Frequently Asked Questions:


What is a MERV rating?

MERV, acronym for "Minimum Efficiency Reporting Value" are ratings that are commonly used to measure the effectiveness and efficiency of a filter. MERV measures the ability of a filter to remove impurities from air as it passes the filter. This scale was designed by ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) to gauge the effectiveness of filters.


What do i find what size i need?

Please ensure the measurements on your current filter to match whichever filter you buy.  Often times a filter has 2 sizes, the "nominal size" and the "actual size".

The nominal size is purely for marketing purposes. Companies often round up or down the measurements in order to get a nice even number. The actual size is the actual measurements of your filter. For example, your filter may have a nominal size of 14x25x1 but an actual size of 13½ x 24½ x ¾.

All of our product listings display the actual size in the description. If you are unsure or cannot find the actual size, please contact us at info@canadianairfilters.com



Which Direction Does The Arrow on An Air Filter Go?

It's a strangely surprising task, changing your home air filters. There’s an arrow on the box, and it says to point in the direction of “Air Flow”, but what does that mean? It means the arrow faces the unit, or in other words, facing inside the space you’re putting it into. Assuming your unit is outside or in your attic, you want the arrow to face the unit.