Lately we have been coming across a lot of homes where the AC filter has not been changed in months, and in some cases close to a year. It is one of the simplest pieces of home maintenance there is, and one of the easiest to forget. It is also behind more AC problems than most homeowners realize. Here is how often you should change it, and what can happen when you do not.
How Often to Change Your AC Filter
The right schedule depends on the type of filter you have and your household, but here are good general guidelines.
A standard one inch filter should usually be changed every one to three months. In South Florida, where your AC runs nearly year round, we recommend checking it every month and changing it at least every 60 to 90 days.
Thicker media filters, often four to five inches, can last longer, commonly somewhere in the range of 6 to 12 months. Check the manufacturer's guidance for your specific filter.
Change it more often if you have pets that shed, if someone in the home has allergies or asthma, if you live in a dusty area or near construction, if you have a lot of people in the home, or if you have been running the AC heavily. When in doubt, hold the filter up to a light. If you cannot see light through it, it is time.
What Happens If You Do Not Change It
A dirty filter does not just sit there quietly. Here is what it can cause.
Restricted airflow. Your system is designed to move a specific amount of air. A clogged filter blocks it, so rooms cool slowly or unevenly and your system has to run longer to keep up.
Higher energy bills. When your system struggles to pull air through a dirty filter, it works harder and uses more electricity to do the same job.
A frozen evaporator coil. This is one of the most common results we see. Without enough warm air moving across the coil, it can get cold enough to freeze over. A frozen coil can lead to warm air from the vents, a system that will not cool at all, and water leaking when the ice melts. If your AC is blowing warm air, the filter is one of the first things to check, and we cover other causes in our post on why your AC is blowing warm air.
Water leaks and drain problems. A frozen coil that thaws can overwhelm the condensate drain, which can lead to water damage near your indoor unit.
Extra strain on your system. The blower motor and other components have to work harder against restricted airflow, which means more wear and a greater chance of a breakdown. Over time, that can shorten the life of your system, which in South Florida already works harder than almost anywhere else.
Poorer indoor air quality. A filter is there to catch dust, pollen, pet dander, and other particles. Once it is full, it stops doing that job well, and the particles keep circulating through your home and settling on your system's components.
Signs Your Filter Is Overdue
Weak airflow from the vents, rooms that are hard to cool, more dust around the house, a system that seems to run constantly, a musty smell, higher energy bills than usual, or ice on the indoor unit or refrigerant lines can all point to a filter problem.
What to Do If It Has Been a While
If it has been months or longer since your last change, replace the filter right away. If your system has been struggling, blowing warm air, or you see ice on the lines, turn the system off and let any ice melt before running it again, and give us a call if the problem continues. If a dirty filter has been running for a long time, it is also worth having the system checked, since dirt that gets past a clogged filter can build up on the coil and blower.
A Few Quick Tips
Know your filter size before you shop, since it is printed on the edge of the filter. Install it with the airflow arrow pointing toward the unit and away from the return. Set a recurring reminder on your phone so it never slips your mind. And do not assume a more expensive or higher rated filter is better for every system, since very dense filters can restrict airflow in some setups. If you are not sure which type is right for yours, we are happy to help.
Let Us Take Care of It
Filters are one of the things we check at every maintenance visit, along with the coil, the drain, and the rest of your system, so small issues get caught early. Our team of licensed technicians serves Broward County and Palm Beach County from Lantana south through Boca Raton, and we are always happy to answer questions.
Cooling and Heating Specialists LLC 954-729-9956 | CoolingHeatingSpecialists.com Licensed & Insured | CAC1824395 Woman Owned, Family Operated
