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. Thicker air filters may automatically seem like the best option.
After all, thicker means more filtration, right? In most situations, that is the case. Thicker air filters tend to last longer because they have more square meters to capture and retain air particles. To put it into perspective, a 1-inch air filter may need to be changed every month, while a 4-inch air filter could last up to six months. A filter that is too small or two large will create gaps around the filter, which in turn will allow air to flow down the sides. On the other hand, having more than one or two fingers of space around the filter indicates that it is too small.
Now, the more CFM of air reaches the furnace system, the more area it can cover with the heating or cooling action. The fiberglass filter will also work, but the frequency with which the filter needs to be changed is about twice that of the pleated filter. An oven filter that is too small or too large for the oven will allow air to pass through the filter. When you go shopping for an air filter, you will notice that there are a large number of options available. But what if the air filter compartment of your oven is only 3 inches thick? In that case, a 1 inch oven filter is the better choice than a 4 inch filter; however, a 3 inch thick air filter is the best choice.
These 4-inch media filters can have a surface area of 20 to 30 feet with their pleated (accordion) filter material. On the other hand, you can use a 1 inch thick filter in compartments that can accommodate a deeper filter. A filter that is ready to be changed will be gray and covered with accumulation, which will prevent air from easily passing through it. Nowadays, air filters have adopted the use of this method and more and more people use specialized air filters with charcoal. If you use a 5 inch media filter, it should be suitable for at least 6 months and up to a year. While you most likely know what size your unit needs, you may not know what type of air filter is best for your home needs.
So you'll not only clean the air better but you'll get a lot more airflow than standard one-inch ones.
