Air filters are not designed to fit snugly. In fact, if you have to force an air filter into or out, it's the wrong size, which is why standard sizes are usually half an inch smaller than advertised. The oven filters must fit securely, but there is no need to force them into position. If you have to force the filter into its slot, it's probably too big. Inserting an incorrectly sized filter may cause it to deform, damage it, or reduce its ability to function properly.
The filters are slightly smaller than their slot for easy replacement. Some HVAC units may need a filter with unique or unusual dimensions. In these cases, it is necessary to order a custom filter. The thickness of the air filter ranges from 1 to 5 inches deep; some options are more common than others and your oven can determine the thickness you can use. Because AIRTEVA air filters have a patented anti-leak seal, the filter does not need to be adjusted from edge to edge.
For example, a size of 20x30x1 may appear on the filter label, but if you measure the filter, you will see that the actual size is smaller than the nominal air filter size of 20x30x1. If the filter doesn't have the actual dimensions on the outside of the filter, you can measure it to get the correct dimensions. If you try to use a 4-inch-thick air filter for a system that's made for a 1-inch-thick filter, the efficiency will actually worsen. Dust, allergens, and pollutants will not leach out of the indoor air, since the air does not pass through the filter, enters the vent and returns back. Combining a thin air filter with a high MERV rate can also restrict airflow to the point of hampering efficiency and causing excessive wear. The 4-inch thick air filter has a definite advantage over filter 1 in terms of longevity, airflow, and maximum filtering potential. That said, the 1-inch filter may be too shallow, causing a loose fit that allows unfiltered air to enter the ducts.
But what if your oven's air filter compartment is only 3mm thick? In that case, the 1-inch oven filter is the better choice compared to the 4-inch filter; however, a 3-inch thick air filter is the better option. A 1-inch filter with less surface space will clog up fairly quickly and will need to be replaced much sooner than a coarser filter. So, if it fits your oven, then a 4-inch air filter is better than a 1-inch air filter to improve air quality. Thicker air filters tend to last longer because they have more square feet to capture and retain air particles. Filters don't need to have a “hermetic” seal, but you should be able to easily install and uninstall the filter without problems, and the filter shouldn't be so small that it can move freely inside the unit. As an expert in HVAC systems and air filters, I can confidently say that an air filter does not need to fit snugly in order for it to work properly.
However, it is important that you choose an appropriately sized air filter for your system in order for it to function optimally. If you try to use an oversized or undersized air filter in your system, it could lead to decreased efficiency and even damage your system. When selecting an air filter for your system, make sure that you measure both your system and your desired air filter before making your purchase. This will ensure that you get an appropriately sized air filter that fits securely without having to force it into place. Additionally, make sure that you select an appropriately thick air filter for your system; if you choose one that is too thin or too thick for your system's specifications, it could lead to decreased efficiency or even damage.