Experts agree that air filters should fit snugly in order to work properly. If there are any gaps around the filter frame, it is likely not the right size for the system. The size of the filter is usually indicated on the side of the frame. Air filters can range from less than one inch to more than four inches in thickness. When it comes to oven filters, they must fit snugly inside the unit.
If it is too loose, air will continue to enter even when the oven is running. On the other hand, if it is too tight, you may not be able to remove it when it's time to change it. These gaps are normal and usually don't cause any problems. When the oven is running, the air pressure forces the filter against the downstream face of the groove, effectively sealing the opening. If the filter is too small, there will be a space around it which allows dirty air to pass through.
It's almost like not having any filters at all. Before purchasing a replacement filter, please check the size of your existing one. If you buy a filter that is too large, it will not slide properly into the slot. If it is too small, it will not cover the entire space and may allow dust and dirt to pass through. If you are unsure of what size filter you need, check the manufacturer's specifications or ask your HVAC technician for help. The filters of the oven must fit securely but must not be forced into position.
If you have to force the filter into its groove, it's probably too big. Forcing an incorrect filter size on a filter can cause it to bend, damage the filter, or reduce its ability to function properly. Filters are smaller than their slot to allow easy replacement. Some HVAC units may require a filter with unique or unusual dimensions. In these cases, you need to order a custom filter.
Since HVAC technicians come to your home and evaluate your specific unit, they know what type of filter your oven can handle and what is best for your system. There are a number of great options available online for purchasing air filters and having them delivered conveniently. To ensure that you get the right size filter for your oven, use a measuring tape or other measuring device to measure the length, width and depth of the inner edge of the groove or frame of the air cleaner. The 4-inch thick air filter has a definite advantage over a 1-inch thick filter in terms of longevity, airflow and maximum filtering potential. If your old air filter does not have its measurements printed on its side, you can measure it yourself.
However, if it is too shallow, this could lead to a loose fit which allows unfiltered air to enter the ductwork. This leads to a somewhat loose fit and because it is located on the roof, the filter must be kept in place in order to close off the vent. You can find out what size filter your unit requires by looking up its model number in this table titled “Find your air conditioner and oven filter by make, model number and size”. When buying an air filter online, make sure that you know both its nominal size (which is often used to label filters) and its actual size. Do not stack several smaller air filters on top of each other in order to fit them into a larger air handling unit. When installing an oven filter, make sure that it is oriented in the right direction - arrows or grooves on one side of the filter indicate which way is up.
A HVAC specialist will check your old filter and then give you a new one that fits your oven properly. Sometimes cleaning or vacuuming an oven filter isn't enough to keep it clean - especially if you have pets with short hair. If you try to use a 4-inch thick air filter for a system that is made for a 1-inch thick filter, this could actually reduce its efficiency.