All Glasfloss air filters are proudly made in the USA in five manufacturing facilities across the country. Florida, Ohio, Texas, Nevada and Wisconsin.

While we give an estimated life of each filter, how often your air filter needs to be changed depends on your individual situation. How many people live/work in your space, if you have pets, and even your location and time of the year can all affect how quickly your air filter gets dirty. We recommend checking your filter once a month to keep track of how dirty it’s getting. Check out our video explaining this in more detail on our “Air Filter Change Frequency” page.

There are two main ways to refer to air filters: their Nominal size and their Actual size. The Nominal size is a simplified version of the dimensions of the filter and is how it is typically labelled and sold. The Actual size, however, is the exact dimensions of the filter. Some filters may have the same Nominal size, but different exact dimensions, which is why the actual size is important when it comes to ordering filters. For more information, please see our article "Nominal vs. Actual Air Filter Size”.

The 18x18x4 HWR Z-Line Series MERV 10 air filters from Glasfloss are designed to be a MERV 10 replacement option for the Honeywell FC40R1185. They also make a great alternative to a 1″ filter for filter grilles that accept only a 1″ air Filter with the added life and efficiency of a 4″ filter. The air filter frame is constructed of heavy-duty, moisture resistant beverage board incorporating post-consumer recycled materials making it very sturdy and easy to install and remove from your HVAC system (similar furnace filters can be difficult to install and remove if they are flimsy or have absorbed moisture). 100% synthetic fibers are used to construct the pleated air filter media that will not support microbial growth or absorb moisture. All of the components are thermally bonded together for high durability and extended reliability.

MERV 10 air filters offer an upgrade from MERV 8 without making your system work harder or adding resistance. They are great for removing many allergens and providing better indoor air quality to your home or business.