When it comes to improving air quality in your home, a 4-inch thick air filter has a clear advantage over a 1-inch filter. It offers better longevity, air flow and maximum filtering potential. So, if it fits your oven, then a 4-inch air filter is the better choice. Thicker filters, known as multimedia filters, are usually 4 to 5 inches thick compared to the ubiquitous 1-inch filters that can even be purchased at grocery stores.
Most air filters are 1 inch thick, but some systems can accommodate filters 2 to 5 inches thick. In tests, it was found that the thicker the filter, the better it performs and the longer the replacement intervals. This means it's better for you and your heating, ventilation and air conditioning (HVAC) system. With 1-inch filters, they need to be replaced at least every 3 months, but many people replace them monthly.
Opting for a 4-inch filter would mean that you would have a filter with at least a MERV 8 rating, which would remove contaminants down to 3 microns (a unit of measurement), including dust mites and some types of pollen. Regardless of the thickness of the filter, home and business owners should regularly inspect their filter to ensure that it is not full of contaminants. Three- or 4-inch filters can last 6 to 9 months, and filters up to 6 inches thick can be replaced once a year. These media filters have much stiffer cardboard frames, and some media filters even have plastic “rails” on the top and bottom so you can slide them inside the oven with a very tight seal.
For example, since you'll be replacing 1-inch filters with a MERV height more frequently than 4-inch filters (see the maintenance section above), you could save money with a 4-inch filter, depending on the MERV you get. Most HVAC technicians recommend changing 1-inch air filters every 30 days, while 4-inch filters can be changed every 3 to 6 months. If you put several 1-inch filters together, it's similar to putting together 5 coffee filters and trying to make a cup of coffee - it just doesn't work. With more surface area to trap air contaminants, a 4-half air filter offers a longer lifespan than a 1-half air filter. When you compare a 1-filter filter to a 4-filter, you'll see that using a thicker filter has several advantages.
Replacing the standard one-inch air filter with a 5-inch pleated filter can improve the air quality inside your home. For comparison, a 4-inch thick filter will have approximately twice as many surface areas as a 2-inch thick filter. Your HVAC technician can provide you with a new filter compartment or modify the existing one to accommodate the thicker filter. Your current filter compartment does not have the capacity to accommodate a larger filter; you cannot simply fit a large filter into the small compartment.
