Not necessarily. The most expensive filter on the shelf isn't always the best one for your system. The right filter balances how much it catches with how much air your system can push through it. Here's how to choose.
What MERV ratings mean
MERV (Minimum Efficiency Reporting Value) rates how well a filter captures particles, on a scale of 1 to 16 for residential and light commercial filters. Higher numbers catch smaller particles.
- MERV 8: catches dust, pollen, lint and pet hair. A solid, affordable choice for most homes.
- MERV 11: also catches finer dust, mold spores and some smoke particles. A good upgrade for homes with pets or heavy dust.
- MERV 13: catches even finer particles, including more smoke. Helpful during wildfire season or for people sensitive to smoke and dust, but only if your system can handle the extra resistance.
Why higher isn't always better: airflow limits
A denser filter is harder for air to pass through. Many residential systems, especially older ones or those with undersized return ducts, aren't designed for the resistance of a thick MERV 13 filter in a standard 1-inch slot. Restricted airflow can make the system run longer, freeze the AC coil, overheat a furnace and raise energy bills. If you want higher filtration, ask a technician to check whether your system can handle it.
When a media filter or air purifier makes sense
If you want better filtration without choking airflow, a 4- or 5-inch media filter cabinet is often the answer. The deeper, pleated filter has much more surface area, so it can filter at a higher MERV with less resistance, and it usually lasts 6 to 12 months. For dust, odors or wildfire smoke, a whole-house air purifier or UV system can add another layer. Learn more about our indoor air quality services.
How often to change your filter
- 1-inch pleated filters: every 1 to 3 months
- Homes with pets, remodeling dust or wildfire smoke: check monthly
- 4- to 5-inch media filters: every 6 to 12 months, per the manufacturer
Check the filter whenever you notice weaker airflow or more dust around the house. A clean filter is one of the cheapest ways to protect your system and your indoor air.
Not sure which filter is right?
Ask us during your next tune-up and we'll recommend a filter that fits your system and your household. If you're interested in better filtration or air purification, schedule a consultation and we'll walk through the options with you.
Need service? Call (760) 858-8000, Monday–Friday 8–5, or send us a message.