Air Conditioning filters are the front door of any central air conditioning system, trapping particles, dust and pollen in the air which helps keep debris from collecting around the evaporator coils which restricts the cooling process, ultimately damaging the system.
The most common air filter sizes are one-inch thick but may go all the way up to 5 inches depending on the type of system in use, including single-stage and multistage central air units. There is some evidence to suggest that a thicker filter lasts longer and may perform better than its slenderer versions, although this may require modifications to your duct work. Some filters are conventional fiberglass while others may be pleated or electrostatically powered. In most cases, especially in Florida, we suggest you replace your air filter monthly, although some residents may wait as long as three months. Low airflow and other central issue problem often arise from dirty filters which restricts air flow and should not be ignored.
Just like SEER ratings help guide the efficiency rating for a split-level air system, there are several industry ratings that relate to AC filters. These range from the Minimum Efficiency Reporting Value (MERV) to Micro-Particle Performance Ratings (MPR). Home Depot has its own rating system while others like the High-Efficiency Particulate-Arresting (HEPA) rating govern electrostatic filters for furnaces.
Replacing central air system filters is a routine maintenance task that could ultimately help you extend the life of your unit and help you save energy dollars. In fact, some estimates put the savings at up to 15% in lower annual energy emphasizing its importance for home owners. An HVAC preventive maintenance plan is a great way to stay on top of this task with two annual inspections that cover air filter replacements.