The short answer
For most Kingwood-area homes, every 1 to 3 months, and closer to monthly in summer. Change it more often if you have:
- Pets, especially dogs or cats that shed
- Allergies or asthma in the household
- Recent construction or remodeling
- Heavy pollen season (spring around Lake Houston is intense)
- Thin, 1-inch filters, which load up faster than 4-inch media filters
Why it matters so much here
Your system moves a lot of air during a long cooling season. A clogged filter restricts airflow across the indoor coil, which reduces cooling, raises electric bills and can freeze the coil. Ice melting later can overflow the drain pan and cause water leaks.
Which filter should you buy?
- MERV 8: a good everyday choice for most homes
- MERV 11 to 13: better for allergies, but check that your system can handle the extra resistance. Very restrictive filters can choke airflow on some systems.
- Avoid cheap fiberglass "see-through" filters. They protect little beyond large debris.
Check the size printed on the edge of your current filter, and write the date on the new one when you install it.
Signs your filter needs changing now
- It looks gray or you can't see light through it
- Dust is building up on vents and furniture
- The system runs longer than usual
- Airflow from vents feels weaker
Where's my filter?
Usually in a return grille in a hallway or ceiling, or in a slot at the air handler or furnace. Some homes have more than one. If you can't find yours, ask the technician at your next tune-up.