When it comes to furnace filters, it's usually better to go thicker. You can find 1-inch filters in most grocery stores, but they may not be the best fit for your HVAC system. Reducing the thickness by one inch shouldn't be a major issue; for example, you should be able to use a 4-inch filter instead of a 5-inch filter. Multimedia filters, which are usually 4 to 5 inches thick, are more effective than 1-inch filters at capturing dust and debris. In addition to providing better filtration, using a 5-inch oven filter instead of a 1-inch filter can also extend the lifespan of your air conditioning system.
While many retailers sell oven filters, 5-inch filters are less common than 1-inch filters. It's important to make sure that the filter fits the oven properly, as an ill-fitting filter can allow unfiltered air to enter the ducts and cause damage to your unit. Not changing the filter often enough can even require you to purchase a new oven. The nominal size of an oven filter is a rounded number that best fits the marketing of standard filters. Manufacturers design 5-inch filters to capture more contaminants over a longer period of time, so if your oven works with a thicker filter, you won't be able to allow more dust and debris to enter your moving parts.
You may need to install a multimedia filter cabinet under the oven or on the side in order to use a thicker filter. The primary purpose of an oven filter is to protect the internal fan from elements such as dust and hair. Stacking 1-inch filters together will cause the oven to push air through a barely penetrable wall. And if you have an older unit, it's essential to check the oven filter regularly, as clogged 1-inch filters get dirty very quickly. In conclusion, it's generally better to use a thicker furnace filter than a thinner one. While 1-inch filters are more widely available, they don't provide as much protection as their thicker counterparts.
If your HVAC system works with a thicker filter, you should consider using one in order to extend its lifespan and improve its filtration capabilities.
