When it's time to replace your air filter, the easiest way to determine the size you need is to look at what it says on your current filter. Air filters usually have their dimensions printed somewhere along the sides. The furnace filters should fit snugly, but there is no need to force them into place. If you have to force the filter into its slot, it's probably too big and can cause it to bend, damage it, or reduce its ability to function properly.
Some HVAC units may require a filter with unique or unusual dimensions, in which case you'll need to request a custom filter. When you buy your air filter online, it's important to be aware that air filters come in two sizes: nominal size (often used to label the filter) and actual size. During a wildfire, you may need to change your filters more often than usual and there are some indicators that can help you know when it's time to change one. An independent test of the effects of MERV filters from 8 to 13 on air flow and HVAC energy consumption concluded that even “if measures are not taken for the greatest pressure drop of high-MERV filters, the air flow and energy penalties are unlikely to be serious, at least until the filter is full of dirt”.HVAC service companies often offer air filter replacement services in addition to system repair and unit installation services. When used in the real world, the air in your home is constantly recirculated through the ducts and passes through the filters each time, so the cumulative effect of the filters increases.
If you have difficulty inserting the air filter into its slot, you should try a different brand furnace filter or a custom-sized air filter with a slightly smaller actual size. There are many options for buying air filters conveniently, whether online, through your HVAC service company, or in a store. There are several great options for buying air filters online and having them conveniently delivered to your door. We believe that manufacturers' concerns are too cautious, in part because a recent innovation in air filters makes it possible to obtain high MERV rates (11 to 1) with a low pressure drop. Most of the air filters are located on the right or at the bottom of the unit and can be easily removed from the slot. For the most common brands of air conditioning systems such as Goodman, Lennox, Trane, Rheem York, Coleman and Carrier, most standard air filter sizes are suitable.
They are installed in wall-mounted return air vents (most common in the south) or in the air handler (more common in Mid-Atlantic and Northern states). It is essential to use an air filter of the right size for your air conditioning unit to keep it running smoothly and take advantage of all its benefits.
