What is MERV? MERV stands for Minimum Efficiency Reporting Value. It is a number from a test method designed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). The number is intended to help people compare filters. Generally speaking, a higher MERV rating indicates better filter performance.

 There are 2 methods that you can use to determine your filter size:

• Measure your current filter.  The filter should have a label on the side stating the size, such as "16x25x1".  Be aware that the labeled size is the nominal (approximate) size.  Actual dimensions are usually smaller than the labeled size.  Once you have measured your filter, you can compare actual dimensions of our filters to yours if you search by stock size (such as 16x25x1) or actual size (such as 15-1/2 x 24-1/2 x 1).  These search options are available on our homepage.

• If you do not have a filter to measure or if you are not sure that your current filter is the correct size, measure the track where your filter should be installed.  You can select a filter that is up to 1/2-in. smaller than the length and width you measured.  As a rule, if your filter track measures (for example) 16x25x1, you will be able to choose from any of our 16x25x1 filters which are designed to fit a 16x25x1 track. 

 TIPS
 
    •    Do not order a filter that is the same size as the opening where the filter is installed.  The filter needs to be slightly smaller than the opening to allow for easy installation and removal.  

    •    If you cannot find a filter listed that matches the exact dimensions of your current filter or one that will fit properly into your filter track, you will need a custom filter.  

    •    If you are still not sure which size you need to order, please contact us for assistance and we will be happy to help you!

Allergy Filter depot makes custom size Accumulair filters, please contact us with the LxWxH measurements (within 1/8 accuracy) and what merv rating you would like and we will take care of the rest.

"OEM" stands for Original Equipment Manufacturer. OEM products are officially sanctioned or directly manufactured by the same company who made the your air cleaner, air handler, furnace, humidifier, etc. Generic aftermarket products are made to the same specifications as OEM product – but are manufactured by a 3rd party. Generic products are typically less expensive than OEM products, and usually exhibit the same quality of construction.