Are you looking for 12x24x1 air filters? You can find them in air filters by size. Flanders, Precisionaire, and Owen all offer products in this range. These medium-efficiency MERV filters can help reduce airborne dust, mold spores, pollen, and even smoke. They may even help alleviate respiratory illnesses.
However, they usually cost more than basic fiberglass filters. When it comes to knowing when it's time to replace your filter, there are some indicators you can look for. If your heating and air conditioning system uses a thicker filter (typically in the range of 4 to 5 inches and usually mounted on the air controller), it's likely that it was specifically designed for medium-efficiency MERV filtration. During a wildfire, you'll need to change your filters more often than you would under normal air conditions. If you have pets, children, or people with allergies in your home or business, replace filters more frequently to maintain superior indoor air quality and reduce your energy costs. These filters are installed on wall-mounted air return ventilation grilles (more common in the south) or on the air controller (more common in the Mid-Atlantic and North Atlantic states).
MERV stands for Minimum Efficiency Reporting Value and is a measure of how effectively a filter removes particles from the air. A recent innovation in air filters allows for high MERV ratings (11 to 1) with a low pressure drop. If a window unit or central air conditioner doesn't work for you, there are also some great options for portable air conditioners. Ultimately, the decision to pay more for a better filter or not comes down mainly to whether cleaner air is a priority for you or not.