The first and foremost difference between 1-inch and 2-inch air filters is their lifespan. When it comes to thickness, the 2-inch oven filter is the clear winner. However, the difference in thickness between the two is not drastic. In our tests, we found that the thicker the filter, the better it works and the longer the replacement intervals.
For 1-inch thick filters, the usual recommendation is three months. For filters that are 4 inch and thicker, it is common for 12 months to pass. Whole house filters usually go to an air controller, which is usually found next to the HVAC system itself or in some cases, directly to the ducts. It's worth noting that, although you usually only have one, you may need more than one filter for the whole house.
Whole house filters are always 4, 5 or 6 inches thick. Most air filters are 1 inch thick, but some systems can accommodate filters 2 to 5 inches thick. When it comes to a 1-inch versus 2-inch oven filter, you can use a 2-inch filter if the vent is deep enough and a 2-inch filter will generally last longer, since it has more media. Around the MERV 8, filter designs often switch to pleated materials (non-woven material made from elements such as fiberglass paper, polyester and plastic) and can reliably capture pollen, mold spores, and many types of household dust. MERV indices range from 1 to 16, and higher numbers correlate with smaller filter pores for better filtration of particles in the air. At MERV 13, the highest rating you'll find for most popular residential HVAC filter sizes.
You can trust that the filter will stop bacteria, smoke and other microscopic particles. So, if it fits your oven, then a 4-inch air filter is better than a 1-inch air filter to improve air quality. Air filters generally come in a variety of standard sizes, and some can be adapted to fit different sizes of filter boxes or air return openings. Household air filters are those that are inserted into the wall when returning air; although, in some homes, they can go to the ceiling or to the duct network itself. This allows you to return a few months later and calculate the remaining useful life of the filters. Most home improvement stores sell HVAC filters ranging from MERV 1 to MERV 13, although CR has tested models as tall as the MERV 16. The 4-inch thick air filter has a clear advantage over filter 1 in terms of longevity, air flow and maximum filtering potential.
Pay attention to what matters most to you and you'll find out which filter is right for you.