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.
Thicker means more filtration, right? In most situations, that's the case. Thicker air filters tend to last longer because they have more square feet 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 can last up to six months. Virtually any HVAC professional will tell you that thicker filters perform better than common 1-inch oven filters. Thicker filters, known as media filters, are generally 4 to 5 inches thick compared to ubiquitous 1 inch filters that you can even buy at grocery stores.
Different filter thicknesses also affect airflow. What do I mean by that? Well, the thicker the filter, the less restrictive it is. This contributes to a better flow of purified air. This means that 2-inch oven filters allow better airflow than 1-inch filters. Routine maintenance of your oven filter is an easy way to keep your oven running at peak efficiency.
That said, the 1-inch filter may be too shallow, causing a loose fit that allows unfiltered air to enter the ductwork. Always follow the filter size guidelines to ensure you choose the correct size filter for your oven. Proper filter size matters, so manufacturers make it easy to find the information you need. A filter that is ready to be changed will be gray and covered with buildup, which will prevent air from easily passing through it. The MERV rating is basically a measure of how well the filter captures particles in the 0.3 to 10 micron size range.
Most residential furnaces don't require the strength of a high MERV rating, so it's generally more beneficial to reduce costs by maintaining a lower rating. The type of filter you use will affect how often it needs to be changed, as well as the size of your home, how often the HVAC system is turned on, if you have pets in your home, and if someone in your household has allergies or other medical conditions. The nominal size of an oven filter is a rounded number that is best suited to the commercialization of standard filters. Filters that are true to size will indicate this by printing “true size” next to the filter dimensions. While the thickness of a filter affects the overall size and surface area, the density of the filter fibers is another factor to consider. The thickness of the air cleaner ranges in size from 1 to 5 inches deep; some options are more common than others, and your oven can dictate the thickness you can use.
Your oven filter has a big job ahead of it, as it filters out all the dust and debris that get between the oven, the air ducts and, finally, your lungs. It is a known fact that the standard dimensions of an oven filter (length and width) have nothing to do with its efficiency. So does thickness really matter when it comes to furnace filters? The answer is yes! Thicker filters provide more filtration power and last longer than thinner ones. They also allow for better airflow which helps keep your HVAC system running efficiently and effectively. When selecting an oven filter for your home or business, make sure you choose one with a true size rating and one that fits your specific furnace model.