The short answer

Most homes should check the filter every month and change it every one to three months. Heavy use, pets, allergies, and dusty conditions mean more frequent changes, while a vacant home may go longer.

Why it matters

Your filter protects your equipment and your air. When it clogs, the system struggles to pull air through, which has several effects.

• Cooling and heating get weaker

• Energy bills rise

• Coils can freeze

• Motors and parts wear out sooner

• More dust circulates through your home

How to tell when it is time

Hold the filter up to a light. If you cannot see light through it, or it looks gray and furry, it is time to replace it. If you are unsure, change it. Filters are inexpensive compared with the repairs a clogged one can cause.

Factors that change the schedule

• Pets that shed

• Allergy or asthma concerns

• Nearby construction or dusty areas

• A large household or heavy cooling use

• Smokers in the home

Choosing the right filter

Filters come in different densities. A basic fiberglass filter protects equipment but catches little. A pleated filter catches more dust and allergens. Very dense filters catch the most but can restrict airflow if your system was not designed for them. Match the filter to the system, and when in doubt, ask us.

Make it automatic

Set a reminder on your phone, buy filters in a multipack, and write the date on each new one. Our Complete Plan includes filter changes, which takes the whole task off your list.