Can I Use a 1 Inch Furnace Filter Instead of a 4-Inch?

When it comes to improving air quality, a 4-inch filter is better than a 1-inch filter. While the size of the filter depends on the oven, if the slot is large enough to accommodate the coarser filter, then you can use it. 4-inch filters cover a higher range of MERV ratings, with a slight overlap with 1-inch filters. With a filter of 4, you'll get at least an 8 MERV rating, with higher ratings of up to 16, allowing you to put controls on supermicro contaminants such as bacteria, viruses and dust particles.

At FilterBuy, the price difference between 1 and 4 inch air filters is usually a few dollars. Because a 4-inch filter lasts longer, it usually offers a better value. Virtually any HVAC professional will tell you that thicker filters perform better than common 1-inch oven filters. Thicker filters are generally 4 to 5 inches thick compared to ubiquitous 1 inch filters that you can even buy at grocery stores.

What needs to be ensured is that the filter rating allows for proper airflow and filter level. If the filter 5 is adjusted and has a similar density, it would allow the system to move air with less resistance. However, increasing filter density may affect unit efficiency. Your HVAC technician can provide you with a new filter compartment or modify the existing one to accommodate the thicker filter.

Air cleaner thickness ranges in size from 1 to 5 inches deep; some options are more common than others, and your oven may dictate the thickness you can use. Size does matter when it comes to oven filters - call the oven installer and ask what size, type and specifications of the filter fits the rack you installed. Particularly vulnerable parts include the air controller or oven blower motor that works overtime to push and draw air through the dirty filter and the heat pump or air conditioning compressor responsible for circulating refrigerant between the outdoor and indoor units. For comparison, a 4-inch thick filter will have approximately twice as many surface areas as a 2-inch thick filter. These 4-inch media filters can have 20-30 feet of surface area with their pleated (accordion) filter material.

If you put together several 1-inch filters, it's similar to putting together 5 coffee filters and trying to brew a cup of coffee - it just doesn't work. Using a 4-inch filter would mean that you would get a filter with at least a MERV 8 rating, which would remove contaminants up to 3 microns (one unit of measure), including dust mites and some types of pollen. Deeper depth can also improve filter life and efficiency; they also make it easier for air to enter and exit the filter. Ovens come in a variety of sizes and configurations, which means there's no one-size-fits-all filter. Covers 1-inch vs. 2-inch vs.

4-inch oven filters with respect to how well they work, how often they need to be replaced, their cost, and other important areas to consider. The clean and clear end result is that size does matter when it comes to oven filters - call the oven installer and ask what size, type and specifications of the filter fits the rack you installed.

Willis Diruzzo
Willis Diruzzo

Typical sushi enthusiast. Infuriatingly humble music geek. Typical internetaholic. Subtly charming social media maven. Lifelong bacon buff.