Frequently Asked Questions

What is APR? APR stands for Accumulair Performance Rating.  This rating has been established by the manufacturer of the Accumulair Filters. This rating exists to demonstrate the different levels of efficiency throughout the Accumulair filter line. Generally speaking, the higher the APR, the better the filter performs in capturing small airborne particles. This rating system is an internal rating system and applies to Accumulair filters only.

How do I know which filter is best for me?  The filter that is best for you depends on health and living conditions.  For example, if you have asthma or severe allergies to things in the air, an APR 1950 filter may be best for you.  Or, if you smoke, a Carbon Odor Block filter may be best.  If you do not have severe allergy problems, don’t smoke in your home, and don’t have any indoor pets, a standard APR 1950 filter is generally the best option for you.

How do I know what size filter I need?  For furnace or air conditioner filters, you can determine your size by measuring your old filter and looking at the size printed on the frame.  For 5” and 6” furnace filters, you can also search our site by your unit’s model number.  For air cleaner or humidifier filters, you can search our site by your unit’s model number. 

What is the difference between Actual Sized and Nominal Sized Furnace/AC filters? Actual sized filters measure the same as the dimensions printed on the frame.  For example, if the frame of the filter says 16.5x21x1, and the filter measures exactly 16.5x21, this is an “actual” size filter.  Nominal sized filters generally measure ½” under the dimensions printed on the frame.  For example, if the frame of the filter says 20x25x1, but the filter actually measures 19 ½ x 24 ½, then this is a “nominal” or “under-cut” filter.  When ordering, it is important to confirm that you are getting the appropriate size by referring to the product description.  The actual size of the filter will be in parenthesis.  Example:    

Accumulair Diamond APR 1950 Filters - 1 Inch
Size: 16.5x21x1 (Actual Size)

Accumulair Diamond APR 1950 Filters - 1 Inch
Size: 20x25x1 (19.5x24.5) 

How do I order a custom size filter?  Go to: Custom Filters Scroll down and choose Accumulair Diamond APR 1950, Platinum APR 1550, Gold APR 650, or Emerald APR 450.  Select the exact dimensions of your filter.  Enter the quantity and add to cart.

Can I return a custom filter?  Unfortunately, you cannot return a custom size filter. A custom size filter is built to your exact specifications, and as a result cannot be reused or resold. We apologize for any inconvenience this may cause.

What is a Whole House filter?  Whole House generally refers to a furnace filter or an air conditioner filter.  These types of units usually supply cool or warm air to your whole house.

Why is my humidifier filter not “wicking” the water?  A humidifier filter will stop wicking when it has dried out.  Mineral deposits in the water supply (hard water) will cause a humidifier filter to dry out.  Some solutions to help your humidifier filter last longer include:  using humidifier water treatment, making sure you don’t let the humidifier run out of water (fill the tank before it gets empty), and cleaning your filter once a week.  You can clean your humidifier filter by soaking it in vinegar for about 15 minutes.  After you soak it in vinegar, rinse it thoroughly under running water, and then put it back in your humidifier unit.

Why is there a black mark on my humidifier filter?   Some evaporator pads come with a black mark on them.  This is simply so that you can identify that this is the top of the filter.

What is this stuff flaking off of my humidifier filter?  This is to be expected from certain humidifier filters. This happens because some evaporator pads have been coated with a non-soluble wetting agent to enhance the efficiency of the humidifier. Some excess coating may flake off before the installation of the filter.

What is the difference between an OEM and aftermarket?  OEM stands for Original Equipment Manufacturer.  Some people refer to these as the “Brand Name” products.  Aftermarket products are not made by the original manufacturer.  Aftermarket products are sometimes referred to as “Replacements.”    

Do your aftermarket filters meet the same specifications as the OEM?  Our aftermarket filters are designed to be as efficient as the OEM filters. In some cases, our aftermarket filters are more efficient than the OEMs.

How will my order be shipped? Standard orders will be shipped via UPS.  If your order is small and weighs less than 5 pounds, it will ship via UPS Surepost and will be delivered by the postal service.  Other orders will ship UPS Ground and will be delivered by a UPS driver.

How do I return my order? What is your return policy? 

If you have ordered an incorrect item or if you simply wish to return your unused product we will gladly refund your money. You must first fill out the back of your packing slip with the appropriate information and place it inside your box with your product. We recommend that you send your order through UPS ground or FedEx ground due to the insurance these two carriers provide for up to $100. If you choose to send your package via the Postal Service, we do recommend that you purchase the insurance just in case the package is lost or damaged. Also, it is recommended to keep a note of your tracking number so we may confirm receipt. Please ship your package, and a copy of your packing sheet/return form to the following address:


Attn: Returns Department

9800 I-65 Service Rd. North

Creola, AL 36525

Filters that are returned must be unused and undamaged when they arrive back at AirFilters.com. Filters that are received damaged by you must be reported within 15 days of receipt in order to file a claim.  Filters that are delivered correctly and in good condition are the responsibility of the recipient. Any package that is refused by the recipient and is returned to AirFilters.com will be credited the price of the filters less the cost of the return shipping. All orders returned to AirFilters.com due to incorrect information (i.e. incorrect name, city, zip code, etc.) will incur an additional charge to cover the inadvertent delivery.

Please allow 10 business days from the time we receive your items back in order to process the return. Filters, not freight, will be credited back to your card on record.