprilaire whole-home air purifier filters are 4 to 6 inches thick and fit into a dedicated Aprilaire cabinet installed in the return air duct. The deeper media pack provides approximately 10 times the surface area of a standard 1-inch filter, enabling MERV 10 to MERV 16 performance at a 12-month service life without the airflow restriction that a 1-inch MERV 13 filter would create.

How do I know which Aprilaire filter to buy?

The filter number is printed on the cardboard frame of the existing filter or on a label inside the Aprilaire cabinet door. The number (201, 210, 410, 413, 501, etc.) directly identifies the compatible cabinet and MERV performance level. If the number is unreadable, the cabinet model number on the cabinet exterior determines the correct filter. The DFS Air Filter Finder can confirm the correct filter by cabinet model.

Can I upgrade to a higher MERV Aprilaire filter in my existing cabinet?

Yes. The 201 (MERV 10) and 213 (MERV 13) both fit the same 2200 and 2250 cabinet. The 410 (MERV 11) and 413 (MERV 13) both fit the 1410, 2410, 3410, and 4400 cabinet. Upgrading from the lower-MERV version to the higher-MERV version of the same filter series is a drop-in replacement that provides finer particle capture -- including bacteria-sized particles at MERV 13 -- without any cabinet modification.

Does the Aprilaire filter need to be installed in a specific direction?

Yes. The airflow arrow on the filter frame must point toward the furnace -- in the direction air flows through the system. Installing the filter backwards does not damage the system but reduces filtration efficiency because the media is designed with a capture side facing the incoming airflow.

How often should I replace an Aprilaire filter?

Every 12 months under normal residential conditions. Households with multiple pets, smokers, high indoor dust levels, ongoing construction, or residents with significant respiratory sensitivities may benefit from replacement every 9 months. The large surface area and deep-pleated design maintain effective airflow and filtration for a full year in most standard households.

What happens if I don't fully seat the Aprilaire filter in the cabinet?

The Aprilaire Self-Seal frame creates a gasket seal against the cabinet walls when the filter is fully inserted. If the filter is not fully pushed in, unfiltered air bypasses around the edges of the filter frame -- the system draws air through the path of least resistance, which is around the filter rather than through it. A correctly installed Aprilaire filter should have no visible gap between the frame and the cabinet walls on any side.

Are aftermarket replacement filters available for Aprilaire cabinets?

Yes. DFS carries compatible replacement filters for all major Aprilaire cabinet models at equivalent MERV ratings to the OEM filters. DFS compatible filters for Aprilaire are engineered to the same nominal dimensions and Self-Seal frame design, ensuring proper fit and air seal performance in the existing cabinet.