Basic fiberglass filters
Thin and inexpensive, they fill quickly in a system that runs most of the year.
Sooner if: Any time the filter looks grey or clogged.
WHY IT MATTERS
Why the filter matters so much in Florida
Florida air conditioning runs most of the year, so the filter sees far more air than one in a cooler state. A clogged filter restricts airflow, which makes the system work harder, can let the evaporator coil get too cold, and pulls dust around the filter instead of through it — straight into the ductwork.
After an air duct cleaning, a fresh filter is the single best thing you can do to keep the system clean for longer.
- Protects the blower and evaporator coil from dust
- Keeps newly cleaned ducts cleaner for longer
- Helps the system move the air it was designed to move
- Traps dust, pollen and pet dander before they circulate
CHOOSING A FILTER
How to choose the right air filter
Four things decide which filter belongs in your system.
Find the exact size
The size is printed on the edge of the filter you have now, as width × height × depth in inches. Buy that exact size: a filter that is even slightly small lets air, and dust, bypass it.
Pick a sensible MERV rating
MERV measures how fine a particle the filter can catch. For most homes, MERV 8 to 11 balances good filtration with healthy airflow. Higher is not automatically better.
Check what your system can handle
Very high MERV filters are denser and can restrict airflow on systems not designed for them. If you want MERV 13 or above, ask an HVAC professional whether your system suits it.
Choose a type you will keep changing
Pleated filters catch far more than basic fiberglass ones. Thicker 4- to 5-inch media filters last longer between changes, where your system has a housing that takes them.
MERV RATINGS
MERV ratings at a glance
MERV stands for Minimum Efficiency Reporting Value. Residential filters generally run from MERV 1 to MERV 16.
- MERV 1–4
- Basic protection. Catches larger dust and lint, mainly to protect the equipment. Usually thin fiberglass filters.
- MERV 5–8
- Good everyday filtration. Captures household dust, pollen and mold spores, and suits most systems.
- MERV 9–12
- Better filtration for homes with pets or allergies. Catches finer particles such as pet dander, with airflow most systems handle well.
- MERV 13–16
- High efficiency, capturing very fine particles. Check your system can handle the airflow restriction before using one.
WHEN TO CHANGE IT
How often to change your air filter
The filter type sets the starting point. Your home decides how much sooner.
1-inch pleated filters
The most common filter in Florida homes. Check it monthly during the months the air runs hardest.
Sooner if: You have pets, allergies, or a renovation under way.
4- to 5-inch media filters
The extra depth gives them far more surface area, so they last longer between changes.
Sooner if: The home is dusty, busy, or the system runs almost continuously.
FILTER DELIVERY
Never forget a filter change
The easiest way to keep up with filter changes is to have the right filter arrive before the old one is due. Filterbuy sells HVAC filters in standard and custom sizes and can deliver replacements on a schedule you choose, so a new filter turns up when it is time to swap.
Order the exact size printed on your current filter, in the MERV rating that suits your home.
