Best Furnace & Air Filter by Size
Furnace and air (for HVAC systems) filters come in a variety of sizes. It is essential that you know the size of your filter in order to replace it correctly.
All filters have their size printed on the edge. Usually in the same area as the arrow that tells you which way to install the filter.
Even an inch off can cause the mesh or screen to not fit correctly. Then in order to “make it fit” you’ll need to jam the filter in thereby crushing some of the mesh. This results in limiting the air flow which in turn can cause a lot of additional wear and cost to your furnace and A/C unit if it’s an HVAC system.
IMPORTANT: The MERV rating has major impact on price and how hard your system works. You should be using a MERV rating that your HVAC system or furnace is rated for. The higher the MERV rating, the more it filters out impurities in your air. BUT the higher the MERV rating, the less air flow there is. And the harder your system needs to work. So there are trade-offs. You can read more about MERV ratings and their impact and meaning here.
Below are the most common sizes for a home system. And the very best replacement furnace and HVAC air filters available.
14x18x1 air filter
Flanders PrecisionAire 14 by 18 by 1 Flat Panel EZ Air Filter
These are very good quality and economical filters. Be aware that they are a MERV 4. That means that they will have great air flow, BUT they will not filter out impurities in the air as well as a higher MERV rated filter.
The actual measurements of this filter are 37 7/8 x 17 3/4 which is a tad smaller which should be fine. The construction is cardboard for the frame which is standard and a metal retainer mesh which really helps it from collapsing. The cleansing material is spun fiberglass. The most common type in a cheaper non-pleated filter. That means less changes and cheaper price.
I recommend this Flanders filter based on cost compared to its features such as sturdiness, adequate performance and providing the needed protection to the furnace.
And if you click here to Amazon, the price was a few bucks cheaper than I could buy these at my local Lowes or Home Depot!
14x18x1 MERV 8 Air Filter & Furnace Filter
Although this filter isn’t a big name brand, it is made in the USA and is quality built. And they have a great price tag as well. They come in packs of 4 for around $20. The higher MERV rating of 8 is what costs more than the lower Flander’s above at a MERV rating of 4.
14x25x1 air filter
16x20x1 air filter
16x24x1 air filter
16x25x1 air filter
18x20x1 air filter
20x20x1 air filter
20x24x1 air filter
20x25x1 air filter
16x25x5 furnace filter
16x25x4 furnace filter
16x25x1 furnace filters
16x25x1 furnace filter
20x25x5 furnace filter
20x25x4 furnace filter