How Often Should You Really Change Your HVAC Filter?

By Sarah Jenkins • October 24, 2023 • 6 min read

The short answer: It depends on the filter type and your household.

While the general rule of thumb is to swap them every 1 to 3 months, dirty filters can actually reduce airflow and make your system work harder, driving up energy bills. A clean filter keeps your indoor air quality high and your HVAC system running efficiently.

Filter Guide

Filter Types & Lifespan

Fiberglass

The standard 1-inch filter. Best for general dust control. Change every 1–3 months. They are disposable and budget-friendly but offer less filtration efficiency.

Pleated

More folds mean more surface area. They trap smaller particles. Change every 3–6 months. A great middle-ground option for homeowners.

HEPA

High-efficiency particulate air filters. Excellent for allergies. Change every 3 months. These are the most expensive and may require a system upgrade to handle the airflow resistance.

Replacement Schedule

Adjust for Your Household

Single Adult

If you work from home or have a pet-free home, you can stretch a pleated filter to 6 months. Keep an eye on dust buildup.

Family with Pets

Dander and fur are relentless. You should change your filter every 2 months, or even every month during heavy shedding seasons.

Allergy Sufferers

For maximum air quality, replace fiberglass filters every 1–2 months. A MERV 11 or 13 pleated filter is recommended.

DIY Guide

Step-by-Step Replacement

A close up of a new pleated air filter being installed into the slot of a white air handler unit

Changing your filter is one of the most cost-effective things you can do for your home. It takes less than five minutes and prevents costly repairs down the line.

1. Turn off the system

Locate your thermostat and switch it to "Off" or "Fan Off." For safety, you can also flip the breaker switch in your electrical panel that controls the HVAC unit.

2. Find the filter slot

Most filters are located in the return air vent in your hallway or the air handler unit in your attic, basement, or closet. Look for a metal or plastic frame with arrows indicating airflow direction.

3. Slide out the old filter

Most slots slide vertically. Slide the old filter out. Make note of which side was facing up (the arrows usually point toward the blower motor).

4. Install the new filter

Slide the new filter in the same direction the old one came out. Ensure the airflow arrows point toward the blower motor (usually toward the inside of the house).

5. Turn the system back on

Reset your thermostat and turn the system back on. You should feel the air starting to circulate. Check for any strange noises or airflow issues.

When to Call a Professional

While filter replacement is a simple DIY task, there are times you should call a Sensibly pro:

  • You can't locate the filter slot.
  • You notice a musty smell or mold around the unit.
  • You need to replace a filter larger than 20x25 inches.
  • Your system is making loud banging noises.

Keep your system running smoothly

Book an HVAC tune-up with Sensibly today. We'll inspect your system, check your filter, and ensure your home stays comfortable all year round.

Book HVAC Service

Free estimates available in your area

More Guides

5 Signs Your AC Needs Freon

Is your AC blowing warm air? Learn the top signs you might be low on refrigerant.

Read article

How to Lower Your Electric Bill

Simple tweaks to your HVAC usage can save you hundreds of dollars a year.

Read article

Understanding SEER Ratings

What does SEER 16 mean? We break down the efficiency ratings so you can buy smart.

Read article