The air filter is the cheapest part of your system and one of the most important. Here's how to pick one and when to change it.
MERV ratings
A filter's MERV rating says how much it catches. Higher catches smaller particles, but also slows airflow more.
- MERV 1 to 4: the thin fiberglass kind. It protects the equipment, but does little for the air you breathe.
- MERV 8: a good everyday choice for most homes: dust, pollen and pet hair.
- MERV 11 to 13: finer particles, including much of wildfire smoke. Good for allergies, if your system can move air through it.
Why the strongest isn't always best
A high-MERV filter in a thin 1-inch slot can choke the airflow. The system then runs longer, cools and heats less, and in bad cases freezes the coil or overheats the furnace. If you want MERV 13, a deeper 4- or 5-inch filter cabinet lets the air through much more easily. Ask us if yours can take one.
How often
- 1-inch filters: every 1 to 3 months, more often with pets, construction or smoke
- 4- to 5-inch filters: every 6 to 12 months
The simplest test: hold it up to a light. If you can't see through it, change it.
Get the size right
The size is printed on the edge of the filter you have now. A filter that's too small lets air go around it, which defeats the point.
Questions about your system's filter, or a better filter cabinet? Call us at 805-965-6326.
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