Are Wider Furnace Filters Better?

Most air filters are 1 inch thick, but some systems can accommodate filters 2 to 5 inches thick. In our tests, we found that the thicker the filter, the better it works and the longer the replacement intervals. This means it's better for you and your heating, ventilation and air conditioning (HVAC) system. In short, the thicker the filter, the more dirt it can hold.

And, as a result, you can enjoy a longer period of time before needing to replace the filter. Replacing a standard one-inch air filter with a 5-inch pleated filter can improve the air quality inside your home. This is because larger air filters have higher MERV ratings, leading to better filtration of contaminants and allergens. However, there are cases where 1-inch and 2-inch filters can be equally efficient, depending on their MERV rating.

The MERV rating is a classification that measures how well the filter blocks particles. Some of these “better filters” can remove particles as small as 0.3 microns, making them compatible with the HEPA standard. Filter ratings range from 1 to 20 on the MERV scale (minimum efficiency report value), with a rating of 1 offering the lowest filtration. The graph shows the static pressure drop curves of filters with four MERV ratings. The vertical axis shows a 0.1 inch wide system static pressure drop, c.

The black line shows the 492 CFPM test standard, and where is the design objective (pressure drop of 0.1) and where a 12 MERV filter labeled “Best” would fall. It is important to note that the standard dimensions of oven filters (length and width) have no bearing on their efficiency. First, 4-inch filters cover a higher range of MERV ratings, with a slight overlap with 1-inch filters. I had bought the wrong size filter and you guys did everything you could to get me the right ones. These filters are sufficient to stop the passage of allergens, dust, mold, bacteria, dust mites and pet dander. For example, since you'll be replacing 1-inch filters with MERV height more frequently than 4-inch filters (see maintenance section above), you could save money with a 4-inch filter, depending on the MERV you get.

But what if your oven's air filter compartment is only 3 inches thick? In that case, the 1-inch oven filter is the better choice compared to the 4-inch filter; however, a 3-inch thick air filter is the best choice. On the other hand, you can use a 1-inch-thick filter in compartments that can accommodate a deeper filter. Furnace filters designed to act as whole-house air filters add stress to the fan of an HVAC system by preventing air flow. In conclusion, size does matter when it comes to oven filters. The larger surface area allows more air to pass through the filter and effectively blocks all harmful particles.

That said, a thinner 1-inch filter with a high MERV rating would clog up very quickly (compared to a 4-inch pleated filter), since there is less surface area available to trap contaminants. On the other hand, 1-inch filters are decent enough to remove typical dust, pet dander, and other particles up to 3 microns in size. If you have an oven in your house, you may find yourself needing to replace its clogged filter every 2 to 6 months.