When it comes to air filters, the biggest difference you'll notice is the cost. OEM filters are usually much pricier because you're paying for a brand name. But when it comes to the material from which each air filter is made, they look and feel identical. These filters protect your HVAC unit from dust and dirt that could damage it, while allowing air to flow freely. Recent innovations in air filters have allowed for high MERV ratings (11 to 1) with low pressure drop.
I've owned three houses and never had problems using pleated filters, but if you ever specify a new air conditioning system, set it up to have thicker filters (2 or 4) for better airflow and longer filter life. The air is charged with particles, sent through the filter only once and the results are measured. If your HVAC system uses a coarser filter (usually in the 4-inch to 5-inch range, and usually mounted on the air handler), it's likely designed specifically for medium-efficiency MERV filtration. Air filters come in various shapes and materials, each with different capacities and prices. You've probably heard how important it is to change your home's air filter regularly.
But those are rare circumstances, and whether or not to pay more for a better filter depends primarily on whether cleaner air is a priority for you. Both are evidence that the smoky air is finding a way around the clogged filter rather than through it, and that it's time to install a new one. While you should review the instructions for your HVAC system and your specific filter for maintenance guidelines, you should usually change your filters at least every season, if not once a month. We have the best options for portable air conditioners, if a window unit or central air does not work for you. The cheapest disposable fiberglass filters only meet the minimum (or slightly better), around MERV 2 or 3, and are designed to protect the inner workings of your HVAC system, rather than indoor air quality.
During a wildfire, you'll need to change your filters more often than you would under normal air conditions, and there are some indicators that can help you know when it's time to replace one. Cost is an important factor to consider when choosing an air filter, but the goal is to find the right balance between air filtration for your family's health, effective airflow and energy efficiency. An independent test of the effects of MERV filters 8 through 13 on HVAC airflow and energy consumption concluded that even “if no adaptations are made for the higher pressure drop of high MERV filters, penalties for airflow and energy is not likely to be serious at least, not until the filter is laden with dirt.”.