How to Pick the Right HVAC Filter (And Why It Matters)

Not all air filters are created equal—and choosing the wrong one can affect your family’s health, your energy bills, and even your HVAC system’s lifespan.

If you're a homeowner in Yorba Linda or surrounding OC cities, this guide will help you choose the right filter for your needs—and explain why it matters more than you think.

What Is a MERV Rating?

MERV stands for Minimum Efficiency Reporting Value. It’s a scale from 1 to 20 that measures how well a filter catches particles.

  • MERV 6–8: Basic filters. Capture dust, lint, and larger particles.

  • MERV 9–12: Mid-range. Better for homes with pets or allergies.

  • MERV 13–16: High-efficiency. Traps pollen, mold, bacteria, smoke, and some viruses.

  • MERV 17–20: Hospital-grade. Not recommended for standard residential systems.

Most homeowners in OC are best off with MERV 11–13, which strikes a balance between air quality and system airflow.

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Filters for Allergies, Pets, and VOCs

If someone in your home has asthma, dust sensitivities, or seasonal allergies, upgrading your filter can make a real difference.

  • For allergies: Choose MERV 11 or higher

  • For pet dander and odors: Look for carbon-infused filters

  • For wildfire smoke or VOCs: Consider whole-home air purification

Reusable vs Disposable Filters

Disposable filters are low-cost and easy to replace every 1–3 months.
Reusable filters are washable and better for the environment—but they must be cleaned regularly to stay effective.

We recommend disposables for most homes because they’re more likely to be changed on time.

How to Measure Your HVAC Filter Size

Not sure which size you need? It’s easier than you think.

Here’s how to measure your HVAC filter:

  1. Remove your current filter

    • Most are located behind return vents (usually in ceilings or side walls) or inside the air handler.

  2. Check the size printed on the side

    • It will look something like 16x25x1 (Width × Height × Depth in inches).

    • This is the nominal size—rounded to the nearest inch.

  3. If it’s not labeled, measure it manually:

    • Use a tape measure to get the exact dimensions (width × height × thickness).

    • Then round up to the nearest inch. For example, 15.5" × 24.5" × 0.75" = 16x25x1

  4. Buy the same size or check your system manual

    • Most systems are designed for a specific filter size—using the wrong size can reduce airflow and strain your system.

Want to skip the guesswork?

How Often Should You Change Your Filter?

Every home is different, but here’s a general guide:

  • Every 1–2 months if you have pets or allergies

  • Every 3 months for standard households

  • Monthly during peak cooling or heating months

  • Check sooner if:

    • You notice more dust than usual

    • Your system is running longer or louder

    • Your energy bills are rising

What Happens If You Don’t?

A clogged or ineffective filter can lead to:

  • Higher energy bills

  • Poor indoor air quality

  • Increased allergens

  • Strain on your HVAC system

  • Costly breakdowns

It’s one of the simplest things you can do to protect your home’s comfort and air quality.

Our Top Filter Picks for Orange County Homes

We recommend high-quality pleated filters with a MERV rating between 11 and 13.
We’ll install them as part of your tune-up or membership visit.

Not sure which one fits your system? We’re happy to help.

Clean Air Starts with a Simple Change

You don’t need a full system upgrade to breathe easier.
Often, it starts with replacing the filter sitting behind your return vent.

If you’re not sure what’s in your system—or you haven’t changed it in a while—give us a call. We’ll take care of it quickly, affordably, and without any pressure.

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