Most furnaces will have a V-shaped filter system, which requires two filters. The filters are placed in a V-shape and should be installed so that the top door covers the oven frame and activates the safety switch. Generally, a home will have two air filters in its intake holes, but this number may vary depending on the size of the house or apartment and the number of floors that need to be supported by the central air system. If you try to operate your furnace without an air cleaner, it will cause damage to the coils, fan motor, and other components.
Additionally, your furnace won't run efficiently, resulting in higher heating bills. If your furnace is a vertical HVAC unit with air that moves up, the filter will be located on the bottom door. To access it, open both the upper and lower doors. If the air is moving downward, then the air cleaner will be on the top door.
Ductless systems are composed of two separate units: an outdoor unit and an indoor unit (which is often wall-mounted). The units are connected via a refrigerant line through a hole in the wall and don't require ducts. A common type of ductless system is the mini-split. The service life of the filters is different, so you may need to replace them more or less frequently depending on their size.
For example, one-inch air filters for return grilles have a depth of one inch and are designed to hold one inch air filters. The air cleaner can also be found in a slot above or below the HVAC unit or behind the return grilles of your home. Although you might think that two filters side by side would provide better filtration, this isn't necessarily true. Dirty furnaces and air conditioners caused by a lack of air cleaner have to work harder to get the job done, consuming more energy and potentially damaging parts such as heating coils or igniter.
If you feel like a single 1-inch filter isn't doing a good job of filtering particles out of the air, then upgrade to a coarser option if possible. If you want your furnace to last longer and save money on your heating bills, then air filters are essential. Most homes have two intake holes covered with an air filter for their central air system. If your house has central air, then your furnace usually shares an air controller with your air conditioner.
Examples of problems that can arise from not having an air filter include clogged condensate drain pipes, damaged or rusted drain pans, broken condensate pumps, unclean air filters, or low coolant levels. To find out what size filter you need for your furnace, take three measurements: the depth of the return air duct, as well as the height and width of the space in which the air cleaner slides. The filters are located inside the indoor unit just below the front panel.
